A spectrophotometric procedure for the determination of ascorbic acid in pure form and in a number of pharmaceutical preparations and real samples has been developed that offers the advantages of simplicity, accuracy, precision and sensitivity over many other methods. The method is based on the oxidation of ascorbic acid by a known excess amount of potassium chromate followed by the estimation ...

A capillary electrophoresis with electrochemical detection was developed for the simultaneous determination of three flavonoids (naringenin, rutin, quercetin) and ascorbic acid. It was found that naringenin, rutin, quercetin and ascorbic acid were well separated within 5 min in borate buffer solution (pH 8.6, 24 mM). The detection limit was 1.0 microM for naringenin, 8.0 microM for rutin, 2.0 m...

A simple, rapid and automatic fluorimetric method for the determination of total ascorbic acid is described. The method makes use of the stopped-flow mixing technique in order to achieve the rapid oxidation of ascorbic acid by dissolved oxygen to dehydroascorbic acid, which then reacts with o-phenylenediamine to form a fluorescent quinoxaline. The initial rate and fluorescence signal of this sy...

a flow injection method is reported for the determination of ascorbic acid based on amperometric detection, using a cobalt(ii) phthalocyanine (copc) modified graphite-epoxy electrode. the amperometric respons was evaluated with regard to ph, ionic strength of the electrolyte, flow rate of the carrier solution, injected sample volume and conditioning time of the electrode. the limit of detection...

Methods based on the ability of ascorbic acid to reduce the dye 2:6-dichlorophenolindophenol (indophenol) to a colourless compound (Tillmans, Hirsch & Reinshagen, 1928) have been widely used in the estimation of ascorbic acid. Many other substances, including thiol compounds, thiosulphates, hydrogen sulphide, polyphenols and reductones (Lugg, 1942; Harris & Mapson, 1947) also decolorize indophe...

Dopamine, uric acid and ascorbic acid have been determined simultaneously on a poly(3,4-ethylenedioxythiophene) modified electrode using electrochemical techniques. On a bare glassy carbon electrode, all three undergo oxidation and appear as a single peak at around 200 mV, whereas on the modified electrode, distinct peaks with clear potential separation are observed, paving way for their simult...

This study demonstrates a new electrochemical method for rapid determination of ascorbic acid in real samples with electrochemically pretreated screen-printed carbon electrodes. Cyclic voltammetry results indicated that the electrochemically activated electrodes possessed an excellent electrocatalytic activity toward ascorbic acid oxidation and can be successfully used for its selective and sen...