Application of the line shape of linear scan and cyclic voltammograms for the determination of the rate constant and reversible E1/2 for a chemical reaction preceded by a reversible charge transfer

1977 ◽  
Vol 49 (1) ◽  
pp. 60-61 ◽  
Author(s):  
Mahboob. Mohammad
2020 ◽  
Vol 36 (2) ◽  
pp. 93-101
Author(s):  
G.A. Irgalina ◽  

The article reflects the assessment of the quality of sour cream at home, and considers methods for determining the quality of sour cream. Organoleptic evaluation was performed for compliance with the requirements of GOST 52092-2003 " Smetana. Technical conditions " in terms of appearance, consistency, color, taste and smell. The consistency of sour cream is determined during its mixing, while evaluating the presence of a glossy appearance of sour cream. Sour cream is considered thick if it slowly drains from the whorl. The smell is determined immediately after mixing. Then we evaluate the taste. When evaluating the quality of the samples under study, it was found that the organoleptic characteristics of the samples fully comply with the requirements of the regulatory document. Analyzing the results of the experiment, we can conclude that in the first experiment, the sour cream purchased on the market was completely dissolved, and the sour cream from the store after dissolution showed small grains. And in the second experiment, the results showed that the color did not change in the sample # 2, but under # 1 it turned blue. The basis of this experiment is a qualitative chemical reaction to starch, which is used as a thickener.


2020 ◽  
Vol 16 ◽  
Author(s):  
Sheng-Yun Li ◽  
Fang Tian

: A spectrophotometry was investigated for the determination of epsilon aminocaproic acid (EACA) with p-nitrophenol (PNP). The method was based on a charge transfer (CT) complexation of this drug as n-electron donor with π-acceptor PNP. Experiment indicated that the CT complexation was carried out at room temperature for 10 minutes in dimethyl sulfoxide solvent. The spectrum obtained for EACA/PNP system showed the maximum absorption band at wavelength of 425 nm. The stoichiometry of the CT complex was found to be 1:1 ratio by Job’s method between the donor and the acceptor. Different variables affecting the complexation were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration limit of 1~6 µg mL-1. The relative standard deviation was less than 2.9%. The apparent molar absoptivity was determined to be 1.86×104 L mol-1cm-1 at 425 nm. The CT complexation was also confirmed by both FTIR and 1H NMR measurements. The thermodynamic properties and reaction mechanism of the CT complexation have been discussed. The developed method could be applied successfully for the determination of the studied compound in its pharmaceutical dosage forms with a good precision and accuracy compared to official method as revealed by t- and F-tests.


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