Of gluconic acid

Ferrous gluconate is a black dye. It is composed of iron bound to two molecules of gluconic acid, which is the acid form of glucose. 

A second principle used widely for glucose analysis, is that of the oxidation of glucose enzymatically, mediated by the action of glucose oxidase with the formation of gluconic acid and hydrogen peroxide (22). In this procedure it is the hydrogen peroxide which is usually assayed for determination of glucose. This method suffers from the action of inhibitors which occur, particularly with patients in a diabetic coma and these need to be removed. 

From the reaction stoichiometry, the concentration of gluconic acid at the end of the ith interval is... 

Problem 22.27 Fischer prepared L-gulose by oxidizing o-glucose to two separable lactones of glucaric acid. These were reduced to lactones of gluconic acid, which were further reduced. Give all the structures in these... 

Efforts to increase the selectivity of this reaction by doping the Pt/C catalyst with Pb resulted in the serendipitous discovery, by the Eindhoven group, of the selective Pt,Pb/C-catalyzed oxidation of gluconic acid to 2-... 

Determination of gluconic acid in honey samples using an integrated electrochemical biosensor based on self-assembled monolayer modified gold electrodes... 

Figure. 16.1 shows the biocatalytic scheme used for the determination of gluconic acid. 

The presence of glucose, fructose, galactose, arabinose and citric, malic and tartaric acid did not produce interference on the quantification of gluconic acid. Only ascorbic acid yielded an amperometric response under the working conditions, due to the electrochemical oxidation of this compound at the applied potential. Nevertheless, the content of gluconic acid in honey samples is remarkably higher than the possible content of ascorbic acid. Consequently, no significant interference should be expected in the analysis of the proposed real samples. 

The biosensor was used for the analysis of gluconic acid in honey samples. No matrix effect was observed and, therefore, the determination was carried out by interpolation of the corresponding amperometric responses into an appropriate calibration graph. 

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