Antipsychotic drugs in hospital wastewater and a preliminary risk assessment

The residues of pharmaceutical and personal care products are the cause of increasing concern around the world. The aim of this study was to carry out the quantification of six antipsychotic drugs in hospital wastewater with the aid of liquid chromatography-mass spectrometry and, subsequently, make a preliminary assessment of the environmental risk posed. Dispersive liquid-liquid microextraction and solid phase extraction were optimized by multivariate design and validated in compliance with international guidelines. The extraction procedures were successfully applied to the quantification of the six selected antipsychotics in samples that were formed each day and collected at two main sampling points of the sewage network over the period of a week, in December 2017. Olanzapine (0.31─0.52 µg L^-1), clozapine (0.56─0.97 µg L^-1), haloperidol (1.43─2.73 µg L^-1), risperidone (0.92─0.98 µg L^-1) and chlorpromazine (0.52 µg L^-1) were found in at least one sampling point. In the case of most analytes, the highest concentrations were determined at sampling point A, which are derived from the psychiatric wing. The environmental risk quotient for clozapine, chlorpromazine and risperidone was ˃600, a very high-risk index, which signals the need for a better control of the emission of antipsychotics and an improvement of the wastewater treatment, especially, with regard to wastewater discharged from the hospital psychiatric wing.

Determination of statin drugs in hospital effluent with dispersive liquid-liquid microextraction and quantification by liquid chromatography

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^-1 for ATO and 0.75 µg L^-1 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^-1 to 35.3 µg L^-1 for ATO, and from 30.3 µg L^-1 to 38.5 µg L^-1 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.

Occurrence of cocaine and metabolites in hospital effluent - A risk evaluation and development of a HPLC method using DLLME

A fast method for the determination of cocaine and its metabolites in hospital effluent samples was worked out by using liquid chromatography with the aid of fluorescence and diode array detection. Solid phase extraction and dispersive liquid -liquid microextraction were employed during the sample preparation stage. The experiment was conducted by using Chromabond^® C18 ec 6 ml/500 mg cartridges, with recoveries higher than 96.6%, 88.3%, 78.7%, and LOQ_m 0.15; 0.18 and 0.30 μg L^-1 for cocaine, benzoylecgonine and anhydroecgonine respectively. In the case of DLLME, different chemical conditions and solvent combinations were tested to find the best settings for the microextraction: pH 9; addition of 0.3 mol L^-1 NaCl; 150 μL extractor (chloroform) and 350 μL disperser (methanol). The recoveries for cocaine were as high as 98.3% with LOQ_m 0.3 μg L^-1. After validation, these methods were applied to quantification of the analytes. While the concentration of the anhydroecgonine, (the main pyrolytic metabolite of cocaine), remained below the limit of detection, the range of concentrations of cocaine and benzoylecgonine determined were 0.4-4.9 μg L^-1 and 0.9-8.6 μg L^-1, respectively. The occurrence has a relatively median/high environmental impact. These concentration values suggest that a role is played by other sources of cocaine, probably related to transport, or handling and the consumption of the drug. The outcome is that cocaine can be quantified by using DLLME as well as SPE, however, DLLME offered clear benefits like simplicity, affordability, and speed, as well as only requiring a small volume of solvents and samples.