Identification of CS Degradation Products in Objects Delivered from the Zone of a Special Military Operation

The formation of a CS aerosol during the combustion of a pyrotechnic mixture in gas grenades is accompanied by the formation of numerous thermolytic degradation products. Many of these products (including CS itself) are highly reactive substances, as a result of which the composition of the aerosol differs significantly from the set of products that can be subsequently detected in environmental objects.

The aim of the work is to detect and identify CS derivatives in soil samples and in the material of gas grenades delivered from the zone of a special military operation to assess their relative content and select promising markers of the fact of CS use.

Research methods. Detection and structural identification of CS degradation products were performed using gas and liquid chromatography-mass spectrometry (lowand high-resolution).

The results of the study. More than 30 compounds have been found that are products of oxidation, reduction, thermochemical degradation and dimerization of CS and its derivatives. The method of liquid chromatography-mass spectrometry, which was not previously used for such work, presumably identified five compounds, information about which in relation to gas grenades is not available in the sources available to us.

Conclusion. In the case of object analysis by gas chromatography-mass spectrometry, the most convenient marker of CS exposure is 2-chlorobenzylmalonyl nitrile, while the content of CS itself may be insignificant. For the variant of analysis by liquid chromatography-mass spectrometry, it is preferable to search for products of cyclization of CS of quinoline origin (positive ionization mode), and for the negative mode products of dimerization and reduction of CS.

1. Timperley CM, Forman JE, Åas P, Abdollahi M, Benachour D, Al-Amri AS, et al. Advice from the Scientific Advisory Board of the Organisation for the Prohibition of Chemical Weapons on riot control agents in connection to the Chemical Weapons Convention. RSC Adv. 2018;8:41731–9. https://doi.org/10.1039/C8RA08273A

2. Olajos EJ, Salm H. Riot control agents: Pharmacology, Toxicology, Biochemistry and Chemistry. J Appl Toxicol. 2001;21:355–91. https://doi.org/10.1002/jat.767

3. Smith PA, Kluchinsky TA, Savage PB, Erickson RP, Lee AP, Williams K, et al. Traditional Sampling With Laboratory Analysis and Solid Phase Microextraction Sampling With Field Gas Chromatography/Mass Spectrometry by Military Industrial Hygienists. AIHA J. 2002;63(3):284–92. https://doi.org/10.1080/15428110208984715

4. Sass S, Fisher TL, Jascot MJ, Herban J. Gas-Liquid Chromatography of Some Irritants at Various Concentrations. Anal Chem. 1971;43(3):462–4. https://doi.org/10.1021/ac60298a040

5. Bettencourt da Silva RJN, Silveira DM, Camões MFGFC, Borges CMF, Salgueiro PAS. Validation, Uncertainty, and Quality Control of Qualitative Analysis of Tear Gas Weapons by Gas Chromatography-Mass Spectrometry. Anal Lett. 2014;47(2):250–67. https://doi.org/10.1080/00032719.2013.832274

6. Borusiewicz R. Chromatographic analysis of the traces of 2-chlorobenzalmalononitrile with passive adsorption from the headspace on Tenax TA and Carbotrap 300. Forensic Sci Int. 2019;303:109933. https://doi.org/10.1016/j.forsciint.2019.109933

7. Gheorghe V, Gheorghe CG, Roxana DP, Mihai S, Calin C, Sarbu EE, et al. Synthesis, Purity Check, Hydrolysis and Removal of o-Chlorobenzyliden Malononitrile (CBM) by Biological Selective Media. Toxics. 2023;11(8):672. https://doi.org/10.3390/toxics11080672

8. Kluchinsky TA (Jr), Savage PB, Sheely MV, Thomas RJ, Smith PA. Identification of CS-derived Compounds Formed during Heat-dispersion of CS Riot Control Agent. J Micro Sep. 2001;13(5):186–90. https://doi.org/10.1002/mcs.1040

9. Kluchinsky TA (Jr), Sheely MV, Savage PB, Smith PA. Formation of 2-chlorobenzylidenemalononitrile (CS riot control agent) thermal degradation products at elevated temperatures. J Chromatogr A. 2002;952:205–13. https://doi.org/10.1016/S0021-9673(02)00096-1

10. Hout JJ, Hook GL, LaPuma PT, White DW. Identification of Compounds Formed During Low Temperature Thermal Dispersion of Encapsulated o-Chlorobenzylidene Malononitrile (CS Riot Control Agent). J Occu. Environ Hyg. 2010;7(6):352–7. https://doi.org/10.1080/15459621003732721