MONITORING OF DINITROTOLUENE AND ITS METABOLITES IN URINE BY SPECTROPHOTOMETRY OF THEIR COUPLED ARYLDIAZONIUM SALTS

A rapid, accurate method was developed for monitoring employee absorpt ion of dinitrotoluene (DNT). The method reduces DNT and its metabolite s in urine to primary arylamines, diazotizes them with nitrous acid, t hen couples the diazo compounds with N-(1-Naphthyl)ethylenediamine, pr oducing a colored complex. Spectrophotometric analysis of the colored complexes at 550 nm provides a measure of DNT absorption. The chemistr y prevents interferences from all but primary arylamines and compounds reduced to primary arylamines. A six-month monitoring program of empl oyees at a DNT manufacturing facility was conducted. Control samples f rom individuals not exposed to DNT were used to define an exposure ind ication level. The exposure indication level was used to correlate DNT exposure with job description or individual activity and was defined as apparent DNT and metabolite concentrations greater than 38 mu g/ml. Group exposure also was indicated and associated with plant activity. Job descriptions were ranked according to a rational evaluation of ex posure potential and correlated well with monitoring data.