Use of liquid chromatography-tandem mass spectrometry to determine reference values for metabolites of solvents in biological samples: Mandelic acid and phenylglyoxylic acid [Impiego della cromatografia liquida accoppiata alla spettrometria di massa per la definizione di valori di riferimento di metaboliti di solventi in campioni biologici: Acido mandelico e acido fenilgliossilico]

Urinary levels of mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined by liquid chromatography-tandem mass spectrometry in samples from 129 healthy Italian subjects, not occupationally exposed to styrene (67 men, 37% smokers). The distribution of styrene metabolites was log-normal. The geometric means (and geometric standard deviations) of MA and PGA concentrations were 0.443 mg/g creatinine (GSD, 2.34) and 0.107 (GSD 3.49) mg/g creatinine, respectively. The reference intervals estimated for MA and PGA were 0.084-2.339 and 0.009-1.238 mg/g creatinine, respectively.