# Electroanalysis of Apocynin Part 2: Investigations on a Boron-Doped Diamond Electrode in Aqueous Buffered Solutions

## TL;DR

This paper presents a new voltammetric method for detecting apocynin using a boron-doped diamond electrode in a phosphate buffer, offering a simple and environmentally friendly approach.

## Contribution

The first voltammetric method for apocynin detection using a boron-doped diamond electrode in a phosphate buffer is developed.

## Key findings

- The oxidation of apocynin is quasi-reversible and involves one electron and one proton.
- The method shows a linear response in the concentration range of 0.213–27.08 mg L−1.
- The method was successfully applied to determine apocynin in a dietary supplement.

## Abstract

In this study, the voltammetric behavior of apocynin on a boron-doped diamond electrode in a phosphate buffer (pH 7.3) has been reported for the first time. The oxidation process is quasi-reversible, diffusion-controlled, and involves one electron and one proton. The product of the electrode reaction is an unstable radical that undergoes successive chemical transformations near the working electrode. The proposed mechanism of this process can be described as EqCi and served as the basis for the development of a new voltammetric method for determining apocynin in natural samples. The analytical signal was the anodic peak on DPV curves at a potential of 0.605 V vs. Ag/AgCl. A linear response was observed in the concentration range of 0.213–27.08 mg L−1. The estimated LOD and LOQ values were 0.071 and 0.213 mg L−1, respectively. The effectiveness of the method was demonstrated both in control determinations and in the analysis of the dietary supplement. This procedure is simple, fast, sensitive, selective, and requires no complicated sample preparation, which is limited only to a simple extraction with ethanol. The low consumption of non-toxic reagents makes it environmentally friendly. To the best of our knowledge, this is the first presentation of a voltammetric procedure to determine this analyte studied in a phosphate buffer solution on a boron-doped diamond electrode. It can also be easily adapted to determine other phenolic compounds with antioxidant properties in various matrices.