Measurement of urinary methoxyphenols and their use for biological monitoring of wood smoke exposure

A urinary assay for methoxyphenols was developed for the biological monitor ing of wood smoke exposure. Methoxyphenols in 10-ml samples of urine were e xtracted after acid hydrolysis using XAD in a solid-phase extraction cartri dge. The methoxyphenols were eluted with ethyl acetate and then analyzed by gas chromatography/mass spectrometry. Specific chemicals quantified were g uaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-propylguaiacol, syringol, 4-m ethylsyringol, 4-ethylsyringol, vanillin, eugenol, and syringaldehyde. Reco veries ranged from 60 to 90%, with coefficients of variation of less than o r equal to 20%. Background levels of the compounds were measured in 21 nons moking adults. Guaiacol, 4-methylguaiacol, eugenol, and vanillin were detec ted in all subjects. An experimental feeding of a commercial wood smoke fla voring demonstrated that methoxyphenols were rapidly and efficiently elimin ated in urine. Preliminary field studies demonstrated that urinary excretio n rates of some methoxyphenols increased after inhalation exposure to wood smoke. (C) 2001 Academic Press.