engleski

Analysis of metabolites in urine as biochemical indicators of human exposure to atrazine

Human exposure to atrazine and other triazine herbicides results in urinary excretion of traces of parent compounds and of their metabolites formed by dealkylation or conjugation with mercapturic acid. The aim of this study was to develop and validate a method for simultaneous extraction of atrazine and its more polar metabolites from human urine and to test its applicability in monitoring of occupational exposure. Atrazine, three dealkylated atrazine metabolites, and atrazine mercapturate were extracted from acidified urine samples (pH 2) with ethyl acetate and the extracts were analysed using high performance liquid chromatography - tandem mass spectrometry (Q-TRAP LC-MS/MS system). At mass concentrations of 50 ng/ml to 200 ng/ml extraction recoveries of atrazine, monodealkylated atrazine metabolites, and atrazine mercapturate ranged from 53% to 73% (RSD 4 % to 9%). The detection limits based on treatment of 2 ml urine samples were 0.2 ng/ml for atrazine and atrazine mercapturate, 4 ng/ml for deethylatrazine, 10 ng/ml for deisopropylatrazine, and 100 ng/ml for didealkylated atrazine. Detection sensitivity of mono- and didealkylated atrazine metabolites was influenced by interferences generated by sample matrix. The method was applied for analysis of atrazine metabolites in spot urine samples collected from agricultural workers at the beginning and at the end of a working day and 12 hours after the end of work. Atrazine and its dealkylated metabolites were not detected in any of 27 analysed urine samples but traces of atrazine mercapturate were measured in all urine samples collected at the end of the work and 12 hours after termination of exposure. The mass concentrations of atrazine mercapturate in positive urine samples ranged from 0.2 ng/ml to 7.9 ng/ml. The results confirmed atrazine mercapturate as a sensitive and useful biochemical indicator of human exposure to atrazine.

Atrazine; atrazine mercapturate; urine; human exposure

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