Recovery of wipe sampling of urban surfaces contaminated with blistering chemical warfare agents

Abstract

Abstract Effective sampling is a key step in the process of proving the use of chemical weapons. An alternative to collecting the respective sample is to perform a wipe of surface contamination. This work deals with the optimization of the wiping process of the surfaces of selected matrices contaminated with bis(2-chloroethyl)sulfide and tris(2-chloroethyl)amine. Optimization of the procedure was carried out in terms of the choice of wiping material, wetting solvent and extraction of the wiped contaminant. Furthermore, the time decrease of surface contamination was monitored. The effect of transport on the change in the observed recovery value was investigated and the measurement deviations of the wipe method were discussed. The resulting values of observed recovery were negatively influenced by the volatility of the analyte, the porosity of the matrix and the time that passed since the contamination. Viscose was evaluated as the most effective wipe material. Low relative standard deviations (≤7 %) were achieved with this material. The optimal wetting solvent was dichloromethane. There was no degradation of contaminants on the surface of the matrices, so the fate was only affected by evaporation and penetration into the material.