Reaction Products of Sulfamethazine and Sodium Nitrite in Swine Muscle Tissues

Abstract

Sulfamethazine (SMZ) is an effective animal drug and is extensively used to treat acute and chronic bacteria infections and to enhance growth in swine. Residual SMZ in animal muscle tissues could react with sodium nitrite during further processing. This study investigated reaction products of SMZ and sodium nitrite in different reaction matrices including in vitro conditions, spiked and incurred in swine muscle tissues. Results from the in vitro study indicated that sodium nitrite and SMZ reacted and produced yellow precipitates under acid conditions. Three major reaction products were detected in the precipitates with molecular weights of 503, 556, and 567, respectively. The compound with molecular mass 567 could be l, 3-di-(4-[N-(4, 6-dimethyl-2-pyrimidinyl)] sulphamoyl-phenyl)-triazen. Three major compounds were detected in the supernatant of the reaction mixture, with molecular weights 307, 279, and 263, respectively. Those could be 4-diazohydroxy-N-(4, 6-dimethyl-2-pyrimidinyl) benzene-sulfonamide, 4-hydroxy-N-(4, 6-dimethyl-2-pyrimidinyl) benzene-sulfonamide, and desaminosulfamethazine, respectively. Only the molecular weight 279 and the molecular weight 263 compounds were detected in the reaction supernatant of the SMZ-spiked swine muscle tissues. Only the molecular weight 263 compound was detected in the reaction supernatant of the SMZ-incurred swine muscle tissues. Possible mechanisms for deriving these compounds were proposed.