detection of organic peroxide explosives through the fenton reaction

38
I. Francis Cheng, Derek F. Laine, Christopher Roske University of Idaho Moscow, ID 83844-2343 Email: [email protected] Tel.: 208-885-6387 Fax: 208-885-6173 Homepage: http://www.chem.uidaho.edu/faculty/ifcheng/ Acknowledgement: NSF-SGER Pittcon 2008 Session 2520-5 University of Idaho, IF Cheng, DF Laine, C Roske 1 Detection of Organic Peroxide Explosives Through The Fenton Reaction O O O O O O

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Detection of Organic Peroxide Explosives Through The Fenton Reaction. I. Francis Cheng, Derek F. Laine, Christopher Roske University of Idaho Moscow, ID 83844-2343 Email: [email protected] Tel.: 208-885-6387 Fax: 208-885-6173 Homepage: http://www.chem.uidaho.edu/faculty/ifcheng/ - PowerPoint PPT Presentation

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Page 1: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

I. Francis Cheng, Derek F. Laine, Christopher Roske

University of IdahoMoscow, ID 83844-2343

Email: [email protected] Tel.: 208-885-6387Fax: 208-885-6173

Homepage: http://www.chem.uidaho.edu/faculty/ifcheng/

Acknowledgement: NSF-SGERPittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske1

Detection of Organic Peroxide Explosives Through The Fenton

ReactionOO

O

O O

O

Page 2: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Triacetone Triperoxide (TATP)

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske2

Wikipedia http://en.wikipedia.org/wiki/Acetone_peroxide

Acetone peroxide (triacetone triperoxide, peroxyacetone, TATP, TCAP) is an organic peroxide and a primary high explosive.

Page 3: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Hexamethylenetriperoxide (HMTD)

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske3

Wikipedia - http://en.wikipedia.org/wiki/Hexamethylene_triperoxide_diamine

Oxley, J.C.; Smith, J.L.; Chen, H.; Cioffi, Eugene. Thermochim. Acta 2002, 388, 215-225.

Page 4: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Outline

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske4

BackgroundDangersRecent News

Need for Detection SystemsFastField Portable (handheld)Selective and LOD

Electrochemical Detection Via Fenton Reaction

Page 5: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – the threat

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske5

• Due to the cost and ease with which the precursors can be obtained, acetone peroxide is commonly manufactured by those without the resources needed to manufacture or buy more sophisticated explosives. When the reaction is carried out without proper equipment the risk of an accident is significant.

• http://en.wikipedia.org/wiki/Acetone_peroxide

Page 6: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP – Ease of Synthesis

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske6

3H2O2 + 3CH3COCH3= ((CH3)2COO)3 + 3H2O

Ice Bath3% H2O2 (30% or more preferable)Acetone (paint thinner)H2SO4 (battery acid)

Page 7: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Ease of HMTD Synthesis

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske7

http://business.fortunecity.com/executive/674/hmtd.html

Hexamethylenetetramine + Citric Acid + H2O2 HMTD

Page 8: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – physiochemical characteristics

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske8

TATPShock SensitiveHeat SensitiveHigh V.P. 7 Pa @

300K

HMTD Shock Sensitive Heat Sensitive Low VP

•Neither have any commercial or military value.

Propellants, Explosives, Pyrotechnics 30 (2005)127J. Am. Chem. Soc. 2005, 127, 1146-1159

Page 9: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP – Most Recent News

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske9

NY Times Sept. 5, 2007

FRANKFURT, Sept. 5 — The German police have arrested three Islamic militants suspected of planning large-scale terrorist attacks against several sites frequented by Americans, including discos, bars, airports, and military installations.

She said the suspects had amassed large amounts of hydrogen peroxide, the main chemical used to manufacture the explosives used in the suicide bombings in London in July 2005.

Page 10: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – London Subway Bombings

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske10

July 7, 2005

http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/05/uk_enl_1121567244/img/1.jpg

Page 11: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD Incidents

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske11

2006 – London airline bombing plot – HMTD 2005 - Joel Henry Hinrichs III – University of

Oklahoma. – TATP. 2001 - Richard Reid, Shoe Bomber – TATP1999 - Millennium bomber Ahmed Ressam.

124 pounds of HMTD1994/95 – Bojinka Plot – TATP? HMTD?1994 – Philippines Airlines - TATP1980’s – present - West Bank Israel – TATP

“Mother of Satan”

Page 12: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP – TSA Fluid Ban

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske12

Effective November 10, 2006, the TSA has advised that travelers may now carry through security checkpoints travel-size toiletries (3.4 ounces/100 ml or less) that fit comfortably in ONE, QUART-SIZE, clear plastic re-sealable bag.

The 3-1-1 Kit contains six 2-1/2 oz and four 1-1/2 oz flexible squeeze tubes, plus one 1-3/4 oz Envirosprayer.

Kit is also compliant with the new International Security Measures Accord.

http://www.easytravelerinc.com/

Page 13: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD Detection - The Challenge

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske13

The Need for a Fast Portable Detector

Innocuous Appearing White Powder

Dogs are only moderately successful at detection of TATP & HMTD - Expensive

Lacks Chromophoric Groups (not detectable by UV-vis absorbance)

Page 14: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – Detector Requirements

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske14

Unknown Materials – Public Safety, e.g. Airports High Selectivity – Low Limits of Detection not Required

Air Samples, e.g. AirportsModerate Selectivity– Low Limits of Detection Required

Debris at Post-Explosion SitesHigh Selectivity– Low Detection Limits

Field Portability

Schulte-Ladbeck, R.; Vogel, M.; Karst, URecent methods for the determination of peroxide-based explosivesAnal. Bioanal. Chem. 386 559-565 (2006)

Page 15: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD - Detectors

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske15

IR-RamanHigh Selectivity – Relatively High LOD

Fluorescence/UV-vis AbsorbanceLow LOD requires tagging

Ion MobilityGood Selectivity, moderate LOD

HPLC or GCExcellent Selectivity and LOD

Page 16: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – State of Detectors

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske16

Costs

Lack of Field PortabilityIdeal – Handheld Sensor

May Require Knowledgeable Usere.g. Commercial Glucose Sensors,

electrochemical devices

Page 17: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

The Fenton Reaction

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske17

H2O2 + e- HO• + HO- Fe(II) Fe(III) + e-

Fe(II) + H2O2 Fe(III) + HO• + HO-

H.J.H. Fenton. J. Chem. Soc. 1894, 65, 889.F. Haber and J.J. Weiss. Proc. Roy. Soc. London, Ser. A. 1934, 147, 332.

Page 18: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

The Fenton Reaction

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske18

FeIIIEDTA + e- = FeIIEDTA

FeIIEDTA + H2O2 = FeIIIEDTA + HO- + HO∙ (fast)

H2O2 + e- = HO- + HO∙ (slow)

Page 19: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

EC’ Voltammetry with the Fenton Reaction Mechanism

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske19

Cyclic voltammetry

•0.1 mM FeIIIEDTA

•0.1M KCl, 0.1 M chloroacetic acid (pH=3.3) under N2 purge

a) 8 mM TBHP or H2O2

b) 0 mM TBHP.

-8.0E-07

1.2E-06

3.2E-06

5.2E-06

-500-400-300-200-1000100200300400

Potential (mV)

Curre

nt (A

)

a

b

Page 20: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – Detection by Electrochemical Means

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske20

Proposed Basis For DetectionFenton Reaction for Organic Peroxides

RO-OR + FeIIEDTA RO- + RO· + FeIIIEDTA

Page 21: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – Electrochemical DetectionReaction with Organic Peroxides is not

Spontaneous

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske21

RO-OR + FeIIEDTA N.R.E0

RO-OR + e- RO- + RO· <-0.5 VFeIIEDTA FeIIIEDTA + e- 0.1 VEcell = Ecath – Eanod -0.6 V

Page 22: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP & HMTD – Electrochemical DetectionReaction with Peroxides and Hydroperoxides is Spontaneous

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske22

E0

RO-OH + e- RO- + HO· ≈0.4 VHO-OH + e- HO- + HO· 0.8 V

FeIIEDTA + RO-OH/HO-OH FeIIIEDTA +

RO∙/HO∙/H+

Requires that TATP & HMTD be degraded

Page 23: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP – Degradation to HOOH/ROOH

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske23

Acid degradation

TATP + H+ H2O2 + Products

Concentrated HCl 1-10 minutes

Page 24: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

HMTD Degradation

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske24

HMTD products + H2O2

Rapid (almost immediate) & Spontaneous

With addition of FeIIIEDTApH effect – 2.1

Page 25: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP – Cyclic Voltammograms after Acid Digestion

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske25

-0.01

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

-500-400-300-200-1000100

Potential (mV)

Curre

nt (m

A)

A

B

Figure 1. Cyclic voltammograms of two solutions both containing 10 mM TATP and 1 mM FeIIIEDTA under dearated conditions, 30 mV/s. A) Acid treated TATP. B) Non-acid treated TATP.

Page 26: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Chronoamperometry

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske26

Background:

FeIIIEDTA + e- = FeIIEDTA

FeIIEDTA + O2 = FeIIIEDTA + O2.-

E- step = -400 mV v. Ag/AgCl

1 mM FeIIIEDTA0.1 NaAc/HAc buffer pH 340% AcetonitrileVigorous Stirring

A) 0.04 mM acid treated TATP

B) 0 mM TATP0.013

0.015

0.017

0.019

0.021

0.023

0.025

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0

Time (s)

Cu

rren

t (m

A)

B

A

Page 27: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

TATP calibration curve

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske27

•The detection limit is 0.9 μM = 3Sb/m,

Sb = standard deviation of blanks m = slope of calibration curve

•Sensitivity of 0.025 mA/mM TATP.

•Background subtracted

•Error bars indicate one standard deviation.

y = 0.025x + 4E-05

R2 = 0.9999

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

[TATP] mM

Cur

rent

(mA)

Page 28: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

HMTD analysis

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske28

0.015

0.03

0.045

0.06

0 20 40 60 80 100 120 140Time (s)

Cu

rren

t (m

A)

y = 1E-05x - 4E-07

R2 = 0.9987

-5.00E-06

0.00E+00

5.00E-06

1.00E-05

1.50E-05

2.00E-05

2.50E-05

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

[HMTD] mM

Cu

rren

t (A

)

Increasing [HMTD]E- step = -400 mV v. Ag/AgCl

1 mM FeIIIEDTAVigorous Stirring

•Detection limit 30 μM = 3Sb/m,

Sb = standard deviation of blanks m = slope of calibration curve

•Error bars indicate one standard deviation.

Page 29: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Detection of TATP in technical mixtures

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske29

Significant concentrations of HOOH and ROOH.

Provides Target for the Detection of Technical Mixtures

TATP purification requires MeOH Recrystallization – More Stable than Technical Mixtures

Page 30: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Detection of HOOH & ROOH

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske30

E0

RO-OH + e- RO- + HO· ≈0.4 VHO-OH + e- HO- + HO· 0.8 V

FeIIEDTA + RO-OH/HO-OH FeIIIEDTA + RO∙/HO∙/H+

Detection LimitsH2O2 0.4 μM

tert-butyl hydroperoxide 21 μM

Page 31: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Literature

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske31

Technique Pre-treatment

Speed (mins)

LOD Simultaneous Detection of TATP/HMTD

Ref

EC’ Fenton TATP

Acid 1-10 1 μM Yes This Work

EC’ Fenton HMTD

None 0 30 μM Yes This Work

HRP Colorimetric

UV 1 0.9 mM No 6*

HRP Fluorescence

UV 30 8 μM No 4*

HPLC Fluorescence

UV 15 2 μM Yes 3*

Amperometric-PBME

UV/laser 1 50nM No 7*

“ Acid 1 55 nM No *Chronoamperometric/ PBME

Acid 1 18 mM No *

*Wang, Joseph et al, Analyst 2007, 132, 560-565.

Page 32: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Other Needs for H2O2 DetectionGlucose Detector

Glucose + H2O + O2 Gluconic Acid + H2O2

H2O2 2H+ + O2 + 2e-

(slow)Immobilized HRPLimited Linear Range to 3 mM

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske32

Page 33: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Advantages of H2O2 via Fenton Reaction

This Work:

FeIIIEDTA + e- = FeIIEDTA (fast)FeIIEDTA + H2O2 = FeIIIEDTA + HO- +

HO∙ (fast)

Does not require immobilization of enzymes Less ExpensiveLinear Range LOD – 100 mM

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske33

Page 34: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Summary

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske34

TATP - 0.9 µM LOD InstrumentalHMTD - 30 µM LOD MethodHOOH – 0.4 µM LOD InstrumentalROOH – 21 µM LOD Instrumental

O2 interferenceFeIIEDTA + O2 FeIIIEDTA + O2

.-

HOOH/ROOH – No Pretreatment Requires Acid Pretreatment

TATP – 1-10 min. Sample PretreatmentHMTD – Instantaneous

Page 35: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Summary

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske35

Proof of concept

No modified electrodes or enzymes required. Reagents can stand up to long term storage.

Allows for development of simple, handheld & inexpensive devices, e.g. glucose sensors

Not a stand-off detection deviceHigh TATP VP may allow for gas phase

sensor

Page 36: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Future Work

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske36

Elimination of O2 interferenceMetal Complex Reduction PotentialKinetics of H2O2 vs. O2 reduction

Optimal Hydrolysis

Design of probesAir SamplesLiquid Sample

Page 37: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

AcknowledgementsNational Science Foundation

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske37

Page 38: Detection of Organic Peroxide Explosives  Through The  Fenton  Reaction

Abstract - Detection of Organic Peroxide Explosives through the Fenton Reaction

Pittcon 2008 Session 2520-5University of Idaho, IF Cheng, DF Laine, C Roske38

There is an urgent need for methods and techniques that are able to detect quantitatively and qualitatively peroxide based explosives, especially triacetone triperoxide or TATP. The basic chemistries for such endeavor have not been fully described. This investigation will examine the electrochemical mediation of the Fenton Reaction as a basis for detection of this class of explosives. The mediation takes place as a result of the homogeneous Fenton Reaction and the electro-reduction of an FeIII complex to FeII followed by oxidation by either a hydroperoxide or hydrogen peroxide:

FeIIcomplex + RO-OH FeIIIcomplex + RO- + HO∙

FeIIcomplex + HO-OH FeIIIcomplex + HO- + HO∙

The current due to the electro-reduction of the FeIII complex is proportional to the square root of the peroxide concentration. The process is expected to be rapid, robust, and inexpensive. We will report on the detection limits, kinetics, optimal conditions for the degradation of TATP to hydroperoxides and H2O 2, and the role of the chelate of that iron complex. The latter is based on considerations of the structure-activity relationships developed by cyclic voltammetric studies.