Department of Applied Science, National Taitung University, 684, Section 1, Chunghua Road, Taitung, 95002, Taiwan.
Anal Bioanal Chem. 2014 Jan;406(2):635-41. doi: 10.1007/s00216-013-7481-1. Epub 2013 Nov 19.
A simple, low-cost, and efficient online focusing method that combines a dynamic pH junction and sweeping by capillary electrophoresis with polymer solutions was developed and optimized for the simultaneous determination of benzoic acid (BA) and sorbic acid (SA). A sample solution consisting of 2.5 mM phosphate at pH 3.0 and a buffer solution containing 15 mM tetraborate (pH 9.2), 40 mM sodium dodecyl sulfate, and 0.100 % (w/v) poly(ethylene oxide) were utilized to realize dynamic pH junction-sweeping for BA and SA. Under the optimized conditions, the entire analysis process was completed in 7 min, and a 900-fold sensitivity enhancement was achieved with limits of detection (S/N = 3) as low as 8.2 and 6.1 nM for BA and SA, respectively. The linear ranges were between 20 nM and 20 μM for BA and 20 nM and 10 μM for SA, with correlation coefficients greater than 0.992. The recoveries of the proposed method ranged from 90 to 113 %. These satisfactory results indicate that this method has the potential to be an effective analytical tool for the rapid screening of BA and SA in different food products.
开发并优化了一种简单、低成本且高效的在线聚焦方法，该方法结合了动态 pH 结和聚合物溶液的胶束电动毛细管色谱（MECC）扫集，用于同时测定苯甲酸（BA）和山梨酸（SA）。该方法采用由 2.5 mM 磷酸盐（pH 3.0）组成的样品溶液和含有 15 mM 四硼酸钠（pH 9.2）、40 mM 十二烷基硫酸钠和 0.100%（w/v）聚环氧乙烷的缓冲溶液来实现 BA 和 SA 的动态 pH 结-扫集。在优化条件下，整个分析过程在 7 分钟内完成，BA 和 SA 的检测限（S/N = 3）分别低至 8.2 和 6.1 nM，灵敏度提高了 900 倍。BA 的线性范围为 20 nM 至 20 μM，SA 的线性范围为 20 nM 至 10 μM，相关系数均大于 0.992。该方法的回收率在 90%至 113%之间。这些令人满意的结果表明，该方法有可能成为快速筛选不同食品中 BA 和 SA 的有效分析工具。
