Method of high-performance liquid chromatography to determine features of feed

Bacitracin is a part of an antibiotics group called polymyxin. It is characterized by cyclic peptide structures with the hydrophobic side chains used as a feed product for non-medical purposes. The most promising direction for optimization of zinc bacitracin (ZnB) qualitative and quantitative identification by means of high-performance liquid chromatography (HPLC) has not been studied at present. The aim of the research was to determine optimal modes and conditions for HPLC chromatography to identify zinc bacitracin antibiotic. The method is as follows: to extract bacitracin antibiotic residue according to the major active bacitracin A component from the analyzed sample: to make qualitative and quantitative identification by means of HPLC. HPLC system was established in order to separate zinc bacitracin antibiotic components analytically and preparatively. Peak moments have been registered without components decomposition under UV detection on Agilent 1260 Infinity and Spectra-Physics Spectra 100 chromatographs at a wavelength of 254 nm. Pre-column derivatization with o-phthaldialdehyde at the presence of 2-mercaptoethanol made it possible to identify the major component of the ВС-А with the help of fluorescence detector Hitachi 850. 0.1 M disodium salt solution of ethylenediaminetetraacetic acid (EDTA) in the aqueous part of the mobile phase was selected as a mobile phase modifier to enhance the sensitivity of bacitracin peaks at low concentrations. The analysis of zinc bacitracin composition was made according to the research conducted with the help of HPLC methods by means of diode-array, UV, and fluorescence detectors. The possibility to increase the HPLC analysis sensitivity by adding an equimolar amount of EDTA in the mobile phase is shown. A method for ZnB identification by means of HPLC in the reversed phase of pre-column derivatization with the ortho-phthalic dialdehyde to enhance fluorescence was developed.