Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
Anal Chem. 2012 Jun 5;84(11):4739-45. doi: 10.1021/ac3001836. Epub 2012 May 18.
A gradient elution system for pressure-driven liquid chromatography (LC) on a chip was developed for carrying out faster and more efficient chemical analyses. Through computational fluid dynamics simulations and an experimental study, we found that the use of a cross-Tesla structure with a 3 mm mixing length was effective for mixing two liquids. A gradient elution system using a cross-Tesla mixer was fabricated on a 20 mm × 20 mm silicon chip with a separation channel of pillar array columns and a sample injection channel. A mixed solution of water and fluorescein in methanol was delivered to the separation channel 7 s after the gradient program had been started. Then, the fluorescence intensity increased gradually with the increasing ratio of fluorescein, which showed that the gradient elution worked well. Under the gradient elution condition, the retention times of two coumarin dyes decreased with the gradient time. When the gradient time was 30 s, the analysis could be completed in 30 s, which was only half the time required compared to that required for an isocratic elution. Fluorescent derivatives of aliphatic amines were successfully separated within 110 s. The results show that the proposed system is promising for the analyses of complex biological samples.
一种用于芯片上压力驱动液相色谱（LC）的梯度洗脱系统被开发出来，用于进行更快、更有效的化学分析。通过计算流体动力学模拟和实验研究，我们发现使用具有 3 毫米混合长度的交叉特斯拉结构对于混合两种液体是有效的。使用交叉特斯拉混合器的梯度洗脱系统被制造在一个 20 毫米×20 毫米的硅芯片上，具有一个分离通道的柱列和一个样品注入通道。在梯度程序开始 7 秒后，将水和甲醇中的荧光素混合溶液输送到分离通道。然后，荧光强度随着荧光素比例的增加而逐渐增加，表明梯度洗脱效果良好。在梯度洗脱条件下，两种香豆素染料的保留时间随着梯度时间的增加而减小。当梯度时间为 30 秒时，分析可以在 30 秒内完成，这只是等度洗脱所需时间的一半。脂肪胺的荧光衍生物在 110 秒内成功分离。结果表明，所提出的系统有望用于分析复杂的生物样品。
