DETECTION OF ILLEGAL CLENBUTEROL USE IN CALVES USING HAIR ANALYSIS - APPLICATION IN MEAT QUALITY-CONTROL

This study describes a real-life situation involving nine calves, 106 days old, which received oral doses of clenbuterol administered throug h their milk. Powdered skim milk containing 6.7 mg of clenbuterol was given daily for fifteen days under supervision (i.e. 100 mg per calf f or the whole study) to seven calves, and two calves did not receive th e drug. Hair samples and urine were taken and subjected to analysis by gas chromatography-mass spectrometry. Hairs were pulverized in a ball mill and 100 mg were incubated in a mildly acidic medium. The sample clean-up procedure involved solid-phase extraction on C-18 cartridges. Metoprolol was used as the internal standard for quantitation, after formation of methylboronate derivatives. The calibration curve for cle nbuterol in hair was linear in the range 20-5000 pg/mg. The limit of d etection of clenbuterol was 16 pg/mg in hair and 0.14 ng/ml in urine. Hair testing was effective after 7-10 days of treatment, and concentra tions were in the range of 20 to 4372 pg/mg. Urinalysis can detect cle nbuterol for up to two weeks after discontinuation of the drug. Conven iently, this is around the time when the hair samples attain greatest sensitivity. Therefore, the combination of the two matrices appears to be the method of choice for testing for the illegal use of drugs in m eat-producing animals. (C) 1997 Elsevier Science B.V.