Screening and Simultaneous Determination of 80 Veterinary Drug Residues in Food by HPLC-MS/MS

A fast method of screening of samples and determination of 80 veterinary drug residues in food safety assessment is proposed. The stage of solid-phase extraction for the purification of the extract in the sample preparation is excluded; here, the matrix effect is neutralized by using isotope-labeled standards. The application of the isotope dilution method makes it possible to exclude the stage of construction of matrix calibration curves and to calculate the concentrations using correction coefficients found from standard aqueous solutions of analytes with a limited number of isotope-labeled standards (one standard each for each class of compounds under determination). The limits of detection of medicinal products (c_min = 0.1–10 ng/g) make it possible to determine their residues at the level of maximum allowable concentrations for food.