scholarly journals Sensitive and Simultaneous Determination of Hydroquinone and Catechol in Water Using an Anodized Glassy Carbon Electrode with Polymerized 2-(Phenylazo) Chromotropic Acid

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Miao Zhang ◽  
Chuang-ye Ge ◽  
Ya-feng Jin ◽  
Liang-bin Hu ◽  
Hai-zhen Mo ◽  
...  

Hydroquinone (HQ) and catechol (CT) are considered as environmental pollutants with high toxicity. We have developed a simple electrochemical sensor using an anodized glassy carbon electrode modified with a stable 2-(phenylazo) chromotropic acid- (CH-) conducting polymer (PCH/AGCE). The PCH/AGCE sensor showed good electrocatalytic activity and reversibility towards the redox of HQ and CT in phosphate buffer solution (PBS, pH 7.0). The cyclic voltammetry (CV) in mixed solution of HQ and CT showed that the oxidation peaks of them became well resolved with a peak separation of 0.1 V. The detection limits of HQ and CT were 0.044 and 0.066 μM, respectively, in a wide linear response range of 1–300 μM for both. Moreover, the sensor displayed an excellent selectivity in the presence of common interferences. This study provided a simple, sensitive, and high recovery method for simultaneous and quantitative determination of HQ and CT in aqueous medium.

2014 ◽  
Vol 955-959 ◽  
pp. 1160-1166
Author(s):  
Shao Hua Li ◽  
Ying Ying Zhao ◽  
Jun Qing Yang ◽  
Guo Yan Zhang ◽  
Ju Rui Qi

A novel multi-walled carbon nanotubes (MWCNTs)-modified glassy carbon electrode (GCE) with excellent stability, repeatability and anti-interference was synthesized and it exhibited an electrocatalytic signal for hydroquinone (HQ) compared to bare GCE, which suggested that the presence of MWCNTs efficiently enhances electron transfer. Various parameters such as pH, modifier volume, and scan rate were optimized using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Under optimum conditions, linear responses for HQ in 0.1mol·L-1 phosphate buffer solution of pH 6.0 were obtained in the range of 5×10-6 mol·L-1 to 2×10-4 mol·L-1 with detection limits of 2.7×10-6 mol·L-1 (signal-to-noise ratio of 3). Such MWCNTs-modified GCE was successfully applied for the determination of hydroquinone in simulated water samples and can be developed for the the detection of HQ.


2013 ◽  
Vol 78 (5) ◽  
pp. 701-711 ◽  
Author(s):  
Addisu Kitte ◽  
Desalegn Assresahegn ◽  
Refera Soreta

We report here the modification of glassy carbon electrode (GCE) with palladium nanoparticles and palladium film. The response to hydrogen peroxide on the modified electrode was examined using cyclic voltammetry and amperometry (at -0.2 V vs Ag/AgCl reference electrode in the phosphate buffer solution pH 7.4). The palladium film and palladium nanoparticle modified GCE showed a linear response to hydrogen peroxide in the concentration range between 10 ?M to 14 mM and 1 ?M to 14 mM with detection limit of 6.79 ?M and 0.33 ?M, respectively.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Sevgi Güney ◽  
Gülcemal Yıldız ◽  
Gönül Yapar

A new voltammetric sensor based on an aryl amide type podand, 1,8-bis(o-amidophenoxy)-3,6-dioxaoctane, (AAP) modified glassy carbon electrode, was described for the determination of trace level of mercury (II) ion by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). A well-defined anodic peak corresponding to the oxidation of mercury on proposed electrode was obtained at 0.2 V versus Ag/AgCl reference electrode. The effect of experimental parameters on differential voltammetric peak currents was investigated in acetate buffer solution of pH 7.0 containing 1 × 10−1 mol L−1NaCl. Mercury (II) ion was preconcentrated at the modified electrode by forming complex with AAP under proper conditions and then reduced on the surface of the electrode. Interferences of Cu2+, Pb2+, Fe3+, Cd2+, and Zn2+ions were also studied at two different concentration ratios with respect to mercury (II) ions. The modified electrode was applied to the determination of mercury (II) ions in seawater sample.


2015 ◽  
Vol 7 (3) ◽  
pp. 1147-1153 ◽  
Author(s):  
Hualing Xiao ◽  
Lingen Sun ◽  
Hongling Yan ◽  
Wen Wang ◽  
Jiali Liu ◽  
...  

Nicotine is determined at a glassy carbon electrode modified with partially electroreduced carboxylated graphene by cyclic voltammetry and semi-derivative treatment after enrichment at −1.1 V in 0.1 M pH 7.0 phosphate buffer solution.


2016 ◽  
Vol 99 (6) ◽  
pp. 1522-1526 ◽  
Author(s):  
Jayant I Gowda ◽  
Rahul B Kantikar ◽  
Devaraddi G Harakuni ◽  
Kirankumar Y Jadhav ◽  
Vinay C Chanagoudar ◽  
...  

Abstract In this article, the electrochemical behavior on a glassy carbon electrode (GCE) was investigated and the electrochemical parameters of albendazole (ALB) were calculated. ALB effectively accumulated on the GCE surface and caused a pair of redox peaks at around 1.095 V and 1.028 V and an oxidation peak at 0.844 V (versus saturated calomel electrode) in 0.2 M phosphate buffer solution (pH 3.0). Under optimized conditions, the anodic peak current was linear to the ALB concentration the range of 1.5 × 10−7 M to 4.0 × 10−5 M. The regression equation was: Ipa (10−6 A) = 0.79 [ALB] (μM) + 0.84 (R2 = 0.982). The detection limit 6.08 × 10−8 M was obtained. The proposed method was successfully used to determine ALB content in tablet samples, with satisfactory results.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1266
Author(s):  
Aftab A. Khand ◽  
Saeed A. Lakho ◽  
Aneela Tahira ◽  
Mohd Ubaidullah ◽  
Asma A. Alothman ◽  
...  

Recently, the oxidative behavior of methotrexate (MTX) anticancer drug is highly demanded, due to its side effects on healthy cells, despite being a very challenging task. In this study, we have prepared porous NiO material using sodium sulfate as an electronic disorder reagent by hydrothermal method and found it highly sensitive and selective for the oxidation of MTX. The synthesized NiO nanostructures were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. These physical characterizations delineated the porous morphology and cubic crystalline phase of NiO. Different electrochemical approaches have been utilized to determine the MTX concentrations in 0.04 M Britton–Robinson buffer (BRB) at pH 2 using glassy carbon electrode (GCE)-modified with electronically disordered NiO nanostructures. The linear range for MTX using cyclic voltammetry (CV) was found to be from 5 to 30 nM, and the limit of detection (LOD) and limit of quantification (LOQ) were 1.46 nM and 4.86 nM, respectively, whereas the linear range obtained via linear sweep voltammetry (LSV) was estimated as 15–90 nM with LOD and LOQ of 0.819 nM and 2.713 nM, respectively. Additionally, amperometric studies revealed a linear range from 10 to70 nM with LOD and LOQ of 0.1 nM and 1.3 nM, respectively. Importantly, MTX was successfully monitored in pharmaceutical products using the standard recovery method. Thus, the proposed approach for the synthesis of active metal oxide materials could be sued for the determination of other anticancer drugs in real samples and other biomedical applications.


2011 ◽  
Vol 239-242 ◽  
pp. 328-333
Author(s):  
Jing Jie Cui ◽  
De Hui Sun ◽  
Hong Liu ◽  
Guan Cong Wang ◽  
Hong Shi Zhao ◽  
...  

The electrochemical behavior of nucleobases has been studied in 0.1 M phosphate buffer solution (PBS), pH 7.4 without removing oxygen, using glassy carbon electrode (GCE). Cyclic voltammetry (CV), electrochemical impedance experiment (EIS) and square wave voltammetry (SWV) were employed in the measurements of the nucleobases electrochemical signals at GCEs. Guanine (G) and adenine (A) produced well-defined oxidation peaks at about +0.66 and +0.96 V under the CV sweep at 100 mV/s, respectively. SWV was particularly useful in investigating the electrochemical behaviour of pyrimidine bases. In the SWV detection, thymine (T) clearly appeared an oxidation peak at 1.1 V, while cytosine (C) and uracil (U) did a complex oxidation peak at 1.3 V. Nucleobases possess an irreversible and adsorption-controlled electrochemical process at GCEs in 0.1 M PBS (pH 7.4). The average surface concentrations (Γ) of G and A on the surface of the GCE were estimated to be about 1.6515×10−10and 8.8232×10−11mol/cm2, respectively. Due to the selective interactions of nucleobases with each other, the nucleobase oxidation peaks shift and new oxidation peaks appeared. The new oxidation peaks at +1.62 and 1.55 V may correspond to the oxidation of GC pairs and AT pairs, respectively. The detection of the electrochemical behaviour and selective binding of nucleobases in a physiological PBS at pH 7.4 is of particular interest for electrochemical sensor applications in physiological media.


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