Gluconic Solution Research Articles

Chemiluminescence Determination of Gluconic Acid in Pharmaceutical Formulations using Ru(bipy)3 2+ – KIO4 – Ce(IV) System

ABSTRACT A new chemiluminescence method for determination of gluconic acid is described. The method is based on the chemiluminescence reaction of gluconic acid with KlO4, Ru(bipy)3 2+ (bipy=2,2'-pyridyl) and Ce(IV) in sulfuric acid medium. Under the optimum conditions, the concentration of gluconic acid is proportional to the CL intensity in the range of 7.6x10−8 ˜1.5x10−5 mol/L. The limit of detection is 1.5x10−8 mol/L and the relative standard deviation is 3.5% for 5.0x10−7 mol/L gluconic solution (n=11). The method is relatively free from interferences from common excipients and co-existing drugs and has been successfully applied to the analysis of gluconic acid in pharmaceutical formulations.

REDUCTION IN CHEMICAL OXYGEN DEMAND OF OZONATED SUGAR SOLUTIONS BY CHARCOAL

ABSTRACTSugar solutions at a concentration of 0.10% were subjected to low‐level ozonation, in order to oxidize the solute directly or indirectly to the corresponding aldonic acid. Charcoal adsorption of the monosaccharides was more efficient after ozonation. Adsorption of the disaccharides was, by far, less efficient after ozonation. The chemical oxygen demand of a standard gluconic acid solution was reduced to 10% of its original concentration by charcoal alone.

Determination of Lead(II) lon in the Presence of Tin(IV) lon by Anodic Stripping Polarography

ln the gluconic acid solution (pH=1.8 y3.3), the Sn(N) ion gave the iil-defined irreversible one step wave because of its distorted shape of polarogram and high overvoltage. On the other hand, the reversible wave for Pb(II)in the solution of O.1 mo1/191uconic acid and O, 4 mol/1 KCI at pH=3.0 showed more positive potential than that for above Sn(N) complexes under the same experimental conditions. The difference between both waves made it possib1e to deter mine the Pb(II)ion in the presence of Sn(W)by anodic stripPing Polarography with the aide of square-wave techniques.The calibration curve for Pb(1) ion was prepared over the range from O. Ol to O.10 ppm in the solution centaining O.1 mol/1 gluconic acid and O.4 mol/1 KCI (pH=2.0); the pre-electrolysis was carried out for 1 minute at the fixed potential of.55 V (vs. SCE). The presence of up te 3PPm of Sn(N)did not interfere with the determinate n f O, 10PPm of Pb(II)I n at pH=2.0, while in the presence of up te 10 ppm ef Sn(N) at pH=2.6 in the similar solu. tion as above, the same was true of this solution.

Anodic oxidation of carbohydrates and their derivatives in neutral saline solution.

Rao and Drake1 have recently reported work on the oxidation of dextrose on platinized platinum in neutral buffer solution (pH 7.4). They have shown that anodic charging curves on platinized platinum electrodes in 0.5 M dextrose solution go through an inflexion at about 0.1 V referred to standard hydrogen electrode (SHE) (where platinum starts to adsorb oxygen in neutral solution), after which oxidation is inhibited. No square root dependence was noted for the transition time to this point, indicating that the inhibitive process was not under diffusion control. In addition, the total number of coulombs required to reach the point of inflexion decreased if increasing concentrations of gluconic acid were added to the dextrose solution. They reported open circuit potential (OCP) of + 0.3 V (SHE) in deaerated gluconic acid solution (10−4 to 10−1 M), and they detected no evidence of gluconic acid oxidation in the potential range −0.6 to 0.0 V (SHE). Their general conclusions were that the only oxidation product of glucose in these conditions is gluconic acid, which adsorbs on the electrode in the potential range −0.2 to 0.0 V (SHE), effectively inhibiting glucose oxidation.