Determination of 50 Pharmaceuticals and Personal Care Products and Their Metabolites in Raw Water and Drinking Water by Online Solid Phase Extraction-Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

To reduce the consumption of water samples and organic reagents and simplify the pretreatment process, the method mentioned by the title was employed to determine 50 pharmaceuticals and personal care products (PPCPs) and their metabolites in raw water and drinking water. Water samples were collected, and 30 mg of ascorbic acid was added per liter of water sample. An aliquot (20 mL) was taken, and passed through a 0.22 µm polytetrafluoroethylene filter membrane. The filtrate was collected, and its acidity was adjusted to pH 2-3 with formic acid, followed by addition of 10 μL of 100 μg·L⁻¹ mixed internal standard solution. An aliquot (5 mL) was taken, and introduced into the online dual solid phase extraction system for purification and enrichment on XBridge C₁₈ online solid phase extraction column. The resulting solution was then transferred via valve switching to the ultra-high performance liquid chromatography-tandem mass spectrometry system. The 50 target compounds were separated on Waters ACQUITY UPLC BEH C₁₈ column using a gradient elution system consisting of 0.1% (volume fraction) formic acid solution and methanol. Quantification was performed in modes of positive electrospray ionization and multiple reaction monitoring using the internal standard method. It was shown that linear relationships between the mass concentrations of 50 target compounds and peak area ratios of target compounds to internal standards were kept in definite ranges, with detection limits in the range of 0.01-1.00 ng·L⁻¹. Test for recovery was made by the standard addition method, giving recoveries in the range of 61.9%-133%, and RSDs (n=6) of the determined values did not exceed 25%. The proposed method was applied to the analysis of 46 water samples, sulfachloropyridazine, sulfamethazine, sulfapyridine, sulfamethoxazole, 1,7-dimethylxanthine, paracetamol, and carbamazepine were detected at detection amounts in the range of 1.99-66.20 ng·L⁻¹.