Trace Determination of 16 Phenolic Endocrine‐Disrupting Chemicals in Environmental Waters: A Validated SPE–UPLC–MS/MS Approach

ABSTRACT Rationale Phenolic endocrine‐disrupting chemicals (EDCs), including alkylphenols (APs) and bisphenols (BPs), pose significant environmental and public health concerns due to their widespread presence in aquatic ecosystems and potential toxicity at trace concentrations. This study developed and validated a sensitive analytical method for the simultaneous determination of 16 phenolic EDCs in environmental waters. Methods The method involves sample acidification to pH 2, hydrophilic–lipophilic balance (HLB), solid‐phase extraction (SPE), and ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) analysis with negative electrospray ionization (ESI−). Systematic optimization revealed that an alkaline mobile phase (methanol/0.1% ammonia) significantly enhanced the ionization efficiency of phenolic compounds, improving sensitivity by approximately an order of magnitude compared to acidic conditions. Chromatographic separation was optimized using an ACQUITY UPLC BEH C 18 column, which provided superior peak shapes and improved retention of hydrophobic compounds. Results Acidification of samples prior to SPE was critical for maximizing analyte recovery (57.9%–94.2%). The validated method demonstrated outstanding analytical performance, achieving low detection limits (0.01–0.4 ng/L), excellent linearity ( R = 0.991–0.999) across a broad concentration range (1.0–50.0 μg/L) and high precision (RSDs = 1.3%–13.6%). Application of the method to environmental samples collected from rivers, wastewater treatment plants, and landfill leachates identified eight target compounds, with alkylphenols detected at higher concentrations than BPs. Conclusion This reliable and robust method provides a valuable tool for monitoring trace levels of phenolic EDCs in diverse aquatic environments, supporting technically comprehensive environmental assessments and regulatory compliance.