program and abstracts - s3.amazonaws.coms3.amazonaws.com/zanran_storage/ · committee: ms. brenda...

1

34th SENIOR TECHNICAL MEETING

AMERICAN CHEMICAL SOCIETY

PUERTO RICO SECTION

“The Many Faces of Chemistry”

PROGRAM AND

ABSTRACTS

NOVEMBER 5, 2010

MAYAGÜEZ RESORT & CASINO

MAYAGÜEZ, PUERTO RICO

2

INDEX

Page

MESSAGE FROM THE PR ACS PRESIDENT 3

BOARD OF DIRECTORS 4

ORGANIZING COMMITTEE 4

OTHER COMMITTEES 4

ACKNOWLEDGEMENTS 6

GENERAL PROGRAM 8

SCIENTIFIC PROGRAM 9

PLENARY LECTURES 14

ORAL PRESENTATIONS 17

POSTER PRESENTATIONS 42

3

34th

SENIOR TECHNICAL MEETING


PUERTO RICO SECTION

Professor Nilka M. Rivera Portalatín American Chemical Society - Puerto Rico Section

The University of Puerto Rico, Mayagüez Campus

Mayagüez, Puerto Rico

Welcome to the 34th

ACS-Senior Technical Meeting! The Puerto Rico Local Section has

the tradition to celebrate the STM during the Fall Semester, where professionals as well

as graduate and undergraduate students have the opportunity to share their scientific

findings with other scientists. This activity brings chemists together in an environment

that promotes the opportunity to start new collaboration, get new ideas and share

knowledge.

This year the theme is “Many Faces of Chemistry”, demonstrating the diversity of

Chemistry in everyday life. Chemistry is everywhere and all the activities we perform

have it involved. As we can appreciate during this activity the Chemistry has many

faces: from atmospheric sciences to forensic sciences.

Today we celebrate our 34th

Senior Technical Meeting in the Mayagüez Resort and

Casino. We have the privilege to count with the presence of the ACS-President, Dr.

Joseph Francisco. We also have the presence of Dr. Suzanne Bell, a Forensic Chemist

from the West Virginia University, who accepted our invitation as a keynote speaker.

We will also have 34 oral presentations from graduate students, postdoctoral and

professors of different universities across the island and 52 poster presentations from

graduate and undergraduate students, including seven posters from the ACS-Student

Chapters. Besides all the difficulties confronted during this year, we have a good

representation of different areas of chemistry, demonstration that the chemistry have

certainly many faces.

In conclusion, I want to welcome you to the beautiful city of Mayagüez. I hope you will

enjoy the presentations and have a great time during the Senior Tech!

4

BOARD OF DIRECTORS

Chairperson: Nilka M. Rivera Portalatín

Past Chairperson: Raphael Raptis

Chairperson Elect: Vacant

Secretary: Mayra E. Cádiz García

Treasurer: Jorge Colón

NE Subsection Chairperson: Néstor Carballeira

SW Subsection Chairperson: Brenda Ramos

Councilor: Ingrid Montes

Alternate Councilor: Idaliz Rodríguez

ORGANIZING COMMITTEE:

Nilka M. Rivera Portalatín

Carlos R. Ruiz Martínez

Brenda J. Ramos Santana

Mayra E. Cádiz García

Ivelisse Padilla

Emilio Díaz Morales

Jorge Benejam Bocanegra

Suasy Acevedo

Harold Ortiz Medina

REGISTRATION COMMITTEE

Ivelisse Padilla

Edmarie Román

Verónica Sánchez

Jessica Torres

Sara Delgado

María Guntín

5

BOOK OF ABSTRACTS COMMITTEE

Mayra E. Cádiz

Emilio Díaz

Ana W. Santiago

PUBLICITY COMMITTEE

Emilio Díaz

Mayra E. Cádiz

POSTER SESSION COMMITTEE

Rafael Estremera

Jorge Benejam Bocanegra

IGARAVIDEZ AWARD COMMITTE

Jorge L. Colón, President

Enrique Meléndez, President

Antonio Alegría

Rafael Arce

Nestor Carballeira

Jose Prieto

6

ACKNOWLEDGEMENTS

The board of directors of the Puerto Rico Section of the American Chemical Society

wishes to thank the sponsors of this event. We gratefully acknowledge for the funds and

logistical support of the University of Puerto Rico-Mayagüez Campus, in particular, the

Chancellor of the UPR-Mayagüez, Dr. Miguel Muñoz, The Arts and Science Dean, Dr.

Juan López Garriga, the Director of the Department of Chemistry, Dr. Francis Patron,

and the Coordinator of the Graduate Program of Chemistry, Dr. Rodolfo Romañach for

their support for this activity. We also acknowledge Ms. Ana W. Santiago for the design

of the webpage, poster, flyers and program book cover. We are also grateful to Dr.

Emilio Díaz for the announcement design. Our special thanks to all the students who

helped in the organization of this activity, including Anixa Hernández, Bárbara De Jesús,

Orlando Vázquez and all the ushers. We also want to acknowledge the support personnel

of the Chemistry Department at Mayagüez, especially Ms. Francheska Becerra, Mr.

Jessica Molina, Mr. Franklyn Troche and Mr. José Ángel Matos for helping with the

paperwork and the webpage. Our special gratitude to all the members of the Organizing

Committee: Ms. Brenda Ramos, Mr. Carlos Ruiz, Dr. Mayra Cádiz, Dr. Emilio Díaz and

Dr. Ivelisse Padilla, Ms. Suasy Acevedo and Mr. Jorge Benejam who worked really hard

to make this activity a success.

We also acknowledge the following ACS Student Chapters for their help promoting this

activity:

Interamerican University, San Germán

Interamerican University, Metro Campus

Pontifical Catholic University, Ponce

University of Puerto Rico, Aguadilla

University of Puerto Rico, Arecibo

University of Puerto Rico, Cayey

University of Puerto Rico, Humacao

University of Puerto Rico, Mayagüez

University of Puerto Rico, Rio Piedras

We are especially grateful for the help received from the ACS Student Chapter of the

University of Puerto Rico, Mayagüez Campus represented by:

Suasy Acevedo, President

Nelvin Acevedo, Vice-President

Keishla Rodríguez, Secretary

Christine Jusino, Treasurer

Sherry Rivera, Vocal

Gisselle Martínez, Vocal

7

and from the ACS Student Affiliate Chapter of the University of Puerto Rico, Aguadilla

Campus represented by:

Harold Ortiz Medina, President

Charlene Ramos Villanueva, Vice-president

Saelys I. Rodríguez Rodríguez, Secretary

Fray M. Arroyo Mercado, Treasurer

Patricia Castro Román, Historian

Jessica I. Velázquez Hernández, Public Relation

Yazahira M. Hernández Saavedra, Vocal

Milimar Castro Bosques, Vocal

Angela Torres Torres, Vocal

Eva I. Gordian, Vocal

Edgar Pérez Matías, Vocal

8

34th



PUERTO RICO SECTION

GENERAL PROGRAM

7:30 AM REGISTRATION AND BREAKFAST

Hotel Lobby

8:30 AM WELCOME REMARKS

Convention Center 1

9:30 AM PLENARY LECTURE I: “Structure and Reactivity of Radical Molecule

Complexes: New Frontiers in Atmospheric Chemistry” Joseph S. Francisco, ACS

President, Department of Chemistry and Department of Earth and Atmospheric

Science, Purdue University

Convention Center 1

10:30 AM COFFEE BREAK

10:45 AM ORAL SESSIONS

Session A: Convention Center 2

Session B: Convention Center 3

Session C: Cacique Room

12:05 PM

ACS RECOGNITIONS AND AWARD LUNCHEON

1:30 PM ORAL SESSIONS

Session D: Convention Center 2

Session E: Convention Center 3

Session F: Cacique Room

3:10 PM PLENARY LECTURE II: “A Sampling of Forensic Chemistry Research:

Explosives and Drugs” Suzanne Bell, Bennett Department of Chemistry/ Forensic

and Investigative Sciences, West Virginia University

Convention Center 1

3:50 PM COFFEE BREAK

4:00 PM ORAL SESSIONS

Session G: Convention Center 2

Session H Convention Center 3

Session I: Cacique Room

6:00 PM COCKTAIL AND POSTER SESSION

Convention Center 4

8:00 PM CLOSING REMARKS

9

34th



PUERTO RICO SECTION

SCIENTIFIC PROGRAM

PLENARY LECTURES Convention Center 1

9:30 AM Plenary Lecture I: “Structure and Reactivity of Radical-

Molecule Complexes: New Frontiers in Atmospheric

Chemistry”

Joseph S. Francisco, Ph.D., ACS President, Department of

Chemistry and Department of Earth and Atmospheric Science,

Purdue University

Moderator: Francis Patron, Ph.D

3:10 PM Plenary Lecture II: “A Sampling of Forensic Chemistry

Research: Explosives and Drugs”

Suzanne Bell, Ph.D, Bennett Department of Chemistry/

Forensic and Investigative Sciences, West Virginia University

Moderator: Marisol Vera, Ph.D.

ORAL SESSIONS

Session A: Convention Center 2

Moderator: Rodolfo Romañach, Ph.D

10:45 AM A-1 Nanostructuring Electrochemical Interfaces: From Li-ion Battery

Anodes to (Bio)Fuel Cell Catalyst/Support System

Carlos R. Cabrera, Ph.D., Department of Chemistry, University

of Puerto Rico, Río Piedras

11:05 AM A-2 Development of a Fast Chromatographic Method for the Detection

of Organoarsenic Antimicrobials

Raymond A. Vélez Calder, Department of Chemistry, University

of Puerto Rico, Mayagüez

11:25 AM A-3 Research at the Center for Environmental Nanotechnology and

Remediation

Félix Román, Ph.D., Department of Chemistry, University of

Puerto Rico, Mayagüez

11:45 AM A-4 Metal/Polymer Nanocomposites as Surface Enhanced Raman

Sensors for the Analysis of Trace Arsenic Antimicrobials

10

Jenifier Olavarría, Department of Chemistry, University of


Session B: Convention Center 3

Moderator: Luis A. Morell, Ph.D

10:45 AM B-1 Consecutive Solvent-C60 Exchange on (η2

- C60)Ir(CO)Cl(PPh3)2

and Catalytically significant Organometallic Reactions on

Ir(CO)(PPh3)2Cl(Solvent)

Tamara Félix, Department of Chemistry, University of Puerto

Rico, Mayagüez

11:05 AM B-2 Model System for the Study of 2D Phase Transitions and

Supramolecular Interactions at Electrified Interfaces: Hydrogen-

Assisted Reductive Desorption of Catechol-Derived Adlayers from

Pt(111) Single Crystal Electrodes

Arnaldo Carrasquillo, Ph. D., Department of Chemistry,


11:25 AM B-3 Synthesis of Palladium Thin Films and Nanoshells by Sputtering

Deposition for Oxygen Reduction Reaction

Lisandra Arroyo-Ramírez, Department of Chemistry, University

of Puerto Rico, Río Piedras

11:45 AM B-4 X-ray Structure Determination of trans-[Pd(4,5-

dimethylthiazole)2Cl2] and trans-[Pd(5-methylthiazole)2Cl2]

Ramón L. Hernández-Castillo, Ph.D., Pontifical Catholic

University of Puerto Rico, Ponce

Session C: Cacique Room Moderator: Enrique Melendez, Ph.D.

10:45 AM C-1 Expression, Purification and Spectroscopic Characterization of

Recombinant Human Apo-Transferrin Binding To Metallocenes:

Elucidation of the Binding Mechanism Protein- Cp2M

Jorge Güete, Department of Chemistry, University of Puerto Rico,

Mayagüez

11:05 AM C-2 Novel Uncatalyzed Synthesis and Characterization of Diacetone

Diperoxide

Eduardo Espinosa, Department of Chemistry, University of

Puerto Rico, Mayaguez, PR 00681

11:25 AM C-3 Is plastocyanin from spinach leaves another cooper protein with

antitumor properties?

Lymari Fuentes, Ph.D., Universidad Metropolitana, San Juan

11:45 AM C-4 The Centrin-Melittin Complex is a Suitable Model for Protein-

Protein Interaction and Amyloidogenesis

Belinda Pastrana, Ph.D., Department of Chemistry, University of


Session D: Convention Center 2

11

Moderator: Arnaldo Carrasquillo, Ph.D.

1:30 PM D-1 Drug Delivery Using Layered Inorganic Nanomaterials

Jorge Colón, Ph. D., Department of Chemistry, University of

Puerto Rico, Río Piedras

1:50 PM D-2 C-H Bond Activation of Wilkinson’s Complex Under Mild

Temperature Conditions

Elvin Igartúa, Department of Chemistry, University of Puerto

Rico, Mayagüez

2:10 PM D-3 Synthesis And Characterization Of Ferrocenecarboxylate

Compounds, Applications As Biosensors And The Cytotoxic Effect

Studies On MCF-7 And Ht-29 Cancer Cell Lines

José Vera, Department of Chemistry, University of Puerto Rico,

Mayaguez

2:30 PM D-4 Biomedical Applications of Nanotechnology: Exploratory

Research on the Use of One Dimensional Nanostructures for

Neurological Bypass

Miguel González, Department of Chemistry, University of Puerto

Rico, Mayaguez

2:50 PM D-5 Resolution of an Octaferric M/P Racemate

Karilys González, Department of Chemistry, University of Puerto

Rico-Río Piedras

Session E: Convention Center 3 Moderator: Jorge Ríos Stainer, Ph.D.

1:30 PM E-1 Owen Wheeler’s Legacy

Rodolfo J. Romañach, Ph.D., Department of Chemistry,

University of Puerto Rico, Mayaguez

1:50 PM E-2 An Analogy Using Pennies and Dimes to Explain Chemical

Kinetics Concepts

José Cortés, Ph.D., Department of Chemistry, University of

Puerto Rico, Mayaguez

2:10 PM E-3 Degradation of Explosive in water using iron oxide

Gloria M. Herrera, Department of Chemistry, University of


2:30 PM E-4 Remote Sensing Of Hazardous Compounds By Raman

Spectroscopy

William Ortiz, Department of Chemistry, University of Puerto

Rico, Mayaguez

2:50 PM E-5 Di(2-ethylhexyl)Phthalate Ester (DEHP)-Degraders Isolated from

Landfill Leachate

María Sevillano, Department of Civil Engineering, University of


12

Session F: Cacique Room Moderator: Nairmen Mina, Ph.D.

1:30 PM F-1 The Chemistry of Nucleation

Miguel Castro, Ph. D., Department of Chemistry, University of


1:50 PM F-2 Phase Transformations in Metastable Structures of

Nanocristallyne Cobalt Mediated by PVP

Celia Osorio, Department of Chemistry, University of Puerto

Rico, Mayaguez

2:10 PM F-3 Open Path FTIR Standoff Detection of High Explosives on

Surfaces

John Castro, Department of Chemistry, University of Puerto

Rico, Mayaguez

2:30 PM F-4 Synthesis of ZNO Nanowires Arrays Aqueous Solutions

Marcia del Rocío Balaguera, Department of Chemistry,


2:50 PM F-5 Variability of Aerosol’s Optical, Physical and Chemical Properties

of Marine, African Dust and Volcanic Ash Air Masses in the

Eastern Caribbean

Héctor Rivera, Department of Physics, University of Puerto Rico,

Río Piedras

Session G: Convention Center 2 Moderator: Nilka M. Rivera Portalatín, Ph.D.

4:00 PM G-1 Structural determinants for the formation of sulfhemeprotein

complexes

Juan López Garriga, Department of Chemistry, University of

Puerto Rico,Mayagüez

4:20 PM G-2 Development of Spectroscopy Based Remote Detection Systems for

Chemical and Biological Threats

Samuel Hernández, Ph.D., Department of Chemistry, University

of Puerto Rico,Mayagüez

4:40 PM G-3 Steroid-functionalized Titanocenes and Ferrocenes

Enrique Meléndez, Ph.D., Department of Chemistry, University

of Puerto Rico, Mayagüez

5:00 PM G-4 World Chemistry Congress IUPAC 2011, Part 1

Gabriel Infante, Ph.D., Organizing Committee, IUPAC2011,

Colegio de Químicos de Puerto Rico

5:20 PM G-5 World Chemistry Congress IUPAC 2011, Part 2

Gabriel Infante, Ph.D., Organizing Committee, IUPAC2011,

Colegio de Químicos de Puerto Rico

13

Session H: Convention Center 3 Moderator: Elsie Parés, Ph.D.

4:00 PM H-1 Complementary Near Infrared and Raman Chemical Imaging in

the Evaluation of a Novel Pharmaceutical Formulation

Jackeline Jérez, Department of Chemistry, UPR-Mayagüez

4:20 PM H-2 Electrochemical and Chemical Characterization of Titanocene

Dichloride Intercalated in Zirconium Phosphate Layers for use in

Biotechnology

Barbara Casañas, Department of Chemistry, UPR-Río Piedras

4:40 PM H-3 Kinetics of Ligand Exchange Reactions on (η2-C60)W(CO)5 in

Solvent

Wanda I. Pérez, Department of Chemistry, UPR-Mayagüez

5:00 PM H-4 Magnetic Nanocomposites to Remove Heavy Metals and

Oxyanions in Aqueous Matrices

Tatiana Luna, Department of Chemistry, UPR-Mayagüez

5:20 PM H-5 Caribbean Plants for Absorption of Energetic Material

Sandra N. Correa, Department of Chemistry, UPR-Mayagüez

Session I: Cacique Room

Moderator: Luis A. Rivera, Ph.D.

4:00 PM I-1 Cytotoxicity of Cu-doped ZnSe@ZnS Quantum Dots in Human

Pancreatic Carcinoma Cells

Sonia Bailón, Department of Chemistry, UPR-Mayagüez

4:20 PM I-2 Bifunctional Materials for the Catalytic Conversion of Cellulose

into Soluble Renewable Biorefinery Feedstocks

Damián Reyes, Department of Chemical Engineering, UPR-

Mayagüez

4:40 PM I-3 Study of Supported Ruthenium Catalysts for the Conversion of

Cellulose to Sugar Alcohols

Darlene Galloza, Department of Chemical Engineering, UPR-

Mayagüez

5:00 PM I-4 Synthesis, Characterization and Application of Biofunctional

Hydrophobic Ru/SBA-15

Shuo Cao, Department of Chemical Engineering, UPR-Mayagüez

5:20 PM I-5 Host-defense Peptide-mimetic Foldamers and Polymers

Patricia Ortiz, Department of Chemical Engineering, UPR-

Mayagüez

POSTER SESSION @ Science Café

Room Convention Center 4

5:30 PM Cocktail and Student Chapters Recognitions

6:30 PM Poster Presentations

8:30 PM Closing Remarks

14

PLENARY LECTURES

15

STRUCTURE AND REACTIVITY OF RADICAL-MOLECULE

COMPLEXES:

NEW FRONTIER IN ATMOSPHERIC CHEMISTRY Joseph S. Francisco

Department of Chemistry and Department of Earth and Atmospheric

Sciences

Purdue University

The chemistry in our atmosphere governs phenomena such as ozone depletion, acid rain,

and climate change. Having a firm understanding of all chemical processes at the

molecular level in the atmosphere will allow for the development of accurate global

climate models. This talk will discuss some of the more traditional chemical reactions,

and challenge our fundamental understanding of how these reactions occur under low

temperature conditions which are characteristic of the atmosphere. Even the simplest

atmospheric reactions involve novel mechanisms linked to radical-molecule complexes.

The effects that radical-molecule complexes will have on the landscape of the atmosphere

in terms of accounting for the abundance of radical species will be discussed. The

chemistry role of radical-molecule has been largely unexplored. The influence and impact

of radical-molecule complexes on both the mechanisms and kinetics on atmospheric

reactions will be discussed.

16

A SAMPLING OF FORENSIC CHEMISTRY RESEARCH:

EXPLOSIVES AND DRUGS

Suzanne Bell

Bennett Department of Chemistry/ Forensic and Investigative

Sciences

West Virginia University

Forensic chemistry encompasses a variety of analytical topics including seized drug

analysis, toxicology, materials characterization, and combustion chemistry. This

presentation will present a sampling of recent research in two of these areas – smoked

drugs of abuse and the characterization of improvised and homemade explosives. Drugs

that are ingested via smoking are delivered directly to the bloodstream, bypassing first

pass metabolism. For potent drugs such as fentanyl, this presents a significant danger to

first-time users. Accordingly, there is forensic interest in determining if a drug has been

ingested via smoking versus other methods such as swallowing or injection.

Analytically, one approach is to identify combustion products associated with drugs and

then determine if these are present in blood and urine. Examples using fentanyl and

methamphetamine will be discussed. In the realm of explosives, new methods of

detection using tandem mass spectrometry will be described, focusing on improvised

materials such as urea nitrate.

17

ORAL PRESENTATIONS

18

A-1

NANOSTRUCTURING ELECTROCHEMICAL INTERFACES: FROM LI-ION BATTERY

ANODES TO (BIO)FUEL CELL CATALYST/SUPPORT SYSTEM

Carlos R. Cabrera, L. Arroyo, I. González, T. Morante, L. La Torre, E. Nicolau, B. Rosario, D. Santiago

Department of Chemistry, University of Puerto Rico at Río Piedras, San Juan, PR 00936

Nanostructuring electrochemical interfaces is of importance in areas such as Li-ion Batteries, Fuel Cells,

and Biofuel Cells. For Li batteries, we have been working on preparing anode electrodes with single-wall

carbon nanotubes by self-assembled techniques. Very stable anode electrodes have been obtained under

charge/discharge cycles. In the area of fuel cells our group has been working on several techniques and

synthetic methods. Recently, our group has developed a rotating disk slurry electrochemical method to

prepare high surfaces catalysts/support materials for regenerative fuel cells. Our interest has been placed on

the preparation of Pt-Ru/Vulcan, Pt/carbon nano-onions, and Pt-Ru/diamond nanoparticle catalysts.

Tailored organometallic compounds and nitrogenated polymers have also been used to prepare Pd-Co

nanocatalysts and nitrogen-doped carbon nanotubes. Both catalysts are being tested for the oxygen

reduction reaction (ORR). Recently, we have started working on a biocatalyst development for the

oxidation of urea from human wastewater. This has led us to a possible urease/Pt biofuel cell system.

A-2

DEVELOPMENT OF A FAST CHROMATOGRAPHIC METHOD FOR THE DETECTION OF

ORGANOARSENIC ANTIMICROBIALS

Raymond A. Vélez Calder and Marco A. De Jesús

Department of Chemistry, University of Puerto Rico, Mayagüez, PR 00681

Organoarsenics have been widely used for veterinary applications as antimicrobial agents and growth

promoters for poultry. The high water-solubility exhibited by these drugs represents a serious

environmental problem since poultry litter is widely used as fertilizer. Once applied to crops, these agents

can leach into bodies of water and readily be absorbed by plants. The use of these drugs at high

concentration levels by poultry farms have been targeted by the FDA due to QA/QC deficiencies related to

feed preparations. This work presents a new rapid resolution LC protocol for the routine analysis of

roxarsone, p-arsanilic acid, and acetarsone using ion-pairing high-performance liquid chromatography (IP-

HPLC) with diode array detection. The developed procedure is linear with a correlation coefficient (R2) >

0.9990 and p-values < 0.05; reproducible in area and tR (%RSD < 1.0 %); and demonstrated a limit-of-

quantitation (LOQ) < 0.03 ppm (for roxarsone and p-arsanilic acid) and < 0.24 ppm (for acetarsone). The

method provides a simple, reliable and cost effective alternative for the routine analysis of organoarsenic

compounds present in water with a complete separation of the target analytes in less than 2 minutes. The

method does not require complex preparation techniques prior to the analysis while is robust enough to

enable the detection of these agents in complex matrixes such as poultry litter leachates. The application of

this method for the detection of organoarsenics in environmental samples discussed.

19

A-3

RESEARCH AT THE CENTER FOR ENVIRONMENTAL NANOTECHNOLOGY AND

REMEDIATION

Felix R.Román and Oscar Perales Pérez

Department of Chemistry, University of Puerto Rico, Mayaguez, PR 00681

Department of Engineering Science and Materials, University of Puerto Rico, Mayaguez, PR 00681

Natural and drinking water supplies are being increasingly contaminated with well-known and emerging

inorganic and organic pollutants. Examples of these pollutants include heavy metals (single cations and

oxyanions), organic solvents, pharmaceutical and personal health care products (PPCP), among others.

Evidently, there is a need for efficient green remediation alternatives to clean and protect our water supplies

from these contaminants. On this basis, our research group in collaboration with local government

agencies, such as Solid Waste Management Authority and The Aqueducts and Seward Authority and the

private sector, represented by REMA Inc. The CENR have been working in the development of green and

low cost recycling and water cleaning alternatives for the last six years. Our current attempts are focused on

the use of recycled materials such a crumb rubber and the dewatered sludge generated in Puerto Rican

water treatment facilities as inexpensive and efficient sorbents. Recently, we have also synthesized novel

bio-nanocomposites capable of removing inorganic and organic contaminants from water. Investigated

sorbents have demonstrated their capability to remove toxic metal ions, PPCP’s and volatile organic

solvents from aqueous matrices. For instance, recycled crumb rubber mesh 14-20 was capable of removing

ethylbenzene, toluene, xylene as well as PAH-type compounds (acenaphthylene acenaphthene and

phenanthrene) from aqueous phase. At 10 g/L of crumb rubber up to 99, 95 and 77% of xylene,

ethylbenzene and toluene were removed from starting 30 ppm water solutions. Also 99% of PAHs were

removed from starting 500, 850 and 900 ppb water solutions of phenanthrene, acenaphthene and

acenaphthylene, respectively at the same conditions. In turn, silicate-based dewatered sludge from the

Miradero’s water treatment plant was capable of removing between 78% and 100% of Se(IV) and 100 %

Se(VI) species, respectively, when ferric chloride was added as a coagulant. A novel alginate-based

magnetic nanocomposite was also developed and evaluated as sorbent for As (III) and As (IV) oxyanions.

Arsenic removal efficiencies of up to 96 % were achieved when 1g/L of the sorbent was contacted with a

10ppm As aqueous solution.

20

A-4

METAL/POLYMER NANOCOMPOSITES AS SURFACE ENHANCED RAMAN SENSORS FOR

THE ANALYSIS OF TRACE ARSENIC ANTIMICROBIALS

Jenifier Olavarría1, Sabrina Wells

2, William Ortiz-Rivera

1, Michael J. Sepaniak

2 and Marco A. De Jesús

1*

1Department of Chemistry University of Puerto Rico-Mayagüez, Mayaguez, PR 00681

2Department of Chemistry, University of Tennessee at Knoxville, 552 Buehler Hall, Knoxville TN 37996,

U.S.A.

Organoarsenic drugs such as roxarsone and arsanilic acid are poultry feed additives widely used in US

broilers to prevent coccidosis, enhance growth and pigmentation. Despite their veterinary benefits there

has been a growing concern in their use since over 90% of these drugs are released intact into litter, which

is often sold as a fertilizing supplement. The biochemical degradation of these antimicrobials in the litter

matrix can release significant amounts of soluble As(III) and As (V) to the environment representing a

potential environmental risk. Surface enhanced Raman spectroscopy (SERS) has proven to be a powerful

tool not only for qualitative and quantitative detection of a diverse range of compounds but for allowing

their unequivocal characterization by rendering large amounts of structural chemical information.

Development in the fabrication of nanocomposite materials has allowed the production of SERS-active

substrates capable of high reproducibility, sensitivity and low detection limits. This study demonstrates the

successful employment of silver polydimethylsiloxane (Ag/PDMS) nanocomposites and Electron Beam

Lithography (EBL) substrates for the detection and characterization of trace amounts of arsanilic acid,

roxarsone, and acetarsone in water by SERS. The results gathered in this study show that organoarsenic

species interact with the surface where the arsonic acid binds onto the embedded silver nanoparticles,

enhancing its characteristic 792 cm-1

stretching band. The chemisorption of the drugs to the metal

facilitates its detection and characterization in the parts per million to parts per billion range. Distinct

spectroscopic features of each drug are presented with emphasis on the interactions of the arsonic acid,

amino, and nitro groups with the metal surface. Impact of design parameters of EBL fabricated substrates,

such as varying nanoparticle gap, and pattern arrangement were assessed. The best signal enhancement was

obtained employing an EBL substrate with ellipses and hexagons (TEH) with 200 nm gap, which rendered

an order of magnitude increase in the apparent SERS signal in relation to Ag/PDMS nanocomposites.

B-1

CONSECUTIVE SOLVENT-C60 EXCHANGE ON (η2 - C60)Ir(CO)Cl(PPh3)2 AND

CATALYTICALLY SIGNIFICANT ORGANOMETALLIC REACTIONS ON

Ir(CO)(PPh3)2Cl(Solvent)

Tamara Félix Massa, and José E. Cortés -Figueroa


The solvent/C60 exchange on (η2 – C60)Ir(CO)(PPh3)2Cl (solvent = benzene and cyclohexane) are biphasic.

Plots of absorbance values vs. time are biexponential for reactions monitored at 550 nm. Identification of

the consecutive processes chemical nature was done by infrared and 1H NMR spectroscopy. The first

segment of absorbance vs. time plots was assigned to C60/benzene exchange on (η2 – C60)Ir(CO)(PPh3)2Cl

producing (η2-benzene)Ir(CO)(PPh3)2Cl, whereas the second segment was attributed to a series of reactions

involving C-H bond oxidative cleavage of 2-coordinated benzene followed by reductive elimination and

cyclometalation or agostic bond formation. Activation parameters for benzene/C60 exchange on (η2 –

C60)Ir(CO)(PPh3)2Cl suggested an interchange associative mechanism. Rate constant values obtained from

the second segment of the plot were [solvent]-independent. However, in solvent solvent1/solvent2 mixtures

the values where [solvent]-dependent, suggesting the existence of a solvent exchange on

(solvent1)Ir(CO)(PPh3)2Cl and (solvent2)Ir(CO)(PPh3)2Cl intermediates. Monitoring the reactions’

progresses by infrared and 1HNMR spectroscopy of actual samples of Vaska’s complex, confirmed that

once the solvated intermediates are produced they undergo C-H bond oxidative cleavage, followed by a

series of parallel PPh3 dissociation and σ-complexes formation.

21

B-2

MODEL SYSTEM FOR THE STUDY OF 2D PHASE TRANSITIONS AND SUPRAMOLECULAR

INTERACTIONS AT ELECTRIFIED INTERFACES: HYDROGEN-ASSISTED REDUCTIVE

DESORPTION OF CATECHOL-DERIVED ADLAYERS FROM Pt(111) SINGLE CRYSTAL

ELECTRODES

Arnaldo Carrasquillo, Jr.1*, Margarita Rodriguez-Lopez

2,3, Antonio Rodes

4, Antonio Berná

4, Victor

Climent4, Enrique Herrero

4, Paulino Tuñon

3, and Juan M. Feliu

4, Antonio Aldaz

4*

1Department of Chemistry, University of Puerto Rico, Mayagüez, PR, 00681

2Pontifical Catholic University of Puerto Rico, Ponce, Puerto Rico

3University of Oviedo, Oviedo, Spain

4University of Alicante, Alicante, Spain

Classical electroanalytical techniques and in-situ FTIR are used to study the oxidative chemisorption of

catechol (o-H2Q) and the hydrogen-assisted reductive desorption of catechol-derived adlayers (o-Q(ads)) at

nearly defect-free Pt(111) single crystal electrodes in 0.5M H2SO4. At near equilibrium conditions (Lim υ →

0) the cyclic voltammetric response does not conform to the behavior expected from classical models of

molecular adsorption at electrochemical interfaces. Instead, attractive interactions play a controlling role,

i.e. hydrogen-assisted displacement of o-Q(ads) takes place as an electrochemically-reversible two

dimensional (2D) phase transition controlled by collision-nucleation-growth phenomena in the presence of

2 mM o-H2Q(aq). In contrast, different desorption dynamics are observed when the reductive desorption of

the adlayers is carried out in clean (0 mM o-H2Q(aq)) supporting electrolyte. Donor-Acceptor (DA)

interactions between the Pt(111)/o-Q(ads) surface adduct and o-H2Q(aq) are postulated as a possible

intervening mechanism leading to the observed differences in the macroscopic electrochemical responses.

The results also demonstrate that in aqueous solutions it is thermodynamically feasible to shift the formal

oxidation potential of catechol-metal adducts to potentials near those of molecular hydrogen via

chemically-reversible, non-dissociative interactions, taking place as a 2D phase transition.

B-3

SYNTHESIS OF PALLADIUM THIN FILMS AND NANOSHELLS BY SPUTTERING

DEPOSITION FOR OXYGEN REDUCTION REACTION

Lisandra Arroyo-Ramírez1,2

, Yaritza Figueroa3, Diego Rodríguez

3, Wilfredo Otaño

2,3, and Carlos R.

Cabrera1,2

1 Department of Chemistry, University of Puerto Rico, San Juan, PR 00936-8377

2 Center for Advanced Nanoscale Materials, University of Puerto Rico, San Juan, PR 00936-8377

3 Department of Physics-Mathematics, University of Puerto Rico, Cayey, PR 00736

The cathode electrodes for direct methanol fuel cells (DMFC) have the problem of requiring high cost

catalysts and its degradation due to methanol crossover. Also, the deposition methods for the catalysts are

complex and time consuming. To solve this drawback is necessary to find a catalyst with high methanol

tolerance and simple methodology for its deposition. Sputtering is a technique that allows easy

modification of different substrates with a great variety of materials and high degree of control of their

properties. Our focus is on the use of this simple method for the synthesis of palladium (Pd) catalytic

nanostructures on highly ordered pyrolytic graphite (HOPG) surfaces as model to be used for fuel cell

applications.

The synthesis of palladium thin films and shell nanostructures by dc-magnetron sputtering deposition on

HOPG surfaces is described. The palladium deposition was carried out at 5 and 13 mTorr and 50 W of

power. Electrospun polymer fibers mats were used as templates for the Pd shell nanostructures formation.

The palladium thickness is between 10 to 75 nm and was controlled by the deposition time. The

morphology was characterized with atomic force microscopy (AFM) and scanning electron microscopy

(SEM). Pd nanostructures were used as catalysts for oxygen reduction reaction (ORR). The ORR activity

was evaluated in sulfuric acid and the methanol tolerance in 1 M MeOH solutions saturated with oxygen.

The Pd shell nanostructures have better ORR activity than Pd thin films.

22

B-4

X-RAY STRUCTURE DETERMINATION OF trans-[Pd(4,5-dimethylthiazole)2Cl2] AND trans-

[Pd(5-methylthiazole)2Cl2]

Ramón L. Hernández-Castillo1 and Karilys González

2

1Pontifical Catholic University of Puerto Rico, Department of Chemistry

2University of Puerto Rico-Río Piedras, San Juan, PR 00936

Cisplatin, cis-diamminedichloroplatinum(II), was the first inorganic compound to show antitumoral

properties. Various unrelated Pt(II) compounds are active in a wide variety of cancer types and can

overcome resistance mechanisms. The complex [Pt(NH3)(2-methylpyridine)Cl2], ZD0473, is a well-known

example of these new platinum drugs. In early stages of metal-based anticancer drug development, metals

other than platinum were somewhat discarded based on reactivity profiles. Anyhow, an appropriate

selection of ligands has produced complexes with activities close to that exerted by cisplatin. With

detoxification via cellular thiols in mind and potential tuning of substitution reactions at the metal center

via incorporation of functional groups, new palladium complexes were synthesized and their structure

solved by single crystal X-ray diffraction. Complexation of ligands was through the nitrogen atom and both

complexes crystallized in a monoclinic unit cell but differ in twisting of the ligand plane respect to the

palladium square plane. [Pd(4,5-dimethylthiazole)2Cl2] has the ligand ring almost perperdicular to the

palladium square plane while the ligand ring in [Pd(5-methylthiazole)2Cl2] is almost coplanar. This

structural difference is expected to have an effect in the substitution reactions at the palladium center; this

could have tremendous implications in the biological activity of these new complexes.

C-1

EXPRESSION, PURIFICATION AND SPECTROSCOPIC CHARACTERIZATION OF

RECOMBINANT HUMAN APO-TRANSFERRIN BINDING TO METALLOCENES:

ELUCIDATION OF THE BINDING MECHANISM PROTEIN- CP2M

Jorge R. Güette Fernández


Transferrin (TF) is a glycoprotein of 679 amino acid residues composed of two homologous lobes. Each

lobe comprises a pocket that has high affinity for reversibly binding to a metal ion. The principal

biochemical function of TF is the transport of Fe+3

into the cells for subsequent utilization. The metal-

binding capabilities of TF have been investigated with more than 30 different metals and anions. Initial

studies have demonstrated that metallocenes (Cp2M) are readily captured and transported by human-TF and

have been shown to exhibit high antitumor activity against a wide range of tumors. In spite of these results,

no critical report has shown a true mechanism explaining the mode of action of TF upon its binding to

Cp2M. The purpose of this study is to elucidate a mechanism for the interactions between TF and Cp2M

using several spectroscopic techniques. TF was harvested after induction of BHK-21 cells grown in a

media containing ultroser-G and [methyl-C-13]-L-methionine. The amount of total protein and its

molecular weight were determined using BCA-Protein Assay and SDS-PAGE, respectively. The

concentration of crude protein extracts was 3.32±0.61 µg/µL. SDS-PAGE showed two protein bands, one

of 80-kDa corresponding to 13

C-Met-TF and another of 50-kDa. Initial purification of 13

C-Met-TF was

performed through an FPLC system using a column for ion exchange. Other chromatographic methods will

be also performed in order to obtain a pure 13

C-Met-TF for NMR and CD studies. UV-VIS spectra were run

for the 13

C-Met-TF with and without Fe+3

. A broad band for proteins at 280-nm was observed as well as

bands at 450-nm and 470-nm for the interaction with Fe+3

. Further spectroscopic characterization of apo-13

C-Met-TF, diferric-13

C-Met-TF and its binding to several metallocenes will be performed using UV-VIS,

NMR and CD. If proton shifts and the presence of new signals in the NMR and CD spectra are observed,

then these results might indicate that new interactions have been formed between 13

C-Met-TF and the

metallocenes. In silico studies will be also conducted in order to compare these experimental results. In

conclusion, these new interactions might be able to show which amino-acid residues are involved in the

formation of coordination bonds with metallocenes, thus making possible the binding of (Cp2M)2-13

C-Met-

TF with the TF receptor and its transport into the cell.

23

C-2

NOVEL UNCATALYZED SYNTHESIS AND CHARACTERIZATION OF DIACETONE

DIPEROXIDE

Eduardo A. Espinosa-Fuentes

Center for Chemical Sensors Development/Chemical Imaging Center, Department of Chemistry,

University of Puerto Rico, Mayaguez, PR 00681

A novel method to synthesize diacetone diperoxide (DADP) from acetone and hydrogen peroxide without

the presence of a catalytic agent is presented. DADP was prepared with a purity of 99.99%. Previously

reported synthesis used acid as catalysts. The key procedure depends strictly on the control of the

acetone:hydrogen peroxide ratio and temperature of reaction mixture. Purified crystalline DADP samples

were characterized using nuclear magnetic resonance, Raman and Infrared spectroscopies, differential

scanning calorimetry, gas chromatography and Open Atmosphere Chemical Ionization mass spectrometry

(OACI-MS). Structural evidence was compared to the well known trimeric cyclic acetone-peroxide cyclic

compound triacetone triperoxide (TATP). In general the acetone peroxide cycle formation depends on

polarity, vapor pressure and solubility of the respective linear polymer precursor. The proposed synthetic

scheme can be useful for preparing small amounts of the cyclic organic peroxide for characterization and

fundamental studies and for formulation of gas chromatography, high performance liquid chromatography

and mass spectrometry standards.

C-3

IS PLASTOCYANIN FROM SPINACH LEAVES ANOTHER COOPER PROTEIN WITH

ANTITUMOR PROPERTIES?

Lymari Fuentes-Claudio, Luis Vazquéz-Quiñones, and Dalia Huguet-Ramírez

Universidad Metropolitana, PO Box 21150 San Juan, Puerto Rico

The quest for therapies for cancer treatment has been an extensive research field in the past years. It has

been questions on the importance of diet and components of specific food or lifestyles on the development

of tumors. The interaction of several components of food has been tested to monitor their impact on the

proliferation of tumor cells. In this study we aim to determine if plastocyanin, a copper protein present in

several vegetables, has an effect on the proliferation of human breast tumor cell line MDA-MB231.

Plastocyanin was purified from spinach leaves and used to supplement the cell culture medium used to

grow this cell line. Cells were exposed to different protein concentrations at different time periods and the

amount of cells were monitored using colorimetric methods. Results indicated that plastocyanin from

Spinach Oleracea presents an inhibition effect on the proliferation of the cell line under study when

compared with a control sample.

24

C-4

THE CENTRIN-MELITTIN COMPLEX IS A SUITABLE MODEL FOR PROTEIN-PROTEIN

INTERACTION AND AMYLOIDOGENESIS

Belinda Pastrana-Rios1*

, Liliana del Valle Sosa1, Eric Schreiter

2, Elisa Alfaro

1, Daniel Narváez

1, Jorge

Santiago1, and Nicole Martinez

1

1Department of Chemistry, University of Puerto Rico, Mayagüez Campus, Mayagüez, PR 00681,

2Department of Chemistry, University of Puerto Rico-Rio Piedras, San Juan, PR 00931-3346

Centrin is a calcium binding protein belonging to the EF-hand superfamily. As with other proteins within

this family, centrin is a calcium sensor with multiple biological target proteins. We chose to study

Chlamydomonas reinhardtii centrin (Ccen) and its interaction with melittin (MLT), as a model for amyloid

fibril formation and calcium binding protein complexes. Our goal was to determine the molecular

interactions that lead to centrin-MLT complex formation, their relative stability, and the conformational

changes associated with the interaction, when compared to the single components. For this, we determined

the thermodynamic parameters that define Ccen-MLT complex formation. FT-IR spectroscopy and two-

dimensional correlation analysis (2DCOS) were used to study the amide I’/I’* band for 13

C-Ccen, MLT,

and the 13

C-Ccen-MLT complex. This approach resulted in the determination of MLT’s increased helicity

upon its interaction with centrin, followed by the thermally induced aggregation of MLT within the

complex, while centrin was observed to be stabilized within the complex. Spectral simulations were

employed to confirm the molecular events during the thermal perturbation of the complex. We also present

the low-resolution structure of the Ccen-MLT complex as ascertained by X-ray crystallography, which

shows that MLT has a different binding.

25

D-1

DRUG DELIVERY USING LAYERED INORGANIC NANOMATERIALS

Jorge L. Colón1, Agustín Díaz

1, Amanda David

1, Riviam Pérez

1, Millie L. González

2, Adriana Báez

2,

Stacey E. Wark3, Tiffany B. Kinnibrugh

3, Paul Zhang

3, and Abraham Clearfield

3

1Department of Chemistry, University of Puerto Rico, P.O. Box 23346, Río Piedras, Puerto Rico 00931

2Departments of Pharmacology and Otolaryngology, School of Medicine, University of Puerto Rico, P.O.

Box 365067, San Juan, Puerto Rico 00936-5067 3Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842

A new approach in nanomedicine is the use of selective inorganic nanomaterials as carriers of drugs,

including anticancer drugs. The drug will reach its target by the higher affinity of tumor cells to

macromolecules and large nanocrystals (about 100 nm) compared with normal cells. In our approach we

use layered inorganic nanomaterials made of zirconium phosphate (ZrP) for preparing nanoparticles

interspersed with insulin or cis-diamminedichloroplatinum(II) (cisplatin), one of the most effective drugs

against cancer. We prepared insulin-intercalated and cisplatin-intercalated ZrP nanoparticles with various

drug’s loading levels following procedures established in our laboratory for direct ion-exchange of –ZrP,

which has an interlayer distance of 10.3 Å.1 The drug-intercalated nanoparticles were characterized using

X-ray powder diffraction, diffuse reflectance, IR, and X-ray photoelectron spectroscopies. In addition,

trasmission electron microscopy was uaed to characterize the size of the nanoparticles. Cellular viability

experiments were performed at the University of Puerto Rico Medical Sciences Campus.

The intercalation experiments were successful. The cisplatin-intercalated ZrP nanoparticles had an

interlayer distance of 9.5 Å, as predicted by molecular modeling based on the assumption that the chloride

ligands are substituted by phosphate ligands from the ZrP framework upon intercalation. This assumption

was corroborated by diffuse reflectance spectroscopy and XPS measurements. Nanoparticles without any

intercalant present proved non-cytotoxic but they were if they contained intercalated cisplatin.

Insulin-intercalated ZrP nanoparticles had an interlayer distance of 27 Å. Circular dichroism experiments

demonstrated that the hormone looses some of its native secondary structure upon intercalation, but regains

most of it upon release from the ZrP carrier.

Drug release experiments demonstrate that a pH stimulus is enough to release these drugs from its carrier.

The study aims to test whether these drugs can be intercalated into this type of material, released to reach

their target under a chemical stimulus, maintaining their effectiveness. The complete results of these

investigations will be presented.

1. “Nanoencapsulation of Insulin into Zirconium Phosphate for Oral Delivery Applications”, Agustín Díaz;

Amanda David; Riviam Pérez; Millie L. González; Adriana Báez; Stacey E. Wark; Paul Zhang; Abraham

Clearfield; Jorge L. Colón, Biomacromolecules 2010, 11, 2465-2470.

26

D-2

C-H BOND ACTIVATION OF WILKINSON’S COMPLEX UNDER MILD TEMPERATURE

CONDITIONS

Elvin Igartúa-Nieves, and José E. Cortés-Figueroa


The chemical behavior of Wilkinson’s catalyst [(Ph3P)3RhCl] has been studied extensively due to

applications in synthesis, catalysis, and C-H bond activation. We have found that Wilkinson’s catalyst

reacts with benzene and chlorobenzene, activating aromatic ring’s C-H bonds under mild conditions (32 -

62°C). This observation contrasts with the reported formation of [(Ph3P)4Rh2(μ-Cl)2] due to PPh3

dissociation formed upon heating [(Ph3P)3RhCl] at ~80°C. In our study reactions were monitored by

following the absorbance at 270 and 292 nm for benzene and chlorobenzene, respectively. Plot of

absorbance vs. time were biphasic, indicating two consecutive processes. The fast process is being

assigned to arenes oxidative addition to [(Ph3P)3RhCl]. Based on the chemical behavior of closely-related

Vaska’s complex, 1H and

31P NMR spectroscopy and cyclic voltammetry, the slow process is being

attributed to a series of reactions that may involve C-H bond oxidative cleavage of η2-coordinated arenes

followed by reductive elimination and formation of sigma-complexes via agostic bond formation.

Keywords: Wilkinson’s catalyst, biphasic reactions, C-H bond activation, oxidative addition, sigma-

complex, agostic bonds.

D-3

SYNTHESIS AND CHARACTERIZATION OF FERROCENECARBOXYLATE COMPOUNDS,

APPLICATIONS AS BIOSENSORS AND THE CYTOTOXIC EFFECT STUDIES ON MCF-7 AND

HT-29 CANCER CELL LINES

José L. Vera, Enrique Melendez* and Liming Gao


New ferrocenecarboxylate derivatives were synthesized and biologically examined in-vitro with two cancer

cells lines. The cytotoxic studies were performed by the MTT biological assay using colon cancer cells

(HT-29) and breast cancer cells (MCF-7). Ferrocenecarboxylic acid was first activated with oxalyl

chloride. The acyl chloride formed was added drop wise into a solution containing ergocalciferol,

bromophenol, estrone, or 4(1H-Pyrrol-1-yl)phenol to form the ester. The complex was purified by column

chromatography using silica as stationary phase and eluted with dichloromethane (same solvent used in all

stages of the reaction). The esters were characterized by FTIR and NMR spectroscopy and the

electrochemical properties were investigated.

Ferrocenecarboxylate modified pyrrole was used for electro-polymerization on indium-tin-oxide (ITO)

coated glass surface. The purpose was to develop a mediator-less glucose biosensor with the entrapment of

glucose oxidase on the ITO surface. Other biosensor is developing for the study of the interaction between

metallocene based drugs and DNA.

27

D-4

BIOMEDICAL APPLICATIONS OF NANOTECHNOLOGY: EXPLORATORY RESEARCH ON

THE USE OF ONE DIMENSIONAL NANOSTRUCTURES FOR NEUROLOGICAL BYPASS

Miguel A. González Santiago1, Roy Suarez

1, Zuleyka Torres

2, Iliane Miranda

1, Kasandra Viera

1, Madeline

León1 and Miguel Castro

1

1Department of Chemistry, University of Puerto Rico, Mayaguez, PR 00681

2Department of Chemistry, University of Puerto Rico, Aguadilla, PR

Novel materials and technologies for brain implants are the subject of fundamental and applied research

due to their potential application to treat neurological disorders. Reliable chronic application of neural

electrodes remains a challenge. The low cost and expected bio compatibility of “organic” carbon positioned

polymers and carbon nanotubes as the micro and nanostructures of choice in pursue of adequate materials

for brain implants. However, the problems in handling and functionalizing organic carbon, as well as

solubility in the body, presents limitations to further advance these technologies. Molecularly guided

assembly, on the other hand, offers the opportunity to growth 1d structures directly on tissue: it presents a

unique opportunity to develop technologies to act on specific tissue areas. We report on the growth of one

dimensional silver nanostructures directly on tissue cut from the brain of sheep. The structures result from

the assembly of silver mediated by mercaptoacetic acid. The one dimensional structures are easily

identified when the deposits are prepared directly on top of the tissue: the structures can not be identified

when the tissue is immersed in the dispersion containing the precursors to the one dimensional structures.

The results are compared with those obtained on functionalized single wall carbon nanotubes deposited on

brain tissue. Ongoing work focuses on establishing the types of communication possible within, and

among, the 1 dimensional nanostructures.

1. MG acknowledges financial support from the UPRM PhD Sloan Program.

2. RS acknowledges an undergraduate scholarship from the UPRM BIOMINDS program.

D-5

RESOLUTION OF AN OCTAFERRIC M/P RACEMATE

Karilys González Nieves, and Raphael G. Raptis*

Department of Chemistry, University of Puerto Rico-Río Piedras

Chirality has become important because of the numerous applications in chemistry, pharmacology,

medicine, material science, catalysis, food analysis and forensic analysis.1 Enantiomers are non-

superimposed mirror images differing in their capability to rotate the polarized light in particular direction.

The unique orientation of each enantiomer can result in different molecular interactions with other chiral

molecules. Hence, chiral separation has received more attention during the last decade since many

techniques and methods have been developed to separate racemic mixtures successfully.

Our research group has synthesized a series of homologous octanuclear iron-pyrazolate complexes, which

crystallized as a racemic mixture of M and P enantiomers. We have applied several separation methods in

order to isolate the enantiopure Fe8 complex.2, 3

We have also designed chiral ligands in order to isolate

diastereomeric forms, suitable for separation by conventional methods. Also, HPLC using a chiral column

has been used to achieve the separation of the Fe8.

References:

1) E. L. Izake, J. Pharm. Sci., 2007, 96, 1659-1676.

2) R. G. Raptis, I. P. Georgakaki and D. C. Hockless, Angew. Chem. Int. Ed., 1999, 38, 1632-1634.

3) P. Baran, R. Boca, I. Chakraborty, J. Giapintzakis, R. Herchel, Q. Huang, J. E. McGrady, R. G. Raptis,

Y. Sanakis and A. Simopoulos, Inorg. Chem., 2008, 47, 645-655.

28

E-1

OWEN WHEELER’S LEGACY

Rodolfo J. Romañach


Dr. Owen H. Wheeler was part of the Mayagüez Chemistry Department from 1958 to 1976. He resigned in

1970 to work with Omni Research, but served ad-honorem until 1976 as research advisor to several

graduate students. Wheeler was research advisor for the first student that completed an M.S. in Chemistry

at Mayagüez, and to at least 14 students who have made significant contributions to Puerto Rico’s

development. His students also contributed to the progress of Mexico and Israel.

Wheeler’s researched encompassed synthetic organic chemistry, physical organic chemistry, nuclear

chemistry and spectroscopy, and resulted in over 100 publications, and over 1900 citations. Wheeler’s

research was published in very prestigious journals, starting with his doctoral research which appeared in

the Journal of the Chemical Society in 1955. Wheeler went on to publish a total of seven articles in the

Journal of the American Chemical Society, eight articles in the Journal of Organic Chemistry, two articles

in the Journal of Chemical Education, and two in Chemical Reviews. In addition, a total of 19 articles were

published in the Canadian Journal of Chemistry and one in Science. In September of 1961, the Journal of

Organic Chemistry included four articles of Wheeler’s authorship. These articles involved work at

Mayagüez, Dalhousie University, UNAM, and collaborations with Brunel College of Technology in

London.

As we approach the 100 years of our RUM it is important to stop for a moment and learn about our legacy,

the people who have contributed to the establishment of the research community that we now have. As one

writer has indicated: “You stop being a child, the moment you appreciate the past”.

E-2

AN ANALOGY USING PENNIES AND DIMES TO EXPLAIN CHEMICAL KINETICS

CONCEPTS

Jose E. Cortés Figueroa


An analogy is presented that uses coins and graphical analysis to teach kinetics concepts and resolve

pseudo-first order rate constants related to transition metal complexes ligand-solvent exchange reactions.

The activity provides opportunity for the assessment of conceptual learning via designed activities. It

promotes graphical analysis as well as the integration of mathematical and kinetics concepts. Most

importantly, it discourages rote learning and application of mathematical procedures without an underlying

understanding of the chemical concepts involved.

Acknowledgment

The author gratefully acknowledge the financial support by The Donors of the Petroleum Research Fund,

administered by the American Chemical Society (grant ACS-PRF-41267-B3).

29

E-3

DEGRADATION OF EXPLOSIVE IN WATER USING IRON OXIDE

Gloria Marcela Herrera


Iron oxide nanoparticles were synthesized through a hydrothermal method. XRD, Raman and infrared

spectra were used to characterize the oxide. The photocatalytic degradation of TNT, DNT and RDX using a

UV irradiation at 365 nm as a light source and iron oxide as a photocatalyst, was investigated. An amount

of nano-oxide was transferred to aqueous solutions of the contaminant in a known concentration. The

quantitative analysis of pollutant degradation was carried out using high-performance liquid

chromatography equipped with diode array UV detector. The concentration of TNT was observed to

decrease as a function of time. This can be attributed as oxidative degradation of the organic compound by

iron oxide. TNT solutions were studied by GC/MS technique to identify main degradation products of the

photo-oxidative process. The best results observed were for RDX degradation where the oxide decreases

the RDX concentration in around of 80%. The experiment was simultaneously carried out with the TNT –

iron oxide mixtures without UV irradiation in order to compare the results and of studying the effectiveness

of the catalyst.

E-4

REMOTE SENSING OF HAZARDOUS COMPOUNDS BY RAMAN SPECTROSCOPY

William Ortiz-Rivera, Leonardo Pacheco-Londoño and Samuel P. Hernandez-Rivera


This study describes the design, assembly and testing of Remote Raman Spectroscopy systems intended for

standoff detection of hazardous chemical liquids. Raman spectra of Chemical Warfare Agents Simulants

(CWAS) and Toxic Industrial Compounds (TIC) were measured in the laboratory at a 6.6 m source-target

distance using continuous wave (CW) laser detection. Standoff distances for pulsed measurements were

35 m for dimethyl methylphosphonate (DMMP) detection and 60, 90 and 140 m for cyclohexane detection.

The prototype systems consisted of a Raman spectrometer equipped with a CCD detector (for CW

measurements) and an I-CCD camera with time-gated electronics (for pulsed laser measurements), a

reflecting telescope, a fiber optic assembly, a single-line CW laser source (514.5, 488.0, 351.1 and

363.8 nm) and a frequency-doubled single frequency Nd:YAG 532 nm laser (5 ns pulses at 10 Hz). The

telescope was coupled to the spectrograph using an optical fiber, and filters were used to reject laser

radiation and Rayleigh scattering. Two quartz convex lenses were used to collimate the light from the

telescope from which the telescope-focusing eyepiece was removed, and direct it to the fiber optic

assembly. To test the standoff sensing system, the Raman Telescope was used in the detection of liquid

TIC: benzene, chlorobenzene, toluene, carbon tetrachloride, cyclohexane and carbon disulfide. Other

compounds studied were CWAS: dimethylmethyl phosphonate, 2-chloroethyl ethyl sulfide and 2-

(butylamino)-ethanethiol. Samples were placed in glass and quartz vials at the standoff distances from the

telescope for the Remote Raman measurements. The mass of DMMP present in water solutions was also

quantified as part of the system performance tests.

30

E-5

DI(2-ETHYLHEXYL) PHTHALATE ESTER (DEHP)-DEGRADERS ISOLATED FROM

LANDFILL LEACHATE

María Sevillano, Sangchul Hwang, Sahid Rosado, Daniel Concepción and Isomar Latorre

Department of Civil Engineering, University of Puerto Rico at Mayaguez

Puerto Rico (PR) has the highest pre-term birth rate in US. Phthalate esters, specifically Di(2-ethylhexyl)

phthalate (DEHP) and Dibutyl phthalate (DBP), were detected at low ppb levels in groundwater wells and

distribution lines in PR. Landfills receive phthalates-containing waste materials (PWMs), including

plastics, food packing, home furnishing, paints, clothing, medical devices, and cosmetic products. PWMs

can be degraded and serve as a potential source of phthalate contamination in groundwater. In this regard,

a hypothesis is made that dynamic microbial activity and physico-chemical conditions within landfills can

enhance degradation of phthalates-containing waste materials and mobility of phthalates in landfills, thus

increasing their release, especially from unlined landfills, into the environment. Batch experiments were

designated to isolate DEHP-degraders from landfill leachate. In the system, the carbon source was

gradually limited to DEHP. A control reactor without addition of DEHP was also operated in parallel to

the treatment reactor. Water quality parameters were periodically measured for COD, SS, TN, and TP

during the experiment.

F-1

THE CHEMISTRY OF NUCLEATION

Miguel Castro Rosario1, Madeline S. León-Velázquez

1, Marissa Morales

2, Marianna Carbo

1, Wilnia

Sepulveda1, Kassandra Viera

1, Stephen Santiago

1, Roberto Irizarry

3, Miguel Gonzalez

1, Daniel Rivera

1,

Eunice Mercado1, Edmy Ferrer

1, and Daniel Rivera

1

1Chemical Imaging Center, Department of Chemistry, University of Puerto Rico at Mayagüez

Mayagüez, Puerto Rico 00681 2Oak Ridge National Laboratory, Oak Ridge, Tennessee

3DuPont Electronics Inc., Research Triangle Park, Rayleigh, North Carolina

The process that results in the formation of nuclei is fascinating, with a broad range of applications in

materials sciences, geology, medicine and physics, to name a few. It all starts with the formation of

embryos which then turn into nuclei. We pay little attention to the chemistry that takes place in the process

of nucleation, giving for granted that nuclei formation emerges from solubility as oppose to a chemical

process. In this presentation we will visit and compare a few nucleation and growth process – formation of

Ag2S nanoparticles, spontaneous deposition of silver on carbon nanotubes, and self assembly of

nanoparticles into one dimensional structure on brain tissue- with the purpose of comparing how the

chemistry facilitates the nucleation process. We hope to drive the interest of chemists to pursue studies

toward the understanding of the elemental steps that are involved in the formation of nuclei.

31

F-2

PHASE TRANSFORMATIONS IN METASTABLE STRUCTURES OF NANOCRISTALLYNE

COBALT MEDIATED BY PVP

Celia M. Osorio-Cantillo1, and Oscar J. Perales-Pérez

2

1Department of Chemistry, University of Puerto Rico, Mayaguez, PR 00681

2Department of Engineering Science & Materials

University of Puerto Rico-Mayagüez, Mayaguez, PR 00681

Actual, and potential applications of metallic cobalt, are consequence of its phase-dependent magnetic

properties. On this basis, the present work addresses the synthesis and characterization of nanocrystalline

cobalt particles produced through a modified polyol-based approach that is conducive to the formation of

epsilon ( -Co) or hcp-Co phases. Metastable -Co could be converted into hcp-Co by controlled additions

of polyvinyl pirrolidone (PVP) in trimethylene-glycol. XRD evidenced the progressive conversion of the -

Co phase into the hcp-Co phase, depending on the molecular weight of PVP, as well as, the PVP /Co mol

ratio employed. PVP would play a dual role in the formation of the cobalt nanoparticles: (i) promoting the

polymorphic transformation of cobalt, and, (ii) inhibiting the growth of nanoparticles and preventing their

aggregation as evidenced by SEM and TEM analyses. Magnetic measurements confirmed the strong

influence of synthesis conditions on crystal structure and hence, on magnetic properties; the coercivity of

the products varied from 134 Oe for -Co to 752 Oe for the hcp-Co (see figure 1). These values agreed with

the soft magnetic nature of epsilon and hard magnetic character of hexagonal phases of cobalt.

Figure 1. M-H loops at 300K for nanocrystalline Cobalt particles synthesized in presence of PVP MW

58000, PVP/Co mol ratios of: (a) 0; (b) 5.5; (c) 11 and (d) 22. The inset shows the M-H data around the

origin for all synthesized samples.

32

F-3

OPEN PATH FTIR STANDOFF DETECTION OF HIGH EXPLOSIVES ON SURFACES

John R. Castro Suárez


An Open-Path Standoff Detection System was designed using an EM27 Fourier Transform Infrared

Telescope with MCT detector. Energetic substances samples deposited on metal surfaces were detected

using this method. Standoff detection experiments on metal surfaces were carried out in passive and active

modes. TNT was used as target and aluminum sheet as support material. The analyzed samples were placed

at different distances (from 4 to 30 m) for the active and passive mode experiments. All experiments were

carried out at room temperature. Different surface temperatures were tested in passive mode standoff

detection system. Surface concentrations (50 to 400 g/cm2) were used for both methods. Statistical

treatment was applied to the recorded spectra. The spectra obtained from metal surface samples were

analyzed using partial least squares (PLS). Both active and passive mode resulted useful to record

remotely TNT vibrational signatures at distances of 20 m and 30 m, respectively

F-4

SYNTHESIS OF ZNO NANOWIRES ARRAYS AQUEOUS SOLUTIONS

Marcia del R.ocío Balaguera Gelves1, Samuel P. Hernández-Rivera

1, Oscar Perales-Perez

2 and Surinder P.

Singh2

1Department of Chemistry, University of Puerto Rico-Mayagüez, Mayaguez, PR 00681

2Department of Engineering Science and Materials,University of Puerto Rico-Mayagüez, Mayagüez PR

00681-9044.

ZnO nanostructures (rods and wires) were grown from aqueous solutions of zinc nitrate hexahydrate and

hexamethylenetetramine on ZnO films deposited by RF magnetron sputtering onto Silicon (100) and ITO

(indium tin oxide) substrates. Hexamethylenetetramine acted as a crystal habit controlling agent by

selectively capping the non-polar crystallographic planes of the wurzite crystal. The type of substrate

affected the morphology of deposited ZnO films and hence, influenced the morphology, orientation and

surface coverage of the rod arrays. Rods and wire-shaped structures, with typical diameters of 60 nm and

lengths exceeding several microns, were obtained after 1.5 hour reaction time at 95 °C. ZnO structure was

confirmed by XRD and EDS techniques. ZnO nanorods were also coated by a 32 nm-thick gold layer.

Such Au coating of ZnO nanorod would exhibit excellent surface-enhanced Raman scattering performance

and shows the possibility of molecule-level detection at wavelength of 785 nm for differents analytes such

as; 4- Nitrobenzenethiol,, TNT and adenine. ZnO nanorods on TO substrates provide opportunities for the

controllable surface modification of semiconductor nanostructures.

33

F-5

VARIABILITY OF AEROSOL’S OPTICAL, PHYSICAL AND CHEMICAL PROPERTIES OF

MARINE, AFRICAN DUST AND VOLCANIC ASH AIR MASSES IN THE EASTERN

CARIBBEAN

Héctor Rivera Vázquez1, Olga Mayol

1, John Ogren

2, Patrick Sheridan

2, and Elisabeth Andrews

2

1University of Puerto Rico -Ites, Department of Physics

2NOAA Earth System Research Lab.

Natural and anthropogenic atmospheric aerosols arrive to Puerto Rico (PR) from different source regions.

These include, for example, the adjacent coastal waters, eastern United States (EUS), the Soufriere Volcano

in Montserrat, and the Sahara and Sahel regions in Africa. Incursions of this particulate matter across the

local area degrade visibility, impact adversely the public health, and affect ecosystems, weather and

climate. The air masses arriving into the Caribbean were classified by their source region to determine the

variability of the optical, physical and chemical properties and their trends with time. The measurements

were made at the Cabezas de San Juan (CSJ) station and complemented with aerosol optical thickness

(AOT) data from a sun photometer in La Parguera (LP). At CSJ we used a condensation particle counter

(CPC) to determine the particle concentration number (CN), a sun photometer to determine volume size

distributions (VSD) and AOT, a 3-wavelength nephelometer to determine the scattering coefficients, and a

3-wavelength particle/soot absorption photometer (PSAP) for the absorption coefficients. Data from the sun

photometer at LP was used to compare AOT measurements made at CSJ. A semi-empirical procedure was

used to estimate the surface area distribution (SAD) and the particle CN using the VSD derived by the sun

photometer and comparing it to the CPC measurements. The difference between the two methods was

around 15 %. The VSD showed bimodal distributions for the four cases clean marine (C), African dust

(AD), volcanic ash (VA) and eastern United States (EUS) with a greater influence of the coarse mode (>1

µm) for the C and AD episodes and an increase in the fine particles for VA and EUS air mass episodes. The

calculated SAD for the VA and EUS episodes also showed a bimodal distribution with some instances

showing three modes. The SADs were dominated by the fine mode suggesting a higher chemical and

physical reactivity. Systematic relationships showed up for the different optical properties as a function of

the aerosol load represented by the total scattering coefficient.

G-1

STRUCTURAL DETERMINANTS FOR THE FORMATION OF SULFHEMEPROTEIN

COMPLEXES

Juan Lopez-Garriga1, Elddie Román-Morales

1, Ruth Pietri

1, Brenda Ramos

1, Serge N. Vinogradov

2

1Department of Chemistry, University of Puerto Rico, Mayagüez Campus, Mayagüez, Puerto Rico 00681

2Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine,

Detroit, Michigan 48201, USA

Historically, hydrogen sulfide (H2S) has been regarded as a poisonous gas with a wide spectrum of

cytotoxic effects. However, a new controversial role is emerging for H2S in the chemistry of biological

systems. It has been found that H2S is synthesized endogenously in mammalian tissues and that it

functions as a neuromodulator, and a smooth muscle relaxant. Furthermore, it has been suggested that the

interaction of H2S with cytochrome c oxidase, hemoglobin (Hb) and/or myoglobin (Mb), can decrease

cellular ATP. In this respect, the reaction of H2S with Hb and Mb, in the presence of H2O2 or O2, results in

covalent modification of the heme pyrrole ring bearing the 4-vinyl group, generating the so-called

sulfmyoglobin and sulfhemoglobin derivatives. Several hemoglobins were explored by UV-Vis and

resonance Raman spectroscopy to define sulfheme complex formation. Evaluation of these proteins upon

the reaction with H2O2 or O2 in the presence of H2S suggest: (a) the formation of the sulfheme derivate

requires a HisE7 residue in the heme distal site with an adequate orientation to form an active ternary

complex; (b) that the ternary complex intermediate involves the HisE7, the peroxo or ferryl species, and the

H2S molecule. This moiety precedes and triggers the sulfheme formation.

Keywords: sulfhemoglobin; sulfmyoglobin; hemoglobin I (HbI); hydrogen sulfide (H2S); hydrogen

peroxide (H2O2); histidine (His); ferryl species

34

G-2

DEVELOPMENT OF SPECTROSCOPY BASED REMOTE DETECTION SYSTEMS FOR

CHEMICAL AND BIOLOGICALTHREATS

Samuel P. Hernandez-Rivera, Leonardo Pacheco-Londoño William Ortiz and John Castro

Department of Chemistry, University of Puerto Rico-Mayaguez, Mayagüez, PR

Remote detection of highly energetic materials (HEM) based on vibrational spectroscopy is an important

topic to include in the review of the classification, composition and properties of explosives. Infrared and

Raman spectroscopies allow for the detection and remote identification of chemicals and biological threats

and also enable the use of chemometrics for enhanced detection and discrimination. An IR system was

configured by coupling an “open path” FTIR interferometer to a reflective IR telescope (for passive

detection) and to a telescope coupled mid-IR source (for active detection). The RRS instrument was built

by fiber coupling a spectrograph to a reflective telescope. HEM samples were detected on stainless steel

surfaces as thin films (50-3400 g/cm2) for IR experiments and as particles (3-85 mg) for Raman

measurements. Nitroaromatic HEMs, including TNT, DNT and RDX; HEM formulations, including C4

and Semtex-H; inorganic HEM (ammonium nitrate) and acetone peroxides (TATP) were used as targets.

For the remote IR experiments, samples were placed at increasing distances and an infrared beam was

reflected from the stainless steel surfaces coated with the target chemicals at an angle of ~ 180° from the

surface normal. Targets were placed at the standoff distance, and SIRS spectra were collected in active

reflectance mode. For RRS experiments, amounts as low as 3 mg of TNT and RDX were detected at 7 m

source-target distance when employing 488 and 514.5 nm excitation wavelengths. A detection and

quantification study of the important formulation of C4 is also discussed. Detection limits (milligrams) as a

function of laser power and acquisition time were measured.

G-3

STEROID-FUNCTIONALIZED TITANOCENES AND FERROCENES

Enrique Meléndez1*, Li Ming Gao

1, José L. Vera

1, Alberto Santana

1, and Jaime Matta

2

1Department of Chemistry, University of Puerto Rico, Mayagüez, PR 00681

2Department of Pharmacology, Toxicology and Physiology, Ponce School of Medicine, Ponce, PR 00732-

7004

Six titanocenyl esters, containing steroids, were synthesized, characterized and their structures determined

by NMR methods combined with DFT calculations. Among those steroids, dehydroepiandrosterone,

transandrosterone,and androsterone are androgens and pregnenolone is a progesterone precursor. These

steroid-functionalized titanocenyls were tested by MTT assay for in vitro cytotoxicity for MCF-7 breast

cancer and HT-29 colon cancer cells. All complexes exhibited more cytotoxicity than titanocene dichloride.

The titanocenyls containing androgen and progesterone derivatives as pendant groups had higher

antiproliferative activities than those with cholesterol steroid compounds. Titanocenyl–

dehydroepiandrosterone complex shows much more sensitivity and selectivity for the MCF-7 cell line. In

addition, three ferrocenyl esters were synthesized and characterized. The selection of the pendant groups is

based on the following. Estradiol and estrone are estrogens which can be recognized by the estrogen

receptors and potentially make the ferrocenyl group selective for hormone dependent breast cancer.

Ergocalciferol is Vitamin D2. Ergocalciferol undergoes enzymatic hydroxylation to yield active Vitamin D

and it can be recognized by Vitamin D Receptor (VDR). Vitamin D belongs to the steroid and nuclear

hormone receptor superfamily. Thus, all the steroids studied could lead to receptor specific drugs. The

cytotoxicities of these ferrocenyl esters in MCF-7 and HT-29 cell lines were investigated. Possible

mechanisms of action of these target specific drugs will be discussed.

35

G-4 G-5

WORLD CHEMISTRY CONGRESS IUPAC 2011

Gabriel Infante, Carlos Tollinche, Edgard Resto and Agnes Costa

Organizing Committee, IUPAC2011, Colegio de Químicos de Puerto Rico.

The International Union of Pure and Applied Chemistry (IUPAC) mission is to advance the worldwide

aspects of the chemical sciences and contribute to the application of chemistry in the service of

humankind..The organization has 56 National Adhering Members and 22 National Adhering Associate

Members around the world.

Puerto Rico will have the honor to present the IUPAC 2011 Congress at the Convention Center, San Juan

from July 31st to August 6, 2011.The first IUPAC Congress at a Latin-American country.. The Congress

will present eight Plenary Speakers including seven Nobel Laurates in Chemistry; about 35 Symposia, 800

oral presentations and 1,500 posters. The participation of about 3.000 scientists from local and abroad is

anticipated. An Exhibition of the state-of-the-art laboratory instrumentation will be also presented. Details

about the scientific program of the Congress will be discussed.

In addition the General Assembly of the United Nations in December 2008 adopted a resolution

proclaiming 2011 as the International Year of Chemistry (IYC) placing UNESCO and IUPAC at the helm

of the event. The IUPAC 2011 Congress in Puerto Rico is one of the three cornerstone events for the

celebration of the IYC.

Several chemistry organizations such as the American Chemical Society, FLAQ, Puerto Rico Universities,

Puerto Rico Legislature and Puerto Rico Executive Government, and others have join efforts with IUPAC

and the Colegio de Químicos de Puerto Rico to make IUPAC 2011, the most important scientific event held

in our island.

36

H-1

COMPLEMENTARY NEAR INFRARED AND RAMAN CHEMICAL IMAGING IN THE

EVALUATION OF A NOVEL PHARMACEUTICAL FORMULATION

Jackeline I. Jérez-Rozo1, Anna Zarow

2, Bo Zhou

3, Rodolfo Pinal

3, Zafar Iqbal

2, Rodolfo J. Romañach

1.

1 Department of Chemistry, University of Puerto Rico, Mayagüez Campus.

2 New Jersey Institute of Technology.

3 Department of Industrial and Physical Pharmacy – Purdue University

Pharmaceutical formulation is the process in which different chemical substances, including the active

drug, are combined to produce a final medicinal product1. It is estimated that over 40% of possible new

drug candidates have very low solubility. One possible approach for improving the solubility of these drugs

is to disperse them throughout a polymer film, and prevent them from aggregating. The component

distribution may impact bioavailability, dissolution, or other product performance attributes. The ability to

visualize and assess the compositional heterogeneity and structure of the end products is extremely

important for both the development and manufacture of solid dosage forms. Recent advances in

spectroscopic detector technologies have enabled spectral as well as spatial information to be recorded

simultaneously. This results in creation of three dimensional spectroscopic images where two dimensions

provide spatial information and one dimension provides spectral information. Hyperspectral image, or

hypercube, provides extremely large data, so the information content of the entire cube is enormous. It is

impractical and not useful to attempt to manually interpret each element independently2. Therefore

multivariate analysis is used to extract the relevant physical and chemical information from the imaging

experiment through multivariate analysis procedures and image visualization tools such as Principal

Component Analysis (PCA) and Partial Least Square Discriminate Analysis (PLS-DA). The type of

chemical information extracted from the images with these algorithms is different; NIR spectra are

characterized by wide overlapping bands that are very difficult to interpret and assign to functional groups.

On the hand, Raman spectra are characterized by much narrower spectral bands that can be assigned to

functional groups or specific bonds, and which also provide important information on the crystallinity of

the compound3. The two techniques are also complementary in that water and O-H bonds are poor Raman

scatterers, while providing strong absorbance bands in the NIR spectral region. In this study near Infrared

chemical imaging (NIR-CI) and Raman mapping have been used to evaluate the distribution of the

components of novel polymeric gel strips containing an active pharmaceutical compound in particulate

form.

References

1. Furukawa, T., Sato, H., Shinzawa, H., & Noda, I. (2007). Analytical L Sciences , 872.

2. Grahn, H. F., & Geladi, P. (2007).Techniques and Applications of Hyperspectral Image Analysis. John

Wiley & Sons, Ltd.335-350.

3. Garsuch, V., Breitkreutz, J. (2009). European Journal of Pharmaceutics and Biopharmaceutics. 73,

195–201.

37

H-2

ELECTROCHEMICAL AND CHEMICAL CHARACTERIZATION OF TITANOCENE

DICHLORIDE INTERCALATED IN ZIRCONIUM PHOSPHATE LAYERS FOR USE IN

BIOTECHNOLOGY Barbara Casañas Montes, Cindy Barbosa, and Jorge L. Colón*

Department of Chemistry, University of Puerto Rico at Río Piedras, San Juan, PR 00936

Zirconium bis(monohydrogen orthophosphate) monohydrate (Zr(HPO4)2·H2O, α-ZrP) is the best

characterized zirconium phosphate (ZrP). The highly hydrated phase of the layered ZrP, known as the 10.3

Ǻ phase, is an acidic ion exchanger that has been used for the immobilization of several photo-, bio- and

redox-active compounds. Among these compounds is a metallocene derivative known as titanocene

dichloride which has been proposed and investigated as a potential anticancer drug. We use the 10.3 Ǻ

phase of ZrP as a host to intercalate by direct ion exchange this metallocene derivative and chemically and

electrochemically characterize it for possible applications in biotechnology. ZrP is suitable to produce

robust titanocene dichloride-intercalated nanomaterials that will have better stability as biosensors and drug

carriers compared to non-layered materials. The direct intercalation reaction of the titanocene dichloride

into 10.3 Å ZrP was performed. The intercalated materials were characterized using IR spectroscopy, X-ray

powder diffraction (XRPD) and X-ray photoelectron spectroscopy (XPS). The XRPD data indicates that

new intercalated phases with expanded interlayer distances of 9.9 Å and 10.0 Å were obtained. For the

cyclic voltammetry experiments of the intercalated materials we prepared modified carbon paste electrodes

at different loading levels of the intercalated material to analyze their electrochemical behavior. We will

present the characterization and electrochemical characteristics of the unintercalated metallocene derivative

as well as those of the intercalated materials.

H-3

KINETICS OF LIGAND EXCHANGE REACTIONS ON (η2-C60)W(CO)5 IN SOLVENT

Wanda Ibelitz Pérez Mercado, and José E. Cortés-Figueroa*

Department of Chemistry, University of Puerto Rico, Mayagüez, PR 00681

Activation parameters reported for ligand exchange reactions on (η2-C60)W(CO)5 in various solvents

suggest that solvent molecules are part of the transition states (TSs) leading to formation of solvent-

W(CO)5 intermediate species. If indeed solvent molecules are part of TSs, then one might expect that the

rate law for the ligand/C60 exchange on (η2-C60)W(CO)5 would include the term [solvent]

p, where p is the

order with respect to solvent concentration. To be meaningful, activation parameters must be determined

from rate constant values (ktrue) without unresolved concentrations. This expectation prompted a kinetic

reinvestigation of the above system in a wider range of solvents to determine if indeed rate constant values

and activation parameters are solvent dependent. In the present study ktrue values were employed to

determine activation parameters. A presumption that p =1 was made. To confirm that p =1 or to determine

the actual p values for various solvents it is necessary to know and to control solvents’ concentration.

Because solvents’ concentration can be controlled in solvent mixtures, ktrue values were determined by

monitoring ligand/C60 exchange in binary solvents mixtures. An isokinetic temperature was observed

indicating a compensation effect. In turn a compensation effect indicates that despite a wide range of

observed activation parameters, the reactions share a common mechanism. A mathematical description of

the method employed and a mechanistic description of the fine tuned mechanism will be presented.

38

H-4

MAGNETIC NANOCOMPOSITES TO REMOVE HEAVY METALS AND OXYANIONS IN

AQUEOUS MATRICES

Tatiana Luna Pineda1, Oscar Perales

2 and Felix Román

1

1Department of Chemistry, University of Puerto Rico-Mayagüez, Mayaguez, PR 00681

2Department of Engineering Science and Materials,University of Puerto Rico-Mayagüez, Mayagüez PR

00681

The presence of diverse contaminants at a variable range of concentrations in water has been subject of

increasing international concern, because this is a severe environmental and public health problem. Special

attention is being given to content of heavy metals and organic carcinogenic compounds in wastewaters and

industrial effluents. The use of alginate biosorbent is one of the most extensively investigated biopolymers

for metal ion removal from aqueous solution since is a natural, non-toxic, biodegradable, biocompatible

polysaccharide found in all species of brown algae. Furthermore, the functionalization of nanoparticles with

DMSA creates a sorbent that can be magnetically collected and has a high capacity and selectivity for the

softer heavy metals. The modification of the nanoparticle surface with DMSA increases its efficacy of the

magnetic for the removal of heavy metals and organic carcinogenic compounds. In this work we take

advantage of the synergistic sorption capabilities of magnetite (Fe304) nanoparticles functionalized with

dimercaptosuccinic acid (DMSA) and immobilized into calcium alginate beads (CAB). The resultant

magnetic nanocomposite represented a novel, inexpensive and environmental-friendly sorbent exhibiting

outstanding capacity to remove a variety of heavy metals ions (Cu, Cd) as well as oxyanions (Cr, As) and

carcinogenic organic compounds such as the polyaromatic hydrocarbons compounds. The capability to

uptake arsenic by this nanocomposite was investigated. The magnetite was synthesized by coprecipitation

and functionalized with dimercaptosuccinic acid (DMSA) using an interchange reaction with oleate group.

The formation of the magnetite nanocrystals was confirmed using X-ray diffraction and their

functionalization was verified by infrared (IR) spectroscopy. The DMSA-magnetite nanocrystals obtained

were immobilized in calcium alginate beads (CAB), to form the corresponding nanocomposite CAB-

DMSA magnetite. The uptake capacities of CAB alone, DMSA-magnetite and CAB-DMSAmagnetite for

arsenite and arsenate species were determined as a function of pH at 25oC. Experiments of arsenic removal

using the nanocomposite to different pHs were carried out.

H-5

CARIBBEAN PLANTS FOR ABSORPTION OF ENERGETIC MATERIAL

Sandra N. Correa Torres


The increase of nitroaromatic compounds in soils, water and air has as source their indiscriminate use in

pharmaceutical products, dyestuff, pesticides and explosives devices. In this study one of the most

representative military energetic materials, 2,4,6-trinitrotoluene (TNT), has been removed from a growth

media using endogenous Caribbean plants such as Rubia Tinctorum, Lippia Dulcis and Spermacoce

Confusa (“Juana La Blanca”). The plants were germinated and micropropagated and clones of plants were

successfully grown in vitro, free of bacteria and fungi to be used in the study. Absorption kinetics for TNT

concentrations of 35 or 70 ppm was investigated. The results demonstrated that the plants are resistant to

high levels of TNT, classifying them as possible phytoremediators. The most significant finding of this

work is the demonstration that Spermacoce Confusa (Juana) was able to remove 100% of TNT in less than

48 hours with partial degradation to 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene and 2,4-

dinitrotoluene and 2,6-dinitrotoluene. Analysis of medium extracts was made using HPLC. Solid phase

micro extraction coupled to GC was used to demonstrate that part of TNT was removed from the growth

medium by evaporation. Absorption kinetics constant were 0.1619 h-1

for Juana, 0.0142 h-1

for Rubia and

0.0078 h-1

for Lippia, confirming “Juana” as excellent candidate for TNT removal. This is an important and

promising result as this plant is a common tropical plant and could be used for nitroexplosives remediation

in Caribbean islands used as military shooting galleries.

39

I-1

CYTOTOXICITY OF CU-DOPED ZNSE@ZNS QUANTUM DOTS IN HUMAN PANCREATIC

CARCINOMA CELLS

Sonia Bailón-Ruiz1, Oscar Perales-Pérez

1,2, and Nilka Rivera

1

1Department of Chemistry, University of Puerto Rico-Mayagüez. P.O.BOX 9019. Mayaguez, PR 00681

2Department of Engineering Science and Materials. University of Puerto Rico-Mayagüez, Mayagüez PR

00681

Due to their particular physic-chemical and optical properties semiconductor quantum dots, QDs, are

considered very promising materials for cell imaging, cancer nanomedicine and related bio-medical

applications. The present work is focused on the development of a microwave-assisted synthesis method to

produce water-soluble and stable Cu-doped ZnSe@ZnS core-shell quantum dots and the evaluation of their

cytotoxicity in human pancreatic cells (PANC-1). The desired nanostructure was produced from starting

zinc chloride and selenide aqueous solutions in presence of 3-Mercaptopropionic acid (MPA) at 140C°.

The dopant (Cu2+

) concentration was 0.1% w/w. The formation of the quantum dots was confirmed by X-

ray diffraction, UV-Vis spectroscopy, PL spectroscopy and ICP-MS analyses. Human pancreatic carcinoma

cells (PANC-1) were cultured in DMEM medium containing 10% (v/v) fetal bovine serum and Gentamicin

50ug/mL at 37°C in air containing 5% CO2. Cells were seeded in 96-well plates and grown to about 80%

confluence. Cu-doped QDots dispersed in buffer phosphate (PBS) were added to each well to achieve a

final concentration (0 ppm, 10 ppm, 50pp, 100ppm, 200ppm, 300ppm, 400ppm, 500ppm) and incubated

during 48h. The cellular metabolic activity was measured by using the CellTiter 96 AQueous Assay at 490

nm and the viability percentage was determined by trypan blue exclusion assay in the cellometer. All

treatments were realized by triplicate. The viability percentage decreased from 70.0% ± 3.6% to 44.8% ±

9.1% using 100ppm and 200 ppm of QDots respectively. The corresponding cellular metabolic activity

decreased from 63.4.0% ± 6.6% to 33.8% ± 4.2%. Massive cell death was observed at QDs concentrations

above 200 ppm after 48 hours of treatment.

I-2

BIFUNCTIONAL MATERIALS FOR THE CATALYTIC CONVERSION OF CELLULOSE INTO

SOLUBLE RENEWABLE BIOREFINERY FEEDSTOCKS

Damián Reyes Luyanda, Pedro Morales Perez, Josseant Flores Cruz, Luis G. Encarnación, Ronald

Carrasquillo Flores and Nelson Cardona Martinez

Department of Chemical Engineering, University of Puerto Rico, Mayagüez PR

The development of bifunctional nanostructured materials for the catalytic conversion of cellulose into

sugar alcohols offers the potential of a sustainable source of renewable biorefinery feedstock. Supported Ru

catalysts were prepared by evaporative deposition on various ordered mesoporous silica (SBA-15) with

different functionalities and compared to Ru/C and the corresponding supports. The activity and selectivity

of the bifunctional catalysts were studied by monitoring the cellulose conversion and production of sugars

and sugar alcohols in a batch reactor. Sorbitol is the main product that is obtained by the hydrolysis of

cellulose to glucose followed by the corresponding reduction. Secondary products include sugars, ethylene

glycol and glycerol. Ruthenium supported on arenesulfonic acid-functionalized mesoporous silica displays

the best catalytic performance. The catalysts were characterized using nitrogen adsorption, X-Ray

Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDAX) and

Scanning Transmission Electron Microscopy (STEM). As a result, 43 % of cellulose conversion was

achieved with 66 and 19 wt. % of polyols and sugars, respectively. This result was obtained at 483 K by 1 h

in presence of acid functionalized mesoporous silica supported ruthenium. The effect of functionality

loading, reaction time and temperature on conversion, selectivity, and catalyst stability will be discussed.

40

I-3

STUDY OF SUPPORTED RUTHENIUM CATALYSTS FOR THE CONVERSION OF

CELLULOSE TO SUGAR ALCOHOLS

Darlene Z. Galloza Lorenzo, and Nelson Cardona Martínez

Department of Chemical Engineering University of Puerto Rico at Mayagüez, Mayaguez PR

The increase in the green house gas emissions, due in part to the accumulation of CO2 gases in the

atmosphere and the increasing world’s energy needs combined with diminishing petroleum resources have

caused a renewed interest of finding alternative ways to produce fuels, such as the conversion of

lignocellulosic biomass by a bifunctional catalyst into sugar alcohols. This work is focused on the study of

the effect of the support acid-base properties on the catalytic performance during the conversion of

cellulose into sugar alcohols, which can be used as renewable biorefinery feedstock for the production of

fuels and high value chemicals. The series of metal oxide supports studied includes MgO, ZrO2, TiO2,

Nb2O5, Al2O3, and SiO2. Furthermore binary metal oxides were also analyzed like SiO2-TiO2, TiO2-WO3

and SiO2-TiO2-WO3.This set of materials displays a wide range of acid-base properties. Ru was supported

using evaporative deposition. The catalytic activity of the materials appears to have some correlation with

the Sanderson electronegativity of the metal oxide passing through a maximum for Ru/Nb2O5 for the

supported catalyst and through ZrO2 for the supports. Ru/Nb2O5 has a significantly lower surface area than

Ru/SBA-15 but displays higher activity. The selectivity of the mesoporous material is better than that of

Ru/Nb2O5. Also comparing the binary metal oxides, TiO2-WO3 had a better activity and selectivity than

SBA-15, probably due to its more acidic character.

I-4

SYNTHESIS, CHARACTERIZATION AND APPLICATION OF BIOFUNCTIONAL

HYDROPHOBIC RU/SBA-15

Shuo Cao, Ranjit Kumar and Nelson Cardona Martinez

Department of Chemical Engineering, University of Puerto Rico at Mayaguez

Throughout most of human history, renewable biomass resources have been the primary industrial and

consumer feedstock. The conversion of lignocellulosic biomass into important intermediates for their use in

fuel production and high-value chemicals will be very important for human beings in the future. This

research focuses on the development of bifunctional mesoporous materials for synthesis of furan

derivatives which is obtained by the acid-catalyzed dehydration of monosaccharides, which have been

identified as key intermediates that bridge carbohydrate and petroleum chemistry. Fructose can be

converted to 2, 5-dihydroxy-methyl-tetrahydrofuran (diHMTHF) via 2,5-hydroxymethyl-furfural (HMF),

which will be as an intermediate in a biphasic system. DiHMTHF is an important monomer in the

production of biomass derived polyesters. Two synthesis procedures were used to prepare bifunctional

hydrophobic Ru/SBA-15 catalysts. The hydrophobic properties promote the conversion of HMF to

diHMTHF in the organic phase. The bifuctional catalysts are also more stable in water and 1-butanol at

130C than the corresponding non-hydrophobic SBA-15.

41

I-5

HOST-DEFENSE PEPTIDE-MIMETIC FOLDAMERS AND POLYMERS

Patricia Ortiz-Bermúdez

Department of Chemical Engineering, University of Puerto Rico, Mayaguez, PR

The laboratory of Dr. Patricia Ortiz Bermúdez is committed to the development and characterization of

effective antimicrobial agents with minimal human toxicity. Our main objective is to modify the structure

of synthetic antimicrobial beta-peptides in order to target them to a specific component on microbial cell

surfaces. Host-defense peptides (HDPs) are produced as part of the innate immune system of all life

forms. HDPs display potent antimicrobial activity, and many research groups have sought to mimic or

improve upon this activity with synthetic oligopeptides composed of natural alpha-amino acid residues.

We will focus on newer and more novel strategies for mimicry of HDPs, based on synthetic oligomers and

polymers that contain unnatural beta-amino acid-based subunits. "Beta-peptides" are oligomers comprised

exclusively of beta-amino acid residues; these molecules display well-defined folding behavior if the beta

subunits are properly chosen. In addition, beta-peptides resist degradation by protease enzymes, in contrast

to natural HDPs and their alpha-peptide analogues.

42

POSTER PRESENTATIONS

43

P-1

SYNTHESIS AND FUNCTIONALIZATION OF CHITOSAN BEADS FOR THE REMOVAL OF

ARSENIC AND VANADIUM CONTAMINANTS

Abigail Padilla Rodriguez, Félix Román

Department of Chemistry, University of Puerto Rico-Mayagüez, Mayaguez, PR 00681

This study aimed to evaluate the adsorption behavior of inorganic arsenic (As+5

and As+3

) and vanadium

(V) onto chitosan beads and its functionalization in aqueous solution. The synthesis and functionalization

of chitosan beads involves the binding with mercaptan groups, due to the high affinity of As and V for the

sulfhydryl groups. The synthesis of chitosan beads was prepared according to a modified previously

published method using a peristaltic pump. These beads were crosslinked with Dimercaptosuccinic acid

(DMSA), N-Acetyl-L-Cysteine (NAC), thioglycolic acid (TGA), alginate (Alg) and gluteraldehyde (GTA).

Arsenate (As+5

) samples at pH 7.00 were placed in contact with O.5000g of chitosan beads for 26 hours.

The samples were collected at different intervals and analyzed by Inductive Coupled Plasma with Mass

Spectrometry (ICP-MS). Arsenate removal was around 64.44% for a concentration of 100ppb.

Characterization of the functionalized beads will be performed by Infrared and Raman Spectroscopy.

Currently the adsorption behavior of arsenite and vanadium onto chitosan beads and its functionalization in

aqueous solution is being evaluated.

P-2

SYNTHESIS AND FUNCTIONALIZATION OF MAGNETIC NANOPARTICLES FOR MDT AND

PDT APPLICATIONS

Christie Rodríguez-Ramirez, Tatiana Luna, Oscar Perales-Pérez


Drug-functionalized magnetic nanoparticles represent an option to overcome limitations and concerns

associated with targeting and drug delivery efficiencies in conventional chemotherapies. The use of an

external magnetic field to guide magnetized nanoparticles to pathological sites to release the chemotherapy

drug can potentially reduce dosage, exposure time and side-effects associated with non-specific drug

uptakes by healthy tissues. The goal of this research is to functionalize magnetic Fe-based oxides with

anticancer agents and/or photo-sensitizers for oncological applications. As a first-stage, magnetite

nanoparticles were synthesized via co-precipitation method using NaOH and NH4OH as precipitating

agents. The influence of the synthesis route on the average crystallite size and magnetic properties of the

nanoparticles were investigated. As-synthesized nanoparticles were functionalized with oleic acid and

mercaptopropionic acid (MPA). XRD measurements indicated an average crystallite size in the 6 nm to 11

nm range. FT-IR analyses evidenced the actual functionalization of the magnetite surface by oleic acid

groups, which explained the remarkable stability of treated nanoparticles in toluene. Room-temperature M-

H measurements showed that the saturation magnetization varied between 50emu/g and 60 emu/g. Ongoing

efforts include optimizing the coverage of magnetite surface with MPA by promoting the Oleic-MPA

ligand exchange reaction.

44

P-3

CARBON NANOFIBER ELECTRODE DEVELOPMENT FOR CHOLESTEROL OXIDASE

IMMOBILIZATION Damaris Suazo-Dávila

1, Carlos R. Cabrera

1 and Meyya Meyyappan

2

1Department of Chemistry, University of Puerto Rico-Río Piedras,

2NASA Ames Research Center

Cardiovascular diseases, caused by high level in cholesterol, are increasing day by day and cardiac arrest is

the major cause of death. Cholesterol and its fatty acid esters are one of the main constituents of

mammalian cell membranes. The development of a biosensor that integrates cholesterol oxidase for the

detection of cholesterol is important as a diagnosis tool. We propose to use a method previously reported

by the Nanotechnology group at NASA-Ames Research Center for the fabrication carbon nanofiber (CNF)

electrodes. This will involve a direct growth of CNFs on a metallic surface. This approach not only

improves the electrical contact between the active sensing material (CNFs) and the conducting substrate,

but also ensures that the sensor is free of impurities. The advantage of this technique is that the tips of the

nanofibers are exposed to the analytes and the CNFs are vertically aligned for the attachment of cholesterol

oxidase. The CNFs serve as the immobilizer and the mediator, at the same time. Different electrochemical

and surface characterization techniques are used to characterize the CNF development such as: Cyclic

Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), Scanning Electron Microscopy

(SEM), Atomic Force Microscopy (AFM), X ray Photoelectron Spectroscopy (XPS) and Ramman which

we can provide information about the conductivity of the surface, the topology and the composition.

P-4

SYNTHESIS OF SUPERCONDUCTING NANOPARTICLES AND APPLICATIONS AS

BIOMARKERS

Daniel Rivera, Madeline León, Marianna Carbo, Wilnia Sepúlveda, Edmy J. Ferrer, Miguel A. González,

and Miguel E. Castro*

Department of Chemistry, University of Puerto Rico-Mayagüez, Mayagüez PR 00681

Materials that exhibit superconductivity at low temperatures are currently being studied for the properties

they exhibit at room temperature, especially for their biomedical applications. We are pursuing alternative

routes for synthesis of superconducting nanomaterials and testing their abilities to function as biomarkers

of cardiac troponin, myoglobin, CK and CK-MB. The superconducting materials synthesized are strontium

titanate (SrTiO3) and barium strontium titanate (BaSrTiO3), through the process of micelle formation.

Because the materials we are studying exhibit a net magnetic moment, this property is suspected to change

in the presence of heart failure markers, such as those mentioned above. Synthesis methods include

ultrasound as well as microwave techniques. Both techniques have the capability of producing high local

temperatures which is needed for the fusion of the metals in our material. Our characterization techniques

include UV-Vis spectroscopy and powder XRD measurements. Optimization of a systematic approach to

the synthesis of superconducting materials is very important because it provides larger yield percentage and

reduction in the cost of producing said materials, with the added benefit of reducing dramatically the time

needed for researching said materials. The studies are being done with varying concentration of reactants

(TiO2 and SrCl2) with ranges from 3x10-3

M to 3x10-2

M, and a micelle concentration of 2x10-2

M in

cyclohexane. This poster will report preliminary UV-Vis spectroscopy data showing the formation of

SrTiO3 using ultrasound and microwave synthesis.

45

P-5

CHARACTERIZATION AND EVALUATION OF THE SORPTION CAPACITY OF THE

SLUDGE FROM SIX WATER FILTRATION PLANTS OF THE WESTERN AREA Diana Sanchez-Rivera

1, Félix R. Román

1, and Oscar Perales-Pérez

2, Joel Lugo

3

1Chemistry Department, University of Puerto Rico, Mayagüez

2Engineering

Science and Materials Department, University of Puerto Rico, Mayagüez

3Western Regional Sub Director of the PRASA

This study addresses the development of a simple and cost effective methodology capable to remove heavy

metals from water using dried sludge from six water filtration plants. The sludge is a waste material from

the Puerto Rico Aqueduct and Sewage Authority (PRASA) filtration plants, which finally is dumped in our

landfills. The expected sorbent capability of the sludge was based on the presence of silicates and oxides

bearing iron and aluminum, as confirmed by XRD analyses. The dried sludge can interact with cationic and

anionic species by ionic exchange or co-precipitation. Removal of 100 ppb Cu(II) at pH 7.0 using 10g/L of

sludge varies from 62% when Sabana Grande sludge was used, up to 100% when used the Cabo Rojo

sludge. Zn(II) under the same conditions, was removed from 88% using the Lajas sludge in comparison

with 100% all other five plants. The removal of Pb(II) was also 100% for all six sludges. The mechanism of

removal is believed to be the cation exchange with calcium or magnesium. The results show that the sludge

could be used as an efficient and low cost-adsorbent for cations at trace levels from aqueous solutions.

Keywords: sludge, PRASA, heavy metals, ICP-MS

P-6

SCREENING MICROORGANISMS FOR PLASMINOGEN ACTIVATOR SECRETION

Edmarie Martinez Rodriguez1, Carlos Rios Velazquez, *

2 and Vibha Bansal

3*

1Department of Biology,

2Department of Biology, University of Puerto Rico at Mayaguez,

3Department of

Chemistry, University of Puerto Rico at Cayey, Cayey, PR-00736

Plasminogen activators (PAs) are proteolytic enzymes clinically administered as thrombolytic agents for

the treatment of strokes and myocardial infarctions. There are a number of PAs currently available for such

treatments. PAs secreted by mammals such as tissue-Plasminogen Activators and urokinase-Plasminogen

Activators are effective but extremely expensive for large-scale therapy. Streptokinase and staphylokinase

are other Plasminogen Activators that have been isolated from bacteria. The PAs secreted by bacteria are

mostly used for cleaning catheters because their non-human origin mounts an undesired immune response.

One of the drawbacks of all these PAs is their short half-life, which adds significantly to the cost of

treatment. There is therefore an acute need for more stable PAs which could lead to a cost effective

treatment for these diseases. This project is based on the hypothesis that enzymes isolated from halophilic

organisms are more stable under non-standard conditions of temperature and pH and will thus have longer

half-lives. Hence, halophiles isolated from the salines in Cabo Rojo, Puerto Rico were screened for

secretion of PAs. The halophiles were cultured in the laboratory in marine broth and the cultures then

centrifuged at 4,000 × rpm, for 20 minutes at 4°C. The supernatant was assayed for PA activity using the

Fibrin Plate Assay method. To check if PA being produced was being retained inside the cell and not

secreted out, the cells were broken and the lysates tested for PA activity using the same assay. One

halophilic bacterial species was identified as positive for PA secretion. The PA is now being isolated and

characterized.

46

P-7

SYNTHESIS AND CHARACTERIZATION OF CONCENTRATED Pt/PS, LATEX JANUS

PARTICLES IN SUSPENSION

Eduardo Moró Pérez, Luis Ruiz Santiago, Elvin Acevedo Gerena

Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus

An emerging challenge in colloidal science and fluid mechanics is the design and synthesis of micro- and

nanomotors that work in a controlled manner in environments dominated by viscous forces and Brownian

motion, especially if such is achieved without external forcing or signaling. Recently, it was shown that

platinum-polystyrene (Pt/PS) Janus particles in the presence of hydrogen peroxide moves autonomously

due to self-created concentration gradients. Catalytically driven motion of Janus particles has led to the

discovery of interesting material properties, opening up a wide range of applications. In the present work,

we study experimentally the motion and structure formation of a Pt-PS Janus particle suspension at

different particle volume fractions. After synthesis and characterization of the particles, an optical

microscope is used to analyze their chemically enhanced motion at various hydrogen peroxide

concentrations and obtain an average diffusivity of the suspension. The results are then compared to the

values obtained by Howse et al. (2007), which also considers the motion of Pt-PS Janus particles but only

at dilute conditions.

Keywords: Janus particles, suspension, catalytically-driven motion, colloids, suspension

P-8

SULFMYOGLOBIN FORMATION WITH NITRIC OXIDE

Erika Y. García-Gutiérrez, Erika López-Alfonso, Elddie Román-Morales, Juan López-Garriga,

Department of Chemistry, University of Puerto Rico at Mayaguez, Mayagüez PR 00681

Recent studies have recognized Hydrogen Sulfide (H2S) as a neurological and cardiovascular modulator.

However, when the human body is exposed to high H2S concentrations, a sulfur atom binds to the heme

group of the hemoglobin (Hb) generating a sulfheme complex with a characterized 620nm Q band. The

complex formation is conditioned to the presence of ferryl species, H2S, and the Histidine amino acid

residue in the E7 position of the Hb active site. This Hb derivative promotes a condition known as

Sulfhemoglobinemia, which decreases the Hb ability to execute its function of oxygen transportation. To

find a treatment for Sulfhemoglobinemia, we need to understand the mechanism that leads to

sulfhemoglobin complex formation. Our goal is to characterize the appropriate conditions for the formation

of Sulfhemoglobinemia; testing the hypothesis that Nitric Oxide (NO) also produces the ferryl species

required for the formation of sulfhemoglobin in combination with H2S.

During this research, horse heart myoglobin (Mb) was used since it has a similar active site structure to the

human Hb and to execute their function, they both bind oxygen. Each step was evaluated by UV-Vis

Spectroscopy in the 300-700nm region. Our experimentation began with Mb in oxidation state FeIII in the

metaquo complex. Sodium Dithionite was used to change the oxidation state to FeII by forming the deoxy

complex. Nitric Oxide is added to the sample too produce the Mb-NO complex. Finally, H2S is added,

completing the sulfmyoglobin formation, which is evaluated by the formation of the 620nm Q band.

Results have shown that Nitric Oxide produces the necessary ferryl species and therefore, promotes the

sulfmyoglobin formation reaction. The 620nm band has been observed in all samples with an approximate

life time of 24-48hours.

47

P-9

QUANTIFICATION OF TNT, DNT, TATP AND PETN ON GLASS SUBSTRATE BY FIBER

OPTIC-GRAZING ANGLE PROBE FTIR SPECTROSCOPY

Gabriel A. Nieves-Colón, Leonardo C Pacheco Londoño, Oliva Primera-Pedrozo, and Samuel P.

Hernández-Rivera*

ALERT-DHS-COE/Center for Chemical Sensors Development, Department of Chemistry, University of

Puerto Rico-Mayaguez, Mayaguez, PR 00681

This research is driven by the need of finding innovative and effective ways of detecting and quantifying

explosives that may represent threats to human lives. They may be present on substrates in trace amounts

and methodologies for their detection are required. We took advantage of the multiple benefits that Fiber

Optic Coupled Infrared Spectroscopy offers to identify materials, in our case explosives, and used them to

develop new methodologies to achieve the main purpose of this project. One of the methodologies under

development consists of a Grazing Angle Probe rendering the latter as a remote sensed and in situ method

of detecting micrograms/cm2 to nanograms/cm

2 of the compounds. Then used chemometrics routines for

data analysis and enhanced detection. A smearing technique was used to transfer the target analytes and

threat agents to the substrates to prepare samples and standards for development of the methodologies.

Recent work centered on obtaining the spectra of TNT, DNT and PETN and the behavior that they present

when deposited on glass substrates at different concentrations. The multiple spectra collected showed that

explosives can be detected and quantified. The quantification was done by PLS1 methodology, an efficient

approach to detect and quantify threat chemicals deposited on glass surfaces. Calibration curves for

different explosives were obtained and cross validations, regression coefficients and error estimations were

used to evaluate the chemometrics models developed. The detection limits and the error of prediction were

found to depend on the sublimation pressure of the explosives.

P-10

ADVANCEMENTS IN THE DEVELOPMENT OF BIMETALICNANOCOMPOSITES FOR THE

DETECTION OF FLUOROQUINOLONES BY SURFACE ENHANCED RAMAN

SPECTROSCOPY Héctor Arreizaga, Marco De Jesús

Department of Chemistry, University of Puerto Rico at Mayaguez, Mayagüez PR 00681

Fluoroquinolones are among the most prescribed antimicrobial agents worldwide and consequently, an

emerging pollutant of concern. Third generation fluoroquinolones like cyproflaxacin, and levofloxacin have

shown chelating interactions to various metal ions like calcium, magnesium and zinc. The formation of

these complexes in environmental matrices could enhance the solubility, persistence and bioavailability of

these agents in wastewaters and soil. Despite this, there is limited information on the kinetics and structural

transformations induced by these interactions. Recent advances in nanotechnology have enabled the

construction of composite materials that facilitate the analysis of drug-metal interactions with potential

applications in biotechnology, engineering and environmental sciences. The work presented here in uses for

the first time, metal/polydimethylsiloxanenanocomposites as a surface enhanced Raman platform to

investigate fluorquinolone-metal interactions under controlled laboratory conditions. This study shows our

current findings in the study and validation of these low cost, field portable detection systems. Optimization

parameters such as film thickness, optical extinction spectra are discussed. Spectroscopic data on the

binding of model pollutants and fluoroquinolone agents are presented. The benefit of the technique to

derive empirical information to model these interactions for biomedical and environmental applications is

presented.

Key words: Surface Enhanced Raman (SERS), Fluoroquinolones, Cyproflaxacin, Levofloxacin,

Polydimethylsiloxane

48

P-11

Bacillus thuringiensis DETECTION AND CHARACTERIZATION BY NORMAL RAMAN AND

SERS AS BIOAEROSOL PARTICLES

Hilsamar Félix1, Roxannie González

2, Kristina Soto

3, Carlos Ríos

3* and Samuel P. Hernández

1*

1Center for Chemical Sensors Development

Chemical Imaging Center / ALERT-DHS-NUE-UPRM Center of Excellence

Department of Chemistry, University of Puerto Rico-Mayagüez, 2Industrial Biotechnology, Biology Department, University of Puerto Rico-Mayaguez Campus

3Microbial Biotechnology and Bioprospecting Lab., Biology Department, University of Puerto Rico-

Mayagüez Campus

Bioterrorism’s high potential for destruction has become a subject of concern. Thus, fast and cost effective

detection techniques for microorganisms have become a very important subject of investigations.

Techniques such as Raman Spectroscopy and Surface Enhanced Raman Spectroscopy (SERS) allow fast

detection that can even be implemented remotely at long distances from the sample. Bacillus thuringiensis

(Bt) is a soil-dwelling bacterium, commonly used as a pesticide. It is closely related to Bacillus anthracis,

which is the cause of anthrax and used as a biological warfare agent. Both these bacteria form spores which

are able to tolerate extreme environments and make them suitable for transport before or during a

biological attack. Normal Raman and SERS spectra can be compared and analyzed to determine differences

and similarities between species present in the sporulation growth stage, for example at 15 h. In future

experiments these results will be used to detect the bioaerosols in air using a Remote Raman telescope. The

development of these techniques could be useful in design of biosensors for other applications such as

medical diagnostics and industrial microbiology. The time required for identification of pathogens is a

determinant factor of infection related sickness; therefore research in this area is very important.

P-12

AFFINITY CHROMATOGRAPHIC PURIFICATION OF PLASMINOGEN ACTIVATOR FROM

MAMMALIAN CELL CULTURE BROTH

Inés M. Rodríguez-Pérez, Marienid Flores-Colón and Vibha Bansal*

Department of Chemistry, University of Puerto Rico-Cayey

Plasminogen Activators (PAs) are serine proteases that convert the zymogen plasminogen into plasmin.

Plasmin is present in blood and its main function is to degrade fibrin blood clots. These proteins are used to

treat thromboembolic diseases that have a tendency to increase in conditions such as myocardial infarction

and cerebral apoplexy. The objective of this project is to isolate and purify new and more effective

plasminogen activators from mammalian cell culture broth using affinity chromatographic techniques.

Three mammalian cell lines (HEK-293, HeLa, and JURKAT-1) were screened for PA secretion using

colorimetric assays. Only HEK-293 and HeLa were found to secrete PAs. These plasminogen activators

were isolated using two different types of commercially available matrices: para-amino benzamidine

Sepharose 4B and lysine Sepharose 4B. The final PA product was further characterized with respect to

protein concentration, enzyme activity, and electrophoresis.

49

P-13

FORMATION OF SULFMYOGLOBIN WITH SODIUM DITHIONITE Ingrid S. Forestier Román, Elddie Román Morales and Juan López Garriga

University of Puerto Rico at Mayagüez

Investigating the formation of Sulfmyoglobin has been a challenging task directed to the exploring of the

characteristics of the reaction that takes place during the formation of the Sulf complex. The purpose of the

experiment was to monitor the prolongation and signal quality of the 620nm band. A series of experiments

had been run with concentrated Myoglobin, making it react with Sodium Dithionite, Oxygen and H2S. As

results of these experiments we have seen a pattern that jump us to the conclusion that at higher

concentrations of H2S, the characteristic band of Sulfmyoglobin, 620nm, is better defined. To make this

possible, first, it was necessary the elimination of the Oxygen in the solution to prevent the reaction with

Sodium Dithionite. When running the solutions in the UV-Visible Spectrophotometer, each one showed

that 24 hours later the 620 band was present, contrary to 48 hours later when, depending on each

concentration, the characteristic band can be observed. Some spectrums may vary because of the use of

different UV-Visible.

P-14

CHARACTERIZATION OF PLSX MUTANT STRAIN OF STREPTOCOCCUS MUTANS 1Joel E. Díaz-Arana,

2Benjamin Metcalf,

2Cory Hubbard,

2Mathew MacGilvray,

2Roberta Faustoferri and

2Robert Quivey

1School of Dental Medicine, University of Puerto Rico Medical Sciences Campus

2Center for Oral Biology, University of Rochester, New York

Streptococcus mutans, the major contributor to dental caries in humans, metabolizes dietary sugars to

produce acid end products. The organism has developed adaptive mechanisms to survive the subsequent

acidic environmental stress, including changes in membrane fatty acid composition. The plsX ortholog of

S. mutans, encoded by SMu0022, has been shown in other organisms to be responsible for packing the fatty

acids into the membrane. Here, we examine the contribution of plsX to the acid adaptive strategy of S.

mutans. A deletion strain of SMu0022 (plsX) was created by ligation independent cloning (Giaever, 2002).

The ∆plsX mutant strain (MU0022) was characterized for its acid and peroxide sensitivity and membrane

fatty acid composition of biofilm cultures was determined by GC-FAME. Our results indicate that loss of

plsX in S. mutans resulted in a more acid resistant phenotype, as compared to the parent strain. We

conclude that PlsX is involved in the acid adaptive response of Streptococcus mutans.

50

P-15

DEVELOPMENT OF NOVEL BIO-FUEL CELLS USING COFFEE WASTES

John K. Morales Rodríguez, M. Duque, M. De Jesús, D. López, and C. Vega

Department of Chemistry, University of Puerto Rico-Mayagüez

The columbic output of a microbial fuel cell was obtained by measurements in a cell with an anodic

compartment using coffee waste rich in Erwinia dissolvens. Mixtures of swamps, mangroves and also

grease residues provide as waste from the university cafeteria were the sediments used for the last semester

of this research. In this new semester we try to find a new sample and we used coffee residues in the anodic

compartment. The cathode compartment consists of a 0.2 molar solution of Sodium Phosphate monobasic

and Sodium Phosphate dibasic. The microbial fuel cells with and without glucose and with and without

mediators was compared in orders to determine the effect of glucose and different mediators as a fuel to

increase the production of energy. The two compartments were electrically connected with two salt bridges

filled with agar saturated with KCl. The electric connection to the voltmeter was made throughout nickel-

chromium thin wires sewn to the carbon cloths that were used as electrodes in both compartments, with the

intention of comparing the effect of the metal electrical connection. The voltage was measured at open and

a close circuit with paraffin and also after a known resistance (220 ohm) was connected in series with the

instrument. Our results show that without adding glucose and adding 1mL of mediator blue of methyline to

the anodic compartment improved the columbic output of this novel bio-fuel cell by more than a ten

percent (>10%).

P-16

NEAR INFRARED CHEMICAL IMAGING SLOPE AS NEW METHOD TO STUDY TABLET

COMPACTION AND TABLET RELAXATION

Jorge Ropero1, Y. Colón

1, B. Johnson-Restrepo

2, and R. J. Romañach

1*

1Department of Chemistry, University of Puerto Rico-Mayagüez, Mayagüez 00681

2Environmental and Chemistry Group, Campus of Piedra de Bolívar, University of Cartagena, Cartagena,

Colombia

Near-infrared chemical imaging (NIR-CI) spectra of lactose monohydrate tablets were acquired and the

spectral slope from each pixel in the data hypercube was used to assess tablet compaction and relaxation.

Tablets were prepared at compaction pressures of 100, 300 and 500 MPa using un-lubricated and

magnesium stearate lubricated lactose monohydrate. Results show that NIR slope distribution is a function

of applied compaction forces and magnesium stearate lubrication. The distribution of NIR slope values was

studied using histograms and statistical parameters. The mean slope value yields a linear calibration curve

that predicts tablet compaction pressure as a function of spectral slope. The NIR-CI slope measurements

were also used to study tablet relaxation which occurs as tablets release some of the stored energy from

compression. The NIR-CI slope method provides a qualitative description of the relaxation process and

provides quantitative information describing relaxation through time.

51

P-17

ANALYSIS OF TRACE ELEMENTS IN TREES AT SHALE HILLS

José A. Morales Collazo


Recently, investigations have been carried out at Shale Hills with the purpose of quantitatively predicting

the creation, evolution, and structure of regolith. This investigation addressed the analysis of trace elements

in the leaf tissue of trees at Shale Hills. Samples were collected from the canopy of different kinds of trees

located in different types of soils within the forest catchment; the samples were washed, dried and digested

for analysis using ICP-MS. Analyses showed low concentrations of trace elements in the leaf tissue. The

elements that showed the higher concentrations were K (200-400 mmol/kg) and Ca (150-250 mmol/kg).

These results were compared to range values of tropical trees. For most of the elements, values in Shale

Hills samples were in the lower part of the ranges except for Na (0.6-1.6 mmol/kg) whose values were

below the range and Mn (40-110 mmol/kg) whose values were in the higher part of the range. Different

kinds of soils (wet or dry soils) and trees (evergreen or deciduous) were compared among the samples, but

due to the low concentrations of the trace metals the differences in the values were not significant. Results

showed that Shale Hills vegetation has low amounts of trace elements which may imply that nutrients in the

soils are low.

P-18

DIRECT SCREENING ANALYSIS OF PAHS IN ATMOSPHERIC PARTICULATE MATTER

WITH HS/SPME AND GC/MS

José R. Rivera Negrón1,2

and Maritza De JesúsEchevarría2*

1Department of Chemical Engineering, University of Puerto Rico-Mayagüez, Mayagüez, PR 00681

2Department of Chemistry, University of Puerto Rico-Mayagüez, Mayagüez, PR 00681

Polynuclear aromatic hydrocarbons (PAHs) are by-products of the combustion of organic matter and are

carcinogenic compounds. Sources of atmospheric PAHs are mostly anthropogenic (e.g. motor vehicles,

industrial processes, domestic heating, waste incineration, and tobacco smoke) and natural processes (e.g.

forest fires and volcanic eruptions). Urban measurements of the atmospheric PAHs in several cities have

been reported and several analytical methodologies have been employed to evaluate the PAHs contents in

the atmosphere. This research validate the promising extraction technique, headspace solid-phase

microextraction HS/SPME due to its several advantages over other extraction techniques, coupled to gas

chromatographic mass spectrometer, GC/MS for the analysis of PHAs traces in air samples. The

preliminary results shows that the HS-SPME followed by GC/MS in Extracted Ion acquisition mode has

been developed for direct determination of PAHs (anthracene and naphthalene) in TSP/PM10 glass filter.

Concentrations as low as 5 ppb were able to identify with the new method. The best SPME fiber was

CW/DVB. The correlation factor of the calibration curve was 0.9695. The analytical performance of the

results showed a potential application as a screening tool for chemical characterization, source

discrimination, and evaluation of isomer distribution in environmental samples saving time and costs.

52

P-19

SURFACE ENHANCED RAMAN CHARACTERIZATION OF TRACE ANTIMICROBIAL

DRUGS USING METAL/POLYMER NANOCOMPOSITES

Legna Figueroa1, Jenifier Olavarria

1, Sabrina Wells

2, William Ortiz-Rivera

1, Michael J. Sepaniak

2 and

Marco A. De Jesús1*

1University of Puerto Rico at Mayagüez, Department of Chemistry, P.O Box 5000, Mayaguez, P.R 00681

2University of Tennessee at Knoxville, Department of Chemistry, 552 Buehler Hall, Knoxville TN 37996,

U.S.A.

Pharmaceutical and personal care products, such as antimicrobial drugs, have became a cause of concern

over the past years since they can reach the environment as intact or partially metabolized compounds by a

large number of routes. Degradation processes such as photodegradation and biodegradation have been

considered as causes for the generation of degradation compounds of equal or more toxicity than parental

compounds. Metal/polymer nanocomposites, such as silver/polydimethylsiloxane (Ag/PDMS), are a class

of surface enhanced Raman spectroscopy (SERS) substrates that prove effective for the sensitive,

reproducible, and field adaptable detection of aromatic acids in water. The work present herein uses metal

polymer and metal oxide nanocomposites as substrates for the detection and characterization of trace

amounts of organoarsenic and fluoroquinolone antimicrobials in water by SERS. Monitoring of fingerprint

region of Raman and SERS spectra allowed for unequivocal identification of each analyte. The results

gathered in this study show that organoarsenic species are distributed into the PDMS surface where the

arsonic acid binds onto the embedded silver nanoparticles, enhancing its characteristic 792 cm-1

stretching

band. The chemisorption of the drugs to the metal facilitates its detection and characterization in the parts

per million to parts per billion range. Distinct spectroscopic features of each drug are presented with

emphasis on the interactions of the peripheral groups with the metal surface which allow assessment of

sorption and chemical orientation of analyte.

P-20

DESIGN OF TARGET SPECIFIC METAL-BASED DRUGS: SYNTHESIS AND BIOLOGICAL

EVALUATION OF FUNCTIONALIZED TITANOCENES WITH ESTROGEN STEROIDS

HORMONE

LiMing Gao, Enrique Meléndez*

Department of Chemistry, University of Puerto Rico, Mayaguez, P.R. 00681-9019

The development of target specific anticancer agents currently still is a scientific challenge. The design of

such species requires careful selection of the sensing/recognition molecule that has the selectivity for a

particular cancer. In this regard, transition metal complexes appended to a biomolecule has played an

important role in the development of target specific anticancer agents. The long term objective of this

project is, using the structure-activity relationship, to design novel functionalized titanocene complexes

with the desired antitumor activity with lower toxicity than cis-platin, and to understand the mechanism of

action at molecular levels. The initial study is focused on the synthesis, chemical, characterization and

biological activity profile of functionalized titanocenes containing estrogen steroid hormone as pendant

groups. Synthetic specific ligands of estrogens possessing cyclopentadienyl side chains at the C-2 position

of the A-ring were designed. Catechol estrogens are implicated as possible causative agents in estrogen-

induced tumorigenesis, so deprotected-MOM estrogens and their metal complexes are becoming more

significantly. Sex estrogen steroids as pendant groups will provide more selectivity to specific cancer cell

lines, resulting in target specific anticancer drugs to hormone dependent cancers. The titanocene complexes

with hormone steroids estrogens were evaluated for estrogen receptor binding activity in MCF-7 human

mammary carcinoma cells.

53

P-21

SYNTHESIS, CHARACTERIZATION OF TITANIUM COMPLEXES OF AROMATIC

ALDEHYDES DERIVATIVES OF DIFFERENT AMINO-ACIDS

LiMing Gao, Enrique Meléndez*

Department of Chemistry, University of Puerto Rico, Mayaguez, P.R., 00681-9019

Group 4 metal complexes of peptide derivatives are receiving an increased interest lately. This field of

coordination chemistry has become of increasing importance with regard to a variety of ongoing

developments from catalysis, material science and medicine.. Thus, titanium–protein complexes may play a

role in the cancerostatic potential of some organometallic complexes of this light Group 4 element.

Titanium complexes of modified peptide ligands have found useful applications in enantioselective

catalysis. This report just describes the detailed synthesis of seven new titanium complexes of aromatic

aldehydes derivatives of different amino-acids. These complexes were characterized and shown to feature a

typical structure where the monoanionic ligand is tridentate, coordinating to the central titanium atom

through both the phenolate oxygen atom and the ester carbonyl oxygen atom as well as through the imine

nitrogen atom.

P-22

ELECTRON TRANSFER CHEMISTRY IN TRINUCLEAR AND HEXANUCLEAR CU-

PYRAZOLATE Logesh Mathivathanan, Raphael G. Raptis

University of Puerto Rico – Río Piedras

Trinuclear Copper centers make up the active centers for several enzymes. The catalytic cycles of these

enzymes primarily involve electron transfer chemistry. Understanding such mechanisms is made easier by

preparing model complexes with trinuclear CuII-cores. We have reported the crystal structure of a mixed-

valent [Cu2Cu(µ3-O)]5+

-pyrazolate complex (formally a CuII

2CuIII

complex), the only such system known.

We have also reported the reversible, one-electron oxidation of [CuII

3(µ3-O)]4+

-pyrazolate to yield

[Cu2Cu(µ3-O)]5+

. In this poster we present the bulk synthesis and the characterization of mixed-valent Cu3-

pyrazolate complexes by XPS and UV-vis-NIR. Hexanuclear Cu-pyrazolate complexes, composed of two

coupled [CuII

3(µ3-O)]4+

-units in an eclipsed manner, undergo two reversible oxidations. We show here the

chemical oxidation of the hexanuclear complex to give formally Cu5IICu

III and Cu4

IICu

III2 complexes and

their spectroscopic characterization. Based on UV-vis-NIR spectroscopic data, we classify our mixed

valence complexes according to the Robin-Day system: trinuclear complexes belong to Class III (strong

electronic coupling) and hexanuclear complexes to Class II (moderate electronic coupling).

54

P-23

REMOVAL OF PAHS USING TIRE CRUMB RUBBER

Luis Alamo-Nole1, Felix R. Román

1, Oscar Perales-Pérez

2

1Chemistry Department. University of Puerto Rico at Mayaguez

2 Department of Engineering Science & Materials. UPRM

The removal of acenaphthene and phenanthrene from aqueous solutions was evaluated using tire crumb

rubber (TCR). The role of the main components of TCR (carbon black and styrene butadiene polymer) in

the sorption process was also evaluated. The analysis of Scatchard plots suggested the sorption by TCR

took place through two different interactions; whereas a single-interaction became evident when CB or

SBP were used. The maximum uptake capacities (Kf) calculated from Freundlich’s equation was 3.32 mg/g

and 54.6 mg/g for acenaphthene and phenanthrene, respectively, using TCR as the sorbent. Its proven

sorption capacity and the low cost compared with commercially available sorbents make TCR a promising

sorbent for Polycyclic Aromatic Hydrocarbons (PAHs) in aqueous solutions.

Key words: waste tire; crumb rubber; sorption; recycling; water treatment; Scatchard plot

P-24

ELECTROCHEMICAL REACTIVITY OF AROMATIC MOLECULES AT NANOMETER SIZED

SURFACE DOMAINS: FROM Pt(hkl) SINGLE CRYSTAL ELECTRODES TO

PREFERENTIALLY ORIENTED PLATINUM NANOPARTICLES

Margarita Rodríguez-López1,2

, Jose Solla-Gullón3, Enrique Herrero

3, Paulino Tuñon

2, Juan M. Feliu

3,

Antonio Aldaz3* and Arnaldo Carrasquillo, Jr.

4*

1Pontifical Catholic University of Puerto Rico, Ponce, Puerto Rico;

2University of Oviedo, Oviedo , Spain,

3University of Alicante, Alicante, Spain;

4University of Puerto Rico, Mayagüez, PR.

This poster compares the electrochemically controlled adsorption of hydroquinone-derived adlayers and

their reductive desorption from nanometer-sized Pt(111) domains present on the surface (i) of model

stepped single-crystal electrodes and (ii) of preferentially-oriented Pt nanoparticles. The results obtained

using a stepped surface series, i.e. Pt(S)[(n-1)(111)x(110)], suggest that in the presence of 2 mM H2Q(aq) the

electrochemically detected desorption-adsorption process takes place selectively from ordered Pt(111)

domains present as terraces, while being precluded at other available surface sites, i.e. Pt(110) steps, where

adsorption takes place irreversibly. This domain-selective electroanalytical detection scheme is employed

later to selectively monitor desorption-adsorption of hydroquinone-derived adlayers from ordered,

nanometer-scaled Pt(111) domains on the surface of preferentially-oriented Pt nanoparticles, confirming

the existence of well-ordered (111) domains on the surface of the Pt nanoparticles. A good correlation is

noted between the electrochemical behaviour at well-ordered Pt(hkl) surfaces and at preferentially oriented

Pt nanoparticles. Key learnings and potential applications are discussed. The results demonstrate the

technical feasibility of performing domain-selective decapping of nanoparticles by handle of an externally

controlled parameter, i.e. the applied potential.

55

P-25

DETECTION AND QUANTIFICATION OF RDX ON SURFACES BY REFLECTION

ABSORPTION INFRARED SPECTROSCOPY WITH FIBER COUPLED GRAZING ANGLE

PROBE AND ITS FIGURES OF MERIT

Migdalia Hidalgo Santiago, Leonardo C. Pacheco-Londoño, Samuel P. Hernández-Rivera

Center for Chemical Sensor Development, Chemistry Department, UPRM

RDX was detected and quantified on four different surfaces (gold, aluminum, plastic and glass) using

calibration curves the from partial least squares multivariate analysis (PLS1). Scan number and size of

sample were varied. The infrared beam of the probe is able to reflect on the surface in an elliptic form, the

size of the ellipse along the major axis is 16 cm and along the minor axis is 3 cm; and the intensity

distribution is Gaussian. Sample size was lower than the beam reflected for all cases. No significant

changes were observed in the standard deviation, correlation coefficient or Limit of detection (LOD) values

when the numbers of scans were changed, due to the size of the beam probe since this is an average of the

surface. Only one scan is required for a good correlation and with no significant difference when compared

to a higher number of scans. Interferences derived from the surface, increased slightly the LOD.

P-26

CYCLIC VOLTAMMETRY: ANALYSIS OF THE REDOX REACTION OF COPPER WITH

HYDROGEN PEROXIDE IN GLASSY CARBON ELECTRODE

Mirelis Santos Cancel, Oscar Lugo Ojeda, Elena Flores Vélez, Carmen Vega

UPR- Mayaguez Campus

Copper is an important trace element worldwide that can exist in two oxidation states. Elevated

concentrations of this ion can be lethal for organisms because can alter the metabolism. In ground waters,

naturally, the ion copper exists in the oxidation state (II), but recent researches have determined the

presence of this cation in the oxidation state (I) due to the presence of hydrogen peroxide. In this work the

principal objective is the determination of the rate constant of oxidation of Copper present in a solution of

Copper Sulfate and KCl with Hydrogen Peroxide in 2:1 quantities. The reactions were scanned and

monitored by implementing Cyclic Voltammetry method using a model CV-50W Voltammetric Analyzer

at a scan rate of 500μV/s on a Glassy Carbon surface electrode. The sweeping was performed from +1V to

-1V and later were screened down to +400μV to -400μV applying a sensitivity of 10 μA/s and then

segments for both cases. All the scans were made at room temperature (25°C).

The presence of hydrogen peroxide is found to accelerate the rate constant (k) of the reduction of Cu(II) to

Cu(I) by approximately 1.1E-08 M, lowers the current of the cathodic peak and inhibits the oxidation of

Cu(I) to Cu(II).

56

P-27

REMOVAL OF THE ANTIMICROBIAL OXYTETRACYCLINE FROM AQUEOUS SOLUTIONS

USING WASTE TIRE CRUMB RUBBER Misael Viruelt Vigo, Félix R, Román, Oscar Perales

UPR, Mayagüez Campus

Our research aimed to evaluate the adsorption behavior of Oxytetracycline (OTC), a veterinary antibiotic of

the Tetracycline family, onto waste tire crumb rubber (WTCR) in aqueous solution. OTC samples at pH

7.00 were placed in contact with 10 g/L of crumb rubber (mesh 14-20) for 72 hours. UV-Vis

spectrophotometry was used to determine 360 nm as the maximum adsorption wavelength. The samples

were collected at different intervals and analyzed by High Performance Liquid Chromatography with a

Diode Array Detector (HPLC-DAD) using an Eclipse XDB-C8 column for separation. Oxytetracycline

removal was around 50 – 55% for a concentration range of 50 ppm to 150 ppm. Also an OTC blank was

prepared to evaluate is degradation. Previous studies reveal that the zinc (Zn) released from crumb rubber

(in the form of zinc oxide), interfered in the OTC adsorption process by forming a Zn–OTC complex. To

maximize the adsorption of OTC onto crumb rubber, the later was washed with deionized water and stirred

for 48 hours. In order determine the amount of Zn release from the crumb rubber into the water, samples

were be analyzed by ICP-MS (Inductive Coupled Plasma – Mass Spectrometry). Currently the adsorption

behavior of Oxytetracycline onto carbon black in aqueous solution is being evaluated, as carbon black is

one of the main components present in the crumb rubber.

Keywords: oxytetracycline, recycled crumb rubber

57

P-28

SYNTHESIS AND CHARACTERIZATION OF ZIRCONOCENE AND TUNGSTENOCENE

DERIVATES COMPLEXES

Moralba Dominguez Garcia, Enrique Meléndez

Department of Chemistry, University of Puerto Rico-Mayagüez. P.O.BOX 9019. Mayaguez, PR 00681

In the United States, Cancer is the second most common cause of death after heart disease, promoting 25%

of all deaths. Different metal based in anticancer complexes have been developed and currently are used in

cancer treatment, however they possess side effects. Therefore the proposed research is focused in the

development of new complexes derivates from zirconocene and tungstenocene, unfortunately little is

known about both as anticancer agents however in the last year has been reported high cytotoxic activity

against human promyelocytic leukemic HL60 cells in zirconium (IV) complexes with coumarins, also high

cytotoxic activity against kidney cancer cell with [Zr{η5-C5H4(CH2C6H4OCH3)}2Cl2] and activity on

ovarian cancer cells with [Zr{Me2-Si(η5-C5Me4)(η

5-C5H3(CMe2CH2CH2CH= CMe2))}Cl2, which is very

interesting and to encourage further substituted zirconocene complexes research as antitumor agents.

The research is based principally in the synthesis of zirconocene and tungstenocene derivates complexes,

and their characterization by different spectroscopy and electrochemical techniques such as NMR, UV,

MS, IR, cyclic voltammetry, and cytotoxic activity of synthesized complexes in breast adenocarcinoma cell

line MCF-7 and the colon cancer cell line HT-29 by the MTT assay. Currently in the research has been

tested several options to synthesis of zirconocene and tungstenocene derivates complex with maltol as

ligand, obtaining satisfactory result during the synthesis using tetrahydrofuran and heat for zirconocene and

water at pH 6.0 for tungstenocene (see scheme 1), at the present it is working in the purification of both

reaction products.

Scheme 1. Synthesis of zirconocene and tungstenocene derivates complex

58

P-29

FIRST TOTAL SYNTHESIS AND ANTIPROTOZOAL ACTIVITY OF THE 16-METHYL-11Z-

HEPTADECENOIC ACID, A RECENTLY DISCOVERED NOVEL FATTY ACID FROM THE

SPONGE DRAGMAXIA UNDATA

Nashbly Montano, Gabriel A. Cintrón1, Carmary Márquez

1, Christopher Fernández-Prada

2, Celia

Fernández-Rubio2, Rafael Balaña-Fauce

2, and Néstor M. Carballeira

1

1Department of Chemistry, University of Puerto Rico, Río Piedras Campus, P.O. Box 23346, San Juan,

Puerto Rico 00931-3346. 2Department of Biomedical Sciences (INTOXCAL), University of León, Campus de Vegazana s/n, 24071

León, Spain

Marine-derivated biologically active natural products continue to be a source of potential therapeutic

compounds as well as a motivation to develop new synthetic strategies for their construction.1 In particular,

marine phospholipid fatty acids have shown interesting antiprotozoal properties. For example, the 17-

methyl-13Z-octadecenoic acid, isolated from the North-East Atlantic sponge Polymastia penicillus2, was

synthesized and displayed antileishmanial activity against Leishmania donovani (IC50 = 67 M) and

inhibited the leishmania DNA Topoisomerase IB at concentrations of 50 M.3 Recently, the unprecedented

fatty acid 16-methyl-11Z-heptadecenoic acid (1), also an iso unsaturated faty acid, was identified by

Rodríguez et. al. in the Colombian marine sponge Dragmaxia undata.4 Aimed at studying the

antileishmanial action of 1, as well as to corroborate the structure of the natural fatty acid, the first total

synthesis of 1 was accomplished in 7 steps and in 44% overall yield. Acid 1 also displayed antileishmanial

activity against L. donovani (IC50 = 166 mM) and inhibited the leishmania DNA Topo-IB with an IC50 =

62.4 0.4 mM. The total synthesis and antileishmanial studies of 1 will be presented and discussed.

Br

OH

7 steps OH

O1

1 Bugni, T. S., Richards, B., Bhoite, L., Cimbora, D., Harper, M. K., Ireland, C. M. J. Nat. Prod. 2008, 71,

1095-1098. 2 Denis, C., Wielgosz-Collin, G., Bretéché, A., Ruiz, N., Rabesaotra, V., Boury-Esnault, N., Kornprobst, J.-

M., Barnathan, G. Lipids 2009, 44, 655-663. 3 Carballeira, N. M., Montano, N., Balaña-Fauce, R., Fernández-Prada, C. Chem. Phys. Lipids 2009, 161,

38-43. 4 Rodríguez, W., Osorno , O., Ramos, F. A., Duque, C., Zea, S. Biochem. Syst. Ecol. 2010, doi:

10.1016/j.bse.2010.0711.

59

P-30

ANALYSIS OF FLUORIDE IN DRINKING WATER MUNICIPALITIES IN PUERTO RICO

Nathalie González Jiménez, and Maritza De Jesús Echevarría

Department of Chemistry, University of Puerto Rico at Mayagüez, Mayagüez Puerto Rico, 00680

Fluoride is an anion naturally found in drinking water. High levels of this ion can cause bone disease and

discoloration of tooth enamel. Because of these negative effects, the Environmental Protection Agency

(EPA) has implemented a maximum concentration limit (MCL) of 4.0ppm. The EPA also requires that

local and state agencies monitor the drinking water. This preliminary research employed the use of the

SPADNS colorimetric method, an EPA-approved method, to measure the concentration of fluoride in

drinking water from different municipalities in Puerto Rico. Other parameters, conductivity, pH, total

dissolved solids (TDS), and percent salinity were also measure for all samples. Some of the municipalities

selected are from the south and west areas of the island. All samples exhibited low concentrations of

fluoride, with a maximum of 0.23mg/L for Cabo Rojo municipality. At the present day, no measurements

exceed the limits impose by the EPA.

P-31

CHEMICAL COMPOSITION OF THE VOLATILE COMPOUNDS IN THE LEAF OF

ERYNGIUM FOETIDIUM L. BY SPME AND GC/MS

Nelmarie Vargas Carrillo 2, and Maritza De Jesús Echevarría

1

1Department of Chemistry, University of Puerto Rico at Mayagüez , Mayagüez, Puerto Rico 00680

2Department of Chemical Engineering, University of Puerto Rico at Mayagüez

Plants have become through time one of the major sources of resources for the developing civilizations.

Their functional diversity has given the humans the opportunity to use them in a great variety of ways,

depending on the application of the final product being develop. One of the major contributions made by

the plants is their use as flavor and seasoning agents in food production. A very common tropical herb that

is used in culinary practices is the Eryngium foetidum L.. This particular plant emits a very strong aroma

that is capable of imprinting itself in the food and in its surroundings. In this research we used the SPME

method and the GC/MS equipment to identify the volatile organic compounds present in the aroma of the

Eryngium Foetidium L. leafs. In the fresh leafs, six mayor volatiles compounds were positively identified

including aldehyde and alcohols. The mayor abundant compound was 3-dodecen-1-al. Another abundant

compounds present in the aroma of the herb was the natural sesquiterpene, trans-caryphyllene followed by

trace amounts of undecane. This results can be use for the evaluation of freshness in the food

manufacturing process using the plant Eryngium foetidum L..

60

P-32

PREPARATION AND CHARACTERIZATION OF UNSUPPORTED IRIDIUM, AND PLATINUM

OXIDES ELECTROCATALYSTS FOR THE OXYGEN EVOLUTION REACTION BY THE

ROTATING Nelson E. Rivera Vélez, Efraín Montañez, Aulcie Scibioh and Carlos R. Cabrera

University of Puerto Rico-Río Piedras

We present preliminary results of Pt/Ir oxides electrocatalysts prepared by the Rotating Disk Slurry

Electrode (RoDSE) as a fast, clean and cost efficient method of materials for water electrolysis. Ir has been

widely studied and is among the best working catalysts in the literature for the Oxygen Evolution Reaction

(OER) and Pt for the Hydrogen Evolution Reaction (HER). Pt/Ir electrocatalysts have shown

bifunctionality in the water electrolysis process. The iridium was electrochemically deposited onto Pt black

by chronoamperometry and Linear Sweep Voltammetry (LSV) was used to characterize its performance for

OER by measuring the onset potential and current density after preparing a Nafion® paste electrode on

Glassy Carbon (GC). One of the samples was treated at 400°C in order to obtain the oxidized material. In

comparison to Pt black and unoxidized Pt/Ir, the oxidized Pt/Ir material showed lower onset potential of

approximately 1.35 V vs. Ag|AgCl and higher current densities in H2SO4 0.5 M.

P-33

DROP-ON-DEMAND (DOD) THERMAL INKJET TECHNOLOGY FOR THE PREPARATION

OF SERS-ACTIVE SUBSTRATES

Pedro Fierro, Samuel P.Hernández

Center for Chemical Sensor Development, Chemistry Department, UPRM

This work describes a very simple procedure based in the drop-on-demand (DoD) thermal inkjet printing

technology to prepare optically tunable nanostructured Ag and Au films. The metal films were studied by

X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The

results show that the films present different morphology depending on the printing parameters. These metal

films prepared exhibit excellent Raman scattering (SERS) activities, and the enhancement factor estimated

using 4-aminobenzenethiol as probe adsorbate reaches ~105. The proposed method is characterized by low

material consumption and less material wastage when compared to other methods. Very stable metal films

can be reproducibly fabricated. The methodology is one of the most cost-effective and is suitable for mass

production of diverse metal films irrespective of the underlying substrates. This attribute can be useful as a

valuable tool in the development of highly sensitive systems for the early detection of chemical and

biological toxic agents based in enhanced Raman detection.

61

P-34

ANTIMICROBIAL BINDING TO METAL/METAL OXIDE SURFACE: PHOTOLYTIC AND

KINETIC EFFECTS

Queziel Rivera, Marco A. De Jesús

Department of Chemistry, University of Puerto Rico-Mayagüez. P.O.BOX 9019. Mayaguez, PR 00681

Pharmaceuticals and personal care products (PPCPs) are substances of widespread use for human and

veterinary applications. Fluoroquinolones and Sulfonamides are wide-spectrum drugs that are available for

general public. The wide use of these agents in therapeutic and veterinary applications has made them an

emerging pollutant of concern. Exposure of these drugs to visible radiation can influence the stability of

the formulation, leading to changes in their physicochemical properties and composition. The influence

that metal ions exert on the chemical decomposition of these agents is often difficult to predict and,

therefore, stability testing of the final preparation is important. The work proposed herein uses liquid

chromatography and vibrational spectroscopy methods to investigate the effect that dissolved metal ions,

suspended and immobilized metal nanoparticles of copper, and iron affect the photolytic reactivity of these

agents in water. The degree to which metal ions affect the photochemical decomposition of these agents is

presented. The efficacy of these processes toward the rapid degradation and safe remediation of trace

antimicrobials in water is discussed.

P-35

DIRECT METHANOL FUEL CELLS BASED ON VULCAN/PT/CEO2 ANODES: THE EFFECT

OF CERIA CONTENT ON THE FUEL CELL PERFORMANCE

Rolando P. Guzmán Blas, Dámaris Suazo-Dávila, M. Aulice Scibioh, Carlos R. Cabrera, Maxime Guinel

Department of Physics and Chemistry-Recinto de Rio Piedras-UPR

A fuel cell is an electrochemical energy conversion devise that convert chemical energy directly into

electrical energy. To achieve the electrooxidation of methanol as the fuel for the fuel cell, Pt-based

electrodes are commonly used. However, adsorbed CO as a result from the methanol oxidation reaction

poisons the catalyst surface and significantly reduces the fuel cell performance. Recently, anode property of

Pt on CeO2 supported on carbon has been investigated for the development of direct methanol fuel cells

(DMFC). For this reason, an impregnation method was developed for the preparation of Vulcan/Pt/CeO2

catalysts using cerium (III) nitrate as the precursor and vulcan/20%Pt. In order to achieve ceria dispersion

EDTA was used. Different concentration of CeO2 were use thus to study the effect on the methanol

oxidation. The material catalysts were characterized by X-Ray photoelectron spectroscopy, transmission

electron microscopy, X-ray diffraction. Their electrochemical characteristics towards methanol oxidation

(CV, LSV, chronoamperometry, EIS) has been examined in half cell mode using three electrode assembly

as well as in full cell operations (Polarization anodic, Polarization cell, Chronoamperometry, cross-over

methanol). The Vulcan/20%Pt-ceria catalyst with 6% ceria seems to exhibit higher methanol oxidation

activity compared to platinum alone.

62

P-36

CO-DEPOSITION OF PT AND CERIA ANODE CATALYST IN SUPERCRITICAL CARBON

DIOXIDE FOR DMFC

Rolando P. Guzmán Blas1, Eunyoung You

2, Eduardo Nicolau1, M. Aulice Scibioh

1,

Carlos R. Cabrera1,;James J. Watkins

2.

1Department of Physics and Chemistry-Recinto de Rio Piedras-UPR

22University of Massachusetts

Pt and Pt-Ceria catalysts were deposited on gas diffusion layers using supercritical fluid deposition

technique with the aim of fabricating thin layer electrodes for direct methanol fuel cell application. The

catalyst layers were subjected to physico-chemical characterizations such as X-ray diffraction (XRD), high

resolution X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy dispersive

spectral (SEM-EDS) analyses. Their electrochemical characteristics towards methanol oxidation has been

examined in half cell mode using three electrode assembly as well as in full cell operations. Different

combinations of layer formations and catalysts compositions were examined. It has been found that the

thin layer electrodes formed via supercritical fluid deposition (SFD) technique exhibited higher

performance in full cell operations compared to conventional way of coating the gas diffusion layers by

brush and paint method. Further, the Pt-ceria catalyst with optimum composition seems to exhibit higher

methanol oxidation activity compared to platinum alone system.

P-37

A LABORATORY EXPERIENCE THAT INTEGRATES BIOCHEMISTRY AND

INSTRUMENTAL ANALYSIS

Rosa V. Flores, M. Solá, Juan C. Torres, Rafael E. Torres, Ernick E. Guzmán

University of Puerto Rico, Río Piedras Campus (UPR-RP)

We have selected the Green Fluorescent Protein (GFP) to develop a laboratory experience where students

study key aspects of protein structure and function using fluorescence spectroscopy. In this experience,

students learn how to: (1) purify GFP from transformed bacterial cells using hydrophobic interaction

chromatography, (2) study GFP structure using open access databases (e.g., Protein Databank and UniProt),

(3) determine the excitation and emission spectrum of GFP, and (4) examine the effect of pH and

temperature on GFP function (i.e., fluorescence). Attendees will have the opportunity to examine the

methodology that led to student experimental results and learn how the laboratory experience compares

with other methods for conducting undergraduate experiments. This work was funded in part by a

Minority Science and Engineering Improvement Program (MSEIP) 2008 Grant from the United States

Department of Education and by the Pre-MARC (Pre-Minority Access to Research Careers) Program from

our institution.

63

P-38

HORSERADISH PEROXIDASE ENZYME KINETICS EXPERIMENT FOR A BIOCHEMISTRY

LABORATORY

Rosa V. Flores, Sorillian Boklan

University of Puerto Rico, Río Piedras Campus (UPR-RP)

We have been developing an enzyme kinetics experiment for a new Biochemistry Laboratory where

students determine the Michaelis-Menten kinetic parameters (i.e., Km, Vmax, kcat) for the oxidoreductase

Horseradish peroxidase (HRP) using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) as one

substrate, while keeping a constant high concentration of peroxide (H2O2), the second substrate. Oxidation

of ABTS involves removal of one electron to form the blue-green radical cation of ABTS, which exhibits a

maximum absorbance at 415 nm. Students determine the optimum enzyme concentration for the kinetic

assay by following product formation with time using a spectrophotometer, at saturating levels of ABTS

for various enzyme levels. Students confirm the time period of the kinetic assay in which product

formation assumes a linear rate. Using the optimum enzyme concentration and time period previously

determined, students collect kinetic data using various ABTS concentrations while keeping the H2O2

concentration high and constant, to determine the kinetic parameters of the system. This laboratory

experiment teaches students how to: (1) record spectra and retrieve data from the ultraviolet/visible

spectrophotometer, (2) analyze the data in Microsoft Excel spreadsheets to obtain the best linear fit in the

Absorbance versus Time, Lineweaver-Burk and Eadie-Hoffstee plots, (3) analyze the data using

Mathematica to obtain the best hyperbolic fit in the Michaelis-Menten plot, and (4) calculate the

propagation of error in the kinetic parameters determined. Preliminary data show that the experimental

kinetic parameters are in agreement with the kinetic parameters reported in the literature for the HRP-

ABTS-H2O2 system. We are currently working on a microplate-format of the enzyme kinetics experiment

which would reduce the amount of reagents and instrument time use needed to obtain the enzyme kinetic

data.

P-39

DEVELOPMENT OF ANALYTICAL METHOD FOR ENHANCED PRODUCTION AND

MEASUREMENT OF SINGLET OXYGEN

Sandra Pena-Luengas1, Luis Rivera-Montalvo

1, Oscar Perales-Perez

2, Surinder Singh

2, Tomar Maharaj

2

1Department of Chemistry, University of Puerto Rico-Mayagüez. P.O.BOX 9019. Mayaguez, PR 00681,

2Department of Engineering Science and Materials. University of Puerto Rico-Mayagüez, Stefani Building,

Office 601, PO Box 9044, Mayagüez PR 00681-9044.

The following paper outlines and explains the generation of singlet oxygen of current interest in

Photodynamic Therapy (PDT). PDT is a revolutionary treatment for cancer and other diseases without

using surgery, chemotherapy or radiation. The chemical reaction is promoted by light and monitored

spectrophotometrically. There is disappearance of 1,3-diphenylisobenzofuran as a chemical quencher in

methanol, which is oxidized to o-dibenzoylbenzene in the presence of rose bengal, methylene blue or

Fe3O4/ZnO core-shell nanoparticles for oxidation reactions. Photochemical properties of three

photosensitizing molecules (rose bengal, methylene blue and Fe3O4/ZnO) were investigated in different

solvents, light sources and quenchers including n,n-dimethyl-4-nitrosoaniline plus imidazole, furfuryl

alcohol, sodium azide, citronellol, 2,5-diphenylfuran, 2,5-dimethylfuran and diphenylisobenzofuran. Good

first- order plots were obtained and the relative slopes used to determine β values and reaction constants.

The β values obtained were 5.45x10-5

, 4.34x10-5

and 1.1x10-5

for rose bengal, methylene blue and

Fe3O4/ZnO core-shell nanoparticles respectively. The photooxidation reaction constants 4.40x109 and

4.38x108 M

-1s

-1 for rose bengal and methylene blue were values in accordance with the literature.

Concentrations of the photosensitizers and chemical quenchers were optimized for photooxidation

reactions. Photoluminescence measurements were made for each photosensitizer and quencher.The

quantum yields of the formation of singlet oxygen were 0.52 for methyelene blue, 0.28 for Fe3O4/ZnO

core-shell nanoparticles and 0.69 for rose bengal. This method is fast, efficient, precise and controllable in

contributing to research in Photodynamic Therapy (PDT). This analytical method opens new windows to

clinical studies in vivo.

64

P-40

KINETICS STUDY OF INSULIN AMYLOID FIBRILS FORMATION IN POLYMERIC

MEMBRANES

Tatiana Quiñones Ruiz, Juan López-Garriga

University of Puerto Rico at Mayagüez, Department of Chemistry, P.O Box 5000, Mayaguez, PR 00681

Amyloids are misfolded proteins that acquire a highly stable β-structure that forms insoluble fibrils. These

fibrils could form plaques that adhere to organs leading to malfunctioning. Polymeric membranes such as

hydrogels could incorporate the protein and reduce its mobility. In order to relate the concentration of the

incorporated protein with amyloid fibrils formation, we calculated the partition coefficient and studied the

kinetics of its formation in differently charged hydrogels. Also different fibrillation acidic solutions were

employed. Amyloids have been closely related to degenerative diseases like Alzheimer. It was recently

found that hydrogen sulfide (H2S) function as a neuromodulator, moreover it was determined that H2S was

severally decreased in patients with Alzheimer disease. Our preliminary results represent a relationship

with H2S concentration and amyloid fibrils formation. These findings could represent new medical and

biomedical relevant data.

P-41

EGG-WHITE LYSOZYME CRYSTALLIZATION Ulises Marrero Llerena, Josiris Rodriguez; Juan López Garriga


Sanderson and Skelly state that “macromolecular crystallography is the study of macromolecules

(proteins and nucleic acids) using X-ray crystallographic techniques for determining their molecular

structure … [but] one of the main requirements for these initiatives is a high-throughput crystallization

facility to speed-up the protein identification process”. Thus for wanting to determine the structure of a

protein, the crystallization process is indeed very important. As for a model in this research lysozyme was

used. Egg-white lysozyme is a widely understood and researched protein which makes it a perfect model

used to practice crystallization methods. Hanging Drop Vapor Diffusion and Batch were used as main

screening techniques. The screening conditions used for lysozyme crystal grow were a gradient of NaCl

ranging from 5% to 30% w/v [ 5%, 7%, 10%, 15%, 25%, 30%] versus a gradient of protein concentration

ranging from 25 to 80 mg/ml [ 25, 40, 60, 80] (for Hanging Drop) and three rates of NaCl|protein of

5.5%|50 mg/ml; 5.0%|55 mg/ml; 6.0%|60 mg/ml (for Batch), plus a NaC2H3O2 0.1M buffer to keep pH

4.8-5 to an optimum. Varying the NaCl saturation can alter nucleation process. It was observed that higher

salt concentrations induce faster nucleation rates. Crystal grow was monitored for three weeks.

65

P-42

ELECTROPHORETIC AND IMMUNO-SPECIFICITY CHARACTERIZATION OF

PLASMINOGEN ACTIVATOR ISOLATED FROM MAMMALIAN CELL CULTURE BROTH

Vivian Rodríguez-Cruz, Alexandra Rosado-Burgos and Dr. Vibha Bansal

Department of Chemistry- UPR Cayey

Plasminogen activators (PAs) are serine proteases known for their ability to dissolve fibrin clots. They do

so by catalyzing the conversion of plasminogen to plasmin which is the enzyme directly responsible for

breaking down the fibrin clots. PAs are used for the treatment of different diseases and cleaning of blocked

catheters in hospitals. There are two types of PAs derived from mammalian cells: tissue plasminogen

activator (tPA) and urokinase plasminogen activator (uPA). The objective of our project is to perform the

electrophoretic and immuno-specificity characterization of plasminogen activators isolated from

mammalian cell culture broth. Three different types of electrophoretic analyses (SDS PAGE, Native PAGE

and Zymography) were performed to characterize the PA isolated from HeLa cell culture broth. The SDS-

PAGE analysis revealed the presence of two bands (one high molecular weight, and the other low

molecular weight) while the Native PAGE showed the presence of only one band. This led us to the

conclusion that both the bands were subunits of one protein molecule and Zymography showed both these

bands to be enzymatically active. The western blot analysis of these bands is now being done.

P-43

SYNTHESIS AND MECHANISTIC STUDIES OF MOLYBDENOCENE COMPLEXES.

INTERACTION OF METALLIC ANTICANCER AGENTS WITH TRANSPORT PROTEINS.

Xiomara Narváez Pita, Dr. Enrique Meléndez PhD.


Ubiquitin is a small human protein that is found throughout our body and whose function is to mark the

malignant cells to take them to the proteasome where they will be removed at a later stage, thanks to its

carrying capacity. The main objective of this research is to synthesize molybdenocene complex and cis-

platinum study the interactions of the metallocene as well as cis-platin with ubiquitin to understand the

mechanism of transport of the drugs by the protein. We will monitor these interactions by spectroscopic

techniques such as UV- VIS, NMR, fluorescence, circular dichroism and study its cytotoxicity using the

MTT assay. Currently the properties of these complexes to be used as anticancer agents are known. These

species can be user to treat a wide range of cancers.

Complex was synthesized molybdenocene with dehydroascorbic acid, which used as a ligand to anchor in

the metallocene; the product being obtained as a dark solid that is soluble in water. The product was

purified by column chromatographic Lipophilic Sephadex (25-100 μm, from Aldrich) as stationary phase

and methanol as solvent, for the respective analysis and verify the new structure , so as its cytotoxicity.

66

P-44

AFFINITY MEMBRANE BASED SEPARATION OF PLASMINOGEN ACTIVATOR FROM

MAMMALIAN CELL CULTURE BROTH Yiaslin Ruiz

1 , Yadhira Lugo Jose

2, Ezio Fasoli Ph.D.

3, Vibha Bansal

1

1Dept. of Chemistry, University of Puerto Rico at Cayey, 2Dept. of Biology, University of Puerto Rico at Cayey,

3Dept. of Chemistry, University of Puerto Rico at Humacao

Plasminogen activators (PAs) are enzymes responsible for conversion of plasminogen to plasmin by

cleaving the Arg-Val peptide bond. The activation of plasminogen is an important process associated with

dissolution of clots and invasive growth of cancer cells. PAs are thus very important clinical agents. The

objective of this project is to develop an affinity membrane based separation process for the isolation of

plasminogen activator from mammalian cell culture broth. As compared to traditional chromatographic

methods, affinity membranes are characterized by a high surface area, reduced diffusion distance, low

operating pressure, and higher cost effectiveness. In this project regenerated cellulose membranes were

chemically modified through linkage to affinity ligands via spacer arms of different lengths (5C, 7C, 12C).

The affinity ligand used was p-aminobenzamidine. The membrane modified with 12-C spacer arm linked p-

aminobenazmidine was found to bind PA with higher efficiency as compatred to other spacer arms. Other

affinity ligands for PAs are now being synthesized based on reports available in literature.

P-45

REAL TIME NEAR INFRARED VALIDATION FOR CONTINUOUS MIXING

Yleana M. Colón, R.Romañach, R.Mendez, L.Obregón, M.Florian, L. Quiñones, C.Velázquez


Process Analytical Technology (PAT) has been used to describe “a system for designing, analyzing and

controlling pharmaceutical manufacturing through the measurements of critical quality and performance

parameters with the goal of ensuring final product quality”. PAT is an approach to monitoring

manufacturing processes on a continuous (during the process) rather than discrete basis.

One of the major goals of the proposed research project is to demonstrate continuous and real-time control

of pharmaceutical manufacturing processes, which so far have been restricted to batch operations. This

proposed research project is for the development, implementation and optimization of multivariate

calibration models capable of providing real-time assay performance of an active pharmaceutical

ingredients using Near Infrared (NIR) Spectroscopy during a continuous process operation. The developed

models should offer the necessary accuracy and precision for sample prediction using cross validation.

A total of sixteen (16) blends containing ibuprofen and 4 excipients were prepared according to a Design of

Experiment (DoE). Concentrations ranging from 0 % (w/w) to 13 % (w/w) were targeted for the

development of a calibration model. An independent set of concentrations ranging from 8.0% (w/w) to

12.0% (w/w) were used to challenge the model precision and accuracy. Experiments were performed in

order to carefully install the NIR system as well as an intermediate precision study to optimize the signal to

noise ratio in the spectra. The model was constructed after we were thoroughly convinced that NIR was

adequately set up for obtaining reproducible spectra. Results obtained were based in a constructed

calibration model with a very high correlation factor (0.99) as well as a low, global error of prediction of

0.4. The calibration model responded with a global error of prediction of 0.56 for the independent set with

an RSD of 3.8%.

67

P-46

THE RIGHT WAY TO THE FUTURE

Harold U.Ortiz Medina, and José M. Acevedo Rodríguez, Edgar Pérez-Matías, José M. Hernández-

Mercado, Héctor Hernández-López, and Brenda J. Ramos Santana

University of Puerto Rico at Aguadilla, Aguadilla PR

American Chemical Society-University of Puerto Rico at Aguadilla (ACS-UPRAG) Student Chapter is

made up of outstanding, simple, and humble Natural Sciences students like as chemical substances called

chemical elements. For the past six years, ACS-UPRAG student have discovered, explored, investigated,

and worked very strong, leading to a current total of four outstanding, one commendable, and now an

impressive Green Chemistry award. Great recognitions inspire new ideas, innovations and spotlight

experiences with more responsibilities. All of us have a conscience of our new generations, which means

new challenges. Our mission consists of develop new critical thinks skills through the research, scientific

discussion and social compromise looking into environmental and sustainability chemist. In the chemical

world, everything looks similar to the periodic table, with periodicity and structural arrangement. How our

chapter can reach this periodic structure that would shows a high performance of our student member?

They are ready to move upon other step, grow up toward a future generations of professionals capable to

take the world inside their hands. Regarding this, the student of the future need to be aware with the new

technology advances, critical think skills and practical experience acquiring a full domain of the matter

using their knowledge to visualize and explain the simple things in their daily lives. Furthermore, it is

essential to stimulate high school students to continue studies in science introduce the student in the

research world and help them to acquire new experiences. Using strategies as the foundation of Chem

clubs, team works, Chemistry field trips around Puerto Rico, participating in Chemistry Wednesday and

writing in the Chapter Newspaper our student affiliates will be prepared for the challenges of the future.

P-47

ACS-UPRA: APPROACHING THE CHEMISTRY SUCCESSFULLY!

Jackeline Nieves, Gabriel Acevedo, Yashira Cabrera, Ivy Vélez and Prof. Maiella L. Ramos.

Department of Chemistry, University of Puerto Rico at Arecibo

Our chapter meets the goal of teaching students the importance and understanding of the chemistry in our

daily lives. The Chapter had the commitment of promoting the education where students strengthen their

experience in educational and professional skills. Our educational concept consists of activities where

students explore the different ways that chemistry works. Our activities are planned with dedication and

hard work in the meetings that are made by the Chapter.

During the academic year 2009-2010 we performed a variety of different activities. We succeeded in that

our chapter had extensive involvement in the community and promoted chemistry in the process by

performing interesting and intriguing experiments which get kids interested in science at an early age. We

conducted many events with high impact. An example of this is that our chapter always participated in

activities at the children museum “El Museo del Niño” in San Juan, where many children participated in

our hands-on chemical experiments. Another activity was the participation of Boy Scouts in the university.

We prepared hands-on experiments and demonstrations in one of our chemistry lab where these kids had

the opportunity to learn safety rules in the laboratory and also to make various experiments for the

enjoyment of them. The activity achievement was that these scouts won the Merit badge in Chemistry and

that they do an assessment of the activity where they express their satisfaction with the activity. We also

performed different activities to promote the knowledge of the green chemistry through scientific posters,

hands-on activities, talks among others.

68

P-48

“M.S.D.S.” AT UPR-CAYEY: EXPLORING THE PRESENT, PREPARING FOR THE FUTURE Frances P. Rodríguez-Rivera, Orielyz Flores-Fernández, Ángel M. Suárez-Márquez, Maraliz Y.Cortés-

Cartagena, and Wilfredo Resto-Otero

Department of Chemistry, University of Puerto Rico at Cayey, 205 Antonio R. BarceloAve., Cayey, PR

Motivating Students Developing Scientists (“MSDS”) is the driving force that leads the continuous efforts

of the “Círculo de Química” at UPR-Cayey. Our chapter, since founded in 1972, has promoted the interest

in Chemistry through several demonstrations, seminars, and other activities that show society how this

science is related to everything that surrounds us. Specifically, this year’s principal goal was to reach every

student from primary school to the undergraduate level through the promotion and the enforcement of our

theme. Furthermore, the activities carried out provided a better understanding of Chemistry by changing its

high-difficulty perception and increasing its significance through the years. Our work is progressive as it

generates interest and cohesion in the student body and the community that lies outside the science field, as

well as beyond our campus. Evidence that supports our activities will be reported.

P-49

ACHIEVEMENTS OF THE CHAPTER OF CHEMISTRY AT THE UNIVERSITY OF PUERTO

RICO AT HUMACAO

Sheila J Moreno Fuentes, and Lilliana V. Palacios Lora

University of Puerto Rico at Humacao, Humacao PR

The chapter of students of chemistry at Humacao has always been recognized in being dynamic not only

academically but in their extracurricular activities. In the past 10 years the chapter has been distinguish for

its exceptional performance providing service for its members and the community in general, celebrating

our Chemistry of Every Day and making others fall in love with the chemistry that we already love.

69

P-50

ACS-RUM : THE CATALIST AGENT IN A FRESHMEN’S LIFE

Suasy Acevedo and Jorge Benejam

Department of Chemistry, University of Puerto Rico-Mayagüez, Mayagüez PR 00681

The American Chemical Society has been in the University of Puerto Rico, Mayagüez Campus since 1954,

making this year 2010 the 56th

anniversary. We help our community and members by developing their

academic and professional skills. During the academic year 2009-2010 we performed many activities

ranging from community to professional level. In the beginning of every year we welcome freshmen

students to the new stage in their life. First, we greet them in our department and we are their mentors

during their first year in College. One of our major activities is the celebration of the National Chemistry

Week (NCW) and we incorporate freshmen in the participation. During NCW we have a diversity of

activities including Goofy Games, Lab tours, Mol’s Day, White Coat Ceremony and Initiation. During

2009-10, we also participated in important events such as SERMACS, ACS-Junior Technical Meeting,

different activities from the Department of Chemistry, and visits to schools. All these activities are

evidence that we reached our goals to help freshmen students being catalyzing agents in their life. We are

focused in ACS vision: “Improving people’s lives through the transforming power of chemistry”.

P-51

SERMACS: A CONQUERED CHALLENGE

Julian Abruña, Ingrid Montes, Omar Acevedo, Wilmer Adorno, Mariangely Almenas, Mayda

Cartagena, Euvelisse N. Jusino, Wilmarie Marrero, Melanie Ortiz, Coralis Ramos, Paula Rios,

Johary Rivera, Danise Rivera, Jorge Torres .University of Puerto Rico, Rio Piedras Campus, Department of Chemistry, P.O. Box 23346, San Juan,

Puerto Rico, 00931

Our ACS Student Member Chapter has dedicated itself to serve the Puerto Rican community. This year we

had the arduous task of catering to the scientific community by being part of the hosting committee for

SERMACS 2009. It was a big year for us, because SERMACS was being merged with the NCW and the

AAAS Caribbean Division meeting. The Puerto Rico local section worked as a unit looking for sponsors,

promoting the event, encouraging undergrads to present their work, developing workshops for students

(elementary, middle and high school) and celebrating NCW with the traditional “Festival de Química”. We

wanted the attendees to witness a well-planned meeting and our commitment towards the promotion of

chemistry. With communication, everyone came together as a big family: ACS chapters from Puerto Rico

and the Southeast Region, Chem Clubs, Strive Club, and the Graduate Students Association. As future

leaders and professionals, these are growing experiences.

70

P-52

A STICKY SITUATION: CHEWING GUM AND SOLUBILITY

Julian Abruña1, Omar Acevedo

1, Wilmer Adorno

1, Mariangely Almenas

1, Mayda Cartagena

1, Euvelisse N.

Jusino1, Wilmarie Marrero

1, Melanie Ortiz

1, Coralis Ramos

1,

Paula Rios1, Johary Rivera

1, Danise Rivera

1, Jorge Torres

1 and Ingrid Montes

1,

Ph.D.

Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, P.O. Box 23346, San Juan,

Puerto Rico, 00931, Puerto Rico

In this Activity, students perform several solubility tests using common food items such as chocolate,

chewing gum, water, sugar, and oil. From their observations during the Activity, students will initially

classify the substances tested as soluble or insoluble. They will then use their understanding of the

chemistry of solubility to classify the substances as polar or nonpolar. The chemical concepts reinforced by

the Activity include solubility, like dissolves like, polar and nonpolar, and phases.

program and abstracts - s3.amazonaws.coms3.amazonaws.com/zanran_storage/ · committee: ms. brenda...

Documents