Urinary thiosulphate as an indicator of exposure to hydrogen sulphide vapour

Urinary thiosulphate analysed as its bromobimane complex by liquid chromatography revealed quantitatively a preceding hydrogen sulphide gas exposure. The highest thiosulphate concentrations were detected 15 h after the exposure. Controls without a contact to sulphides showed low excretion rates of thiosulphate so that exposures clearly below the fatal hydrogen sulphide gas concentrations could be detected. The urinalysis can therefore be used in the occupational health care as well as for forensic ends.