新型毛细管电泳非接触电导检测器的设计

Design of novel contactless conductivity detector for capillary electrophoresis

基于电容耦合设计了一种集激励信号发生器、检测池和检测电路于一体的新型毛细管电泳非接触电导检测器,介绍了检测器原理、检测池结构以及电路组成。用常见阴离子混合物(C l-,NO2-,NO3-,SO42-和H2PO4-)对该检测器的性能进行了测试。结果表明:基于3倍基线噪音,检出限除H2PO4-为250μg/L外,其他离子均为10μg/L。峰高的相对标准偏差均小于5%(n=10)。该检测器操作方便、结构简单,具有较高的灵敏度,其分析性能优于多参数传感器。

Based on capacitively coupling principle, a novel contactless conductivity detector for capillary electrophoresis is designed, which integrates excitation signal generator, detection cell and circuit. The working principle,configuration of the detection cell and framework of the electronics used in the present detector are described. The performances of the detector have been demonstrated for the separation of a common anion mixture composed of Cl^- ,NO2^- ,NO3^- ,SO4^2- and H2PO4^-. Experimental results show that detection limits of 10μg/L can be obtained for all anions of interest except for H2PO4^-（250μg/L） based on three times baseline noise. Relative standard deviations of the peak height are less than 5 % for all anions of interest （n = 10）. The detector has great flexibility in capillary handling and rather simple mechanical parts and electronics, possesses higher sensitivity. Its performances are superior to multiparameter sensors.