Evaluation of Molecular Markers and Analytical Methods Documenting the Occurrence of Mustard Gas and Arsenical Warfare Agents in Soil

Abstract

The chemicals warfare agents (CWAs) are an extremely toxic class of molecules widely produced in many industrialized countries for decades, these compounds frequently contained arsenic. The plants where the CWAs have been produced or the plants where they have been demilitarized after the Second World War with unacceptable techniques can represent a serious environmental problem. CWAs standards are difficult to find on market so in present work an environmental assessment method based on markers has been proposed. Triphenylarsine, phenylarsine oxide and thiodiglycol have been selected as markers. Three reliable analytical methods based on gaschromatography and mass detection have been proposed and tested for quantitative analysis of markers. Methods performance have been evaluated testing uncertainty, linearity, recovery and detection limits and also comparing detection limits with exposure limits of reference CWAs. Proposed assessment methods have been applied to a case study of a former industrial plant sited in an area characterized by a high background of mineral arsenic.

Unexpected Reaction Pathways Leading to Thiodiglycol During the Degradation of Long-Chain Sulfur Mustards

“…1 H NMR (CDCl 3 ) δ: 2.79 (s, 4H, CH 2 ), 2.90 (t, J = 7.8 Hz, 4H, CH 2 ), 3.65 (t, J = 7.8 Hz, 4H, CH 2 ). MS (EI, 70 eV) m/z (%B): 218(M + , 7), 182 (21), 123(100), 109(67), 73(30), 63(59), 45(33). MS (CI, NH 3 ) m/z (%B): 236 [M + NH 4 ] + (89), 183(100), 155 (16), 140 (13), 123(29).…”

“…Following an analogous procedure from 1.8 g (9.2 mmol) of the intermediate obtained from 0.47 g (20.4 mmol) of metallic sodium, 1 g (10.64 mmol) of 1,3propanethiol and 1.64 g (20.38 mmol) of 2-chloroethanol, 1.26 g of 7b was obtained as a yellow oil (1.27 g, 5.45 mmol, 59% yield, 77% purity as determined by 1 H NMR). 1 H NMR (CDCl 3 ) δ: 1.88 (q, J = 6 Hz, 2H, CH 2 ], 2.69 (t, J = 6 Hz, 4H, CH 2 ), 2.86 (t, J = 6 Hz, 4H, CH 2 ), 3.64 (t, J = 6 Hz, 4H, CH 2 ) MS (EI, 70 eV) m/z (%B): 232(M + , 8), 196(9), 169(100), 133 (17), 107(33), 87(20), 73 (34), 63 (23), 45 (21) Bis(2-chloroethylthioethyl)ether, 8. To a solution of metallic sodium (17 mmol, 0.39 g) in 20 mL of absolute EtOH, 2mercaptoethanol (net, 16 mmol, 1.25 mL) was added dropwise under an argon atmosphere.…”

“…The alleged use of CWAs is supervised by the Organization for the Prohibition of Chemical Weapons (OPCW) through a very restrictive verification protocol. , This protocol establishes that, to unambiguously determine the use of a CWA, the identification of an unaltered agent or any of its degradation products must be based on at least two different analytical techniques giving consistent results; the primary technique must be a data rich spectrometric technique . From a forensic approach, should a degradation compound originate from two different CWAs, the identification of this compound must be traced to more than one chemical.…”