The H-point standard addition method was applied to kinetic data for simultaneous determination of citric and ascorbic acid or selective determination of ascorbic acid in presence of citric acid. The method is based on the difference in the rate of reaction of citric and ascorbic acid with copper(II)-ammonia complex. The linear dynamic ranges for the two analytes of citric and ascorbic acid are...

the antimicrobial activity of some novel ascorbic acid-metal complexes [bisascorbate complexes of copper (ii), zinc(ii), manganese (11), iron (111), cobalt(ii), lead(ii) and cadmium(ii)] was investigated. four standard strains of bacterial species - staphylococcus aureus, escherichia coli, bacillus subtilis and klebsiella pneumonia and four fungal species - trichophyton sp. penicillium sp., asp...

background: the most devastating manifestations of diabetes mellitus are vascular complications. although there are many factors involved in the pathogenesis of diabetic vasculopathy, many studies suggest a role for glucose–induced oxidative stress. studies in animal models, have demonstrated that the administration of antioxidants restores normal endothelial functions. the study was designed t...

Biochemical changes in the plants of Pistia stratiotes L., a free floating macrophyte exposed to different concentrations of hexavalent chromium (0, 10, 40, 60, 80 and 160 microM) for 48, 96 and 144 h were studied. Chromium-induced oxidative stress in macrophyte was investigated using the multivariate modeling approaches. Cluster analysis rendered two fairly distinct clusters (roots and shoots)...

Background: The most devastating manifestations of diabetes mellitus are vascular complications. Although there are many factors involved in the pathogenesis of diabetic vasculopathy, many studies suggest a role for glucose–induced oxidative stress. Studies in animal models, have demonstrated that the administration of antioxidants restores normal endothelial functions. The study was designed t...

A sensitive and selective kinetic-spectrophotometric method is proposed for the determination of microg mL(-1) amounts of Cu2+ based on its catalytic effect on the oxidation of L-ascorbic acid by Methylene Blue in a strongly acidic medium. The reaction is monitored spectrophotometrically by measuring the decrease in color intensity of Methylene Blue at 665 nm. The analysis of Cu2+ ion is perfor...

In this study, bimodal mesoporous silica, i.e. UVM-7, was synthesized and functionalized withsulfonic acid and characterized using XRD, nitrogen physisorption, SEM, TEM and acid/basetitration. The results displayed that bimodal mesopore structure was firmly formed and acidicfunctional groups were grafted on the surface of the UVM-7. The concentration of the acidicfunctional groups was determine...

In this laboratory a study of the oxygen capacities of chemically modified hemoglobins has recently been undertaken. In connection with this work the reduction of methemoglobin under carefully controlled conditions offered itself as a problem, since the combination of a ferriheme with globin leads to methemoglobin. In view of this consideration and of the recent reports of Cox and Wendel (l), M...