A microassay for urinary phenol using capillary gas chromatography and optimised enzymic hydrolysis.

An improved capillary gas chromatography method is described for the assay of urinary phenol for the assessment of benzene exposure. Enzymatic hydrolysis with an extract of Helix pomatia is used to liberate phenol from its glucuronide and sulphate conjugates in urine and has the advantage in that complete hydrolysis occurs and clean chromatograms are produced. Furthermore, an internal standard (2,4-xylenol) has been incorporated in the method enabling rapid and single step extraction of phenol. The microassay can be used to measure phenol concentrations as low as 1 mg/l in urine thus making it a suitable method for monitoring benzene exposure.