Development of a solid phase microextraction-gas chromatography method to determine N-hydroxymethyl-N-methylformamide and N-methylformamide in urine.

A headspace solid phase microextraction (SPME) method has been developed to determine metabolites of dimethylformamide, N-hydroxymethyl-N-methylformamide, and N-methylformamide (NMF) as NMF in urine by gas chromatography with nitrogen-phosphorus detector (GC-NPD). An SPME holder with a 65-microm PDMS/DVB fiber coating was used. Optimal desorption conditions were 250 degrees C for 1 min, adsorption at 80 degrees C for 15 min, and 3.

[Assessment of urinary trans, trans-muconic acid as a biomarker of exposure to benzene].

Objective: To assess the use of trans, trans-muconic acid as a biomarker of occupational exposure to benzene.

Methods: Trans, trans-muconic acid in urine samples of exposed (exposed group, n=36) and non-exposed (non-exposed group, n=116) workers to benzene. Urinary levels of trans, trans-muconic acid were quantified by high-performance liquid chromatography.