title: Clenbuterol - regional food contamination a possible source for inadvertent doping in sports.
abstract: The misuse of the sympathomimetic and anabolic agent clenbuterol has been frequently reported in professional sport and in the livestock industry. In 2010, a team of athletes returned from competition in China and regular doping control samples were taken within the next two days. All urine samples contained low amounts (pg/ml) of clenbuterol, drawing the attention to a well-known problem: the possibility of an unintended clenbuterol intake with food. A warning that Chinese meat is possibly contaminated with prohibited substances according to international anti-doping regulations was also given by Chinese officials just before the Bejing Olympic Games in 2008. To investigate if clenbuterol can be found in human urine, a study was initiated comprising 28 volunteers collecting urine samples after their return from China. For the quantification of clenbuterol at a low pg/ml level, a very sensitive and specific isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed using liquid/liquid re-extraction for clean-up with a limit of detection and quantification of 1 and 3 pg/ml, respectively. The method was validated demonstrating good precision (intra-day: 2.9-5.5 %; inter-day: 5.1-8.8%), accuracy (89.5-102.5%) and mean recovery (81.4%). Clenbuterol was detectable in 22 (79%) of the analyzed samples, indicating a general food contamination problem despite an official clenbuterol prohibition in China for livestock.
authors.affiliation: Institute of Biochemistry and Center of Preventive Doping Research, German Sport University Cologne, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Guddat
authors.forename: G
authors.initials: G
authors.lastname: Fußhöller
authors.forename: H
authors.initials: H
authors.lastname: Geyer
authors.forename: A
authors.initials: A
authors.lastname: Thomas
authors.forename: H
authors.initials: H
authors.lastname: Braun
authors.forename: N
authors.initials: N
authors.lastname: Haenelt
authors.forename: A
authors.initials: A
authors.lastname: Schwenke
authors.forename: C
authors.initials: C
authors.lastname: Klose
authors.forename: M
authors.initials: M
authors.lastname: Thevis
authors.forename: W
authors.initials: W
authors.lastname: Schänzer
mesh_terms: D000318:Adrenergic beta-Agonists / Q000652:urine*; D000818:Animals; D002681:China; D002853:Chromatography, Liquid / Q000379:methods; D002976:Clenbuterol / Q000652:urine*; D004300:Doping in Sports; D005260:Female; D005506:Food Contamination; D006801:Humans; D058751:Livestock; D008297:Male; D008460:Meat; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000318:Adrenergic beta-Agonists; D002976:Clenbuterol