On-line concentration sample stacking coupled with water-in-oil microemulsion electrokinetic chromatography

详细信息    查看全文

• 作者：Hsi-Ya Huang  ; ;   ; ^{hyhuang@cycu.edu.tw} ; Wan-Ling Liu ; Brenda Singco ; Shih-Huan Hsieh ; Yung-Han Shih
• 关键词：Water-in-oil microemulsion ; Microemulsion electrokinetic chromatography ; On-line concentration ; Food sample
• 刊名：Journal of Chromatography A
• 出版年：2011
• 出版时间：21 October 2011
• 年：2011
• 卷：1218
• 期：42
• 页码：7663-7669
• 全文大小：548 K

文摘

This study describes for the first time, the ability of a normal stacking mode (NSM) on-line concentration step coupled with water-in-oil (W/O) microemulsion electrokinetic chromatography (MEEKC), using six common penicillin antibiotics (oxacillin, penicillin V, penicillin G, nafcillin, ampicillin, and amoxicillin) as test analytes. Optimization of penicillin separation in the conventional W/O MEEKC system demonstrated that change in the type and concentration of the oil phase (1-butanol) and column temperature had a pronounced effect on the separation. With the subsequent development of the NSM coupled with W/O MEEKC, improved separation and detection sensitivities were observed when an organic solvent plug (1-propanol; 1.04 cm) was placed between the W/O microemulsion and the sample solutions. This could be attributed to the solution viscosity difference between the aqueous sample zone and the organic solvent plug causing the penicillin to be stacked in this 1-propanol plug. The optimal NSM W/O MEEKC provided about 12-fold increase in detection sensitivity compared with conventional sample injection (50 mbar, 3 s). Finally, this proposed method was successfully applied in the analyses of several food samples (porcine organs) spiked with penicillin.