Ultrasensitive determination of bisphenol A and its chlorinated derivatives in urine using a high-throughput UPLC-MS/MS method.

Bisphenol A (BPA) is a well-known endocrine disruptor. Chlorinated derivatives of BPA (ClxBPA) may be formed by reaction of chlorine with BPA present in drinking water. ClxBPA exhibit a higher level of estrogenic activity than BPA. While many studies have reported detectable BPA concentrations in urine, only very few studies were conducted in regards to ClxBPA. Since ClxBPA are potentially more toxic, it is important to assess large-scale exposure of the general population. Indeed, in the field of environment health, large studies are required to assess exposure to pollutants at ultratrace concentrations; therefore, analytical methods have to be rapid and sensitive. This work intends to validate a highly sensitive and rapid analytical method suitable to evaluate BPA and ClxBPA exposures during large-scale biomonitoring studies. For that purpose, a method based on online solid-phase extraction coupled with isotope dilution ultrahigh - performance liquid chromatography-tandem mass spectrometry was developed and validated according to accepted guidelines. The matrix-matched calibration curve ranged from 0.25 to 16.0 ng mL(-1) and from 0.025 to 1.60 ng mL(-1) for BPA and ClxBPA, respectively. This method was precise (the intra- and inter-day coefficients of variation of quality control were <16.4%) and accurate (bias ranged from -4.0 to 16.8%). The limit of quantification was validated at 0.25 and 0.025 ng mL(-1), for BPA and ClxBPA, respectively. The limit of detection was estimated for each experiment performed. Finally, this method is rapid and sensitive enough to be carried out during biomonitoring studies of BPA and ClxBPA in human urine.