engleski

Clenbuterol residues in plasma and urine samples of food-producing pigs during and after subchronic exposure to a growth-promoting dose

The aim of the study was to evaluate suitability of plasma and urine as matrices for clenbuterol residue determination during and after its subchronic administration at a growth-promoting dose to male pigs, using previously validated enzyme-linked immunosorbent assay (ELISA) as a screening method and liquid chromatography tandem mass spectrometry (LC-MS/MS) as a confirmation method. A high correlation coefficient between these analytical methods was obtained for both urine (r=0.9800) and plasma (r=0.9970) concentrations. Study results showed the plasma and urine concentration to vary greatly during oral treatment with clenbuterol for 28 days. The peak urine concentration (88.54± ; 50.54 ng/mL) recorded on day 21 was 40-fold peak plasma concentration (2.25± ; 1.54 ng/mL). After withdrawal period, the peak urine clenbuterol concentration (42.93± ; 10.52 ng/mL) recorded on day 0 was 24-fold plasma concentration (1.79± ; 0.97 ng/mL). The maximal allowed concentration of 0.5 ng/g in the liver as a regulated matrix for control of clenbuterol abuse was achieved in plasma on day 3 (0.52± ; 0.26 ng/mL) and in urine on day 7 of treatment withdrawal (0.45± ; 0.11 ng/mL). Study results indicated that urine and plasma may be suitable matrices in the control of clenbuterol abuse during food producing pig fattening but have a limited value because of the rapidly decreasing concentration upon treatment withdrawal, in plasma in particular.

clenbuterol residues; growth promoting; subchronic exposure; pig; urine; plasma

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