scholarly journals Characterization of Cr-Curcumin Complex by Differential Pulse Voltammetry and UV-Vis Spectrophotometry

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Maurice O. Iwunze

Differential Pulse Voltammetry (DPV) and UV-Vis techniques were used in characterizing the complexation of chromium with curcumin. It was observed that chromium complexed with curcumin in a 1 : 3 ratio. The experimental values that were used to calculate this ratio were independently determined by the two techniques used. The values obtained from each technique agree with each other reasonably well, within limits of experimental error. The stability constant or formation constant, Kf, of the complex, 1.58×1010, was determined using the Lingane equation and Gibb’s free energy of formation was calculated as −58.18 kJ.

2013 ◽  
Vol 78 (6) ◽  
pp. 827-838 ◽  
Author(s):  
Maria-Laura Soare ◽  
Eleonora-Mihaela Ungureanu ◽  
Emilian Georgescu ◽  
Liviu Birzan

This work is devoted to the synthesis and characterization of new indolizine derivatives. Particular attention was paid to the electrochemical investigations by cyclic voltammetry and differential pulse voltammetry. The redox processes for each compound were established, analyzed and assessed to the particular functional groups at which they take place. This assessment was based on detailed comparison between the electrochemical behaviour of the compounds, similarities in their structure, as well as substituent effects.


Mineralogia ◽  
2019 ◽  
Vol 50 (1-4) ◽  
pp. 3-12
Author(s):  
Magdalena Wołowiec ◽  
Magdalena Tuchowska ◽  
Paulina Kudła ◽  
Tomasz Bajda

AbstractOne of the most effective methods for the immobilization of toxic metals involves the use of minerals from the apatite supergroup. The formation of cadmium chlorapatite may lead to successful entrapping of cadmium; thus, it is important to examine the solubility constant to determine the stability of cadmium in the the apatite structure. Cadmium chlorapatite was synthetized and characterized by X-ray diffraction, infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy. The solubility constant (log) Ksp of cadmium chlorapatite was -65.58. The Gibbs free energy of formation of cadmium chlorapatite reached -3950.48 kJ mol−1. The solubility constant turned out to be low but was enough for cadmium chlorapatiteto be considered a very stable compound..


2003 ◽  
Vol 10 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Clarissa Pires de Castro ◽  
Jurandir SouzaDe ◽  
Carlos Bloch Jr

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.


1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4344
Author(s):  
Merve Uca ◽  
Ece Eksin ◽  
Yasemin Erac ◽  
Arzum Erdem

Hydroxyapatite nanoparticles (HaP) and ionic liquid (IL) modified pencil graphite electrodes (PGEs) are newly developed in this assay. Electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and cyclic voltammetry (CV) were applied to examine the microscopic and electrochemical characterization of HaP and IL-modified biosensors. The interaction of curcumin with nucleic acids and polymerase chain reaction (PCR) samples was investigated by measuring the changes at the oxidation signals of both curcumin and guanine by differential pulse voltammetry (DPV) technique. The optimization of curcumin concentration, DNA concentration, and the interaction time was performed. The interaction of curcumin with PCR samples was also investigated by gel electrophoresis.


2021 ◽  
Author(s):  
Yan Jin ◽  
Tong QI ◽  
Yuqing Ge ◽  
Jin Chen ◽  
Li juan Liang ◽  
...  

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by hydrophilic TiO2 modified glassy carbon electrodes for the first time. Differential pulse voltammetry (DPV) method is proposed...


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