Detection of 2,5-hexanedione in the urine of persons not exposed to n-hexane.

The neurotoxic n-hexane metabolite 2,5-hexanedione was detected by gas chromatography--mass spectrometry in urine samples from human subjects not exposed to n-hexane or related hydrocarbons. Quantitative determinations by multiple ion detection revealed an amount of 2,5-hexanedione ranging from 0.12 to 0.78 mg/l (0.45 +/- 0.20 mg/l; means +/- SD). The amounts of 2,5-hexanedione actually measured in urinary extracts depended on the pH employed for acid hydrolysis of the samples.