Simplified solid-phase extraction procedure combined with liquid chromatography tandem-mass spectrometry for multiresidue assessment of pharmaceutical compounds in environmental liquid samples

- A Solid Phase Extraction procedure in only three steps was optimized.
- Reduction of time and solvent respect to conventional extraction was achieved.
- A multi-residue method combined SPE and LC-MS was developed.
- Eighteen pharmaceuticals were detected and determined in all samples from two WWTPs.

To follow the twelve “green analytical chemistry” (GAC) principles, it is necessary to continuously develop analytical extraction and determination methodologies to assess the presence of micropollutants, such as pharmaceuticals, in environmental samples.A reduction in the analysis time and solvent quantity, which is one of the GAC principles, has been achieved through a simplified solid-phase extraction (SPE) procedure combined with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of twenty-three pharmaceuticals in liquid environmental samples using N-vinylpyrrolidone-divinylbenzene copolymer (OASIS HLB) cartridges. The optimal SPE conditions were studied. In these optimized conditions, 82.6% of the data have a median recovery above 70% for all compounds in each sample. The relative standard deviations (RSDs) were below 14.4% and 22.0% for intra- and inter-day repeatability, respectively. Method detection limits (MDLs) and method quantification limits (MQLs) ranged from 0.011 to 188 ng L−1 and from 0.033 to 628 ng L−1, respectively. The applicability of the method was evaluated in real samples from natural and conventional wastewater treatment plants (WWTPs), and results were obtained in concentration ranges from 0.013 to 91.5 μg L−1 and from 0.004 to 49.1 μg L−1, respectively.