Development and validation of a direct injection liquid chromatography-tandem mass spectrometry method for the analysis of illicit drugs and psychopharmaceuticals in wastewater

A direct injection liquid chromatography-tandem mass spectrometry method was successfully developed for the analysis of 19 illicit drugs and psychopharmaceuticals in raw and treated wastewater. The method includes the analysis of stimulants and opioids, and antidepressant, antipsychotic, antianxiety, appetite suppressant and hallucinogen drugs. The method limits of quantification range from 5 - 59 ng L -1 and 2 - 38 ng L -1 in raw and treated wastewater, respectively. Analysis of raw and treated wastewater sam-ples collected daily for a week from a wastewater treatment plant operating with oxidation ditch tech-nology showed that codeine and tramadol were the drugs with the highest median mass concentra-tions in raw wastewater (1800 and 1000 ng L -1, respectively). The presence of some of the drugs in treated wastewater samples implies incomplete removal of illicit drugs and psychopharmaceuticals dur-ing wastewater treatment. This method offers an alternative to existing methods for faster screening of wastewater samples without the need for sample pre-concentration techniques, such as solid-phase ex-traction, with limits of detection in the low nanogram per litre range.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

A direct injection liquid chromatography-tandem mass spectrometry method was developed for analyzing illicit drugs and psychopharmaceuticals in wastewater. The method offers a faster screening alternative without sample pre-concentration techniques, and it revealed incomplete removal of these substances during wastewater treatment.