Contactless Conductivity Detection in Capillary Electrophoresis in Combination with Capillaries with Thin Inner Diameter

Sensitivity of the capacitively coupled contactless conductivity detector ((CD)-D-4) was tested in combination with silica capillaries of inner diameter (i.d.) 10 - 75 mu m. The detector response was measured in wide range of specific conductivities of KCl solutions 0 - 1295 mS.m(-1) (0 - 100 mmol/L). (CD)-D-4 in combination with wide capillary (i.d. 75 mu m) provides a high sensitivity in low conductivity solution. On the other hand the use of thin capillary is more convenient in high conductivity solutions. Advantages of CE/(CD)-D-4 analysis in thin capillaries were demonstrated at the separation of Cs+, NH4+ and K+ ions.