우유중의 잔류 설파제 동시 다제 분석법에 관한 연구

Simultaneous determination of multiple sulfonamide residues in milk

A new multiresidual analysis method was developed to determine 8 sulfonamides-sulfanilamide (SNL), sulfathiazole (STZ), sulfamerazine (SMR), sulfamethazine (SMZ), sulfisoxazole (SIX), sulfamonomethoxine (SMM), sulfadimethoxine (SDM), and sulfaquinoxaline (SQM) in milk. The milk sample was deproteinated with acetone and defatted with hexane. The residual sulfonamides were extracted with ethyl acetate, concentrated under vacuum, reconstituted with the acetate buffer-methanol mixture, reacted with fluorescamine, and then analyzed by HPLC-fluorescence detector (Ex. 395 nm, Em.495 nm) with methanol : acetate buffer (3/2, v/v) as a mobile phase. The results obtained in this experiment were summarized as follows; 1. All the sulfonamides tested were separated well. on the HPLC chromatogram. The retention times of SNL, STZ, SMR, SMZ, SIX, SMM, SDM and SQN were 6.45, 7.50, 8.00, 8.60, 8.85, 9.20, 11.95 and 14.15 minutes, respectively. 2. The minimal detectable concentration of each sulfonamide was 2.25 ppb for SNL, 3.29 ppb for SIX, 3.50 ppb for SMM, 3.62 ppb for SMR, 4.21 ppb for STZ, 4.34 ppb for SDM, 4.89 ppb for SMZ and 10.00 ppb for SQN. 3. When sulfonamides were injected into HPLC with the amounts of 0.5 ng, 1 ng, 2 ng and 5ng to obtain the calibration curves, the fluorescence intensities were proportionally increased to the amounts of sulfonamides injected. 4. When sulfonamides were fortified into milk at the levels of 10 and 20 ppb, extracted and quantitated under the conditions described in the text, the recovery rates were 53.3-97.5% and 57.2-95.1%, respectively. 5. The fluorescence intensities of the sulfonamide-fluorescamine fluorophors were highest at 1 hour, and were stable up to 4 hours after the reaction.