Desenvolvimento de método para determinação de resíduos de medicamentos veterinários em salmão por UHPLC-MS/MS

Abstract

The aquaculture industry has been growing, developing and highlightning in the last few years. Many countries and international organizations have invested in developing the activity according to available resources. Chile stands out in the world market in salmon production (Salmo salar) being the main supplier of the product to Brazil. Veterinary drugs may be used during the production process for the proper management and prevention of financial losses. Once administered, veterinary drugs can be absorbed and remain in fish meat as residues. Many drugs are banned for veterinary use, many others are authorized and require application, attendance and appropriate withdrawal period to not leave residues in the product. The presence of drug residues is of great concern, since small doses given daily can lead to the development of bacterial resistance. Monitoring of the presence of residues can be carried out through programs and regulations. The presence of residues of veterinary drugs in products of animal origin is determined by reliable and suitable analytical methods. Therefore, the objective of this work was to develop an analytical method for the determination of residues of nitroimidazoles, quinolones, tetracyclines, amphenicoles, sulfonamides, macrolides, pyrethroids and benzamides in salmon (Salmo salar) using UHPLC-MS/MS. The development of the method was performed by assays for evaluation of the solvents used in the extraction and sorbents used in the sample preparation step. The conditions of the UHPLC-MS/MS system, such as mobile fase composition, chromatographic column, mobile phase elution gradient, mobile phase flow rate, desolvation gas temperature and tension applied to the capillary were also evaluated. The method of sample preparation was based on the extraction with acetonitrile and clean up step using SPE. The determination step was performed in UHPLC-MS/MS Xevo TQ® system. The mobile phase used was aqueous solution and acetonitrile, both 0.1% formic acid (v/v) at the flow rate of 0.1 mL min-1 in gradient mode. The chromatographic column used was an Acquity HSST3 (50 x 2.1 mm, 1.8 μm) at 60 ° C. The injection volume was 10 μL. The conditions of the ionization source (ESI) were desolvation gas temperature of 600 °C, capillary voltage of 2000 V, source temperature 150 °C. The validation of the method developed was based on documents CD/657/EU and SANTE, 2017. The results of recovery varied between 71 and 120% with deviations less than 24%. The quantification limits ranged from 5 to 25 μg kg-1 . Matrix effects were mostly negative ranging from -45 to -22%. The method was applied in the analysis of 15 real samples. The method is suitable for the determination of residues of veterinary drugs in routine laboratories for 5 of the classes under study within the limits established by the legislation.