Determination of urinary styrene metabolites in the general Italian population by liquid chromatography-tandem mass spectrometry.

Abstract

To apply mass spectrometry-based techniques for the determination of background levels of metabolites of widespread organic solvents, such as styrene, in unexposed subjects from the general population. The study population consisted of 129 healthy Italian subjects, not occupationally exposed to styrene (67 men; 37% smokers). Urinary levels of mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using LC-MS/MS, we were able to detect the peaks of MA and PGA in 100% of samples. The distribution of styrene metabolites was log-normal, the geometric means of MA and PGA concentrations being 0.443 mg/g creatinine [geometric standard deviation (GSD) 2.34] and 0.107 mg/g creatinine (GSD 3.49), respectively. The reference intervals estimated for MA and PGA were 0.084-2.339 and 0.009-1.238 mg/g creatinine, respectively. The application of highly sensitive and selective mass spectrometry-based analytical techniques could be useful in the definition of reference values for metabolites of organic pollutants and for better assessment of low-level occupational exposure to organic solvents.