کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1167807 | 1491153 | 2009 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A liquid chromatography–tandem mass spectrometry confirmatory assay for the simultaneous determination of several tetracyclines in milk considering keto–enol tautomerism and epimerization phenomena A liquid chromatography–tandem mass spectrometry confirmatory assay for the simultaneous determination of several tetracyclines in milk considering keto–enol tautomerism and epimerization phenomena](/preview/png/1167807.png)
A liquid chromatography-electrospray ionization tandem mass spectrometric (LC–ESI-MS/MS) method for the analysis of several tetracyclines residues in bovine milk has been developed. Milk deproteinization/extraction of samples was performed with acidified acetonitrile. After diluting and purification by solid-phase extraction (SPE), the extracts were injected into the instrument operated in Multiple Reaction Monitoring (MRM) acquisition mode. The reversible epimerization at C-4 of oxytetracycline, tetracycline and chlortetracycline and the keto–enol tautomerism of chlortetracycline between C-11a and C-12 were considered for reliable quantification. Degradation was also taken in account and minimized for the same purpose. A central composite (response surface) design with desirability function was employed for the optimization of extraction and clean-up steps. The optimization improved the extraction efficiency of the more polar analytes reaching 93.9% for 4-epioxytetracycline and 95.8% for oxytetracycline at 100 μg L−1. The validation was performed following the criteria established by Commission Decision 2002/657/EC.
Journal: Analytica Chimica Acta - Volume 656, Issues 1–2, 10 December 2009, Pages 72–84