Capillary electrophoresis with indirect electrochemiluminescence detection

An indirect electrochemiluminescence (IECL) detection for capillary electrophoresis (CE) is presented in this article. IECL is based on the inhibition of Ru(bpy)(3)(2+)/TPA system. The developed technique is successfully applied to the analysis of phenolic compounds: phenol, o-chlorophenol, p-nitrophenol, and 2,4,6-trinitrophenol. The factors that influenced the separation and detection were investigated in detail. On the optimized condition, the tested phenols (phenol, o-chlorophenol, p-nitrophenol, and 2,4,6-trinitropheno) could inhibit the ECL signal from the luminescence reagent, and the components of the mixture could be separated and recognized. In addition, when 2 mM phenol was the analyte, the relative standard deviations for migration time and negative peak height were 0.27% and 2.29%, respectively (n = 6). And the linear correlation coefficient was 0.996 for phenol (0.5-5 mM). The preliminary results showed that the CE-IECL might be applied to the detection of phenolic compounds or other samples.