On-line sensitive chemiluminescence detection of trace amounts of polyphenols using MEKC

A high-performance capillary electrophoresis with chemiluminescence detection (CE-CL) method has been developed for the determination of three polyphenols (catechol, hydroquinone and pyrogallol) in this work. The effects of several factors such as the acidity and concentration of running buffer, the applied voltage, the injection time, the pH and concentration of CL reagents were investigated in detail. Under the optimum conditions, the baseline separation of three polyphenols was obtained within 6 min. Detection limit (S/N = 3) was 1.0 x 10(-10) M for catechol, 1.0 x 10(-9) M for hydroquinone and 3.0 x 10(-11) M for pyrogallol, respectively. The excellent detection limits of the analytes were 1-5 order lower than that of methods reported in literatures.