Small-Bore LC/Laser Fluorescence

Laser-induced fluorescence detectors are discussed regarding their suitability for different miniaturized liquid chromatographic (LC) systems. In this respect, four different flow cell designs are critically evaluated. The limiting flow rate of the free falling jet detector was experimentally determined. A flow rate of 20 µl/min is obtainable; thus, the detector can be used with small-bore LC columns. Experiments were also performed to study the dispersion in fused-silica capillaries of different dimensions. Laserinduced on-column fluorescence detection was then found to be very practical with cell volumes less than 1 nl. Applications of laser-based detectors for small-bore LC are reviewed.