144 Development of a New Hs-Gc-Ms Method for Concurrent Analysis of Acetone, Methylethylketone, Methylisobutylketone and Cyclohexanone in Urine

Abstract

Abstract Mixed exposure to chemical products is a topical issue for occupational health. Because very few methods are available for evaluating these mixed exposures, the aim of this work was to develop a simple biomonitoring method for assessing simultaneous occupational exposures to four ketones: acetone, methylethylketone (MEK), methylisobutylketone (MIBK) and cyclohexanone in urine. These ketones were selected for their industrial use and their adverse effects on the workers’ health. Some sectors of activity, like the plastic industry for instance, may even expose workers simultaneously to several of these ketones. Volatile organic compounds were analyzed using static headspace gas chromatography coupled to mass spectrometry (sHS-GC-MS), and the four unmetabolized ketones were measured in the headspace phase, after an in-vial pentafluorobenzylhydroxylamine (PFBHA) derivatization step. The calibration was performed using synthetic urines spiked with known amounts of the four ketones. A satisfactory level of sensitivity, whose limits of quantification (LOQ) were between 5 and 20 µg/L was achieved. Calibration curves were linear in the 5-2000 µg/L range, with R2 correlation coefficients from 0.9967 to 0.9990. At 20 µg/L, within-day precision varied from 1.7 to 5.6 % and between-day precision ranged from 4.5 to 9.5 %. Tests on real urinary samples obtained from unexposed persons showed concentrations coherent with those of the general population for acetone and MEK. In conclusion, a fast, sensitive, specific and easy-to-use method was developed for extracting and quantifying simultaneously four ketones from urinary samples using sHS-GC-MS. This method will be a valuable tool for the monitoring of occupational exposures.