RESUMO
Sulfanilamide is a common antibacterial drug that is used in clinical practice and in the industry. However, its abuse has emerged as a serious problem in the aquaculture industry, and more predominantly in the poultry industry, where it is administered for therapeutic purposes or as a growth promoter. In this study, a novel technical platform, heat-assisted desorption-dielectric barrier discharge ionization mass spectrometry (HAD-DBDI-MS), was used to detect sulfanilamide in situ. A method for the rapid identification of five typical sulfanilamide drugs sulfamopyridine, sulfamethoxan, sulfamethoxoline, sulfamidine, and sulfamethoxazole was established after optimizing a series of parameters. Secondary mass spectrometry was used to distinguish the sulfanilamide drugs from one another and from other isomers. Our HAD-DBDI-MS method enhanced the sulfanilamide sensitivities by reducing the limits of detection by about 1-2 orders of magnitude compared to those obtained with the DBDI-MS method. As further research, the profiles of chicken feed with added sulfamopyridine standard as well those of commercial feed with added sulfamidine and sulfamethoxazole were obtained using HAD-DBDI-MS respectively. With the HAD-DBDI-MS method, sulfamopyridine could be directly detected in the complex chicken meat matrix. However, satisfactory results were not obtained when direct HAD-DBDI-MS was used for sulfamidine and sulfamethoxazole detection in the feed matrix. The identification ability was improved when methanol was introduced as the assisting solvent. In this method, chicken feed spiked with sulfamidine and sulfamethoxazole standards were pressed into tablets, and methanol was dropped on the tablet surface. The experimental data indicate that HAD-DBDI-MS is suitable for the rapid identification of sulfanilamide drugs in poultry feed and meat products, thus showing potential value as a detection tool for future application.