Solvent extractionqfraction of solute extracted1-qfraction of solute unextracted

Tech.phase 1phase 2LLEraffinateExtractant\ChromatographystationarymobileDialysisretentatediffusate

is the ratio of total amount (weight) of A in one phase to that in the 2nd phasepartition ratio (capacity factor)

phase ratio

(1) Partition coefficient

(2)

(3)

(4)

Single contact

Multiple extraction

Effect of pH value on extractionKD D ( distribution coeff. )

HAoorg.aq. HAaq + H2O H3O+ + A-

(b) at pH very acid [H+] >>Ka D=KD(c) [H+] KD

Effect of pH value on extractionKD D ( distribution coeff. )

Boorg.aq. BH+aq H+ + B

(b) at pH very acid [H+] >>Ka D >> KD(c) [H+]

Suppose that the partition coefficient for an amine, B, is 0.33 and the acid dissociation constant of BH+ is Ka=1.0x10-9. If 50 mL of 0.010M aqueous amine is extracted with 100 mL of solvent. What will be the formal concentration remaining in the aqueous phase (a) at pH 10.0? (b) 8.0?

ApplicationExtraction of metal ions

chelator (HL)

Extraction of Metal Ions with RTIL

RTIL,, RTIL(1-butyl-3-methylimidazolium hexafluorophosphate , [BMIM][PF6]) RTIL.

Guor-Tzo Wei*, Zusing Yang, Chao-Jung Chen, Anal. Chimica, Acta 2003, 488(2), 183. Guor-Tzo Wei*, Jin-Chu Chen, Zusing Yang, J. Chin. Chem. Soc. 2003, 50, 1123.

-: . -:a.supercritical fluid CO2

b.ionic liquid(IL)

Presidential Green Chemistry Challenge Awardshttp://www.epa.gov/greenchemistry/ Mission: To promote innovative chemical technologies that reduce or eliminate the use or generation of hazardous substances in the design, manufacture, and use of chemical products. 1996:Alternative Synthetic Pathways Award: Monsanto Company, The Catalytic Dehydrogenation of DiethanolamineAlternative Solvents/Reaction Conditions Award: Dow ChemicalThe Development and Commercial Implementation of 100 Percent Carbon Dioxide as an Environmentally Friendly Blowing Agent f or the Polystyrene Foam Sheet Packaging MarketDesigning Safer Chemicals Award: Rohm and HaasDesigning an Environmentally Safe Marine AntifoulantSmall Business Award: Donlar CorporationProduction and Use of Thermal Polyaspartic AcidAcademic Award : Prof. Mark Holtzapple, Texas A&M Univ.Conversion of Waste Biomass to Animal Feed, Chemicals, and Fuels

The Twelve Principles of Green Chemistry*

1.Prevention It is better to prevent waste than to treat or clean up waste after it has been created.2.Atom Economy Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.3.Less Hazardous Chemical Syntheses Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment.4.Designing Safer Chemicals Chemical products should be designed to effect their desired function while minimizing their toxicity.5.Safer Solvents and Auxiliaries The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used.6.Design for Energy Efficiency Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.7.Use of Renewable Feedstocks A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable.

*Anastas, P. T.; Warner, J. C. Green Chemistry: Theory and Practice, Oxford University Press: New York, 1998, p.30.

What is a Room Temperature Ionic Liquid (RTIL)?(Room Temperature Molten Salt)Liquid salt consisting of at least one organic component (cation or anion) with melting point below room temperatureProperties:Negligible vapor pressureHigh thermal stability (~250-400C)High viscosityHydrophobic or hydrophilicDissolve many organic, organometallic, and inorganic compounds

RTILs are regarding as Green solvents

Ethyl ammonium nitrate (EtNH+3)(NO-3), which has a melting point of 12C, was first described in 1914.P. Walden, Bull. Acad. Imper. Sci. (St. Petersburg) 1800 (1914).

Osteryoung & Wilks, late1970, chloroaluminate salts in electrochemistry

Sneddon & Hussey, 1980, groups chloroaluminate salts in electrochemistry and organometallic researches.

After 1990, used as solvents for synthesis

Late 2000, the application in separation

Pure Appl. Chem., 2000, 72, 22752287

RTIL StructuresCations

AnionsPF6-SbF6-BF4-CF3SO3- (TfO)Cl-N(CF3SO2)2- (NTf2)

1-butyl-3-methylimidazolium, BMIM, C4MIMR: methyl; R: n-butyl 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6]1-octyl-3-methylimidazotetrafluoroborate [OMIM][BF4]

General syntheses of ionic liquid: Green Chemistry, 2003. 5. 181-186.

Effect of the nature of anion on physical properties of BMIM salt-----------------------------------------------------------------------------------Anionm.p. d Viscosity Conductivity oC g/cm3 cP (20oC) S/m----------------------------------------------------------------------------------BF4- -82(g) 1.17 233 0.17PF6--8 1.36 312 0.14Cl-65 1.10 solid solidCF3COO-~-40(g) 1.21 73 0.32CF3SO3-16 1.29 90 0.37(CF3SO2)N--4 1.43 52 0.39C3F7COO-~-40(g) 1.33 1820.10C4F9SO3-20 1.47 373 0.045----------------------------------------------------------------------------------(g) Glass transitionP.S. viscosity of water 1 cP.

Dissolution of Cellulose with Ionic LiquidsR.P. Swatloski, R.D. Rogers, et al. J.A.C.S. 124 (2002) 4974.

Room-temperature ionic liquids: a novel versatile lubricantChengfengYe , WeiminLiu , YunxiaChen and LaiguiYu, Chem. Commun., 2001, (21), 2244 - 2245 Alkylimidazolium tetrafluoroborates are promising versatile lubricants for the contact of steel/steel, steel/aluminium, steel/copper, steel/SiO2, Si3N4/SiO2, steel/Si(100), steel/sialon ceramics and Si3N4/sialon ceramics; they show excellent friction reduction, antiwear performance and high load-carrying capacity

Uses of RTILs in Anal. Chem.Novel solvents in liquid-liquid or micro extractionsRun buffer additives in CEMatrixes in Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometryStationary phases in gas-liquid chromatography

Illustration of various equilibra involved in metal ion extraction with ionic liquid .Extraction of Metal Ions with RTIL

colorlessmetal complex(red)dithizone

+++Cu2+Cu2+Cu2+2H+2H+2H++++222GreenBlueBlueBlueVioletYellowOrangeRedDithizoneOxinePAN

The pH value effect on the extraction of lead ion with dithizonein ( ) ionic liquid, ( ) chloroform.

Comparing the extraction of copper ions with ionic liquid and dichloromethane with PAN

PAN IL/CH2Cl2

The effect of pH value on the extraction efficiencies of metal ions with dithizone by IL.

The effect of pH value on the extraction efficiencies of metal ions with PAN by IL.

Hg2+ Zn2+ Pb2+ Ca2+ Cr3+ Mn2+ Cd2+ As5+Co2+ Ag+The effect of 100 ppm cation on the extraction of 5 ppm Cu2+ with dithizone

Chart2

81.632653061220.38933

99.333610995472.75771

99.541857559478.33795

98.708871303687.35218

99.125364431580.91344

98.708871303679.19645

92.877967513550.00751

99.125364431569.32372

99.125364431579.41107

76.009995835121.8917

IL

Dichloromethane

Sheet1

81.632653061220.38933

99.333610995472.75771

99.541857559478.33795

98.708871303687.35218

99.125364431580.91344

98.708871303679.19645

92.877967513550.00751

99.125364431569.32372

99.125364431579.41107

76.009995835121.8917

Sheet1

IL

Dichloromethane

Sheet2

Sheet3

SCN- citrate Cl- CO32- PO43- CH3COO-The effect of 100 ppm anion on the extraction of 5 ppm Cu2+ with dithizone

Chart2

96.96086226797.2191650158

96.96086226791.2576124441

96.96086226794.696969697

96.96086226799.9706508181

96.96086226791.9454838946

96.739994699294.2383887299

IL

Dichloromethane

Sheet1

96.96086226797.2191650158

96.96086226791.2576124441

96.96086226794.696969697

96.96086226799.9706508181

96.96086226791.9454838946

96.739994699294.2383887299

Sheet1

IL

Dichloromethane

Sheet2

Sheet3

SCN- citrate Cl- CO32- PO43- CH3COO-The effect of 100 ppm anion on the extraction of 5 ppm Cu2+ with PAN

Chart1

97.60425909499.4202898551

97.82608695656.7632850242

97.60425909498.9371980676

97.604259094911.5942028986

97.60425909498.2125603865

97.16060337188.9371980676

IL

Dichloromethane

Sheet1

97.60425909499.4202898551

97.82608695656.7632850242

97.60425909498.9371980676

97.604259094911.5942028986

97.60425909498.2125603865

97.16060337188.9371980676

Sheet1

IL

Dichloromethane

Sheet2

Sheet3

Preconcentration of Pb2+

TimesTheoreticalValue (ppm)Experimental Value (ppm) Recovery() 510.0010.001001020.0020.001002040.0038.2095.52550.0045.7595.850100.0099.0099.0

(a) Separation of different metal ions; (b) Reproducibility of Cadmium ions with reusal [C4MIM][PF6] Average = 43.31% RSD = 5.69%(a)(b)

Solute A has a partition coeff. of 1/3 between toluene and water. Suppose that 100 mL of a 0.010 M aqueous solution A is extract with toluene. What fraction of A remains in the aqueous phase (a) if one extraction with 500 mL if performed and (b) if five extractions with 100 mL are performed?

Solute A has a partition coeff. of 1/3 between toluene and water. Suppose that 100 mL of a 0.010 M aqueous solution A is extract with toluene. What fraction of A remains in the aqueous phase (a) if one extraction with 500 mL if performed and (b) if five extractions with 100 mL are performed?

Dithizone PAN ligand:dithizone dithizone PAN