Sulfonamide residue in honey existed in a form bonded to sugar via the N-glycosidic bond.It would result in the possible underestimation of concentration of sulfonamide if it is not decomposed by chemical methods.However,in China's Mainland and Taiwan（P.R.China）,the regulation for sulfonamide residue analysis does not include hydrolysis and has been applied to a very broad range of samples,for example,egg,milk,meat,seafood as well as honey.This paper demonstrates the necessity of hydrolysis of it prior to extracting honey.The breaking efficiencies of N-glycosidic bond were investigated by 2 mol/L hydrochloric acid,pure methanol and 0.5 mol/L hydrochloric acid in methanol,respectively.It was found that acid plays the key role in breaking the N-glycosidic bond,and it was also noticed that the dissolution of liberated sulfonamide in methanol could carry the reaction forward in favor of breaking the N-glycosidic bond.
WANG Yan-huaLI LiCHEN Chia-hungCHENG Shuenn-renLEE Mu-shengYU Pu-pingCHANG-CHIEN Guo-ping]
