Abstract: An analytical method was established for the determination of bisphenol A (BPA) and bisphenol S (BPS) in drinking water by solid-phase extraction and ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS). BPA and BPS from samples were enriched by an Oasis HLB SPE cartridge, eluted with methanol and concentrated with nitrogen. The analytes were separated on an C18 column with 1 mmol/L NH4F aqueous-acetonitrile as the mobile phase, and then analyzed by UPLC-MS/MS using multiple reaction monitoring (MRM) under the negative-ion mode. The limits of detection (LODs) of the method for BPA and BPS were 1.0 and 0.2 ng/L, respectively. The mean recoveries at three spiked levels of BPA ranged from 88.3% to 114.8%, with relative standard deviations (RSDs) of 10.0%–16.2%. The recoveries of BPS were 83.7%–98.2%, with RSDs of 5.9%–12.3%. The method was proved to be sensitive, accurate and efficient, and it was suitable for qualitative and quantitative analysis of BPA and BPS in drinking water.

Key words: bisphenol A, bisphenol S, ultra performance liquid chromatography-tandem mass spectrometry, drinking water, solid-phase extraction