Flow electrochemical determination of ascorbic acid in real samples using a glassy carbon electrode modified with a cellulose acetate film bearing 2,6-dichlorophenolindophenol

Electrocatalytic Determination of L-Ascorbic Acid by Modified Glassy Carbon with Ni(Me2(CH3CO)2[14]tetraenoN4) Complex

“…For the bare GC, the peak current of L-ascorbic acid was linear up to 4 × 10 -3 M and the detection limit was 7.0 × 10 -5 M. However, for the modified electrode, the mediated oxidation peak current of L-ascorbic acid was linear up to 6.2 × 10 -3 M, and can be described by the equation I(µA) = 4.34 + 2.33 × 10 4 CAsA, r = 0.9991, n = 9, where I(µA) is the oxidation peak current, CAsA is the analyte concentration (M), r is the correlation coefficient and n represents the number of determinations. The detection limit (3σ) was 3.1 × 10 -7 M. This value is comparable with the values obtained by other research groups (Tzouwara-Karayanni and coworkers 30 (0.01 mM), Angnes et al, 31 (2.84 × 10 -6 M) Raoof et al, 10 1.08 × 10 -5 M, Bae et al 1,2 (8.8 × 10 -7 M and 4.7 × 10 -7 M). Thus, the catalytic oxidation of L-ascorbic acid can be readily applied for the determination of L-ascorbic acid.…”

“…A variety of examples of the electrochemical determination of AsA have been proposed. These include a glassy carbon electrode (GCE) and a carbon paste electrode with complexes and organic compounds, such as, 1,5,8,12,tetraaza-2,4,9,11-tetramethylcyclotetradecinatonickel(II), 1,2 cobalt hexacyanoferrate, 3 meso-tetrakis(o-nitrophenyl)tetrabenzoporphyrin with Fe(III), Ni(II), Mn(III) and Co(II), 4 ferricyanide-doped Tosflex, 5 ruthenium(III) diphenyldithiocarbamate, 6 ferrocene, 7 ferrocene with β-cyclodextrin, 8 ferrocenecarboxylic acid, ferroceneacetic acid, ferrocenemetanol, 9,10 ferrocene in lipid film, 11 pentachloroiridite, 12 benzoquinone, 13 norepinephrine, 14 pyrocatechol sulfonephthalein, 15 poly(glutamic acid), 16 cellulose acetate film bearing 2,6-dichlorophenolindophenol 17 and aniline. 18 In addition, some chemically modified electrodes with various active mediators immobilized at the metal electrode surface, such as, an aluminum electrode with pentacyanonitrosylferrate films, 19 a gold electrode with the electrodeposition of platinum, 20 3,4-dihydroxybenzoic acid and aniline 21 for the mediated oxidation of AsA, have been used.…”

Simple and Sensitive Electroanalytical Method for the Determination of Ascorbic Acid in Urine Samples Using Measurements in an Aqueous Cationic Micellar Medium

“…2, inset), thus indicating that the electrode reaction is controlled by difussion. 16,32,33 Another important observation is the oxidation peak potential, which shifts positively, increasing the scan rates, indicating a kinetic limitation towards the electrooxidation reaction of AA in cationic micelles environments. In order to comprove these considerations, the apparent diffusion coefficient of the AA in micellar medium was estimated.…”

A Comparative Study on Electrochemical Determination of Vitamin C in Liver and Tomato Using Platinum and Glassy Carbon Electrodes (Original Article)

“…These include titrimetric [12], [13], fluorometric [14], Flow Injection Photoamperometric [15], Flow electrochemical determination [16], direct injection liquid chromatography [17], high-performance liquid chromatography [18], spectrophotometric [19], [20], [21], [22], Photoelectrochemical [23], amperometric [24][25][26][27][28][29][30], Sonovoltammety [31], Electrocatalytic Determination [32][33][34][35][36][37], Electrochemical [38][39][40][41][42][43]. The vitamin C levels in some biological samples have been reported by several investigators.…”