Determination of bisphenol-A levels in human amniotic fluid samples by liquid chromatography coupled with mass spectrometry

Bisphenol A (BPA) is one of the environmental endocrine-disrupting chemicals used widely in common consumer products. There is an increasing concern about human exposure to BPA, particularly in fetuses, due to the potential adverse effects related to the estrogenic activity of BPA. In assessing environmental exposure to BPA, it is essential to have a sensitive, accurate, and specific analytical method, particularly for low BPA levels in complex sample matrices. In this study, we developed and validated an accurate, sensitive, and robust liquid chromatography-mass spectrometry (LC-MS) method for determining the BPA concentrations in human amniotic fluid (AF). In this method, BPA and the internal standards C-13(12)-BPA were extracted from 500 mu L of human AF using solid-phase extraction. Calibration curves were linear over a concentration range of 0.3-100 ng/mL for BPA. The analytes were quantitatively determined using LC-MS operated in a negative electrospray ionization selected ion monitoring mode. This validated method has been used successfully in the clinical sample analysis of BPA in second-trimester AF specimens.