Desenvolvimento e validação de metodologia para a determinação de resíduos do antibiótico cloranfenicol em diferentes matrizes alimentícias

Abstract

In some stages of the food production of animal origin, antibiotics as chloramphenicol (CAP) can be used. In the human therapy, CAP is only used in severes cases against multiresistant microorganisms due to your toxicological effects to the organism, which can cause an aplastic anemia. Therefore, the objective of this study was to optimize the sample preparation conditions, optimize the GC/ECD chromatographic separation conditions and validate the optimized method at in-house level with the optimized conditions. The method was optimized by assays using CAP standards and samples of muscle of shrimp and tilapia; honey; pollen; ostrich, sheep and goat meat; and goat milk. The optimized conditions were as followed: derivation with lyophilized CAP and at low humidity conditions should be used, the silanization reaction of CAP went conducted for 15 min at 80 ºC; the best purification conditions were obtained by hexane washes and SPE-C18 cleaning; for the chromatography conditions, the splitless must be done with a liner of 2 mm with split valve opening at 0.5 min; it should be used an DB1 column (60 m x 0.25 mm x 0.25 µm), at temperature conditions as follow: 90 ºC / 1 min heating 60 ºC / min until 200 ºC / 7 min, raising 5 ºC / min until 230 ºC / 3 min heating 5 ºC / min until 260 ºC / 35.17 min. The assays with food samples shows that the optimized conditions are not indicated for application at honey, pollen, shrimp, tilapia and ostrich meat. Howerver, at the optimized conditions, the sheep meat, goat meat and goat milk matrix are indicated for development of studies for chloramphenicol residues validation method. With this, the goat milk CAP residues determination method were in-house validated by GC/ECD. The identification was made by retention time comparation and by GC/MS, and the quantification by external standard. The validated method for goat milk was especific, linear(0.998), precise (5.8- 13.4%), exact (69.87-73.71%) and robust. The DL and QL were 0.03 and 0.10 µg/kg, respectively. The validated method attended to the MERCOSUL and Codex Alimentarius norms.