Dual detector with fluorescence/contactless conductometry for capillary electrophoresis

A dual detector with fluorescent and contatless conductometric measurements for capillary electrophoresis was constructed and evaluated. The detector shares a common detection zone and has synchronized responses in both detection modes. Conditions of excitation voltage and its frequency on contactless conductometric response were optimized. In fluorescent detection, a high-brighness light-emitting diode ( LED ) of 470 nm was used as excitation source, and an optical fiber was used to collect and transmit the emitted fluorescence to a photomultiplier tube. Model mixture of six inorganic ions and fluorescein isothiocyanate ( FITC ) was used to evaluate the performance of the dual detector in capillary electrophoresis. The results showed that the performance of the detector was the same as those of any individual detector.