Screening for benfluorex and its major urinary metabolites in routine doping controls.
Benfluorex [1-(m-trifluoromethylphenyl)-2-(β-benzoyloxyethyl)aminopropane] has been widely used for the treatment of atherogenic metabolic disorders and impaired carbohydrate metabolism (particularly in obese type-II diabetic patients) as well as an anorectic drug. Due to its potentially performance-enhancing properties, benfluorex has been added to the list of prohibited compounds and methods of doping by the World Anti-Doping Agency (WADA) in 2010, necessitating the implementation of the drug as well as its major metabolites into routine doping control procedures. In the present study, human urinary metabolites of benfluorex were characterized by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) as well as liquid chromatography-electrospray ionization-high resolution/high accuracy tandem mass spectrometry (LC-ESI-MS/MS). Commonly employed sports drug testing approaches consisting of liquid-liquid extraction followed by GC-MS or urine dilution and immediate LC-MS/MS analysis were expanded and validated with regard to specificity, recovery (48-54%, GC-MS only), intra- and interday precision (<25%), limits of detection (5-8 ng/mL for LC-MS/MS and 80 ng/mL for GC-MS), and ion suppression (for LC-ESI-MS/MS only) to allow the detection of benfluorex metabolites 1-(m-trifluoromethylphenyl)-2-(2-hydroxyethyl)aminopropane (M1), 1-(m-trifluoromethylphenyl)-2-(2-carboxymethyl)aminopropane (M2), and 1-(m-trifluoromethylphenyl)-2-aminopropane (M3) as well as the glucuronic acid conjugate of M1.
Institute of Biochemistry-Center for Preventive Doping Research, German Sport University Cologne, Cologne, Germany. m.thevis@biochem.dshs-koeln.de
Mario
M
Thevis
Gerd
G
Sigmund
Vassilios
V
Gougoulidis
Simon
S
Beuck
Nils
N
Schlörer
Andreas
A
Thomas
Dorota
D
Kwiatkowska
Andrzej
A
Pokrywka
Wilhelm
W
Schänzer
D002853:Chromatography, Liquid; D004300:Doping in Sports; D005277:Fenfluramine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D058573:Performance-Enhancing Substances / Q000737:chemistry / Q000378:metabolism* / Q000652:urine*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods* / Q000592:standards; D053719:Tandem Mass Spectrometry
D058573:Performance-Enhancing Substances; D005277:Fenfluramine; C001584:benfluorex