Fluorescence detection in short capillary and chip using a variable wavelength epi-fluorescence microscope

Fast, efficient separation of five free acid forms of porphyrins was achieved in a short capillary and a chip, respectively. The capillary was 6 cm long from injection end to detector with an electric field strength of 214 V cm(-1). Separations were performed within 5 min. A glass microchip device was fabricated using standard photolithographic procedures and chemical wet etching. The channels were sealed using a direct bonding technique. For a separation length of 2.8 cm with electric field strength of 500 V cm(-1), electrophoretic separations with baseline resolution were achieved in less than 2 min. A variable wavelength epi-fluorescence microscope was used as an on-column detector.