Analytical & Testing Center, Sichuan University, Chengdu 610064, China.
J Chromatogr A. 2010 Aug 27;1217(35):5622-7. doi: 10.1016/j.chroma.2010.06.070. Epub 2010 Jul 1.
In order to extend the application of field amplified sample injection (FASI) in high throughput analysis, a convenient and simple procedure, namely two-end field amplified sample injection (TE-FASI), was developed for the simultaneous stacking of cationic and anionic compounds in a single run capillary zone electrophoresis (CZE). Following the capillary-filling with a buffer of high conductivity, water plug was loaded into each end of the capillary; and two high-field strength zones were generated at both heads of the column when high voltage was applied. Therefore, under suppressed EOF cations and anions can be selectively FASI stacked at anode and cathode head, respectively. After separation, the stacked anions and cations are detected by a common detector placed in the center of the capillary. Under the optimized conditions, the limits of detection for the model cationic (matrine and oxymatrine) and anionic (5-sulfosalicylic acid) compounds were determined as 0.2, 0.2 and 0.06 ng/mL, respectively. Compared with non-stacking conditions, the sensitivities of these compounds were enhanced 1003-, 1330- and 1380-fold, respectively. The results of reproducibility, linearity and real sample analysis show that the proposed procedure is promising to be applied for the simultaneous quantification detection of trace cationic and anionic analytes.
为了将场放大进样（FASI）在高通量分析中的应用扩展，开发了一种简便的方法，即两端场放大进样（TE-FASI），用于在单次运行毛细管区带电泳（CZE）中同时堆积阳离子和阴离子化合物。在用高电导率缓冲液填充毛细管后，将水塞加载到毛细管的每一端；当施加高电压时，在柱的两端会产生两个高强度场区域。因此，在抑制的EOF 下，阳离子和阴离子可以分别在阳极和阴极头处选择性地进行 FASI 堆积。分离后，堆积的阴离子和阳离子由放置在毛细管中心的通用检测器检测。在优化条件下，模型阳离子（苦参碱和氧化苦参碱）和阴离子（5-磺基水杨酸）化合物的检测限分别确定为 0.2、0.2 和 0.06 ng/mL。与非堆积条件相比，这些化合物的灵敏度分别提高了 1003、1330 和 1380 倍。重现性、线性和实际样品分析的结果表明，该方法有望用于痕量阳离子和阴离子分析物的同时定量检测。
