Alireza Mohadesi; Rasool Roohparvar; Nahid Yaghoobi
Abstract
The use of additives is a standard method in both electrowinning and electrorefining of copper. They have multiple roles in the electrodeposition of copper. They are diffusion barriers and/or complexing agents for copper. In addition, they can perform other important roles as well. Thiourea has been ...
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The use of additives is a standard method in both electrowinning and electrorefining of copper. They have multiple roles in the electrodeposition of copper. They are diffusion barriers and/or complexing agents for copper. In addition, they can perform other important roles as well. Thiourea has been extensively used as an additive in industrial copper electrorefining processes. The effect of thiourea on anode passivation, nodule formation in the cathode, and polarization of copper reduction has been investigated. In this study, we reviewed the most important studies conducted on the mechanism of thiourea effect in the copper electrorefining process, as well as the methods of determination and monitoring thiourea in real samples of copper refinery.
Karim Asadpour-Zeynali; Yaser Arteshi
Volume 4, Issue 1 , March 2017, , Pages 51-58
Abstract
In this research, an inexpensive and effective method for determination of Isoniazid (INH) is presented by using a poly (Eriochrome black T) modified pencil lead electrode. The potential of modified electrode in electrochemical sensing of INH was evaluated by cyclic voltammetry and hydrodynamic amperometry ...
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In this research, an inexpensive and effective method for determination of Isoniazid (INH) is presented by using a poly (Eriochrome black T) modified pencil lead electrode. The potential of modified electrode in electrochemical sensing of INH was evaluated by cyclic voltammetry and hydrodynamic amperometry methods. The overall number of electrons involved in oxidation of INH was fond 4 electrons. The calculate diffusion coefficient for INH was equal to 9.74 × 10-7 cm2/s. Calculated limit of detection for method was 66.0µM and 20.4µM applying cyclic voltammetry and hydrodynamic amperometry methods, subsequently. The ability of prepared electrode for determination of INH in real sample was evaluated by applying the proposed method to human plasma analysis and the results were compared with the standard method, presented by United State Pharmacopeia. Presented method exhibited a satisfying precision (%RSD=4.64). Also the proposed method showed a good accordance with standard method in confidence level of 95%.
Ghasem Karim-Nezhad; Sara Pashazadeh
Volume 2, Issue 2 , September 2015, , Pages 100-107
Abstract
In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear ...
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In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear response in the concentration range of 3×10−4 to 2.1×10−3 mol L-1 with a correlation coefficient of 0.9953. The overall number of electrons involved in the catalytic oxidation of isoniazid was found 4 electrons. The diffusion coefficient of 3.11×10−5 cm2 s-1 for isoniazid was also estimated using chronoamperometry study. It has been shown that using the silver oxyfluoride modified silver electrode, isoniazid can be determined by amperometry method with limit of detection of 3.85 µmol L–1. The method was successfully applied for analysis of isoniazid in solid pharmaceutical formulations. The results of the analysis suggest that the proposed method has promise for the routine determination of isoniazid in the products examined.
