A green method for the determination of illicit drugs in wastewater and surface waters-based on a semi-automated liquid-liquid microextraction device

• Published in: Journal of Chromatography A Vol. 1710; p. 464230
• Main Authors: Nascimento, Madson Moreira, Nascimento, Melise Lemos, Pereira dos Anjos, Jeancarlo, Cunha, Ricardo Leal, da Rocha, Gisele Olimpio, Ferreira dos Santos, Ivanice, Pereira, Pedro Afonso de Paula, de Andrade, Jailson Bittencourt
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 08-11-2023
• Subjects: Drugs of abuse; Environmental waters; Gas chromatography; Microextraction; Miniaturization; Microextraction; Gas chromatography; Drugs of abuse; Miniaturization; Environmental waters
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2023.464230

•A new semi-automated customized LPME device is proposed.•A simple LPME procedure allowed the simultaneous determination of nine illicit drugs.•Cocaine was the main illicit drug found in wastewater samples.•The proposed method is a green alternative according to the AGREE metrics.
Liquid-phase microextraction (LPME) is a simple, low-cost, and eco-friendly technique that enables the detection of trace concentrations of organic contaminants in water samples. In this work, a novel customized microextraction device was developed for the LPME extraction and preconcentration of nine illicit drugs in surface water and influent and effluent wastewater samples, followed by analysis by GC–MS without derivatization. The customized device was semi-automated by coupling it with a peristaltic pump to perform the collection of the upper layer of the organic phase. The extraction parameters affecting the LPME efficiency were optimized. The optimized conditions were: 100 µL of a toluene/DCM/EtAc mixture as extractor solvent; 30min of extraction time under vortex agitation (500rpm) and a solution pH of 11.6. The limits of detection and quantification ranged from 10.5ng L−1 (ethylone) to 22.0ng L−1 (methylone), and from 34.9ng L−1 to 73.3ng L−1 for these same compounds, respectively. The enrichment factors ranged from 39.7 (MDMA) to 117 (cocaethylene) and the relative recoveries ranged from 80.4% (N-ethylpentylone) to 120% (cocaine and cocaine-d3). The method was applied to real surface water, effluent, and influent wastewater samples collected in Salvador City, Bahia, Brazil. Cocaine was the main drug detected and quantified in wastewater samples, and its concentration ranged from 312ng L−1 to 1,847ng L−1. Finally, the AGREE metrics were applied to verify the greenness of the proposed method, and an overall score of 0.56 was achieved, which was considered environmentally friendly.