220 research outputs found
Fast quantification of THCA using microwave-accelerated derivatization and GC-MS/MS analysis
A rapid and sensitive determination of cannabinoids in urine is important in many fields, from workplace drug testing over toxicology to the fight against doping. The detection of cannabis abuse is normally based on the quantification of the most important metabolite 11-nor-∆9-tetrahydrocannabinol-9-carbolxylic acid (THCA) in urine. In most fields THCA needs to be present at a concentration of exceeding 15 ng/mL before a positive result can be reported.
In this paper a fast confirmation method is described to quantify THCA in 1 mL of urine. This method combines a 4 min GC-QqQ-MS method with a fast sample preparation procedure using microwave assisted derivatisation in order to complete the quantification of THCA in urine in 30 min.
The method is selective, linear over the range 5 – 100 ng/mL and shows excellent precision and trueness and hence, the estimated measurement uncertainty at the threshold level is small. The method also complies with applicable criteria for mass spectrometry and chromatography. Therefore the method can be used for rapid screening and confirmatory purposes
Development and validation of a fast gas chromatography combustion isotope ratio mass spectrometry method for the detection of epiandrosterone sulfate in urine
In doping control, to confirm the exogenous origin of exogenously administered anabolic androgenic steroids (AAS), a gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) analysis is performed. Recently published work suggests that epiandrosterone sulfate (EpiAS) is a promising IRMS target compound for the detection of AAS, capable of prolonging the detection window. However, EpiAS is only excreted in urine in its sulfoconjugated form, while all other IRMS target compounds are excreted glucuronidated, meaning that EpiAS cannot be incorporated in the existing IRMS methods. A separate extensive sample preparation needs to be performed on this compound with a different hydrolysis and extraction procedure and a different liquid chromatography (LC) clean-up.
The current work presents a new, fast, and easy to implement EpiAS IRMS method. The approach was based on the direct GC analysis of non-hydrolyzed EpiAS, making the solid phase extraction, hydrolysis, and acetylation step redundant. Sample preparation consisted of a simple liquid-liquid extraction, followed by LC fraction collection. A population study was performed to check compliance with the criteria drafted by the World Anti-Doping Agency (WADA). To verify the applicability of the developed approach, the method was applied to the samples of four administration studies (i.e. dehydroepiandrosterone (DHEA), testosterone gel (T gel), androstenedione (ADION), and intramuscular testosterone undecanoate. In contrast to previously published data, the strength of EpiAS as the target compound and the prolongation of the detection window in comparison with the conventional IRMS target compounds was less pronounced
In vitro metabolic studies of REV-ERB agonists SR9009 and SR9011
SR9009 and SR9011 are attractive as performance-enhancing substances due to their REV-ERB agonist effects and thus circadian rhythm modulation activity. Although no pharmaceutical preparations are available yet, illicit use of SR9009 and SR9011 for doping purposes can be anticipated, especially since SR9009 is marketed in illicit products. Therefore, the aim was to identify potential diagnostic metabolites via in vitro metabolic studies to ensure effective (doping) control. The presence of SR9009 could be demonstrated in a black market product purchased over the Internet. Via human liver microsomal metabolic assays, eight metabolites were detected for SR9009 and fourteen metabolites for SR9011 by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Structure elucidation was performed for all metabolites by LC-HRMS product ion scans in both positive and negative ionization mode. Retrospective data analysis was applied to 1511 doping control samples previously analyzed by a full-scan LC-HRMS screening method to verify the presence of SR9009, SR9011 and their metabolites. So far, the presence of neither the parent compound nor the metabolites could be detected in routine urine samples. However, to further discourage use of these potentially harmful compounds, incorporation of SR9009 and SR9011 into screening methods is highly recommended
Synthetic cannabinoids : general considerations
Around 2008 synthetic cannabinoids were found to be present in and responsible for the psychoactive effects of herbal mixtures with names like ‘Spice’ or ‘K2’. In response to the increased popularity of these products, (inter)national organizations and governments started banning these cannabimimetics gradually. However, the lack of an uniform and international regulation makes it hard to control this issue.
For the different types of synthetic cannabinoids the scientific knowledge in terms of pharmacokinetics and pharmacodynamics is limited. This also means that little is known on the health of users, both on short and long term.
In the last years effort has been made to make detection of these products possible in different biological matrices. However, since the number of cannabimimetic compounds on the market appears to grow every month, both scientist and legislators run after a moving target
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