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Yiping Zhao - One of the best experts on this subject based on the ideXlab platform.
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highly sensitive detection of Clenbuterol in animal urine using immunomagnetic bead treatment and surface enhanced raman spectroscopy
Scientific Reports, 2016Co-Authors: Jie Cheng, Shi Wang, Yiping ZhaoAbstract:Combining surface-enhanced Raman spectroscopy (SERS) of aggregated graphene oxide/gold nanoparticle hybrids with immunomagnetic bead sample preparation method, a highly sensitive strategy to determine the Clenbuterol content in animal urine was developed. Based on a linear calibration curve of the SERS characteristic peak intensity of Clenbuterol at Δv = 1474 cm−1 versus the spiked Clenbuterol concentration in the range of 0.5–20 ng·mL−1, the quantity of Clenbuterol in real animal urine samples can be determined and matches well with those determined by LC-MS/MS, while the detection time is significantly reduced to 15 min/sample. The limits of detection and quantification in the urine are 0.5 ng·mL−1 and 1 ng·mL−1, respectively, and the recovery Clenbuterol rates are 82.8–92.4% with coefficients of variation <9.4%. The day-to-day variation of the detection is less than 6.41%, and the shelving life of the SERS substrates is no less than 4 weeks. All these indicate that this proposed SERS detection protocol for Clenbuterol is reproducible, reliable, and can be easily developed for the routine monitoring of the illicit use of Clenbuterol in animal farming.
Heinrich H. D. Meyer - One of the best experts on this subject based on the ideXlab platform.
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Development of Clenbuterol reference materials: lyophilized bovine eye samples free of Clenbuterol (CRM 673) and containing Clenbuterol (CRM 674). Part 2: certification.
Fresenius' journal of analytical chemistry, 2001Co-Authors: Michael W. Pfaffl, Leendert A. Van Ginkel, J. D. G. Mcevoy, Guy Maghuin-rogister, Heinrich H. D. MeyerAbstract:The certification by inter-laboratory testing of two candidate reference materials (RMs) for the mass concentration of the anabolic agent Clenbuterol in bovine eye material is described: RM 674 with ca 10 µg Clenbuterol per kg of eye matrix and RM 673 Clenbuterol-free eye matrix as the negative control (
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Development of Clenbuterol reference materials: lyophilized bovine eye samples free of Clenbuterol (CRM 673) and containing Clenbuterol (CRM 674). Part 1. Preparation, homogeneity and stability
Fresenius' journal of analytical chemistry, 2001Co-Authors: Michael W. Pfaffl, Leendert A. Van Ginkel, J. D. G. Mcevoy, Guy Maghuin-rogister, Heinrich H. D. MeyerAbstract:Within the EU Standards, Measurement and Testing Program (SMT) two Clenbuterol reference materials (RMs) were developed. Since Clenbuterol readily accumulates and is slowly depleted from pigmented tissues such as the retina, homogenized eye liquid content is the most sensitive tissue for the detection of Clenbuterol misuse. Therefore, both of the RMs were produced from bovine eye matrix: a negative control – RM 673 eye reference material, Clenbuterol free (
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Accumulation of the β2-adrenoceptor agonist Clenbuterol in calf hair of different pigmentation
Archiv Fur Lebensmittelhygiene, 1996Co-Authors: Andreas Gleixner, H. Sauerwein, Heinrich H. D. MeyerAbstract:The objective of this study was to develop an analytical approach to detect the illegal application of Clenbuterol in cattle as an anabolic agent by hair analysis. Special emphasis was layed on the time course of the incorporation of Clenbuterol into growing hair and on the influence of hair pigmentation on Clenbuterol concentrations in hair. Twelve male veal calves of different coat color were fed with.8μg of Clenbuterol/kg BW, twice daily, for 10 d as prescribed for the therapeutic use that is registered in most European countries. During and after the treatment hair samples were obtained and analyzed for Clenbuterol residues. An appropriate method to extract Clenbuterol from hair for subsequent enzyme immunological quantification was developed. Clenbuterol residues could be detected in hair from d 4 (∼1 ng/g) of the treatment to d 60 after the end of treatment (-20 ng/g). The accumulation of Clenbuterol was considerably higher in black hair (∼100 ng/g) than in lighter colored hair (-5 ng/g) demonstrating the importance of hair pigmentation for the binding of Clenbuterol to the hair matrix. During d 11 to 25 of the experiment most of the incorporated Clenbuterol could be detected in the hair fiber (∼300 ng/g for black hair vs. ∼20 ng/g for lighter colored hair). Our results suggested that hair analysis is a powerful mean to detect and track the illegal use of Clenbuterol in animal production.
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The pharmacokinetics and residues of Clenbuterol in veal calves.
Journal of animal science, 1991Co-Authors: Heinrich H. D. Meyer, L. M. RinkeAbstract:Seven female Brown Swiss calves were used to study the pharmacokinetics of Clenbuterol after an effective anabolic dosage of 5 micrograms/kg of BW was given twice daily for 3 wk. Analyses of Clenbuterol concentrations in different tissues was done by enzyme immunoassay (EIA). Tissue samples were taken from three calves on the last day of administration and from two more after 3.5 or 14 d of Clenbuterol withdrawal. The rate of Clenbuterol elimination was dependent on time and tissue. Clenbuterol concentrations in the lung dropped from a mean of 76 ng/g to a level of less than .08 ng/g after 14 d, whereas in the liver the Clenbuterol concentrations decreased from 46 ng/g to .6 ng/g within 14 d of withdrawal. Highest levels were always found in the eye: 118 ng/g, 57.5 ng/g, and 15.1 ng/g after 0, 3.5, and 14 d of withdrawal, respectively. These data reveal that different compartments contribute to the elimination of Clenbuterol; therefore, concentrations in urine do not follow first order kinetics. An initial rapid decline in the concentration of Clenbuterol in urine with a half-life of 10 h is followed by a slower elimination with a half-life of about 2.5 d. Treatments using the anabolic dose of 5 micrograms/kg of BW require longer withdrawal times than the therapeutic dose (.8 micrograms/kg BW).
Liang Zhong - One of the best experts on this subject based on the ideXlab platform.
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Highly sensitive detection of Clenbuterol using competitive surface-enhanced Raman scattering immunoassay
Analytica Chimica Acta, 2011Co-Authors: Yongjun Hu, Liang ZhongAbstract:Abstract In this report, we present a novel approach to detect Clenbuterol based on competitive surface-enhanced Raman scattering (SERS) immunoassay. Herein, a SERS nanoprobe that relies on gold nanoparticle (GNP) is labeled by 4,4′-dipyridyl (DP) and Clenbuterol antibody, respectively. The detection of Clenbuterol is carried out by competitive binding between free Clenbuterol and Clenbuterol-BSA fastened on the substrate with their antibody labeled on SERS nanoprobes. The present method allows us to detect Clenbuterol over a much wider concentration range (0.1–100 pg mL−1) with a lower limit of detection (ca. 0.1 pg mL−1) than the conventional methods. Furthermore, by the use of this new competitive SERS immunoassay, the Clenbuterol-BSA (antigen) is chosen to fasten on the substrate instead of the Clenbuterol antibody, which could reduce the cost of the assay. Results demonstrate that the proposed method has the wide potential applications in food safety and agonist control.
Jie Cheng - One of the best experts on this subject based on the ideXlab platform.
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highly sensitive detection of Clenbuterol in animal urine using immunomagnetic bead treatment and surface enhanced raman spectroscopy
Scientific Reports, 2016Co-Authors: Jie Cheng, Shi Wang, Yiping ZhaoAbstract:Combining surface-enhanced Raman spectroscopy (SERS) of aggregated graphene oxide/gold nanoparticle hybrids with immunomagnetic bead sample preparation method, a highly sensitive strategy to determine the Clenbuterol content in animal urine was developed. Based on a linear calibration curve of the SERS characteristic peak intensity of Clenbuterol at Δv = 1474 cm−1 versus the spiked Clenbuterol concentration in the range of 0.5–20 ng·mL−1, the quantity of Clenbuterol in real animal urine samples can be determined and matches well with those determined by LC-MS/MS, while the detection time is significantly reduced to 15 min/sample. The limits of detection and quantification in the urine are 0.5 ng·mL−1 and 1 ng·mL−1, respectively, and the recovery Clenbuterol rates are 82.8–92.4% with coefficients of variation <9.4%. The day-to-day variation of the detection is less than 6.41%, and the shelving life of the SERS substrates is no less than 4 weeks. All these indicate that this proposed SERS detection protocol for Clenbuterol is reproducible, reliable, and can be easily developed for the routine monitoring of the illicit use of Clenbuterol in animal farming.
Josef E. Fischer - One of the best experts on this subject based on the ideXlab platform.
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Decreased myofibrillar protein breakdown following treatment with Clenbuterol
The Journal of surgical research, 1991Co-Authors: D. W. Benson, Teri Foley-nelson, William T. Chance, Fu-sheng Zhang, J H James, Josef E. FischerAbstract:Daily treatment of Fischer-344 rats for 14 days with the β2-adrenergic agonist, Clenbuterol, increased gastrocnemius muscle mass and protein content. Coadministration with the β-adrenergic antagonist, nadolol, significantly reduced these anabolic effects of Clenbuterol. Although Clenbuterol treatment reduced food intake during the first 4 days, Clenbuterol-treated rats were hyperphagic during the second week of drug administration. Nadolol treatment also blocked these effects of Clenbuterol on feeding. In a second experiment, in vitro incubation of extensor digitorum longus muscles taken from postweaning food-deprived rats demonstrated decreased release of 3-methylhistidine by Clenbuterol-treated rats, suggesting decreased breakdown of myofibrillar protein. Protein synthesis was not increased in vitro in the soleus muscles taken from these rats. These experiments demonstrate that the anabolic effect of Clenbuterol is due in part to β-adrenergic activity and may involve reduced myofibrillar protein degradation. These results appear to have direct application to nutrition and protein repletion in various catabolic diseases.