A lamp light-emitting diode-induced fluorescence detector for capillary electrophoresis

A light-emitting diode-induced fluorescence detector (LED-FD) for capillary electrophoresis was constructed and evaluated. A lamp LED with an enhanced emission spectrum and a band pass filter was used as the excitation light source. Refractive index matching fluid (RIMF) was used in the detection cell to reduce scattering light and the noise level. The limit of detection (LOD) for fluorescein was 1.5 nM (SNR = 3). The system exhibited linear responses in the range of 1 × 10−8 to 5 × 10−6 M (R = 0.999). Application of the lamp LED-FD for the analysis of FITC-labeled ephedra herb extract by capillary electrophoresis was demonstrated.