RESUMO
The implementation of quality control procedures in analytical laboratories around the world has become essential in order to ensure the quality and safety of food. This article describes the procedure adopted by the Brazilian government in order to achieve this goal, specifically in the area of analysis of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The validation of a multiresidue method, the calculation of measurement uncertainty, and the quality control procedure adopted in the determination of these compounds in beef cattle fat were performed as set out in national legislation (Brasil, 2011), which is aligned with international guidelines. Evaluation was made of selectivity, linearity, precision (repeatability and reproducibility), accuracy, and limits of detection and quantification. Stability studies were also undertaken. The technique was extended to three other matrices (poultry, horse, and pig adipose tissues), with evaluation of matrix effects, selectivity, linearity, and accuracy. The analyses were performed by gas chromatography with electron capture detection (GC-ECD) and mass spectrometric detection (GC-MS). In recent years, analyses conducted under the National Plan for Control of Residues and Contaminants (PNCRC) have shown no exceedances of the maximum permitted residue levels (MRLs) of pesticides and PCBs in these tissues, as observed in other countries that carry out effective monitoring of these contaminants.