A fast immunoassay for the screening of β-agonists in hair†

Abstract

Hair has been shown to be an excellent site for the accumulation of clenbuterol residues. Compared with other matrices, hair sampling is very easy and this might result in large numbers of samples. In this study, a simple digestion-extraction procedure was combined with a sensitive clenbuterol ELISA, which resulted in an easy screening procedure suitable for the detection of at least four beta-agonists. Hair from untreated cows (n = 40) resulted in low blank levels (0.9 +/- 0.7 and 0.5 +/- 0.2 ng g-1 for black and white hair, respectively). The detection limits for clenbuterol, bromobuterol, mapenterol and mabuterol were determined as 1-1.5 ng g-1 for white and 3-4 ng g-1 for black hair. The accumulation of mabuterol and mapenterol in black and white hair from treated calves was demonstrated by GC-MS. The screening assay is not suitable for the detection of cimbuterol (owing to the low extraction efficiency) and for salbutamol and terbutaline (owing to the low cross-reactivity of the antibodies used for the ELISA and the low extraction efficiency). Black hair samples from cows treated with clenbuterol were still found to be positive (> 5 ng g-1) at 23 weeks after treatment. The fast screening procedure is a powerful means to detect and track the illegal use of clenbuterol, bromobuterol, mabuterol and mapenterol in animal production.

Control of the illegal use of clenbuterol in bovine production

“…The possibility of an easy, simple and fast sample collection, with no added danger for the operator, as is the case with blood or urine collections, is an advantage which cannot be disregarded. However, as can be proved by analysing the results, the hair colour has a major importance in clenbuterol accumulation [29], particularly when comparing the rates found in hair and retina samples of the same animal. The relation between clenbuterol concentrations found in hair and retina (hair/retina) can vary between a minimum of zero, with no perceivable relation, in the case of a white-haired bovine, and a maximum of about 4/1, in the case of black-haired bovines, in-between values of 3/1 being found in brownhaired animals, or 2/1 when the bovine hair is blonde.…”

Determination of β2-Agonists in Porcine Urine by Molecularly Imprinted Solid Phase Extraction Followed Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry Detection

“…SPE with mixed phase mode sorbent was often used to extract and clean the b 2 -agonists in a complicated sample matrix to decrease the sample matrix effect (Ramos et al 2000;Haasnoot et al 1998;Nielen et al 2008) due to its association of apolar and ionic mechanisms (Chen et al 1992). In this study, the comparison of MIP-SPE and mixed phase mode SPE was carried out to evaluate the cleaning efficiency and suppression ratio of sample matrix for target analytes by using SPE with MIP.…”

Hair analysis for veterinary drug monitoring in livestock production

“…Even if IAs represent a rapid, convenient and quite sensitive screening for the presence of drugs in hair [44,54,60], chromatography is undoubtedly the analytical technique of choice ( Table 1). The great selectivity of LC or GC analytical columns allows the separation of the target analyte(s) from the interferences of the matrix as well as the DAD, or MS detectors may provide elements to confirm the identification [7].…”

“…The addition of TMIS, 2-mercaptoethanol, DTT, DTE or NH 4 I has also been proposed to improve the efficiency of the derivatization reactions [16,22,33,40,45,54,55,61].…”

“…Purification of hair extracts containing ␤-agonists has been carried out by LLE with TBME or hexane [32,53,54], by SPE cartridges (mixed-mode C 8 + SCX; C 18 ) [39] or by affinity chromatography [44].…”