Study of the Long-Term Stability of Bis(2-chloroethyl)sulfide Biomarkers in Biomedical Samples.

We studied the stability of plasma samples spiked with sulfur mustard (SM) and urine samples spiked with the SM metabolite, 1,1'-sulfonylbis[2-(methylsulfinyl)ethane] (SBMSE), upon long-term storage. The stability of biomarkers in biomedical samples was evaluated by measuring the concentrations of spiking chemicals during the storage at 4 and 30°C. Plasma samples were analyzed by GC–MS/MS for SM regenerated from protein adducts under the action of conc. HCl and by HPLC–HR-MS/MS for albumin adduct [S-HETE]-CPF. Urine was analyzed for intact SBMSE by HPLC–HR-MS/MS, and SBMSE reduced to 1,1'-sulfonylbis[2-(methylthio)ethane] was determined after its conversion with TiCl3 followed by GC–MS/MS measurements. A reference compound of SBMSE was synthesized and characterized in terms of authenticity and quantitative content. Procedures for the quantification of SM markers in biomedical samples in the concentration range 1–100 ng mL–1 were validated. The plasma samples were stable upon storage at 4 and 30°С for at least 41 days after spiking, whereas the urine samples proved to be unstable upon long-term storage at elevated temperatures. The results of the present study can be taken into account in selecting conditions for the transportation and storage of biosamples and for interpreting the results of the determination of the SM biomarker in samples from individuals affected in incidents related to exposure to sulfur mustard. [ABSTRACT FROM AUTHOR]