Gerhardt Renata F, Peretzki Andrea J, Piendl Sebastian K, Belder Detlev
Institute of Analytical Chemistry, University of Leipzig , Linnéstraße 3, 04103 Leipzig, Germany.
Anal Chem. 2017 Dec 5;89(23):13030-13037. doi: 10.1021/acs.analchem.7b04331. Epub 2017 Nov 15.
We introduce an approach for the integration of high performance liquid chromatography and droplet microfluidics on a single high-pressure resistant microfluidic glass chip. By coupling these two functionalities, separated analyte bands eluting from the HPLC column are fractionated into numerous droplets in a continuous flowing oil phase. The compartmentalization of the HPLC-eluate in a segmented flow was performed with droplet sizes of approximately 1 nL and with droplet frequencies reaching up to 45 Hz. This approach prevents peak dispersion and facilitates post column processing of chromatographic fractions on chip. A reliable generation of droplets is also possible in reversed phase gradient elution mode as demonstrated by applying a solvent gradient from 20% to 100% acetonitrile. A chip design with an incorporated dosing unit enabled the directed postcolumn addition of reagents to individual droplet fractions. The capability of this dosing function was successfully evidenced by post column addition of a reagent which quenches the fluorescence signal of the analytes. The chip-integration of gradient HPLC, fractionation, detection and post column addition of reagents opens up new avenues to perform multistep chemical processes on a single lab-on-a-chip device.
我们介绍了一种在单个耐高压微流控玻璃芯片上集成高效液相色谱和液滴微流控的方法。通过结合这两种功能，从HPLC柱洗脱的分离分析物带在连续流动的油相中被分馏成许多液滴。在分段流中对HPLC洗脱液进行分隔时，液滴大小约为1 nL，液滴频率高达45 Hz。这种方法可防止峰展宽，并便于在芯片上对色谱馏分进行柱后处理。如通过应用从20%到100%乙腈的溶剂梯度所证明的，在反相梯度洗脱模式下也能够可靠地产生液滴。带有内置加样单元的芯片设计能够将试剂定向柱后添加到各个液滴馏分中。通过柱后添加一种淬灭分析物荧光信号的试剂，成功证明了这种加样功能的能力。梯度HPLC、分馏、检测以及试剂的柱后添加在芯片上的集成，为在单个芯片实验室设备上执行多步化学过程开辟了新途径。
