| Summary: | 碩士 === 靜宜大學 === 應用化學系 === 100 === During the last decades, sulfonamides have been widely used in veterinary medicine. Now, sulfonamides are used to not only treat diseases but also be promoted animal growth. It may cause medicine residual and microbial resistance. According to related reports that sulfonamides are stable in the environment because they are resistant to biodegradation. So, it is necessary to develop a method for determining of sulfonamides. Five sulfonamides, such as sulfamethoxazole, sulfathiazole, sulfadiazine, sulfamethazine, sulfadimethoxine, were extracted by voltage-assisted liquid-phase microextraction (VA-LPME) and analyzed by capillary electrophoresis (CE) in this study. The parameters of VA-LPME, such as donor phase, acceptor phase, organic solvent, equilibrium time, stirring rate, and voltage-applied, were also studied. The optimal condition of VA-LPME were donor phase of 20 mM phosphate (pH 4.5); acceptor phase of 0.01 M NaOH; stirring rate of 750 rpm; 2-octanone; equilibrium time 20 min. Good liner range (50-1000 ng/mL, r2 ≥0.995) and complying with regulatory requirements of maximum residue levels (100 ng/mL), acceptable limit of detection (8.2-16.2 ng/mL) were obtained. VA-LPME could reduce the equilibrium time and provide a good reproducibility. It could be applied in determination of water samples, and the acceptable relative recoveries were gained from 79.4 to 89.3%. The parameters affected separating efficiency of CE, such as pH, the type of buffer, ionic strength, were investigated. The optimized conditions of CE were 70mM phosphate buffer (pH7.5), 25 kV and within 10 minutes.
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