a new and simple method followed by atomic absorption spectrometry has been developedfor indirect determination of ascorbic acid (aa). the proposed method was based on the oxidationof aa to dehydroascorbic acid with cu2+cation(200mgl-1)in an ammonium thiocyanatesolution atph2.4. aa reduces cu2+to cu+followed by the precipitation of cu+ with scn-. then, the excess ofcu2+in the solution was measu...

in this study, a new reaction system for quantitative determination of ascorbic acid was introduced. the developed method is based on inhibitory effect of ascorbic acid on the orange g-bromate system. the change in absorbance was followed spectrophotometrically at 478 nm. the dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

In this study, a new reaction system for quantitative determination of ascorbic acid was introduced. The developed method is based on inhibitory effect of ascorbic acid on the Orange G-bromate system. The change in absorbance was followed spectrophotometrically at 478 nm. The dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

In this study, a new reaction system for quantitative determination of ascorbic acid was introduced. The developed method is based on inhibitory effect of ascorbic acid on the Orange G-bromate system. The change in absorbance was followed spectrophotometrically at 478 nm. The dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

a simple and rapid method has been developed for the determination of ascorbic acid in fruit and pharmaceutical products. the method is based on the measurement of the reaction rate between ammonium molybdate and ascorbic acid in acidic media. the reaction was monitored spectrophotometrically at 800 nm by fixed-time and variable-time methods. the calibration graph was linear in the range of 5 0...

A simple and rapid method has been developed for the determination of ascorbic acid in fruit and pharmaceutical products. The method is based on the measurement of the reaction rate between ammonium molybdate and ascorbic acid in acidic media. The reaction was monitored spectrophotometrically at 800 nm by fixed-time and variable-time methods. The calibration graph was linear in the range of...

voltammetric techniques have been considered as important methods among the analytical techniques used for the identification and determination of trace concentrations of many biological molecules such as l-ascorbic acid (aa). l-ascorbic acid is an electro-active molecule, though it is difficult to determine its value directly with a majority of electrodes made of carbon and transition metals, ...

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...

abstract: Ascorbic acid (Vitamin C) is an essential Vitamin which participates in many different biological processes. The ascorbic acid content in vegetables and fruits is a maturity index and its determination in such samples is of special interest in quality control. In this paper we present a titrimetric method with potassium bromide for the determination of ascorbic acid in walnut, cabbage...

1. The kinetics of the reaction between HCHO and I-ascorbic acid or chemically related substances have been studied. 2. Indirect evidence is produced for the possible structure of the HCHO-1-ascorbic acid complex. / 3. Lugg's method for determination of I-ascorbic acid has been examined from the point of view of the above experiments, and necessary precautions are stressed. 4. Suggestions for o...