Modification and validation of miniaturized QuEChERS method for multi-residual determination of antibiotics in milk from a tropical region

[Display omitted] •Antibiotic residues are among the primary contributors to the chemical contamination of milk and its by-products.•Antibiotic milk contamination drives antimicrobial resistance.•The implementation of quantitative tests to determine antibiotic residues is essential to avoid inappropriate disposal of milk.•Miniaturized QuEChERS method validated for antibiotic quantification milk. Daily monitoring is carried out worldwide using analytical methods to detect and quantify antibiotic residues in milk. This study was carried out to develop and validate the miniaturized multi-waste method QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) for identifying antibiotics in Dutch-Zebu cow’s milk. The miniaturized QuEChERS method was applied in the sample preparation stage, with quantification and identification of the analytes by high-performance liquid chromatography and validated according to the Resolution of the Collegiate Board − RDC n° 166, of July 24, 2017. The validated method was applied to commercial milk samples. This method was shown to be selective by identifying the three analytes separately. Linearity was proven with a coefficient of determination > 0.990. Intraday and interday accuracy showed relative standard deviation ranging from 1.06 % to 6.55 % and from 1.79 % to 12.79 %, respectively. The accuracy was proven by the recovery of the analytes (>90 %). The limit of detection and quantification were 0.20 and 0.80 μg L−1, respectively. The matrix effect demonstrated conformity. The actual milk samples were in accordance with the legislation. We conclude that the method is effective in identifying and extracting residues of oxytetracycline, tylosin and sulfadoxine in milk.