Double-Cross Hydrostatic Pressure Sample Injection for Chip CE: Variable Sample Plug Volume and Minimum Number of Electrodes

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• 作者：Yong Luo ; Dapeng Wu ; Shaojiang Zeng ; Hongwei Gai ; Zhicheng Long ; Zheng Shen ; Zhongpeng Dai ; Jianhua Qin ; Bingcheng Lin
• 刊名：Analytical Chemistry
• 出版年：2006
• 出版时间：September 1, 2006
• 年：2006
• 卷：78
• 期：17
• 页码：6074 - 6080
• 全文大小：363K
• 年卷期：v.78,no.17(September 1, 2006)
• ISSN：1520-6882

文摘

A novel sample injection method for chip CE was presented. This injection method uses hydrostatic pressure,generated by emptying the sample waste reservoir, forsample loading and electrokinetic force for dispensing.The injection was performed on a double-cross microchip.One cross, created by the sample and separation channels, is used for formation of a sample plug. Anothercross, formed by the sample and controlling channels, isused for plug control. By varying the electric field in thecontrolling channel, the sample plug volume can belinearly adjusted. Hydrostatic pressure takes advantageof its ease of generation on a microfluidic chip, withoutany electrode or external pressure pump, thus allowing asample injection with a minimum number of electrodes.The potential of this injection method was demonstratedby a four-separation-channel chip CE system. In thissystem, parallel sample separation can be achieved withonly two electrodes, which is otherwise impossible withconventional injection methods. Hydrostatic pressuremaintains the sample composition during the sampleloading, allowing the injection to be free of injection bias.