Serge MBOKOU FOUKMENIOK

International Institute of Tropical Agriculture, IITA-Benin

Title: Functionalization of Arabic Gum by both oxidation and acylation: Application as sensing materials for the electrochemical determination of phenolic compounds

---

Biography

Serge MBOKOU, born on October 29, 1988 in Dschang (Cameroon). PhD in Electrochemistry and Chemistry of Materials since 2017. During the doctoral internship at the Angers University (France), I worked on the development of electrochemical modified electrodes for environmental purposes and for quality control analyses. In addition, I developed for the first time a fungal biofuel cell type Acetaminophen/O2, where electrodes were used for monitoring the anodic compartment. In May 2018, I went for a postdoctoral internship at the University of Ouagadougou (Burkina Faso), where I developed electrodes dedicated to pesticide residues. Since May 2021, I work as postdoctoral consultant at the International Institute of Tropical Agriculture (IITA-Benin), where I’m using analytical methods (HPLC, GC-MS and electrochemical techniques) to screen pesticide residues and heavy metals in various matrix. I intent to invest myself on the development of disposable kits for a rapid detection of pesticide residues in vegetables.

Abstract

Oxidation and acylation of Arabic Gum (AG) led to their use as modifiers of carbon paste electrodes for the simultaneous determination of two flavonoids (quercetin (QCT) and rutin (RUT)), and both paminophenol (PAP) and acetaminophen (APAP) in 0.1 M phosphate buffer solution (PBS), pH 6.0. The identification of different functional groups located on the surfaces of the raw, acetylated and the oxidized AG was performed using Fourier transform infrared spectroscopy (FT-IR). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used to investigate the electrochemical behavior of QCT, RUT, PAP and APAP on both modified electrodes. The electrochemical responses of tested compounds increased significantly when the electrode was firstly modified with acylated gum in comparison to the unmodified electrode. The obtained signals became more important with the insertion of oxidized gum in the carbon paste. Using oxidized AG modified carbon paste electrode (OAG-CPE), the linear range of the determination for both QCT and RUT was 0.020-0.090 mg L-1, and that for both PAP and APAP was from 1.000 to 9.000 mg L-1. The limit of detections (3S/m) were found to be 0.005, 0.023, 0.039 and 0.105 mg L-1 for QCT, RUT, PAP and APAP respectively. The application of the present approach was firstly for the direct quantification of exact amount of APAP in commercialized tablets of Doliprane® 500 with a recovery of 94.30%, and secondly, for the simultaneous detection of both QCT and RUT in human urine.