Determination of 15 Biomarkers of Endocrine Disrupting Chemicals in Human Saliva by Gas Chromatography–Mass Spectrometry
Thi Hoang Van Vu, Hyun‐Hee Lim, Ho‐Sang Shin
Abstract
A sensitive method was developed to simultaneously determine 15 biomarkers of endocrine disrupting chemicals (EDCs) in human saliva using dispersive liquid–liquid microextraction (DLLME) and gas chromatography–mass spectrometry. This study also confirmed that the phthalate diesters were converted by glucuronidase/aryl sulfatase to their respective primary metabolites –mono‐esters, but not to the secondary metabolites. The amount of 100 μL β‐glucuronidase/aryl sulfatase hydrolyzed about 95% of the phthalate diesters (500 μg/L) within 3 h. The problems of hydrolysis of phthalate diesters by β‐glucuronidase/aryl sulfatase are discussed. Ethyl acetate and acetonitrile were selected as extraction and disperser solvents in DLLME, and then the extracts were subjected to derivatization with N ‐methyl‐N‐(tert‐bultyl dimethyl silyl) trifluoroacetamide directly without concentration after extraction. After optimizing the required conditions, good linearity of analytes was achieved. The limit of detection (LOD) and the limit of quantification (LOQ) were in the ranges of 0.015–3.0 μg/L and 0.05–10 μg/L, respectively.