Determination of trinitrotoluene and metabolites in urine by means of gas-chromatography with mass detection.

Biological monitoring of chemicals and/or their metabolites has been a recent development in South Africa with the publication of the Hazardous Chemical Substance Regulations in 1995. Although trinitrotoluene (TNT) exposure has been included in recent legislative developments, only occupational exposure limits have been set. TNT does not have a biological exposure index in South Africa or internationally. This study was conducted to determine levels of TNT and its metabolite excretion in a sample of munition workers by using gas-chromatography with mass detection methodology. The metabolites 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT) in urine of exposed subjects, as well as total TNT (the sum of 4ADNT and 2ADNT), were used to determine absorption and excretion due to TNT exposure. Results indicated an increased absorption of TNT during the working week as compared to other published international studies. Post-shift values exceeded pre-shift levels in all samples. More reliable and specific research is necessary to set a biological threshold limit for TNT and its metabolites since monitoring indicated no definite symptoms, signs or biological effects due to increased excretion.