Determination of the sulfur mustard hydrolysis product thiodiglycol by microcolumn liquid chromatography coupled on-line with sulfur flame photometric detection using large-volume injections and peak compression.

A selective, direct and relatively rapid method has been developed for the determination of thiodiglycol (TDG) in aqueous samples. TDG is the main hydrolysis product of the chemical warfare agent sulfur mustard. The method of analysis is based on the on-line coupling of reversed-phase microcolumn liquid chromatography and sulfur-selective flame photometric detection. To improve sensitivity and efficiency, peak compression by displacement was used in combination with large-volume injections. A concentration of 1% n-propanol was added to the sample to obtain the best sensitivity and efficiency after a 10 microliters injection. Detection limits of 0.25 microgram/ml were achieved with efficiencies of 4.10(5) plates per meter. The method was successfully applied during the Fourth Official Proficiency Test organized by the Technical Secretariat of the Organization for Prohibition of Chemical Weapons for the determination of TDG in a soil sample.