A multiclass method for endocrine disrupting chemical residue analysis in human placental tissue samples by UHPLC-MS/MS

The group of compounds commonly called endocrine-disrupting chemicals covers a wide range of synthetic and natural substances able to alter the normal hormone function of wildlife and humans, consequently causing adverse health effects. Bisphenol A (BPA) and its chlorinated derivatives, benzophenones (BPs) and parabens (PBs), belong to this group of compounds. In this work, we propose a multiclass ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine BPA, its four chlorinated derivatives (monochloro-, dichloro-, trichloro-and tetrachloro-bisphenol A), six BPs (benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-6, benzophenone-8 and 4-hidroxybenzophenone) and four PBs (methylparaben, ethylparaben, propylparaben and butylparaben) in human placental tissue samples. The method involves an extraction step of the analytes from the samples using ethyl acetate, followed by a clean-up step by centrifugation prior to their quantification by UHPLC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface in the negative mode. Deuterated bisphenol A (BPA-d(16)) was used as surrogate. The limits of detection (LOD) found ranged from 0.03 to 0.6 ng g(-1), the limits of quantification (LOQ) from 0.1 to 1.4 ng g(-1), while inter- and intra-day variability was under 8%. The method was validated using matrix-matched calibration standard and a spike recovery assay. Recovery rates for spiked samples ranged from 95% to 106%. This method was satisfactorily applied to the determination of these compounds in 50 placental tissue samples collected from women who live in the province of Granada (Spain).