Development of analytical method for the determination of methylphenidate, the analog ethylphenidate and their metabolite ritalinic acid in oral fluid samples by micro-QuEChERS and liquid chromatography-tandem mass spectrometry.

The aim of this study was to develop a quantitative method for the analysis of methylphenidate, the analog ethylphenidate and their metabolite ritalinic acid in oral fluid, using micro-QuEChERS extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Oral fluid samples were collected with Quantisal™ device, extracted by micro-QuEChERS technique and analyzed by LC-MS/MS. The developed method met the validation criteria of Academy Standards Board (ASB) Standard Practices for Method Validation in Forensic Toxicology (Standard 036, 2019) with limits of detection and quantification of 0.5 ng/mL and calibration curve from 0.5 to 50 ng/mL. Within-run imprecision was greater than 18.7% while between-run imprecision was greater than 17.0 % for all analytes. Bias did not vary more than 7.7 %. No evidence of carryover was found. Stability studies presented satisfactory results for 24 h on autosampler (10 °C), after 3 cycles of freeze/thaw, 7 days on freezer (-20 °C) and until 7 days on refrigerator (4 °C) for methylphenidate. The validated method was further successfully applied to the analysis of 5 authentic oral fluid samples collected from volunteers at parties and music festivals from different cities in Brazil. Four samples had positive results for methylphenidate and ritalinic acid, and only one sample was positive for methylphenidate. Ethylphenidate was not detected in the samples. The method showed acceptable analytical performance and is environmentally friendly, requiring reduced use of solvents and reagents, with potential to be applied to clinical and forensic analyses.

Determination of Drugs of Abuse in Hair by LC-MS-MS: Application to Suicide Attempts Investigation.

Considering that the use of psychoactive substances (PSs) is a risk factor to either higher intensity or frequency of suicidal behavior, hair analysis was conducted to investigate the most consumed PSs (opiates, amphetamine stimulants, marijuana, cocaine and heroin) in patients who attempted suicide and received urgent care at emergency service. Hair samples were extracted using methanol and sonicated under heating and then analyzed using liquid chromatography-tandem mass spectrometry. During validation, the method complied with international recommended criteria, with limits of detection between 0.0025 and 0.05 ng/mg and linearity between 0.1 and 4 ng/mg for methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), morphine, amphetamine, 6-acetylmorphine, 3,4-methylenedioxyamphetamine (MDA), fenproporex, diethylpropion and codeine; between 0.025 and 1 ng/mg for tetrahydrocannabinol (THC), benzoylecgonine and cocaethylene and between 0.25 and 10 ng/mg for cocaine and mazindol. A total of 109 hair samples were analyzed and segmented in 404 parts. Among all analyzed samples, 30.3% were positive for at least one PS (n = 33), such as cocaine (90.9%), codeine (12.1%), morphine (3.0%), MDMA (3.0%) and THC (3.0%). In segmental analysis of cocaine positive samples (n = 30), 76.7% of the samples indicated recent exposure to cocaine (<1 month). This same behavior was observed when analyzing codeine (n = 4) and morphine (n = 1). THC positive samples indicated exposure dated ∼4 months prior. In conclusion, the method was validated following international recommendations for the 12 most consumed PSs in Brazil, as well as two of the most common found metabolites.

Prevalence of new psychoactive substances (NPS) in Brazil based on oral fluid analysis of samples collected at electronic music festivals and parties.

BACKGROUND: New psychoactive substances (NPS) use is a worldwide public health issue. Knowing the prevalence of NPS guides public health and legal policies to address the problem. The objective of this study was to identify NPS in Brazil through the analysis of oral fluid (OF) samples collected at parties and electronic music festivals. METHODS: Anonymous questionnaires and oral fluid samples were collected from volunteers (≥18 years) who reported the consumption of at least one illicit psychoactive substance in the last 24 h. Oral fluid sample collections occurred at eleven parties and two electronic music festivals over 16 months (2018-2020). Questionnaire answers were matched to oral fluid toxicological results. RESULTS: Of 462 oral fluid samples, 39.2 % were positive for at least one NPS by liquid chromatography‒tandem mass spectrometry (LC-MS/MS). The most prevalent NPS was ketamine (29.4 %), followed by methylone (6.1 %) and N-ethylpentylone (4.1 %); however, MDMA was the most commonly identified (88.5 %) illicit psychoactive substance. More than one drug was identified in 79.9 % of samples, with two (34.2 %) and three (23.4 %) substances most commonly observed. Only 5 % of volunteers reported recent NPS consumption. CONCLUSION: MDMA is still the most common party and electronic music festival drug, although NPS were identified in more than one-third of oral fluid samples.