Abstract
Multicomponent residue analysis of veterinary drugs by HPLC-MS/MS is relevant for food safety. A significant problem is the determination of veterinary drugs whose molecules are large in size. Electrospray ionization of such molecules is difficult, and it is difficult to achieve the required sensitivity by classical separation from the matrix with subsequent detection. Such drugs include avilamycin and nosiheptide. To solve this problem, it is possible to fragment the molecules into smaller and easily detectable residues by hydrolysis, which in turn raises the problem of optimizing the conditions of such preparation, as well as assessing the uniqueness of the selected marker. The possibility of simultaneous determination of avilamycin and nosiheptide in chicken meat by their alkaline hydrolysis to the markers dichloroisoverninic acid and 4-hydroxymethyl-3-methylindole-2-carboxylic acid, respectively, has been demonstrated. The conditions of extraction, hydrolysis and methods of further purification were studied. Under the selected conditions, analyte recovery was >85% and satisfactory reproducibility was achieved (sr ≤ 0.15). The detection limits were 5 µg/kg. The developed method is highly selective, rapid, easy to perform, inexpensive and has good analytical performance.