scholarly journals A Low-Cost Layered Double Hydroxide (LDH) Based Amperometric Sensor for the Detection of Isoproturon in Water Using Carbon Paste Modified Electrode

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Herve Leclerc Tcheumi ◽  
Aude Peggy Kameni Wendji ◽  
Ignas Kenfack Tonle ◽  
Emmanuel Ngameni

In this work, a Layered Double Hydroxide (NiAl-LDH) was obtained by coprecipitation method and used to elaborate an electrochemical sensor for the determination of isoproturon, which is a hazardous pollutant, widely used in agriculture, and its residue is distributed into aqueous environment through run-off and leaching from the soil. Various physicochemical techniques such as FT-IR spectroscopy, X-ray diffraction, and thermal analysis were used to characterize this material. The anionic exchange capacity of NiAl-LDH on carbon paste modified electrode was investigated toward [Fe(CN)6]3- using cyclic voltammetry. Used as electrode modifier of carbon paste electrode for isoproturon detection, a remarkable increase in isoproturon signal on modified carbon paste electrode by LDH was observed. The peak current obtained after 3 min of preconcentration in 25 μM ISO on NiAl-LDH/CPE was 2.6 times higher than that exhibited by the same analyte on the unmodified CPE, thereby opening the way to the development of a sensitive method for the detection of ISO. Other parameters that can affect the stripping response (preconcentration time, pH of detection medium, and LDH loading within the paste) were investigated to optimize the proposed sensor. After optimization, a linear calibration curve was obtained in the concentration range from 2 × 10−8 to 1.8 × 10−7 M, leading to a detection limit of 1 × 10−9 M (S/N = 3). The relative standard deviation for 5 identical measurements was 2.7%. The interfering effect of some compounds and ions was examined on the stripping response of ISO. The applicability of the method was verified by the determination of ISO in spiked water sample.

2021 ◽  
Author(s):  
TCHEUMI Herve Leclerc ◽  
KAMENI WENDJI Aude Peggy ◽  
TONLE KENFACK Ignas ◽  
NGAMENI Emmanuel

Abstract Environmental pollution by usage of pesticides as fenuron increases health risk, due to carcinogenic and teratogenic properties of these compounds. There are needs to develop a rapid and cheaper detection methods for quantification of fenuron. In this work, an inorganic-organic composite material was obtained by intercalation of sodium dioctylsulfosuccinate (DSS) within the interlayer space of a Nickel-Aluminum Layered Double Hydroxide (NiAl-LDH). The structure of the pristine LDH and the intercalated-LDH was confirmed using Fourier transform infrared spectroscopy, X-ray diffraction and thermal analysis. The modified LDH was used to elaborate an amperometric sensor for fenuron herbicide by differential pulse voltammetry (DPV) via a carbon paste electrode (CPE). The electrochemical procedure for fenuron analysis was based on the immersion of the working electrode in the electrolytic solution containing appropriate amount of herbicide, followed by voltammetry detection without any preconcentration step. The peak current obtained on the CPE modified by the organo-LDH was 2-fold higher in comparison with the pristine LDH/CPE. The observed increase in the signal of fenuron was attributed to the high organophilic character of this composite material induced by the modification using DSS. The effects of some experimental parameters (pH of medium and percentage of the modifier in the paste) on the stripping response were investigated in order to optimize the sensitivity of the organo-LDH modified electrode. Linear calibration curves were obtained in the fenuron concentration ranging from 0.5 to 1 μmol.L -1 and 1 to 5 μmol.L -1 . The limit of detection (LOD) calculated on the basis of a signal-to-noice ratio of 3 was 1.8×10 -9 mol.L -1 (low concentration range) and the limit of quantification (LOQ) was 6×10 -9 mol.L -1 . The interference effect of various inorganic ions likely to influence the stripping determination of the fenuron was also examined, and the applicability of the method was verified by the determination of fenuron in a river sample collected down-town Yaoundé.


2019 ◽  
Vol 84 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Mohadeseh Safaei ◽  
Hadi Beitollahi ◽  
Masoud Shishehbore ◽  
Somayeh Tajik ◽  
Rahman Hosseinzadeh

A carbon paste electrode (CPE) was modified with N-(ferrocenylmethylidene) fluorene-2-amine and graphene/ZnO nanocomposite. The electrooxidation of captopril (CAP) at the surface of the modified electrode was studied using electrochemical approaches. The electrochemical study of the modified electrode, as well as its efficiency for the electrocatalytic oxidation of captopril, is described. The electrode was used to study the electrocatalytic oxidation of captopril, by cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV) as diagnostic techniques. It has been found that the oxidation of captopril at the surface of modified electrode occurs at a potential of about 340 mV less positive than that of an unmodified CPE. DPV of captopril at the electrochemical sensor exhibited two linear dynamic ranges (0.1?100.0 and 100.0?800.0 ?M) with a detection limit (3?) of 0.05 ?M.


2010 ◽  
Vol 75 (5) ◽  
pp. 681-687 ◽  
Author(s):  
Zsigmond Papp ◽  
Valéria Guzsvány ◽  
Szymon Kubiak ◽  
Andrzej Bobrowski ◽  
Luka Bjelica

The objective of the work was to investigate the possibility of using a tricresyl phosphate-based carbon paste electrode for the direct voltammetric determination of the neonicotinoid insecticide thiamethoxam. The analyte was determined by differential pulse voltammetry in Britton-Robinson buffer pH 7.0 in the concentration range of 3.72 - 41.5 ?g mL-1. The reproducibility of the analytical signal at the 7.29 ?g mL-1 level was characterized by a relative standard deviation of 1.3 %. The applicability of the developed method was evaluated by determining thiamethoxam in a river water sample and a commercial formulation Actara 25 WG.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Venu Gopal ◽  
Tukiakula Madhusudana Reddy ◽  
P. Shaikshavali ◽  
G. Venkataprasad ◽  
P. Gopal

Abstract A small scale of environmentally hazardous 4-aminophenol can show significant impact on human health. Hence, in the present work, we have designed L-Valine film (Vf) modified carbon paste electrode (Vf/CPE) for the determination of 4-aminophenol. Herein, a facile in-situ L-Valine film was developed by electrochemical polymerization method onto the surface of bare carbon paste electrode (BCPE) with the help of cyclic voltammetry (CV) technique. A two-folds of electrochemical peak current enhancement was achieved at Vf/CPE in comparison with BCPE towards the determination of 4-aminophenol in optimum pH 7.0 of phosphate buffer solution (PBS). This was achieved due to the large surface area and conductive nature of Vf/CPE, which was concluded through the techniques of cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The effect of pH of buffer and scan rate studies were successfully studied. Morphological changes of BCPE and Vf/CPE was studied with the help of scanning electron microscopy (SEM). The formation of Vf on CPE was also analyzed by Fourier transform infrared (FTIR) spectra. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of 4-aminophenol were estimated with the aid of chronoamperometry (CA) technique and was found to be 9.8 μM and 32 μM, respectively. Finally the proposed method was found to have satisfactory repeatability, reproducibility and stability results with low relative standard deviation (RSD) values.


2020 ◽  
Vol 34 (1) ◽  
pp. 25-39
Author(s):  
Denekew Alemayehu ◽  
Bhagwan Singh Chandravanshi Chandravanshi ◽  
Tesfu Hailu ◽  
Merid Tessema

A new method has been developed for the electrochemical determination of Hg(II) with N-p-chlorophenylcinnamohydroxamic acid (CPCHA) modified carbon paste electrode by square wave anodic stripping voltammetry (SWASV). Hg(II) was accumulated on the electrode surface by the formation of the complex in an open circuit and the resulting surface was characterized by electrochemical reduction and stripping. The optimum voltammetric response was observed using a carbon paste composition of 7.5% (w/w) CPCHA and preconcentration time of 210 s in 0.1 M sodium acetate at pH 8 followed by electrochemical SWASV in 0.3 M NH4Cl solution at pH 4 at a reduction potential of -0.6 V. The voltammetric signals were linear in the range of 1-25 µM Hg(II) with a detection limit of 12.9 nM. The voltammetric response for six replicate measurements of 15 µM Hg(II) was reproduced with 3.8% relative standard deviation (RSD). Many coexisting metal ions had little or no effect on the determination of Hg(II). Five spiked samples of water were evaluated by using the developed method giving recoveries of Hg(II) in the range 98-105%.   Bull. Chem. Soc. Ethiop. 2020, 34(1), 25-39. DOI: https://dx.doi.org/10.4314/bcse.v34i1.3


2008 ◽  
Vol 91 (6) ◽  
pp. 1478-1482 ◽  
Author(s):  
Tahereh Rohani ◽  
Mohammad Ali Taher

Abstract 2-(P-sulfophenylazo)-1,8-dihydroxy-3,6-naphthalene disulfate (SPADNS) was adsorbed on surfactant modified zeolite type A by electrostatic interaction in the aqueous phase. The dye was strongly retained and not easily leached from the surfactant-modified zeolite matrix. This compound was incorporated into a carbon paste electrode for anodic stripping voltammetric determination of trace amounts of copper. The calibration plot was linear over the copper concentration range 2.0800 g/L. The detection limit was found to be 0.4 g/L Cu(II), and for 5 successive determinations of 50 and 150 g/L Cu(II) the relative standard deviations were 1.6 and 1.2, respectively. The modified electrode prepared in this study could be used for the determination of Cu(II) in water samples and human hair with good results.


2019 ◽  
Author(s):  
Chem Int

In this study voltammetric behaviour of secnidazole (SCZ) at 1, 4-Benzoquinone Modified Carbon Paste Electrode (1,4-BQMCPE) was investigated in Britton Robinson buffer solution using cyclic voltammetric technique. A well-defined cathodic peak was observed for the SCZ in the entire pH range. The current increases steadily with scan rate and the results indicated that the process is irreversible reduction and adsorption controlled. The number of electrons transferred and different kinetic parameters like transfer coefficient and rate constant were calculated by using cyclic voltammetry technique. Differential pulse voltammetric method has been used for the determination of SCZ content in pharmaceutical tablet. This method enabled to determine SCZ in the concentration range 1.0 × 10-8 to 4.0 × 10-4 M. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 2.13 × 10-9 and 2.85 × 10-9 respectively. The method was applied to determine the content of SCZ in different sample solutions of SCZ tablet with excellent recovery and relative standard deviation results (99.892±1.53 respectively) for spiked standard SCZ in tablet sample solutions. The selectivity of the method for SCZ was further studied in the presence of selected potential interferents such as fluconazole, azithromycin etc and confirmed the potential applicability of the developed method for the determination of SCZ in real pharmaceutical tablets.


2013 ◽  
Vol 96 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Ashwini K Srivastava ◽  
Reena R Gaichore

Abstract Simultaneous determination of L-tyrosine and caffeine was performed at a carbon paste electrode modified with 4-tert-butylcalix[6]arene and in situ Ni2+ ions. Surface characterization of the electrode was carried out by means of scanning electron microscopy. Electrochemical impedance diagnosis revealed that oxidation of both molecules is kinetically facile on the modified electrode. The electrochemical behavior of both molecules was studied using cyclic voltammetry, and further quantified using differential pulse voltammetry (DPV). The results revealed a high sensitivity for their simultaneous detection. DPV allowed simultaneous detection of L-tyrosine and caffeine in the range of 10–6 to 10–3 M, with LODs of 2.19 × 10–7 and 4.03 × 10–7 M, respectively. The modified electrode was used for individual determination of L-tyrosine and caffeine in various pharmaceutical formulations and simultaneous monitoring in human body fluids.


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