电容耦合非接触电导检测器的研制

Construction of capacitively coupled contactless conductivity detector

利用电容耦合的原理,将环形电极直接包在石英毛细管外壁,研制成一种电容耦合非接触电导检测(C^4D)。采用毛细管电泳技术评价了该检测器,对碱金属、碱土金属的浓度检测限为5×10^(-7)～5×10^(-6)mol/L,响应值在10^(-6)～10^(-3)mol/L的线性相关系数R>0.999。该检测器结构简单,彻底克服了电化学检测器电极易污染的缺点。

A capacitively coupled contactless conductivity detector (C4D) for capillary electrophoresis (CE) was constructed and evaluated. The detector consists of two hollow electrodes around the CE capillary and a electronic circuit. Under optimized conditions, the concentration detection limits for six alkali metals and alkaline-earth metals were 5×10-7-5×10-6mol/L, with linear dynamic range from 10-6 to 10-3 mol/L (linear regression coefficient r≥0.999). The advantages of the C4D are simple in structure, free of electrodes contamination, and robust in operation.