In some cases, clenbuterol from doping pills can be distinguished from clenbuterol originating from contaminated cattle meat or liver. This was demonstrated by Rikilt in collaboration with German and Polish researchers. It will now finally be possible to find out whether Alberto Contador used doping or ate a contaminated steak during the 2010 Tour de France.
In a project financed by the World Anti Doping Authority (WADA), the researchers examined whether they were able to make a distinction between two optical varieties of clenbuterol. A doping pill or medicine contains the same amounts of the two variants, whereas a steak or liver from a treated animal contains primarily the active variant of clenbuterol. To be able to demonstrate the difference in composition, the researchers had to develop and validate a special screening method.
And they were successful. With a combination of chromatography and mass spectrometry, the researchers were able to demonstrate the distinction between pharmaceutical clenbuterol and clenbuterol found in beef. In addition, the different compositions of clenbuterol became visible in the urine of people who had taken a pill or the ones who had eaten contaminated cattle meat or liver, the researchers report in Food Additives & Contaminants.
Using this test, the WADA could now test the claims of sportsmen who were tested positive for clenbuterol and claim that they are innocent because they ingested contaminated meat, says Saskia Sterk of Rikilt. A delicate point is the fact that the composition of clenbuterol in beef can greatly vary.
Clenbuterol is a medicine for asthma that dilates the respiratory tract. In high concentrations, it has a growth stimulating effect. The substance is on the prohibited drug list for sportsmen, and in the Netherlands it may not be used on people – only on horses affected by asthma. It is a popular substance among bodybuilders, because it stimulates muscle growth and fat loss. The use as a growth stimulant in cattle is prohibited in many countries, but there is illegal use in livestock farming.
The cyclist Alberto Contador was caught with 0.00000000005 grams of clenbuterol per millilitre of urine. Contador pointed out the consumption of contaminated meat, but was suspended.
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