Reliable quantification of bisphenol A and its chlorinated derivatives in human urine using UPLC–MS/MS method

Bisphenol A (BPA), a widespread man-made chemical classified as an endocrine disruptor, is increasingly considered as a major cause of concern for human health. Chlorine present in drinking water may react with BPA to form chlorinated derivatives (ClxBPA), which have demonstrated a heightened level of estrogenic activity. If many epidemiological studies report that more than 90% of people have detectable BPA levels in their urine, then no such study has been undertaken regarding ClxBPA. The purpose of this work is to propose a highly sensitive and accurate analytical method adapted to large-scale biomonitoring studies aimed at assessing exposure to BPA and ClxBPA through the use of human urine. To achieve this, we have comprehensively validated a method using salting-out assisted liquid/liquid extraction (SALLE) coupled to UPLC–MS/MS and isotope dilution quantification, to measure unconjugated BPA and ClxBPA in human urine according to the accepted guidelines. Deutered BPA as well as deutered 2,2′-DCBPA was used as internal standards. The matrix calibration curve ranged from 0.05 to 1.60ngmL−1 and from 0.5 to 16.0ngmL−1 for ClxBPA and BPA respectively, and provided good linearity (r²>0.99). This method was precise (the intra- and inter-day coefficients of variation were