Simulation and Experimental Study on Doubled-Input Capacitively Coupled Contactless Conductivity Detection of...

In this contribution, we optimize the structure of double-input capacitively coupled contactless conductivity detector (DIC⁴D) that proposed before by our group and successfully applied it in the capillary electrophoresis of inorganic ion analysis. Furthermore, we present the detail theoretical analysis and simulation to exploring the working mechanism of DIC⁴D. Compared with C⁴D, under identical experimental conditions and by using the same current-to-voltage converter, both the theoretical and experimental results suggest that the effectiveness and feasibility of DIC⁴D. The improved DIC⁴D diminished the baseline drift effects in C⁴D, provides lower noise, higher sensitivity and notably stable baseline. The LODs of DIC⁴D are 1.0 μM for K⁺ and 1.5 μM for Li⁺ (S/N = 3). DIC⁴D provides a better linear relationship (R = 0.997 and 0.998 for K⁺ and Li⁺, respectively) with the range of 2.0 μM ~ 2.5 mM.