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A fast method for multiclass determination of 20 pharmaceuticals in drinking water using SPE with a polymeric sorbent and UHPLC-MS/MS was developed and validated.

Statins are classified as being amongst the most prescribed agents for treating hypercholesterolaemia and preventing vascular diseases. In this study, a rapid and effective liquid chromatography method, assisted by diode array detection, was designed and validated for the simultaneous quantification of atorvastatin (ATO) and simvastatin (SIM) in hospital effluent samples. The solid phase extraction (SPE) of the analytes was optimized regarding sorbent material and pH, and the dispersive liquid-liquid microextraction (DLLME), in terms of pH, ionic strength, type and volume of extractor/dispersor solvents. The performance of both extraction procedures was evaluated in terms of linearity, quantification limits, accuracy (recovery %), precision and matrix effects for each analyte. The methods proved to be linear in the concentration range considered; the quantification limits were 0.45 µg L for ATO and 0.75 µg L for SIM; the matrix effect was almost absent in both methods and the average recoveries remained between 81.5-90.0%; and the RSD values were <20%. The validated methods were applied to the quantification of the statins in real samples of hospital effluent; the concentrations ranged from 18.8 µg L to 35.3 µg L for ATO, and from 30.3 µg L to 38.5 µg L for SIM. Since the calculated risk quotient was ≤192, the occurrence of ATO and SIM in hospital effluent poses a potential serious risk to human health and the aquatic ecosystem.

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Zucchini is one of the most cultivated and consumed vegetables in the world and often requires pesticide treatment. In this context, a simple and straightforward method for determining pesticide residues in zucchini was proposed based on an effective QuEChERS extraction approach followed by dilution of the unclean extract and analysis by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). During the development of the sample preparation step, the cleanup of the extract using dispersive solid-phase extraction with different sorbents was compared with the analysis of unclean extract. Different dilution rates of the raw extract with ultrapure water were evaluated, and a dilution of 5 times presented adequate analysis performance, minimizing the matrix effect. The established method was suitable for 99 pesticides presenting satisfactory results for trueness, with recoveries ranging from 70 to 120% and precision in terms of relative standard deviations (RSD) ≤ 20%. Practical method limit of quantification ranged from 0.005 to 0.010 mg kg− 1 for all compounds. The method was successfully applied to 20 commercial samples of zucchini, and 15 samples showed the presence of 12 different pesticides, especially the insecticide imidacloprid. The method proved to be simple and effective for routine analysis.