Anti‐cancer Herbal Drug Berberine – Sensitive Determination Using Boron‐doped Diamond Electrode

Determination of berberine, an isoquinoline plant alkaloid, with antibacterial, antiparasitic, antifungal, hypotensive and antitumoral effects, was proposed by introducing square wave voltammetry on boron‐doped diamond electrode. At optimized experimental parameters, in Britton‐Robinson buffer solution pH 5 berberine provides 3 oxidation peaks (+0.63; +1.14 and +1.34 V) and one reduction (+0.15 V) (vs. Ag/AgCl electrode), with good repeatability (relative standard deviation of 2.6 % and 1.9 % for 8 measurements at 0.5 and 10 µM concentration level, respectively). Calibration curve was linear in wade linear range from 0.1 to 50 µM with limit of detection of 0.04 µM. The proposed procedure was successfully applied for the determination of berberine in seed extract from Argemone mexicana with satisfactory recovery (102–102.6 %). The developed method may represent a sensitive alternative to highly toxic mercury electrodes, modified electrodes and chromatographic methods.