INDIRECT FLUORESCENCE DETECTION IN MICELLAR ELECTROKINETIC CHROMATOGRAPHY

Detection of neutral analytes separated by micellar electrokinetic capillary chromatography (MECC) has been accomplished by indirect fluorescence detection using quinine sulfate as the visualizing agent. The separation buffer was composed of 100.0 mM sodium dodecyl sulfate (SDS) and 0.50 mM quinine sulfate at a pH of 6.8. The detection mechanism involves a combination of displacement of the fluorophore from the micelle by the analytes and net reduction of the quantum efficiency of the fluorophore in the sample zone. The selectivity of this detection technique is demonstrated with data showing the separation of several aliphatic alcohols and some phenolic compounds. The effect of quenching by the analyte on the sensitivity of detection is also discussed.