Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, Minamiohsawa, Hachioji, Tokyo 192-0397, Japan.
Talanta. 2013 Mar 30;107:111-7. doi: 10.1016/j.talanta.2012.12.058. Epub 2013 Jan 8.
In this work, we propose a piezoelectric droplet generator for injection of well-defined amounts of sample in capillary electrophoresis. We demonstrate stable, precise and drop-on-demand droplet formation for various solutions, with precise control of waveform driving piezoelectric crystal inside the ink-jet head. By tuning the waveform, we can also manipulate the droplet size and delivery frequency. This injector was used in sampling for capillary electrophoresis. As a state-of-the-art application, the analysis of theobromine, caffeine and theophiline using micellar electrokinetic chromatography was developed. The volume of sample (single droplet) analyzed in this experiment was 179 pL (RSD=1.2%, n=10). The detection limits for caffeine, theobromine, and theophiline are 0.02, 0.08 and 0.06 mM L(-1), respectively. Compared with conventional methods, the combination of picoliter droplet dispenser with capillary electrophoresis allows precise and accurate sampling, as well as for reduced sample consumption, which will prove to be an efficient tool in quantitative separation and analysis.
在这项工作中，我们提出了一种用于在毛细管电泳中注射定义量样品的压电液滴发生器。我们证明了对于各种溶液可以稳定、精确和按需形成液滴，并且可以精确控制喷墨头内的压电晶体的波形。通过调整波形，我们还可以控制液滴大小和输送频率。该注射器用于毛细管电泳中的取样。作为一种最先进的应用，开发了使用胶束电动色谱法分析可可碱、咖啡因和茶碱。本实验分析的样品体积（单个液滴）为 179pL（RSD=1.2%，n=10）。咖啡因、可可碱和茶碱的检测限分别为 0.02、0.08 和 0.06mM L(-1)。与传统方法相比，皮升液滴分配器与毛细管电泳的结合允许进行精确和准确的取样，以及减少样品消耗，这将被证明是定量分离和分析的有效工具。
