A reliable UHPLC-MS/MS method for the determination of legacy and emerging bisphenol analogues in human urine

An efficient technique for quantitative analysis of BPA, BPF, BPS, and 11 emerging bisphenol analogues in human urine has been developed, which combined solid phase extraction (SPE) with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Stable isotope internal standards were added to 1.0 mL of urine, which was hydrolyzed by β-glucuronidase overnight, and the target analytes were enriched and purified using an HLB 96-well plate, concentrated to dryness by nitrogen blowdown and reconstituted in 0.5 mL of 20 % aqueous methanol solution. Separation of the 14 analytes was achieved using Acquity BEH C₁₈ (100 mm × 2.1 mm, 1.7 μm) as the analytical column and gradient elution with water and methanol as the mobile phase. Qualitative and quantitative analyses were performed in multiple reaction monitoring (MRM) mode with parallel positive and negative ion detection. Fourteen analytes showed good linearity in the concentration range of 0.1-50 ng/mL with correlation coefficients (r) greater than 0.999. The method detection limits (MDLs) range from 0.01 to 0.07 ng/mL and the method quantification limits (MQLs) were between 0.02 and 0.23 ng/mL. Recoveries across three spike levels were within the range of 72 % to 127 %. Intra-day precision and inter-day precision were below 12.7 % and 15.1 %, respectively. The proposed method successfully determined bisphenol analogues in 187 urine samples from young people in Beijing, revealing high prevalence rates for BPA (98.9 %) and BPS (80.2 %), with median concentrations of 6.44 μg/L and 0.17 μg/L, respectively. No significant differences in BPA and BPS levels were observed between genders, suggesting similar exposure patterns in males and females. Notably, the detection rate of the new alternative DBSP reached 32.6 %, indicating its significant exposure in the population. This study highlights the ongoing public health concerns regarding exposure to bisphenol analogues, encompassing both traditional compounds (such as BPA and BPS) and emerging alternatives.