Detection of sildenafil and its 9 metabolites in a post-race horse urine sample: A case report.

The use of prohibited substances in horse racing is a major concern that jeopardizes both the fairness of competitions and the health of horses. This problem can stem from the use of licensed drugs for animal health, as well as unlicensed substances. Horse doping laboratories monitor the potential use of these substances in racehorses within the framework of regulations set by the International Federation of Horse Racing Authority. In this context, sildenafil and its major metabolite n-desmethyl sildenafil were detected in a post-race horse urine sample sent to the Pendik Veterinary Control Institute Doping Control Laboratory through a screening analysis performed with Liquid Chromatography Triple Quadrupole Mass Spectrometry. These results were confirmed by Q Exactive Orbitrap Mass Spectrometry and follow-up analyses were performed. As a result of these analyses; simultaneous detection of 9 metabolites in horse urine was reported, two of them for the first time. In addition, the pioneer and comprehensive data resulting from this study provide preliminary data for future studies and anti-doping analyses.

Cocktail drug usage and etofenamate detection in post-race equine urine sample: A case report.

A recent trend in the use of high-resolution accurate mass screening (HRAMS) for doping control testing in both human and animal sports has emerged owing to significant improvement in high-resolution mass spectrometry in terms of sensitivity, mass accuracy, mass resolution and mass stability. Several HRAMS methods have been reported for the detection of multidrug residues in human or equine urine. These improved analytical technologies have led to changes in the use of prohibited substances, and the administration of more than one substance at low concentrations as a "cocktail" has become one of the methods used to alter performance in racehorses. In one of horse urine samples transferred to the analytical laboratory in Turkey for analysis, 5-hydroxymethyl meloxicam (2.96 ng/ml), etofenamate (2.15 ng/ml), flufenamic acid (108.92 ng/ml) and cobalt (200 ng/ml) were detected. These findings reveal that more than one prohibited substance was used together as a cocktail to alter the racing performance at low doses. In this case report, flufenamic acid was detected as a metabolite of etofenamate along with the parent drug. This case study also supports the advantages of metabolite analysis for anti-doping laboratories.

Seminal trace elements and their relationship with sperm parameters.

Male reproductive problems may derive from many reasons including the environmental toxicants which may either intaken by occupational exposure, nutrition or bad air quality. The increased exposure to these substances due to rapid industrial development and technology has raised the questions: Is there a relationship between sperm parameters and these substances, and if so, in what extent? Results of studies on the subject reported conflicting results, many of which were not investigated in the seminal plasma. The aim of the current study was to evaluate the relationship between 23 metals and trace elements in human seminal plasma and semen parameters many of which were not investigated before. Levels of 23 metals in human seminal plasma were assessed by inductively coupled plasma mass spectrometry (ICP-MS). We examined the differences between subjects with normal ejaculate (normozoospermia) and pathologic ejaculate (with at least one abnormal semen parameter) according to the WHO criteria. The only significant difference was detected for Se while the other element's difference was not statistically significant. Se was statistically significantly increased in normal semen group suggesting the positive effect of this element on semen parameters.

Simultaneous quantification of caffeine and its main metabolites by gas chromatography mass spectrometry in horse urine.

Caffeine is a naturally occurring alkaloid and it is metabolized to paraxanthine, theophylline and theobromine. Analysis of caffeine and its metabolites is challenging since the metabolites theophylline and paraxanthine generate similar product and precursor ions. In this study, a new method was developed for the simultaneous analysis of caffeine, paraxanthine, theobromine and theophylline in horse urine using gas chromatography-mass spectrometry (GC-MS). Urine samples were treated using solid-phase extraction followed by the elution with dichloromethane-isopropanol (90:10) after the pH was adjusted to 6, and then derivatization with N-methyl-N-trimethylsilyl-trifluoroacetamide-1% trimethylchlorosilane before analysis with GC-MS. Sample preparation and derivatization steps were optimized and the method permitted elution all of these analytes within 13 min. The method was fully validated according to Commission Decision, 2002/657/EC guidelines. The calibration curves were linear with a correlation coefficient of >0.99. Precision and accuracy were well within the 15% acceptance range and the method was robust. The validation results demonstrated that the method is highly reproducible, easily applicable and selective. The method was applied to urine samples collected from racehorses to demonstrate its applicability.