Analysis of drugs of abuse and contaminants in individuals under drug surveillance programs: A study in hair samples.

Analysis of over 900 hair samples from drug users in São Paulo and Rio Grande do Sul, Brazil, found that 29.8% tested positive for at least one drug. Cocaine and its metabolites were most common, with benzoylecgonine in 111 cases, cocaine in 88, and cocaethylene in 37. Cannabinoids were also frequent, including THC in 57 cases and CBN in 48. Adulterants like phenacetin (76 cases), levamisole (14), and strychnine (3) were detected, along with the synthetic cannabinoid 5F-MDMB-PINACA (5 cases) and ketamine (9). Poly-drug use was prevalent, often combining THC with cocaine or benzoylecgonine. The findings illustrate the evolving drug landscape in Brazil and the utility of hair analysis for monitoring drug use.

Study at a glance

Abstract

In this study, over 900 hair samples from individuals using drugs of abuse in São Paulo and Rio Grande do Sul, Brazil were analysed for classical drugs and new psychoactive substances (NPS) in hair samples. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed for the detection of some drugs (25B-NBOMe, 25C-NBOMe, 25E-NBOH, 2C-C, 2C-I, 3,4-MDPHP, 3-MeO-PCP, 5F-MDMB-PINACA, 5-MeO-DMT, cannabidiol, ethylone, JWH 073, ketamine, mephedrone and UR-144) and drug adulterants (levamisole, phenacetin, strychnine); other substances including cocaine, amphetamines, benzodiazepines, opioids, cannabinoids were also analysed. The methods demonstrated good selectivity, linearity with lower limits of quantification ranging from 0.02 to 0.26 ng/mg, as well as precision and accuracy meeting ISO/IEC 17025 criteria. A total of 29.8 % samples were positive for at least one drug. Cocaine and its metabolites were the most frequently detected, with benzoylecgonine (111 cases), cocaine (88 cases), and cocaethylene (37 cases), highlighting prevalent cocaine use. Cannabinoids were also common, with THC (57 cases) and CBN (48 cases) detected. The presence of adulterants such as phenacetin (76 cases), levamisole (14 cases), and strychnine (3 cases) were also identified. Additionally, 5F-MDMB-PINACA was also detected (5 cases), along with ketamine (9 cases). Findings also highlighted a prevalence of poly-drug consumption, where THC was frequently detected with cocaine (20 cases) and benzoylecgonine (26 cases). CBN also showed notable associations with cocaine (16 cases) and benzoylecgonine (22 cases). These findings provide important insights into the evolving drug landscape in Brazil and highlight the effectiveness of hair analysis as a tool for monitoring drug use.