Analysis of ecologically relevant pharmaceuticals in wastewater and surface water using selective solid-phase extraction and UPLC-MS/MS

A rapid and sensitive method has been developed for the analysis of 48 human prescription active pharmaceutical ingredients (AFIs) and 6 metabolites of interest, utilizing selective solid-phase extraction (SPE) and ultraperformance liquid chromatography in combination with triple quadrupole mass spectrometry (UPLC-MS/MS). The single-cartridge extraction step was developed using a mixed mode reversed-phase/cation-exchange cartridge (Oasis MCX) and validated in both wastewater effluent and surface water. Recoveries for the majority of compounds ranged from 80% to 125%, with relative standard deviations generally below 15%. Analytes were quantified using a multiple injection analysis with four chromatographic runs, with a combined run time of 48 min and SPE-UPLC-MS/MS method detection limits ranging from 1.0 to 51 ng/L. The analysis of seven wastewater effluents and one surface water sample revealed at least one detection for 38 of the 54 compounds, with effluent concentrations ranging from 7 to 2950 ng/L and surface water concentrations ranging from 10 to 140 ng/L. This initial data demonstrates that a significant number of the selected target analytes are present in wastewater treatment plant discharges.