Determination of berberine in Rhizoma coptidis using a β-cyclodextrin-sensitized fluorescence method

Abstract

In this work, a method for the determination of berberine in Rhizoma coptidis using β-cyclodextrin-sensitized fluorescence technology is established. Berberine is the main extract of Rhizoma coptidis, a medicinal material, which causes an envelope reaction with β-cyclodextrin to generate fluorescence sensitization. In the environment of its own aqueous extract, with 0.0065 mol L⁻¹ of β-cyclodextrin, a fluorescence excitation wavelength (λ_ex) of 345 nm and an emission wavelength (λ_em) of 540 nm were selected to avoid interference from other distractors. The fluorescent sensor for the detection of berberine exhibits a low limit of detection (3.59 × 10⁻⁹ mol L⁻¹) and a wide linear range from 2.7 × 10⁻⁷ mol L⁻¹ to 2.7 × 10⁻⁶ mol L⁻¹. Our sensor can be also used to detect berberine in real medicinal materials. The content of berberine in Rhizoma coptidis medicinal material was found to be 7.60% using this method with an average recovery rate of 99.5%. The result obtained by thin-layer chromatography with fluorescence detection was 7.61%, which is consistent with the result from the β-cyclodextrin sensitized fluorescence method. This method is simple and environmentally friendly with high sensitivity and good selectivity and gives reliable results, which is promising for practical application.