DETECTING VX METABOLITES IN A HUMAN VICTIM KEL DANIEL MARSHALL UNIVERSITY FORENSIC SCIENCE PROGRAM APRIL 11, 2014

Transcription

1 DETECTING VX METABOLITES IN A HUMAN VICTIM KEL DANIEL MARSHALL UNIVERSITY FORENSIC SCIENCE PROGRAM APRIL 11, 2014

2 2 OUTLINE VX Background - Toxicity Banning - Chemical Weapons Convention Analysis of serum from a confirmed victim Proof of VX use New preparation method for analysis to increase sensitivity Conclusions

3 VX BACKGROUND Chemical Name: O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate Irreversible Acetylcholinesterase inhibitor Injection, Inhalation, Ingestion, Absorption LD 50,intravenous = mg/kg 3/100 th of a drop 4,400 tons 3 trillion deaths 3

4 CHEMICAL WEAPONS CONVENTION International treaty banning the possession and use of chemical weapons As of October 14, 2013: State parties signed and ratified: 190 State parties signed but not ratified: 2 State Parties neither signed nor acceded to the CWC: 4 North Korea South Sudan Egypt Angola 4

5 5 CHEMICAL WEAPONS CONVENTION The US has destroyed 90% of its Category 1 chemical weapons. Category 1: VX, Sarin, Soman, Tabun, Sulfur Mustards, Saxitoxin, Ricin and precursors

6 6 CHEMICAL WEAPONS CONVENTION Blue Grass Army Depot in Kentucky still houses 523 tons of VX, Sarin, and Mustard Gas

7 7

8 8 VICTIM OF VX Aum Shinrikyo Japanese cult Created g of VX and kg of Sarin Sarin used in: Matsumoto City: 8 killed and hundreds injured Tokyo subway: 13 killed and thousands injured VX used to eliminate a former member

9 VICTIM OF VX 9

10 VICTIM OF VX Biomarker: unchanged VX?? MPA? 10

11 11 VICTIM OF VX VX Derivatized!

12 AQUEOUS LAYER t-bdms GC-CI-MS-MS product ion spectrum of [M+H] + confirming ID of t-bdms derivatization of 12

13 ORGANIC LAYER DAEMS GC-CI-MS-MS product ion spectrum of showing DAEMS 13

14 PROOF OF VX IN HUMAN BODY 14

15 PROOF OF VX IN HUMAN BODY 15

16 PROOF OF VX IN THE HUMAN BODY To be used for forensic purposes, a biomarker must: 1. Lifetime Alleged military use several days, possibly longer Terrorism much less 2. Chemical stability in biological sample 3. No non-chemical warfare sources 4. Detectable at trace levels Organization for the Prohibition of Chemical Weapons Diagnosis of victims Monitor health of employees at destruction facilities 16

17 NEW DETECTION METHOD 17

18 NEW DETECTION METHOD Na 2 SO 4 Na + Na + Na + SO 4-2 Na + SO 4-2 SO 4-2 Na + Na + Na + Na + Urine impurities SO

19 NEW DETECTION METHOD PFBBr = detectable at low concentrations using negative ion chemical ionization PFBBr PFBBr PFBBr PFBBr PFBBr Urine impurities 19

20 NEW DETECTION METHOD Phosphate Buffer and Hexane PFBBr PFBBr PFBBr PFBBr PFBBr Urine impurities 20

21 NEW DETECTION METHOD Phosphate Buffer and Hexane Urine impurities SO -2 SO Na + Na + Na + Na + Na + Na + Phosphate Buffer SO 4-2 SO 4-2 Hexane PFBBr PFBBr PFBBr PFBBr Na + Na + PFBBr 21

22 22 NEW DETECTION METHOD Direct derivatization with pentafluorobenzyl bromide on solid support Liquid-liquid extraction Reduced analyte loss and improved recovery Isotope-dilution gas chromatography-negative ion chemical ionization tandem mass spectrometry in selected reaction monitoring mode Quantitative calibration linear range ng/ml with R 2 = LOD = 0.02 ng/ml

23 23 CONCLUSIONS VX is very bad. Thankfully, 98% of the world has agreed to the CWC Research is still necessary due to terrorism and clean-up contamination Methods are being developed that have high sensitivity for the metabolites present in biological samples These methods can be used to determine if VX is used in a deliberate attack or if destruction workers are accidentally exposed

24 24 ACKNOWLEDGEMENTS Topic Advisor: Dr. Lauren Waugh Dr. Pamela Staton Practice Audience members: Nickel B. Daniel Penelope A. Daniel

25 25 REFERENCES 1. Coleman, K. A History of Chemical Warfare; Palgrave Macmillan: New York, Hoenig, S. L. Handbook of Chemical Warfare and Terrorism; Greenwood Press: Westport,Conn., Masson, P.; Lockridge, O. Butyrylcholinesterase for Protection from Organophosphorus Poisons: Catalytic Complexities and hysteretic Behavior. Archives of Biochemistry and Biophysics. 2010, 494, Benschop, H. P.; De Jong, L. P. A. Nerve agent stereoisomers: analysis, isolation and toxicology. Acc. Chem. Res. 1988, 21, Conference on Disarmament. The Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction. CD/1170, Geneva, August Organization for the Prohibition of Chemical Weapons. Note by the Technical Secretariat. Status of Participation in the Chemical Weapons Convention as at 14 October S/1131/ October

26 REFERENCES CONT. 8. Organization for the Prohibition of Chemical Weapons. Report of the OPCW on the Implementation of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction in C-17/4, 27 November Tsuchihashi, H.; Katagi, M.; Nishikawa, M.; Tatsuno, M. Identification of Metabolites of Nerve Agent VX in Serum Collected from a Victim. J. Anal. Toxic. 1998, 22, Black, R. An Overview of Biological Markers of Exposure to Chemical Warfare Agents. J. Anal. Tox. 2008, 32, Subramaniam, R.; Ostin, A.; Nilsson, C.; Astot, C. Direct Derivatization and Gas Chromatrography Tandem Mass Spectrometry Identification of Nerve Agent Biomarkers in Urine Samples. J. Chromat. B. 2013, 928, Lin, Y.; Chen, J.; Yan, L.; Guo, L.; Bidong, W.; Li, C.; Feng, J.; Liu, Q.; Xie, J. Determination of Nerve Agent Metabolites in Human Urine by Isotope-Dilution Gas Chromatography-Tandem Mass Spectrometry After Solid Phase Supported Derivatization. Anal. Bioanal. Chem

27 PICTURE REFERENCES html 5. n-rebels-used-sarin-gas-un-human-rights-investigator

28 QUESTIONS? 28