Enhancement of native fluorescence intensity of berberine by (2-hydroxypropyl)-β-cyclodextrin in capillary electrophoresis coupled by laser-induced fluorescence detection: Application to quality control of medicinal plants

•Berberine is a plant alkaloid.•There has been a growing interest on the pharmaceutical activities of berberine.•A sensitive CE–LIF method was developed for the determination of berberine.•The fluorescence intensity of berberine was enhanced by 2-HP-β-CD.•The developed method was successfully applied to medicinal plants and supplements. A sensitive method for the determination of berberine, a plant alkaloid, was developed by capillary electrophoresis coupled with laser induced fluorescence detection. With the addition of (2-hydroxypropyl)-β-cyclodextrin (2-HP-β-CD) to the separation electrolyte, the low fluorescence signal intensity of berberine in aqueous medium was enhanced considerably by 162 fold. The optimal background electrolyte was selected as 20mM acetic acid, 35mM 2-HP-β-CD, and 20% methanol at pH 5. The limit of detection of the method for berberine was 15.7ng/mL. The intra and interday repeatabilities of corrected peak areas as RDSs were 1.83% and 3.75%, respectively. The developed method was successfully applied for the determination of berberine contents in Chinese medicinal plants and herbal supplemental tablets.