Green analytical toxicology method for determination of synthetic cathinones in oral fluid samples by microextraction by packed sorbent and liquid chromatography-tandem mass spectrometry

Author(s)

da Cunha, Kelly Francisco ; Oliveira, Karina Diniz ; Costa, Jose Luiz

• Document type: Journal article
• Source: Forensic Toxicology; v. N/A, p. 13-pg., 2023-07-28.

Abstract

PurposeWe developed and validated a method for quantitative analysis of ten synthetic cathinones in oral fluid (OF) samples, using microextraction by packed sorbent (MEPS) for sample preparation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).MethodOF samples were collected with a Quantisal & TRADE; device and 200 & mu;L was extracted using a C18 MEPS cartridge installed on a semi-automated pipette and then analyzed using LC-M/SMS.ResultsLinearity was achieved between 0.1 and 25 ng/mL, with a limit of detection (LOD) of 0.05 ng/mL and a limit of quantification (LOQ) of 0.1 ng/mL. Imprecision (% relative standard deviation) and bias (%) were better than 11.6% and 7.5%, respectively. The method had good specificity and selectivity against 9 different blank OF samples (from different donors) and 68 pharmaceutical and drugs of abuse with concentrations varying between 400 and 10,000 ng/mL. No evidence of carryover was observed. The analytes were stable after three freeze/thaw cycles and when kept in the autosampler (10 & DEG;C) for up to 24 h. The method was successfully applied to quantify 41 authentic positive samples. Methylone (mean 0.6 ng/mL, median 0.2 ng/mL), N-ethylpentylone (mean 16.7 ng/mL, median 0.35 ng/mL), eutylone (mean 39.1 ng/mL, median 3.6 ng/mL), mephedrone (mean 0.5 ng/mL, median 0.5 ng/mL), and 4-chloroethcathinone (8.1 ng/mL) were quantified in these samples.ConclusionMEPS was an efficient technique for Green Analytical Toxicology purposes, which required only 650 & mu;L organic solvent and 200 & mu;L sodium hydroxide, and the BIN cartridge had a lifespan of 100 sample extractions. (AU)

• FAPESP's process: 17/02147-0 - Single drop chromatography and its coupling to mass spectrometry: instrumental strategies, development of materials, automation and analytical applications
• Grantee: Fernando Mauro Lanças
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/10809-5 - Microextraction techniques in forensic toxicology
• Grantee: José Luiz da Costa
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/11849-0 - The toxicology of New Psychoactive Substances (NSP): epidemiology of consumption by oral fluid samples and characterization of their in vitro metabolism
• Grantee: Kelly Francisco da Cunha
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/00432-1 - The Toxicology of New Psychoactive Substances (NSP): epidemiology of consumption by the analysis of hair and oral fluid samples
• Grantee: José Luiz da Costa
• Support Opportunities: Regular Research Grants