Development of Simultaneous Determination Method of Phthalate Monoester Metabolites in Urine by LC/MS/MS and Its Application to Assessment of Phthalate-Ester Exposure

Abstract

Phthalate esters (PEs) are widely used as industrial plasticizers in the production of polyvinyl chloride and other plastics. Recent studies on human exposure are required to develop an analytical method for measuring monoester metabolites of PEs in human urine samples. In the present study, we developed an accurate and selective analytical method for the simultaneous determination of phthalate monoester metabolites, such as mono-buthyl phthalate (MBP) and mono-2-ethylhexyl phthalate (MEHP), in urine by using LC/MS/MS accompanied by solid-phase extraction. The developed method was applied to occupational exposure to urine in order to assess human exposure due to environmental circumstance. The average value of each MBP and MEHP for working exposure subjects was significantly higher than that of normal subjects. Furthermore, a good correlation was observed between MBP and MEHP in all of the urine samples.