Analysis of Stimulants in Sweat and Urine Using Disposable Pipette Extraction and Gas Chromatography Coupled to Mass Spectrometry in the Context of Doping Control.

Urine is initially collected from athletes to screen for the presence of illicit drugs. Sweat is an alternative sample matrix that provides advantages over urine including reduced opportunity for sample adulteration, longer detection-time window and non-invasive collection. Sweat is suitable for analysis of the parent drug and metabolites. In this study, a method was developed and validated to determine the presence of 13 amphetamine- and cocaine-related substances and their metabolites in sweat and urine using disposable pipette extraction (DPX) by gas chromatography coupled to mass spectrometry. The DPX extraction was performed using 0.1 M HCl and dichloromethane:isopropanol:ammonium hydroxide (78:20:2, v/v/v) followed by derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide at 90°C for 20 min. DPX extraction efficiencies ranged between 65.0% and 96.0% in urine and 68.0% and 101.0% in sweat. Method accuracy was from 90.0% to 104.0% in urine and from 89.0% to 105.0% in sweat. Intra-assay precision in urine and in sweat were <15.6% and <17.8%, respectively, and inter-assay precision ranged from 4.70% to 15.3% in urine and from 4.05% to 15.4% in sweat. Calibration curves presented a correlation coefficient -0.99 for all analytes in both matrices. The validated method was applied to urine and sweat samples collected from 40 professional athletes who knowingly took one or more of the target illicit drugs. Thirteen of 40 athletes were positive for at least one drug. All the drugs detected in the urine were also detected in sweat samples indicating that sweat is a viable matrix for screening or confirmatory drug testing.

Investigation of Ayahuasca ß-Carboline Alkaloids and Tryptamine in Sweat Samples from Religious Community Participants by GC-MS.

Ayahuasca, a hallucinogenic beverage used in religious rituals in South America, has become a global phenomenon. Its main active components are the ß-carbolines alkaloids, harmine (HRM) and harmaline (HRL), as well as the potent hallucinogen N,N-dimethyltryptamine (DMT). Despite its rising consumption, information regarding possible clinical applications and toxicological effects of ayahuasca is still limited. This study presents the first investigation of the use of sweat for the determination of DMT, HRM and HRL in ayahuasca users during a religious ritual. Sweat is an alternative matrix with advantages over many conventional biological samples, mainly because the collection procedure is non-invasive, easy and simple and samples can be collected without disturbing the religious ritual. In the study, solid-phase extraction was performed under basic conditions. Linearity was observed ranging from 20 to 1500 ng/patch with coefficients of determination (R2) higher than 0.99 for all analytes. The results indicated high selectivity for all investigated analytes, with extraction efficiency exceeding 70%, accuracy ranging from 87.5 to 102.4%, intra-assay precision of 1.85-9.44% and inter-assay precision between 3.34 and 9.85%. The limits of detection were 15 ng/patch for HRM and HRL and 10 ng/patch for DMT. The sweat proved to be a viable option to monitor ayahuasca use.

A Gas Chromatography-Mass Spectrometry Method for Toxicological Analysis of MDA, MDEA and MDMA in Vitreous Humor Samples from Victims of Car Accidents.

Vitreous humor (VH) shows excellent potential as a matrix of choice for postmortem analytical toxicology due to the ease of sampling and low metabolic activity. This study demonstrates a simple and rapid analytical method to identify and quantify 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxy-ethylamphetamine in VH. Samples were collected with a simple eye puncture procedure, followed by liquid-liquid extraction and derivatization with heptafluorobutyric anhydride and analysis via gas chromatography-mass spectrometry. The accuracy of the method ranged 97-103%, intra-assay precision was between 4.54 and 9.14% relative standard deviation (RSD) and interassay precision ranged from 6.92 to 10.59% RSD. Limits of detection and quantification ranged from 1.0 to 2.5 ng/mL and 10 ng/mL, respectively. The validated method was successfully applied to detect methylenedioxyamphetamine derivatives in VH samples collected from victims of fatal car crashes.

Understanding alterations on blood and biochemical parameters in athletes that use dietary supplements, steroids and illicit drugs.

In recent years it was verified there are an alarming growing number of teenagers and young adults using a combination of dietary supplements (DS) anabolic androgenic steroids (AAS) and drugs of abuse. This practice is used to improve physical fitness and appearance, may cause serious side effects. This article shows the alterations in the hematological and renal function parameters associate with these substances in 40 athletes. This research involved three steps: 1-the administration of a self-completion questionnaire ; 2-the assessment of hematological and biochemical parameters of renal function and; 3-toxicological urinalysis. Hematological and biochemical tests were conducted in an accredited laboratory and the toxicological urinalysis was validated in our laboratory using liquid-liquid extraction (LLE) and gas chromatography-mass spectrometry (GC-MS). The testosterone levels in the participants who consumed steroids increased 20-60% and alterations in serum creatinine, urea and uric reached values of up to 1.9; 60.6 and 7.5mg/dL, respectively. The toxicological urinalysis supports self-reports confirming the use of AAS and recreational drugs, putting at risk the health of those athletes increasing the chances of kidney diseases.