A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry. The anodic oxidation peak for ascorbic acid occurs at about 490 mV on a Pt disc working electrode (versus SCE). The influence of the potential sweep speed on the peak height was studied. The obtained calibration graph shows a linear dependence between peak height and ascorbic acid c...

The objective of this work is to provide a tool for the electrochemical detection and quantification of dopamine in biological environments in the presence of ascorbic and uric acids (AA, UA). Sonogel electrodes modified with L-Cysteine prepared in this work showed very remarkable electrochemical performance for the determination of dopamine; the results obtained show good selectivity and sensi...

a chemically modified carbon paste electrode with 2-chlorobenzoyl ferrocene (2cbf) and carbon nanotube (2cbfcnpe) was employed to study the electrocatalytic oxidation of ascorbic acid in aqueous solution using cyclic voltammetry, square wave voltammetry and chronoamperometry. the diffusion coefficient (d = 1.42 × 10-6 cm2 s-1), and the kinetic parameter such as the catalytic rate constant (k = ...

The metabolic fate of l-ascorbic acid-1-(14)C and -6-(14)C has been investigated in two species in two genera of Vitaceae. Results suggest that ascorbic acid metabolism in the Vitaceae involves splitting the 6-carbon chain into 4- and 2-carbon fragments. The former, corresponding to C1 through C4 of ascorbic acid, is further oxidized to tartaric acid while the latter, corresponding to C5 and C6...

CONTEXT Some animal studies suggest that orally administered ascorbic acid may chelate lead and decrease the risk of the toxic effects of lead. However, results from several small studies in humans have yielded inconclusive evidence of a beneficial effect of ascorbic acid on lead toxicity. OBJECTIVE To examine the relationship between serum ascorbic acid levels and prevalence of elevated bloo...

The ACh-releasing factor, which is required for ACh release in presence of 2 mM ATP, 2 mM Mg and 10(-5) M Ca from isolated synaptic vesicles, was purified from the synaptosomal cytoplasm of rat brain by Sephadex G-15, DEAE-Sephadex, Sephadex G-10 and AG50W-2X column chromatographies and identified as ascorbic acid. A low concentration of L-ascorbic acid (5 x 10(-6) M) produced a release of ACh ...

As the initial step in the use of fibroblasts as a model system for 'in situ kinetics', ascorbic acid (vitamin C) accumulation in normal human fibroblasts was investigated for the first time. Ascorbic acid was transported into fibroblasts and accumulated against a concentration gradient up to 20-fold, as measured by h.p.l.c. with coulometric electrochemical detection. Ascorbic acid accumulation...