A green and verified high-performance liquid chromatographic technique for the concurrent measurement of a few veterinary drug residues in milk

Milk is a widely consumed dietary product due to its high nutritional value. The presence of veterinary drug residues in milk constitutes a potential risk to human health and undesirable effects on consumers. In this study, a chromatographic method was developed and optimized for quantitative analysis of imidocarb dipropionate (IMD), flunixin meglumine (FNM), and sulfadimidine (SDD) residues in milk. These drugs are used together as a combination therapy for the management of anaplasmosis in cattle. The chromatographic separation was performed using an ODS Hypersil C18 column with UV detection at 270 nm. The mobile phase consisted of 0.05 M phosphate buffer, pH 3: acetonitrile: methanol (55:30:15, by volume), with a flow rate of 1 mL/min. Before analysis, a protein precipitation procedure was performed to extract the studied drugs from milk by using methanol as an extractor/deproteinization agent. The proposed method was successfully employed to quantify the studied drug residues in cattle milk samples within and after their withdrawal periods. The developed method was statistically compared with reported methods, demonstrating no significant difference in terms of accuracy and precision. Greenness and environmental impact were also evaluated for the proposed procedure, verifying it was a green and eco-friendly analytical method.