An on-column miniature conductivity cell and a photocouple separator for conductivity detection by capillary electrophoresis

A new miniature conductivity cell was developed as a conductivity detector in conjunction with the capillary electrophoresis system. The advantages of this cell were found to be the large electrode area, minimal dead volume, good resolution and high sensitivity. Moreover, the effect of common ground between the high voltage electrophoresis circuit and the detection system was eliminated effectively by a specially designed photocouple separator. This system was used successfully for the determination of amino acids in hydrolysed samples of human hair.