Xenobiotic clenbuterol in food producing male pigs: Various tissue residue accumulation on days after withdrawal

Determination of Salbutamol Residues in Goat Various Tissues After Exposure to Growth-promoting Doses

In order to monitor salbutamol (SAL) use in goats as a repartitioning, we determined SAL residues in various tissues of goats after repeated oral SAL administration at a dose of 0.15 mg/kg daily for 21 days. SAL concentrations were measured by ultra performance liquid chromatography tandem mass spectrometry in extracts of tissues from goats sacrificed 0.25, 1, 3, 7, 14, 21 and 28 days after the last dose. Our results showed that on Day 0.25 of the withdrawal period, the residual proportions of SAL (expressed as percentage) in liver, kidney, lung, hair, stomachs and muscle were 19.5%, 15.3%, 3.3%, 9.6%, 28.2% and 0.8%, respectively. As the withdrawal time increased, the SAL concentrations in most tissues (except hair) decreased rapidly over the first 3 days and more slowly in the following 25 days. After a 28-day withdrawal period, hair, lung, muscle, liver, fat, eyes, rumen, kidney and abomasum still contained ~32.3%, 15.3%, 7.1%, 6.5%, 5.6%, 1.5%, 0.8% and 0.5% compared to the initial residual concentrations determined on Day 0.25, respectively. On withdrawal Day 28, the highest concentrations of SAL were found in hair (16.58 ± 9.48 μg/kg), followed by liver (7.01 ± 0.94 μg/kg), lung (2.81 ± 1.23 μg/kg), kidney (0.64 ± 0.56 μg/kg), whereas the concentrations in other tissues were lower than limit of quantification (0.50 μg/kg). SAL residues were not detected in bile, plasma and brain on Days 7, 7 and 3 after discontinuation of dosing. These findings indicated that the distribution and depletion rates of SAL differed between tissues. It should be noted that SAL residues in stomach were higher than those in muscles during the early withdrawal. We conclude that hair is the preferred tissue to monitor the administration of SAL to living goats, whereas liver can be used to monitor SAL in the carcass for determination of compliance with food safety regulation.

Clenbuterol Distribution and Residues in Goat Tissues After the Repeated Administration of a Growth-Promoting Dose

This study was conducted to investigate the deposition and depletion process of clenbuterol (CL) in goat tissues, plasma and urine after the repeated administration of a growth-promoting dose. The experiment was conducted in 24 goats (21 treated and 3 controls). Treated animals were administered orally in a dose of 16 µg/kg body mass once daily for 21 consecutive days and randomly sacrificed on days 0.25, 1, 3, 7, 14, 21 and 28 of the withdrawal period. CL in goat tissues was extracted with organic solvents and determined using liquid chromatography tandem mass spectrometry. The depletion rates of tissue differed significantly. The highest concentrations of CL in all tissues are detected on day 0.25 of treatment discontinuation. After administration had been discontinued for 28 days, CL still residues in all tissues, especially, in whole eye, where the concentrations reach 363.29 ± 31.60 μg/kg. These findings confirmed that the whole eye, which are rich in pigment, showed a much higher concentration than any other studied tissue during the withdrawal period.

An Amperometric Immunosensor Based on a Polyelectrolyte/Nano Gold Particle Layer-by-Layer Assembly Modified Electrode for the Determination of Clenbuterol in Meat

This paper introduces a novel amperometric immunosensor consisting of hemin (Fe(III)-protoporphyrinIX) layers formed by layer-by-layer assembly for determination of clenbuterol (CLB). Layer-by-layer assembly of hemin with Poly(allylamine hydrochloride) (PAH) is achieved on the electrode surface which is modified by single-wall carbon nanotubes (SWCNTs) based on the electrostatic attraction between negatively charged hemin and positively charged Poly(allylamine hydrochl- oride). The modified electrodes were characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), and X-ray photo electron spectrum (XPS). The decrease of current results from the increasing concentration of CLB antigen, which leads to a linear decrease in CLB antigen concentration ranges from 0.5 ~ 10 ng/mL with the detection limit of 0.2 ng/mL (3σ).