Abstract: Disclosed is a method for and an apparatus for detecing amines or amino acids, which apparatus generally includes a capillary electrophoresis separation tube with a post-capillary reactor positioned at the end of the tube to immediately receive separated samples from the tube. The post-capillary reactor includes a solution of Ru(bpy).sub.3.sup.2+ buffered with a base. The post capillary reactor further includes an electrode assembly for providing current to the solution to convert nonluminescing Ru(bpy).sub.3.sup.2+ to luminescing Ru(bpy).sub.3.sup.3+. The method generally includes separating the desired analyte from the sample, contacting the analyte with the solution to produce luminescence, and then photometrically measuring the amount of analyte present as a function of the luminescence.