Indirect chemiluminescence detection for capillary zone electrophoresis of monoamines and catechol using luminol-K3[Fe(CN)6] system

Indirect chemiluminescence (ICL) detection for capillary electrophoresis (CE) of monoamines and catechol using luminol-K3[Fe(CN)6] system was described. A strong and stable background chemiluminescence (CL) signal can be generated by luminol-K3[Fe(CN)6] reaction. Based on the principle of that some phenolic compounds may be oxidized in the presence of K3[Fe(CN)6], quenching effect of catecholamines for luminol-K3[Fe(CN)6] CL reaction results in a quantifiable decrease in the background signal. The conditions for CE separation and the CL detection for four standard catecholamines were systematically investigated using a homemade CE–ICL system. Under the optimum conditions, the detection limits of dopamine (DA), epinephrine (EP), norepinephrine (NE) and catechol (CA) were determined to be 0.18 μM 0.39 μM 0.48 μM and 0.09 μM, respectively. It also has been successfully applied to analyze seven pharmaceutical samples and seven human urine samples.