Abstract:

A method was developed for determining residual sulfonamides (SAs) such as sulfamethazine (SM2), sulfamonomethoxine (SMM), sulfamethiazole (SMZ), sulfadimethoxine (SDM) and sulfaquinoxaline (SQ) in pork and chicken using solid-phase extraction (SPE) and high performance liquid chromatography (HPLC) with a photodiode array detector. The samples were extracted with ethyl acetate. An NH2 column was used for clean up. For the HPLC determination, an Intersil ODS-2 column was used with a mixture of methanol-acetonitrile-water-acetic acid (2∶2∶9∶0.2, v/v) as the mobile phase. The detection limits (S/N=3) were 3 μg/kg for SM2， SMM and SMZ, and 7 μg/kg for SDM and SQ. The quantitation limits (S/N=10) were 10 μg/kg for SM2, SMM and SMZ, and 25 μg/kg for SDM and SQ. The linear ranges were 30-5000 μg/L for SM2, SMM and SMZ, and 60-5000 μg/L for SDM and SQ. The recoveries were between 73.2% and 97.3% with the relative standard deviations between 2.5% and 11.6% originated from the spiked level of 50 μg/kg.

Key words: high performance liquid chromatography, meat , residues, sulfonamides, solid-phase extraction