scholarly journals Detection of Selenium and Nickel Metal Ion in Water Using Mn3O4-Cn-Modified Electrode

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Neetha John ◽  
K. E. Abraham
Keyword(s):  
Metal Ion ◽  
Supporting Electrolyte ◽  
Simultaneous Detection ◽  
Correlation Coefficients ◽  
Peak Shape ◽  
Site Testing ◽  
Nickel Metal ◽  
Peak Intensity ◽  
Scan Rate ◽  
Best Responses

The present study reports the design of the Mn3O4-Cn electrode and its use for simultaneous detection of selenium and nickel in water. The designed electrode can be used as a convenient electrochemical device for on-site testing of Se (IV) and Ni (II) levels in affected regions. The best responses are obtained with 0.1 M phosphate buffer saline (PBS) and 5 mM Fe (CN)6 as supporting electrolyte. The scan rate and the number of cyclic repetitions have a great effect on peak shape and intensity. It is seen from our study that peak intensity is directly proportional to Se (IV) and Ni (II) concentrations in the range of 5 to 250 µg/L (correlation coefficients 0.952 and 0.984) when the optimized parameters are used. The detection limit of 0.533 µg/L Se (IV) and 0.718 µg/L for Ni (VI) with a response time of 18 s for 5–250 µg/L concentration is obtained, respectively. Enhanced analytical results for different water samples establish that the proposed method is appropriate for Se (IV) and Ni (II) detection. FESEM images confirm the Mn3O4-Cn nanocomposite formation on the electrode.

scholarly journals A CV Study of Copper Complexation with Guanine Using Glassy Carbon Electrode in Aqueous Medium

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Md. Sohel Rana ◽  
Mohammad Arifur Rahman ◽  
A. M. Shafiqul Alam
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Metal Ion ◽  
Supporting Electrolyte ◽  
Complex Mixture ◽  
Step Height ◽  
Rate Variation ◽  
Carbon Electrode ◽  
Copper Complexation ◽  
Scan Rate

Voltammetric behaviors of Copper (II) nitrogen bearing nucleobases, such as Guanine (C5H4N5O2) was studied in electro analyzer using cyclic voltammetry (CV) on a Glassy Carbon Electrode. Assessment of the chemical and physical conditions that may favor optimum current enhancement was done by studying the effect of variation of concentration of metal and ligand ions, variation of scan rate, variation of step height, variation of pH values, and variation of supporting electrolyte as (NH4)2SO4, KCl, and NaCl. It was observed that Copper and Guanine forms a 1 : 2 ratio complex. The work reflects that increasing the concentration of either metal ion or ligand ion increases the corresponding current. Increasing the scan rate increases the corresponding current linearly with the square root of the scan rate. As the step height decreases the peaks become sharp. Anodic and cathodic current increases linearly with decreasing step height. For the complex mixture the complexation occurs maximum at a pH of 2.3–7.0 and is badly restricted in the slightly alkaline medium and the complexing order of the supporting electrolyte showed a trend as (NH4)2SO4>NaCl>KCl.

scholarly journals An Electrochemical Strategy for the Simultaneous Detection of Doxorubicin and Simvastatin for Their Potential Use in the Treatment of Cancer

Biosensors ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Iulia Rus ◽  
Mihaela Tertiș ◽  
Cristina Barbălată ◽  
Alina Porfire ◽  
Ioan Tomuță ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Electrolyte Solution ◽  
Electrode Material ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Simultaneous Detection ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Formulations ◽  
Promising Tool ◽  
Scan Rate

The aim of this study was to develop a disposable, simple, fast, and sensitive sensor for the simultaneous electrochemical detection of doxorubicin (DOX) and simvastatin (SMV), which could be used in preclinical studies for the development of new pharmaceutical formulations for drug delivery. Firstly, the electrochemical behavior of each molecule was analyzed regarding the influence of electrode material, electrolyte solution, and scan rate. After this, the proper electrode material, electrolyte solution, and scan rate for both active substances were chosen, and a linear sweep voltammetry procedure was optimized for simultaneous detection. Two chronoamperometry procedures were tested, one for the detection of DOX in the presence of SMV, and the other one for the detection of DOX and SMV together. Finally, calibration curves for DOX and SMV in the presence of each other were obtained using both electrochemical methods and the results were compared. The use of amperometry allowed for a better limit of detection (DOX: 0.1 μg/mL; SMV: 0.7 μg/mL) than the one obtained in voltammetry (1.5 μg/mL for both drugs). The limits of quantification using amperometry were 0.5 μg/mL for DOX (dynamic range: 0.5–65 μg/mL) and 2 μg/mL for SMV (dynamic range: 2–65 μg/mL), while using voltammetry 1 μg/mL was obtained for DOX (dynamic range: 1–100 μg/mL) and 5 μg/mL for SMV (dynamic range: 5–100 μg/mL). This detection strategy represents a promising tool for the analysis of new pharmaceutical formulations for targeted drug delivery containing both drugs, whose association was proven to bring benefits in the treatment of cancer.

scholarly journals Adsorption of Cr6+ Onto Unmodified and Hydrochloric Acid Modified African Nutmeg Pod (Monodora myristica) from Aqueous Solution

2019 ◽  
pp. 1-8
Author(s):  
F. U. Okwunodulu ◽  
H. O. Chukwuemeka-Okorie ◽  
N. M. Mgbemena ◽  
J. B. I. Kalu
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Low Ph ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Particle Sizes ◽  
Monodora Myristica ◽  
Best Fit

The removal of Cr6+ from aqueous solution using unmodified and hydrochloric modified African nutmeg pod was studied. The effects of particle size, pH and initial metal ions concentration adsorbed were investigated. The amount of metal ion adsorbed increased as the initial metal ion concentration increased and also decreased at low pH of 2 for both modified and unmodified African nutmeg pod.  400 µm and 250 µm were the optimum particle sizes for both modified and unmodified African nutmeg pod respectively, values given as 75.8 mg/g for the modified and 93.39 mg/g for the unmodified. Generally, it was observed that the unmodified African nutmeg pod showed greater adsorption capacity than the modified African nutmeg pod. The equilibrium experimental data were examined via Langmuir and Freundlich isotherm models.  Freundlich isotherm model gave the best fit for the data in both unmodified and modified African nutmeg pod based on the correlation coefficients (R2 values) gotten. The results of the study showed that the African nutmeg pod is efficient for the removal of Cr6+ from aqueous solutions especially when unmodified.

scholarly journals Bismuth/hydroxyapatite-modified carbon screen-printed electrode for heavy-metal ion detection in aqueous media

2019 ◽  
Vol 76 ◽  
pp. 02001
Author(s):  
Aamir Amanat Ali Khan ◽  
Huma Ajab ◽  
Asim Yaqub ◽  
Mohd Azmuddin Abdullah
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Active Sites ◽  
Anodic Stripping Voltammetry ◽  
Simultaneous Detection ◽  
Current Response ◽  
Screen Printed Electrode ◽  
Square Wave ◽  
Screen Printed

Square-wave voltammetric stripping analysis is attractive for environmental monitoring and trace metal ion determination. The sensitivity is a result of analytes preconcentration steps on the electrode and advanced measurement procedures, where metal analytes are stripped away from the electrode at appropriate potential scan. Screen-printed electrode (SPE) has great advantages for in situ assays of heavy metal ions. Modification of SPE with bismuth (Bi) film improves the amalgamation of metal ions and the addition of hydroxyapatite (HA) increases the ion sorption, and enhances the current response due to the large porous structure and surface active sites for the metal ion binding. The ionization of the functional groups on the electrode surface upon contact with the aqueous system further assists the cation binding. The analytical performance of Bi and HA-modified SPE for simultaneous detection of Cd(II) and Pb(II) ions by square wave anodic stripping voltammetry (SWASV) was evaluated. Under the optimized electrochemical working conditions, calibration graph is linear for 240 s deposition time, in 0.1 M acetate buffer at pH 7.6 with the detection limit of 16.8 ppb for Pb(II). Two peaks corresponding to Cd(II) at -0.8 V and Pb(II) at -0.6 V can be discerned suggesting that Bi-HA modification had increased the current responses.

Pulse cyclic voltammetry. I. Static solutions

1987 ◽  
Vol 65 (5) ◽  
pp. 1051-1057 ◽  
Author(s):  
Gordon N. Eccles ◽  
William C. Purdy
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Carbon Electrode ◽  
Peak Shape ◽  
Static Solutions ◽  
Scan Rate ◽  
Cyclic Voltammetry Test

By using pulse cyclic voltammetry rather than cyclic voltammetry at a relatively high scan rate, an increase in sensitivity and a lowering of the detection limit by more than a factor of two are demonstrated for the ferricyanide–ferrocyanide couple at a carbon electrode. The test for reversibility based on peak shape or symmetry comparison is enhanced significantly with pulse cyclic voltammetry. Another reversibility test, by observing peak variations as a function of scan rate, was applied to pulse cyclic voltammetry and was found to be as diagnostically informative as the cyclic voltammetry test. These tests are illustrated by a study of the hydroquinone–quinone couple.

scholarly journals Electrochemical Oxidation of Paracetamol Mediated byMgB2Microparticles Modified Glassy Carbon Electrode

2011 ◽  
Vol 8 (2) ◽  
pp. 553-560 ◽  
Author(s):  
Mohammed Zidan ◽  
Tan Wee Tee ◽  
A. Halim Abdullah ◽  
Zulkarnain Zainal ◽  
Goh Joo Kheng
Keyword(s):  
Cyclic Voltammetry ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Supporting Electrolyte ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Diffusion Controlled ◽  
Scan Rate ◽  
Degree Of Stability ◽  
A Current

A MgB2microparticles modified glassy carbon electrode (MgB2/GCE) was fabricated by adhering microparticles of MgB2onto the electrode surface of GCE. It was used as a working electrode for the detection of paracetamol in 0.1 M KH2PO4aqueous solution during cyclic voltammetry. Use of the MgB2/GCE the oxidation process of paracetamol with a current enhancement significantly by about 2.1 times. The detection limit of this modified electrode was found to be 30 μM. The sensitivity under conditions of cyclic voltammetry is significantly dependent on pH, supporting electrolyte, temperature and scan rate. The current enhancement observed in different electrolytic media varied in the following order: KH2PO4> KCl > K2SO4> KBr. Interestingly, the oxidation of paracetamol using modified GC electrode remain constant even after 15 cycling. It is therefore evident that the MgB2modifiedGCelectrode possesses some degree of stability. A slope of 0.52 dependent of scan rate on current indicates that the system undergoes diffusion-controlled process.

Cyclic Voltammetry of Iodine at the Organic Liquid/Aqueous Solution Interface

2007 ◽  
Vol 72 (7) ◽  
pp. 917-926 ◽  
Author(s):  
Shaoai Xie ◽  
Jinping Jia ◽  
Hong-Jin Chen
Keyword(s):  
Metal Ion ◽  
Composite Electrode ◽  
Polar Solvent ◽  
Electrochemical Reaction ◽  
Organic Liquid ◽  
Supporting Electrolyte ◽  
Cyclic Voltammetric ◽  
Solution Interface ◽  
Donor Solvent ◽  
Solvent Complex

The electrochemical behavior of iodine extracted with an organic solvent at the liquid/liquid interface was studied using a new composite electrode. The effects of various solvents and supporting electrolyte on the electrochemical reaction of iodine were analyzed by cyclic voltammetric curves. The formation of a polar solvent complex of iodine and a strong donor solvent in organic solution was comfirmed by UV-VIS spectra. A possible mechanism was suggested based on experiments. This method makes it possible to measure heavy metal ion in solution indirectly.

scholarly journals Preconcentration of Bismuth(III) and Copper(II) by Solid-Phase Extraction and Subsequent Determination by Differential Pulse Polarography

2001 ◽  
Vol 84 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Anju Bhalotra ◽  
Bal Krishan Prui
Keyword(s):  
Solid Phase ◽  
Supporting Electrolyte ◽  
Saturated Calomel Electrode ◽  
Correlation Coefficients ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Relative Standard ◽  
Microcrystalline Naphthalene

Abstract A differential pulse polarographic method is proposed for the trace determination of bismuth and copper from large volumes of aqueous samples after adsorption of their 1-(2-thiazolylazo)-2-naphthol complexes onto microcrystalline naphthalene in the pH ranges of 7.2–9.0 and 4.0–7.8, respectively. Bismuth and copper are desorbed from microcrystalline naphthalene with 9 mL 1M HCl. Well-defined peaks are obtained at Ep = −0.09 and −0.20 V versus a saturated calomel electrode, in an HCl–isoquinoline medium as the supporting electrolyte, for bismuth and copper, respectively. Bismuth is reduced reversibly with a 3-electron change, whereas copper is reduced irreversibly under these conditions. The detection limits are 55 ng/mL for bismuth and 91 ng/mL for copper. Linearity is maintained in the concentration ranges of 0.18–13.5 and 0.30-17.3 μg/mL for bismuth and copper, respectively, with corresponding correlation coefficients of 0.9996 and 0.9885. The relative standard deviations are 1.0% for bismuth at 2.0 μg/mL and 1.4% for copper at 5.0 μg/mL. Various parameters were optimized to develop conditions for the determination of these metal ions in various samples.

The Adsorption of Copper Ions by Sodium Alginate Immobilized Bacillus Subtilis Body and Purify Copper of Mine Wastewater

2011 ◽  
Vol 356-360 ◽  
pp. 1469-1474
Author(s):  
Jun Jing Guo ◽  
Wen Bin Chen
Keyword(s):  
Bacillus Subtilis ◽  
Aqueous Solutions ◽  
Sodium Alginate ◽  
Metal Ion ◽  
Copper Ions ◽  
Orthogonal Experiment ◽  
Correlation Coefficients ◽  
Sorption Process ◽  
Mine Wastewater ◽  
Bacillus Subtilus

In this study, calcium alginate immobilized bacillus subtilis body was used as an adsorbent for the aim of adsorpting Cu(Ⅱ) ions form the aqueous solutions, On sutiable condition, this study use purely bacteria eliminate other bacteria come in life-form bacteria .Through the orthogonal experiment obtains the optimum condition of sodium alginate fossilization bacillus subtilus pellet to the Cu(Ⅱ) adsorption, The biosorption efficiency was strongly influenced by the pH and the initial concentration ofthe Cu(Ⅱ) aqueous solutions. We also discusses the influence of single factor to the sodium alginate fossilization bacillus subtilus pellet to the Cu(Ⅱ) adsorption ,which included pH, contact time, temperature, initial metal ion concentrations and ionic strength in the adsorption process. The adsorption of the adsorbent on Cu(Ⅱ) is related to its concentration . From the research,we know the maximum adsorption rate to the Cu(Ⅱ) is about 83.2%. Using different model to analyse data. The sorption process follows pseudo-second-order kinetics very well,and the correlation coefficients R all reached to 0.9, and the rate constant of this kinetics model for the adsorption processes, k2, increased with the increasing temperatures. The isothermal data could be well described by the Langmuir adsorption isothermal equations．The experimental results showed that heavy metals could be eficciently accumulated by the immobilized bacteria.

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