The occurrence and exposure risk assessment of psychoactive drug residues and metabolites in aquatic environment

D P Masemola; E N Nxumalo; H Nyoni; Tti Nkambule; B B Mamba; T A M Msagati

doi:10.1016/j.jpba.2019.112944

The occurrence and exposure risk assessment of psychoactive drug residues and metabolites in aquatic environment

J Pharm Biomed Anal. 2020 Jan 30:178:112944. doi: 10.1016/j.jpba.2019.112944. Epub 2019 Oct 31.

Authors

D P Masemola¹, E N Nxumalo¹, H Nyoni¹, Tti Nkambule¹, B B Mamba¹, T A M Msagati²

Affiliations

¹ Nanotechnology and Water Sustainability (NanoWS) Research Unit, University of South Africa, College of Science and Engineering and Technology (CSET), UNISA Science Campus, 1710 Roodepoort, Johannesburg, South Africa.
² Nanotechnology and Water Sustainability (NanoWS) Research Unit, University of South Africa, College of Science and Engineering and Technology (CSET), UNISA Science Campus, 1710 Roodepoort, Johannesburg, South Africa. Electronic address: msagatam@unisa.ac.za.

PMID: 31708266
DOI: 10.1016/j.jpba.2019.112944

Abstract

Increased use of psychoactive drugs and their continuous release into the aquatic environment threatens the aquatic life, human and animal's life. As such this study was aimed at investigating the occurrence and the associated exposure human health risks of psychoactive drugs residues. The psychoactive drugs investigated include amphetamine, methylphenidate, heroin, cocaine and metabolites included are mainly morphine, 6-acetylmorphine and benzoylecgonine. Method for analyzing these drugs was optimized and validated using ultra-high-performance liquid chromatography coupled to quadrupole-time of flight mass spectrometer (UHPLC-QTOF-MS) after solid phase extraction (SPE) sample pretreatment. Analytes of interest were separated through Acquity UHPLC BEH C₁₈ column at 20 °C. The recovery percentages for the target analytes ranged from 82 % (amphetamine) to 121 % (heroin). The accuracy assessed through bias calculation ranged from 80 % (amphetamine) - 123 % (amphetamine) and the precision reported as a percentage of error in relation to the theoretical concentration values was between 0.03 % (6-acetylmorphine) and 1.93 % (morphine). The limit of detection (LOD) and limit of quantification (LOQ) varied from 0.03 μg/L (amphetamine) - 0.11 μg/L (morphine) and 0.09 μg/L (amphetamine) - 0.36 μg/L (morphine) respectively. Further to this, this study evaluated the associated potential toxicities of these compounds. The toxicological effects were evaluated using the margin of exposure (MOE) risk assessment approaches. The MOE of all psychoactive drugs in wastewater (influent and effluent) was above 1000, suggesting lesser adverse effects and toxicity on human. However, MOE of less than 1000 (755.86 and 994.04) were observed for heroin in Florida lake and Florida stream, suggesting that heroin possess a significant health risk to human through possible drinking of such contaminated water.

Keywords: Margin of exposure; Minimum therapeutic dose; Psychoactive drugs; Toxicity; UHPLC-ESI-QTOF-MS.

MeSH terms

Chromatography, High Pressure Liquid / methods
Humans
Limit of Detection
Psychotropic Drugs / adverse effects*
Psychotropic Drugs / metabolism*
Risk Assessment
Solid Phase Extraction / methods
Wastewater / analysis*
Water / analysis*
Water / chemistry*

Substances

Psychotropic Drugs
Waste Water
Water