Toxicological Analysis of Victims' Blood and Crime Scene Evidence Samples in the Sarin Gas Attack Caused by the Aum Shinrikyo Cult

2011

Biological and chemical warfare agents (BCWAs) are diverse in nature including synthetic low molecular weight chemical warfare agents (gaseous choking and blood agents), volatile nerve gases and blister agents, nonvolatile vomit agents and lachrymators, biological toxins (polar low molecular weight toxins and proteinous toxins), and microorganisms (viruses, rickettsia, chlamydia and bacteria). In the consequence management against chemical and biological warfare terrorism, speedy decontamination of casualties, goods, items and equipments, buildings and field is required for the minimization of the terrorism damage. At present, washing casualties and contaminated materials with large volumes of water is the basic way, and hypochlorite solution is mainly used to decompose BCWAs. However, it still remains unsolved how to dispose the waste water contaminated with BCWAs, and decontaminating reagents have serious problems of high toxicity to human, despoiling nature to environment, long finishing time and non-durability. In addition, the present decontamination technologies are not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up usable decontamination system surpassing the present system. The author introduces the joint project of research and development of the novel decontamination system against BCWAs, in the purpose of realizing non-dangerous, rapid, specific, effective and economical on-site decontamination. The project consists of establishment of the evaluation methods for decontamination, and verification of the present technologies and utilization of bacterial organophosphorus hydrolase, development of specific adsorptive elimination technologies using molecular recognition devices, and development of deactivation technologies using photocatalysis.

Section: Introductionmentioning

confidence: 99%

Research and Development of On-site Decontamination System for Biological and Chemical Warfare Agents

2011

“…In fact, we were not able to detect sarin hydrolysis products from all of the victims in the Tokyo subway sarin attack. 11) The covalently bound compounds that are formed from xenobiotics and biological macromolecules are called adducts. Adduct analysis has stolen the limelight as a method of demonstrating exposure to CWAs.…”

Section: Introductionmentioning

confidence: 99%

Mass Spectrometric Identification of Chemical Warfare Agent Adducts with Biological Macromolecule for Verification of Their Exposure

Tsuge

2009

Exposure to chemical warfare agents (CWAs) can be verified by detecting their degradation products in biological samples. However, the half-lives of these CWA degradation products in the body are short. CWAs are known to combine with biological macromolecules and the covalently bound compounds are called adducts. The residence time of adducts in the human body is longer than that of the corresponding CWA degradation products. Therefore, development of analytical methods to detect these adducts is a more realistic way of verifying CWA exposure. In this mini review, we describe the present state of research on analytical methods for identifying CWA adducts, and mainly introduce our research on nerve gas adducts using a direct method. Novel analytical methods for verifying low level exposure to nerve gases use liquid chromatography-mass spectrometry (LC-MS). Butyrylcholinesterase (BuChE) has been purified by affinity chromatography and sodium dodecylsulfate poly-acrylamide gel electrophoresis. The purified enzyme is inhibited by nerve gases (sarin, VX and soman) and digested by chymotrypsin, and then the peptides are analyzed by LC-MS and LC tandem MS. The peptide fragment that is combined with nerve gas is detected by LC-MS. Furthermore, the chemical structure of the adduct peptide characterized by MS provides structural information about the analyte. The detection limit of BuChE or BuChE adduct is estimated at 4 ng/injection (53 fmol/injection). If at least 1% of BuChE activity is inhibited by nerve gas, the adduct can be detected at a level of 1% BuChE inhibition in the victim's serum.

“…2) We adopted gas chromatography-mass spectrometry (GC-MS) as an identification technique for nerve gases and related compounds. However, it was difficult to detect both RMPAs and MPA in some specimens.…”

Section: Introductionmentioning

confidence: 99%

Laboratory Identification of the Nerve Gas Hydrolysis Products Alkyl Methylphosphonic Acids and Methylphosphonic Acid, by Gas Chromatography-mass Spectrometry after <i>tert</i>-Butyldimethylsilylation

Kanamori-Kataoka

2008

Alkyl methylphosphonic acids (RMPAs) and methylphosphonic acid (MPA), both nerve gas hydrolysis products, can be identified by gas chromatography-mass spectrometry (GC-MS). We adopted tertbutyldimethylsilylation (TBDMS) as a derivatization technique for the identification of these products by GC-MS. We found that it was difficult to detect RMPAs and MPA from evidence specimens such as soils and body fluids, and ascertained several causes for this. The first is the interference from the TBDMS derivatization. It was determined that the TBDMS derivatization of RMPAs and MPA was suppressed in the presence of divalent metal cations such as calcium and magnesium ions, as well as some neutral compounds like carbohydrates. A cleanup procedure using a strong anion-exchanger (SAX)-solid phase extraction (SPE) method was optimized to remove the interfering compounds. The second reason that detection was difficult was because of strong matrix adsorption. We elucidated that the aqueous extraction recoveries for all phosphonates were inversely correlated with the phosphate adsorption coefficient in the soil samples. To diminish the adsorption of phosphonates to soils, a method of alkali extraction was adopted. For human serum samples, we adopted acetonitrile or trichloroacetic acid deproteinization which worked to break the binding between the proteins and the phosphonates. The detection yields of RMPAs and MPA from soils and human serum were dramatically increased using these pretreatment procedures combined with extraction and/or SAX-SPE. The method of SAX-SPE was applied to various types of samples, such as seawater, drinks and human urine, and good detection yields of RMPAs and MPA were provided by GC-MS.