[A novel light-emitting diode-induced fluorescence detector for micro-scale flow analysis system].

A compact light-emitting diode-induced fluorescence detector based on collinear scheme is described. The detector was assembled by all-solid-state optical-electronic components and easily coupled with micro-scale flow analysis system by on-column detection mode. Fluorescein isothiocyanate (FITC) and FITC-labeled amino acids were used as test analytes to evaluate the detector performance by capillary electrophoresis and flow injection analysis techniques. The concentration limit of detection was 10(-8) mol (circle) L-1 for FTC-labeled phenylalanine at a signal-to-noise ratio (S/N) of 3 (on-column, 0. 05 mm i.d.). The system exhibited a good linear response in the range of 1 X 10(-7) -2 X 10(-5) mol (circle) L-1 (r(2) = 0.999). The relative standard deviation (RSD) of 6 repetitive injections on peak heights is less than 3 %.