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G. Van Vyncht S. Preece P. Gaspar G. Maghuin-Rogister E. DePauw 《Journal of chromatography. A》1996,750(1-2):43-49
β-Agonists are substances used in veterinary and human medicine for the treatment of pulmonary disorders. They have found a use as growth promoters to improve meat-to-fat ratios in cattle but they are not authorized for use in the European Union. Due to their presence in trace levels (usually less than 1 μg/kg), to the diversity of the illegally used compounds and to the complexity of the biological matrices analysed, the detection of these residues requires a very sensitive and specific method of determination. This work describes the strategy of analysis we developed for five β-agonists in urine and liver. The combination of improved solid- or liquid-phase extraction methods and LC or GC-MS-MS (in the multiple reaction monitoring mode) has shown to provide a system suitable for the control of these substances. The efficiency of extraction and the sensitivity and selectivity allow this multiresidue detection down to, and below, the UK regulatory level of 0.5 μg/kg. Moreover, the use of LC removes the need for the derivatisation step (cyclic methylboronate derivatives) which is required prior to GC-MS-MS analysis. 相似文献
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The control of illegal use of clenbuterol and other β2-agonist drugs as growth promoters in the European Union countries has led to outlaw practices for synthesizing new concept molecules, showing similar biological activity but not detectable by test methods usually employed to perform the official monitoring programmes. The synthesis schemes of some β2-agonist compounds, formally derived from clenbuterol, were found out by Italian detective authorities. These compounds were synthesised ex novo in our laboratories: then, both their molecular structures and biological activities were characterised. In this paper, we describe different strategies for purifying some β2-agonist drugs of new concept, more hydrophobic than clenbuterol. A two-step clean up procedure, prior to gas chromatography-mass spectrometry analysis, was developed for the multi-residue determination of these β2-agonists from bovine hair and urine. The purification strategy we chose was based on adsorption solid phase extraction and, subsequently, on specific molecular recognition by affinity chromatography. The affinity columns were homemade by coupling bovine α1-acid glycoprotein, a plasmatic acceptor for basic drugs, to a chromatographic support; their effectiveness for purifying new β2-agonists was discussed. The data about method recoveries and repeatability were also reported. 相似文献
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应用太赫兹时域光谱技术获取了盐酸克伦特罗在0.2~2.6 THz波段的光谱特征,并计算获得了盐酸克伦特罗在室温下的折射率谱和吸收谱.分别理论计算了克伦特罗分子、盐酸克伦特罗分子和盐酸克伦特罗晶体的振动频率.根据理论计算和实验光谱的对比,对盐酸克伦特罗的THz特征吸收峰进行了分析指认.实验结果显示,基于固体仿真的方法能够... 相似文献
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A method for the determination of trace clenbuterol is described. Multi-walled carbon nanotubes (MWCNTs)-Nafion composite
was used to modify the glassy carbon electrode (GCE). The modified electrode showed high sensitivity and good selectivity
for clenbuterol detection. It offered a linear range of 1.0 × 10−9–1.0 × 10−6 mol · L−1 with a detection limit of 5.0 × 10−10 mol · L−1 in pH = 1.2 solution. The oxidation mechanism of clenbuterol on the electrode was also investigated.
Correspondence: Xiao-Ya Hu, Department of Chemistry, Yang Zhou University, Yang Zhou, Jiang Su, P.R. China 相似文献
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