Propylene glycol monomethyl ether (PGME) occupational exposure - 1. Biomonitoring by analysis of PGME in urine

An analytical method was developed for the determination of free and conjug ated PGME-alpha in urine. The method involves a solid-phase extraction on L C-18 columns and a GC/FID analysis after derivatization with trimethysilyli midazole. The assay was linear (least-squares regression coefficient 0.996) , specific, reproducible (intraassay variability 10%, interassay variabilit y 10%), and allowed a high level of PGME recovery (more than 90%). The assa y was applied to the analysis of urine samples from three workers who were occupationally exposed to PGME to estimate their exposure. The highest valu e of PGME concentration in urine was 7.78 mg/l. Air concentrations of PGME ranged between 20 and 40 ppm. A statistically significant correlation was f ound between measurements of external exposure and PGME in urine. An import ant fraction of PGME in urine was found to be conjugated.