Determination of sarin and soman in industrial emissions by gas-chromatographic method using pulsating flame-photometric detector

Abstract

Methods of gas chromatographic determination of trace amounts of sarin and soman in industrial emissions at a level of 1.0 × 10–6 mg/m3 have been developed. The capture and concentration of the target analyte was carried out using a specially designed sampling fluoroplastic cartridge filled with a pre-prepared sorbent Tenax TA with a grain size of 60/80 mesh and a volume of 8 cm3. The extraction of concentrated substances from the sampling cartridge was carried out using a modified and improved method of thermal desorption which consists in involving hot vapors of the solvent (resulted from the introduction of a liquid solvent into the cavity of the sampling cartridge with subsequent heating to 200°C) into desorption process in addition to the inert carrier gas. The substantially higher efficiency of the modified method of thermal desorption compared to the classical methods of extracting target substances from sorbents has been experimentally proved. Data on the quantitative content of sarin and soman were obtained by gas chromatographic method using a Varian CP-3800 gas chromatograph equipped with a pulsating flame-photometric detector, the mixture was separated on a VF-5ms capillary column. The sensitivity of a classical flame photometric detector and a pulsed flame photometric detector to sarin and soman has been studied. The developed methods have a relative error of determination about 27 %, and the duration of analysis of one sample is 3 h 30 min. The methods were tested on the real objects of control, appropriately certified and implemented in practice.