Fast liquid chromatographic determination of urinary trans,trans-muconic acid

trans,trans-Muconic acid (1,3-butadiene-1,4-dicarboxylic acid, MA), a minor urinary metabolite of benzene exposure, was determined, after clean-up by solid-phase anion-exchange chromatography, by reversed-phase HPLC on a C₁₈ column (5 x 0.46 cm I.D., 3 μm particle size), using formic acid-tetrahydrofuran-water (14:17:969) as mobile phase and W detection at 263 nm. The recovery of MA from spiked urine was >95% in the 50-500 μg/l range; the quantification limit was 6 μg/l; day-to-day precision, at 300 μg/l, was C.V.=9.2%; the run time was less than 10 min. Urinary MA excretion was measured in two spot urine samples of 131 benzene environmentally exposed subjects: midday values obtained in non-smokers (mean±S.D.=77±54 μg/l, n = 82) were statistically different from those of smokers (169±85 μg/l, n = 30) (P