Premium
Profiling cocaine residues and pyrolytic products in wastewater by mixed‐mode liquid chromatography–tandem mass spectrometry
Author(s) -
GonzálezMariño Iria,
EstévezDanta Andrea,
Rodil Rosario,
Da Silva Katyeny Manuela,
Sodré Fernando Fabriz,
Cela Rafael,
Quintana José Benito
Publication year - 2019
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.2590
Subject(s) - benzoylecgonine , chromatography , chemistry , liquid chromatography–mass spectrometry , wastewater , mass spectrometry , detection limit , tandem mass spectrometry , metabolite , solid phase extraction , waste management , biochemistry , engineering
This work provides a new analytical method for the determination of cocaine, its metabolites benzoylecgonine and cocaethylene, the pyrolytic products anhydroecgonine and anhydroecgonine methyl ester, and the pharmaceutical levamisole in wastewater. Samples were solid‐phase extracted and extracts analyzed by liquid chromatography–tandem mass spectrometry using, for the first time in the illicit drug field, a stationary phase that combines reversed‐phase and weak cation‐exchange functionalities. The overall method performance was satisfactory, with limits of detection below 1 ng/L, relative standard deviations below 21%, and percentages of recovery between 93% and 121%. Analysis of 24‐hour composite raw wastewater samples collected in Santiago de Compostela (Spain) and Brasilia (Brazil) highlighted benzoylecgonine as the compound showing the highest population‐normalized mass loads (300–1000 mg/day/1000 inhabitants). In Brasilia, cocaine and levamisole loads underwent an upsurge on Sunday, indicating a high consumption, and likely a direct disposal, of cocaine powder on this day. Conversely, the pyrolytic product resulting from the smoke of crack, anhydroecgonine methyl ester, and its metabolite anhydroecgonine were relatively stable over the four days, agreeing with a non‐recreational‐associated use of crack.