lism. Severe changes in the concentration of uric acid causes several diseases such as gout, hyperuricemia and Lesch–Nyhan syndrome. Therefore, the accurate determination of uric acid in urine samples can be a powerful indicator of diagnosing diseases. Thus, many researchers have focused to develop a simple, sensitive and accurate method for determining uric acid. Various methods have been deve...

An optode was designed for an indirect determination of ascorbic acid by using neocuproine, which has been coated on transparent triacetylcellulose film as a membrane. The proposed method is based on the oxidation of ascorbic acid to dehydroascorbic acid with the Cu(II) and neocuproine reagent. The increase in the absorbance value of the optode at the maximum wavelength of 455 nm was related ...

A carbon Paste electrode modified with cobalt (II) phthalocyanine (CoPC) was used as a sensitive potentiometric sensor for determination of ascorbic acid in aqueous solutions. The potential response of the electrode is a linear function of ascorbic acid concentration over the range 5 10 to 10 M (?1- 1800 µg ML ) with a Nernstian slope of 56 mV at pH 7. The limit of detection was 0.2 µg ...

A simple and sensitive flow injection fluorometric method for the determination of ascorbic acid is described. Perylenebisimide-linked nitroxide (PBILN) is used as a fluorescent reagent, which permits the selective determination of ascorbic acid. The fluorescence of the perylenebisimide moiety in PBILN is quenched by the nitroxide moiety, which is linked to the perylenebisimide. When a stream o...

a carbon paste electrode modified with cobalt (ii) phthalocyanine (copc) was used as a sensitive potentiometric sensor for determination of ascorbic acid in aqueous solutions. the potential response of the electrode is a linear function of ascorbic acid concentration over the range 5 10 to 10 m (?1- 1800 µg ml ) with a nernstian slope of 56 mv at ph 7. the limit of detection was 0.2 µg ml ascor...

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...

Chemical methods for the determination of reduced ascorbic acid (Zascorbic acid) are based upon its reducing properties. The indophenol method of Bessey (1, 2) and the perinaphthindantrione hydrate method of Moubasher (3) are examples of these methods. Modifications to increase the specificity of the indophenol method have been presented by Robinson and Stotz (4), Lowry, Lopez, and Bessey (5), ...

in this study, incorporation of iron ion-doped natrolite nanozeolite, multi-wall carbon nanotubes into chitosan-coated glassy carbon electrode for the simultaneous determination of ascorbic acid, epinephrine, uric acid and tyrosine is studied. the results show that the combination of multi-wall carbon nanotubes and iron ion-doped natrolite zeolite causes a dramatic enhancement in the sensitivit...

A method for the determination of total selenium in wheat and wheat flour using graphite furnace atomic absorption spectrometry (GFAAS) with palladium/ascorbic acid as a chemical modifier was studied. The effects of nickel nitrate, palladium/ascorbic acid, and palladium/magnesium nitrate as chemical modifiers on the sensitivity in the determination of selenite, selenate and selenomethionine by ...