Development and validation of a multi-class solid-phase extraction and liquid chromatography tandem mass spectrometry method for emerging contaminants in water.

A robust and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous quantification of 39 multi-class emerging contaminants (ECs), encompassing diverse groups including industrial chemicals (n = 6), pharmaceuticals (n = 19), personal care products (n = 4), and pesticides (n = 10). LC-MS/MS parameters were systematically optimized, including compound-specific transitions, source conditions, mobile phase composition, injection volumes, and chromatographic flow rates, to maximize signal intensity and ensure reproducible detection. Solid-phase extraction (SPE) was further optimized through evaluation of reconstitution solvent composition, evaporation settings, washing solvents, and elution strategies to improve recoveries and minimize matrix effects. The final method achieved instrument detection limits as low as 0.01 fg on-column, with method detection and quantitation limits of 0.01-1.32 ng/L and 0.03-3.96 ng/L, respectively. Calibration linearity (R² >0.99), recoveries within 70-130%, and intra-/inter-day precision (RSD ≤20%) confirmed the robustness and reproducibility of the protocol. Application to six real water matrices, bottled water, tap water, surface water, seawater, wastewater effluent, and influent, revealed the highest concentrations and widest range of analytes in influent, lower but quantifiable levels of persistent compounds in effluent, and predominantly trace-level detections or non-detects in natural and potable waters. Complementary greenness and applicability assessments using AGREE, MoGAPI, and BAGI highlighted moderate environmental sustainability and strong practical utility, reinforcing the suitability of the method for routine monitoring, source tracking, regulatory compliance, and risk assessment applications requiring ultra-trace sensitivity, high selectivity, and broad chemical coverage.