Target quantification and ion mobility-HRMS suspect screening of BPA and its alternatives in human urine

Bisphenol A (BPA) and its structural alternatives are contaminants of concern due to their endocrine-disrupting properties and widespread human exposure. The progressive replacement of BPA by alternative bisphenols has increased the need for sensitive analytical methods capable of monitoring both regulated and emerging analogues in biological matrices. In this study, a fast analytical approach based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and ion mobility-high-resolution mass spectrometry (IM-HRMS) was developed for the determination and suspect screening identification of bisphenols in human urine. Following enzymatic deconjugation and solid-phase extraction, BPA and eight priority bisphenols were quantified by UHPLC-MS/MS. Method validation demonstrated excellent linearity (r² = 0.9976-0.9999), limits of quantification of 0.1 ng/mL, relative recoveries between 89.1 and 135.0%, and intermediate precision generally below 10.0%. Application of the method to urine samples from 25 healthy volunteers revealed widespread exposure to BPA, bisphenol S (BPS), and bisphenol F (BPF). To extend chemical coverage, the same extracts were analyzed by IM-HRMS-based suspect screening, leading to the identification of additional bisphenols, including bisphenol G (BPG) and bisphenol M (BPM). The integration of IM provided collision cross section (CCS) values and enabled the discrimination of structurally related and isobaric compounds, improving annotation confidence. Furthermore, new experimental CCS reference values were established for bisphenol E (BPE), BPG, and BPM, expanding the currently available database for bisphenol characterization. The proposed approach provides a comprehensive strategy for monitoring human exposure to both of known and emerging bisphenols and supports future biomonitoring and risk assessment studies.