Electrochemical Behavior of Folic Acid at a Boron-Doped Diamond Electrode: Its Adsorptive Stripping Voltammetric Determination in Tablets

Abstract

The electrochemical properties of folic acid were investigated in pH range 1.0-9.0 by cyclic, linear sweep and adsorptive stripping voltammetry. The compound was irreversibly oxidized at an anodically pretreated boron-doped diamond electrode in one or two oxidation steps, which are concentration- and/or pH-dependent. Using square-wave stripping mode, folic acid yielded well-defined voltammetric responses in both 0.1M perchloric acid and 0.1M Britton-Robinson buffer, pH 6.0 with limits of detection 0.035 μg/mL (7.93 10-8 M) and 0.14 μg/mL (3,2 × l0-7 M), respectively, after an accumulation of 120 s at open-circuit condition. Practical applicability of the newly developed approach was verified by the direct assays of tablet dosage forms.