Desenvolvimento de método para determinação simultânea de sulfonamidas e trimetoprima em medicamentos de uso veterinário e em carne de frango

Abstract

Veterinary drugs were used in the worldwide to promote animal health, provide economic gains and increased productivity of the foodstuffs industry of animal origin. However, the absence of an effective monitoring programand the use of excessive or inappropriate these drugs present a threat to consumers, because they contribute with the presence of residues in animal tissues destined for food production. These residues, in long term, contribute to the appearance of microbial resistance by antimicrobials used in human clinicalpractice, beyond to enable the development of allergic reactions in hypersensitive individuals. Being the food safety an issue increasingly relevant due to the increasing search for a better quality of life, and the awareness consumers about the right to purchase insurance products to health, the aim of this study was to develop a technique for quality control simultaneous analysis of veterinary drugs containing the antimicrobial agents sulfamethoxazole (SMX) and trimethoprim (TMP) in their formulations, beyond development of a method for sulfonamides analysis, sulphadiazine(SDZ), sulphamethoxypyridazine (SPZ) e sulphamethoxazole(SMX), in chicken breast, which could be used in a routine laboratory. For the method of quality control there was no need to develop a sample preparation, being sufficient the achievement of dilutions for quantification of analytes by high performance liquid chromatography, with Thermo BDS Hypersil®C18column (150 mm x 4,6 mm x 5 µm) and ultraviolet detection (UV). The quality control method demonstrated linearity in the range of 5 to 70 µg mL-1for SMX and 1 to 30 µg mL-1for TMP (r2=0.99 for both compounds). The relative standard deviation was =5%, and and test of standard addition indicated that the methodwas accurate. The proposed method shows great potential for simultaneous analysis of the drugs evaluated and represents a new alternative approach to quality control of veterinary medicines. For the analysis of sulfonamides in chicken breast, a method was developed, based on the technique QuEChERS modified using high performance liquid chromatography coupled toa diode array detector and LiChrospher 60 RP -Select B®C18 (250mm x 4.6 mm x 5 µm) columnat 40°C,mobile phase constituted by phosphate buffer:acetonitrile (75:25, v/v) at a initial flow rate of 0.5 mL min-1, increased by 1.2 mL min-1(total run time of 20 min) and detection at 265 nm. The QuEChERS method is inexpensive, fast and easy, and the extraction of the analytes of the matrix was successfully employed. In addition, the method presented linearity, in the range of 30 to 200 µg kg-1, for SDZ, and 25 to 200 µg kg-1,for SMX and SPZ. The precision, evaluated by repeatability and intermediate precision, presented relative standard deviation of1.4 to 14% forlow, medium and high levels of the linear range. The detectability of the method was satisfactory, since the limits of detection and quantitation obtained were 10 and 25 mg kg-1, respectively, and the maximum residue limit recommended by the Ministry of Agriculture, Livestock and Supply of Brazil is equal to100 mg kg-1. The procedure of sample preparation QuEChERS is simple, fast and has been successfully used in the matrix studied. The results suggest that the method developed is useful for monitoring residues of SMX, SDZ and SPZ in samples of chicken breast, since its performance meets all the requirements and criteria acceptable in accordance with regulatory guides, including the Community European and Ministry of Agriculture, Livestock and Supply of Brazil, for the evaluation of residues in foods, aiming to consumer safety.