Trace analysis of 47 psychotropic medications in environmental samples by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)

Psychotropic medications are one of the most prescribed pharmaceuticals in the world. Given their frequent detection and ecotoxicity to the no-target organism, the emission of these medications into environments has gradually draw attention. The study developed a sensitive and reliable analytic method to simultaneously investigate 47 psychotropic medications in four matrices: wastewater, surface water, activated sludge, and sediment by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). These 47 target analytes include 24 antidepressants, 17 antianxiety drugs, 5 anticonvulsants, and 1 relevant hormone. Solid phase extraction (SPE) was employed to extract analytes from water-phase samples. Ultrasonic Solvent Extraction method with Enhanced Matrix Removal clean-up (USE-EMR) was utilized to extract target compounds from solid-phase samples, which requires more straightforward and convenient procedures than previous methods. The extraction recoveries of all analytes ranged from 80 % to 120 % in these four sample matrices. In this study, The limit of quantitation for 47 psychotropic medications were 0.15 ng/L (estazolam) to 2.27 ng/L (lorazepam), 0.08 ng/L (desvenlafaxine) to 2 ng/L (mianserin), 0.22 ng/g (dry weight, dw) (nordiazepam) to 3.65 ng/g (dw) (lorazepam), and 0.07 ng/g (dw) (carbamazepine) to 2.85 ng/g (lorazepam), in wastewater, surface water, sludge, and sediment, respectively. In addition, the developed method was employed to analyse actual samples in two wastewater treatment plants and their receiving rivers. Carbamazepine, escitalopram, clozapine, desvenlafaxine, diazepam, lamotrigine, sertraline, temazepam, and venlafaxine were nearly ubiquitous in all matrices. Moreover, this study indicated that the inadequate removal efficiencies of psychotropic medications in wastewater treatment plants (WWTPs) had resulted in a persistent discharge of these contaminants from human sources into environments.