Simultaneous Determination of 4‐Chlorophenol and Oxalic Acid Using an Expanded Graphite‐Epoxy Composite Electrode

Abstract

An expanded graphite-epoxy composite electrode (EG-Epoxy) was employed for the simultaneous determination of 4-chlorophenol (4-CP) and oxalic acid (OA) by using cyclic voltammetry (CV), chronoamperometry (CA), and differential pulse voltammetry (DPV). The results indicated that OA could be determined in the presence of the same concentrations of 4-CP within the concentration range of 0.1 mM to 0.5 mM with a relative standard deviation (RSD) smaller than 5%. Electrode fouling occurred during CA for 4-CP concentrations larger than 0.5 mM. The DPV method was used for the simultaneous determination of 4-CP and OA before and after electrochemical oxidation by chronopotentiometry under galvanostatic conditions (j ¼ 0.04 mA cm À2 , t ¼ 2 h) of a tap water sample spiked with 0.19 mM 4-CP and 0.1 M Na 2 SO 4 .

Decontamination of Wastewaters Containing Organics by Electrochemical Methods

“…Compared with the initial concentration of 4-CP, cyclic voltammogram shape recorded after chronoamperometry applying is changed, the current at the higher potential value but below oxygen evolution increased. This aspect could be explained by the intermediate formation of 4-CP oxidation which is oxidizable at higher potential value, e.g., carboxilic acid that is oxidized on composite electrode at the potential value of 1.1 V vs. SCE [59]. This behaviour is in concordance with spectrophotometric and COD results, denoting a good accuracy of the voltammteric method and suitability for degradation process control.…”

Electrochemical detection of Sudan I by using an expanded graphite paste electrode

“…Recently, EG was used as electrode material for the determination of tryptophan, phenol, and simultaneous determination of 4-chlorophenol and oxalic acid [24][25][26]. In this work, we prepared expanded graphite paste electrode (EGPE) and used it for the electrochemical determination of Sudan I.…”

Simultaneous determination of Ponceau-4R and Allura Red in soft drinks based on the ionic liquid modified expanded graphite paste electrode

“…Recently, EG was used as electrode materials for the determination of catechol [18], Sudan I [19], Sunset yellow [20], Ponceau-4R [21], simultaneous determination of 4-chlorophenol and oxalic acid [22], and simultaneous determination of Ponceau-4R and Tartrazine [23]. The presence of EG could facilitate the adsorption of the analyte and the charge transfer, and thus improved the sensitivity of resulting electrodes.…”