Determination of 15 phthalates metabolites and 9 bisphenols in human serum by using high-performance liquid chromatography coupled with tandem mass spectrometry.

Endocrine disrupting chemicals (EDCs) are a class of emerging contaminants that have raised significant public health concerns. Human co-exposure to mixtures of specific EDCs, such as phthalate and bisphenols, and the associated health risks remain poorly understood. To support biomonitoring and epidemiological studies on these compounds, there is a critical need for sensitive and reliable methods for their quantification in human specimens. Herein, we developed and validated an analytical method based on ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of 15 phthalate metabolites and 9 bisphenols in human serum. A systematic comparison between liquid-liquid extraction (LLE) and high-efficiency matrix removal (HMR) clean-up approach revealed that HMR offered advantages in terms of extraction efficiency and matrix effect reduction, and was ultimately selected as the final clean-up method for this study. The developed method demonstrated satisfactory performance, with recoveries ranging from 81 % to 115 %, with the relative standard deviations (RSD) below 18 %. The calibration curves established using isotope-labeled internal standards exhibited good linearity, with correlation coefficients (R2) consistently above 0.997. The limits of detection (LODs) and limits of quantification (LOQs) were determined to be in the range of 0.01 ng/mL to 0.2 ng/mL and 0.04 ng/mL to 0.7 ng/mL, respectively. Both intra-day and inter-day precision were satisfactory, with RSDs values ranging from 4.2 % to 13 % and 6.9 % to 14 %, respectively. This sensitive analytical method was successfully applied to the determination of target analytes in human serum samples from 15 pregnant women, demonstrating its applicability for monitoring of these emerging contaminants in human serum.