A Spectrophotometric Determination of Ascorbic Acid

Abstract

A new, simple and sensitive method for the spectrophotometric indirect determination of ascorbic acid in fruits, beverages, and pharmaceuticals is described. In this method, the ascorbic acid reduces Cu2+ to Cu+ and reacts with 2,9‐dimethyl‐1,10‐phenanothroline (neucoproine) to form Cu (neucoproine)+ complex, and it was extracted with N‐phenylbenzimidoylthiourea (PBITU) in chloroform. The apparent value of molar absorptivity of the complex in terms of ascorbic acid is (3.52) × 104 L mole−1 cm−1 at λmax, 460. The detection limit of ascorbic acid is 40 μg L−1 and the method obeys Beer's law over the concentration range of 0.1–4.0 μg mL−1. The proposed method was successfully applied for the determination of ascorbic acid in various samples. The validity of the present method was checked by the flow injection analysis (FIA) method.

Copper Oxide Microstructures with Hemisphere Pineapple Morphology for Selective Amperometric Determination of Vitamin C (L‐ascorbic Acid) in Human Fluids

“…Several analytical techniques have been used for assessment of ascorbic acid including spectroscopic , chromatographic , enzymatic and electrochemical methods . Among them, electrochemical methods have received much attention because of its fast response, easy handling and low cost.…”

Coccoloba uvifera(L.) (Polygonaceae) Fruit: Phytochemical Screening and Potential Antioxidant Activity

“…However, humans are unable to synthesize vitamin C. When there is insufficient vitamin C in the diet, humans suffer from the potentially lethal deficiency disease scurvy. More than 90% of the vitamin C in human diets is supplied by fruits and vegetables [29]. Ascorbic acid is an electron donor (reducing agent or antioxidant), and probably all of its biochemical and molecular functions [30].…”

“…The ascorbyl free radical can be converted back to reduce ascorbate by accepting another hydrogen atom or it can undergo further oxidation to dehydroascorbate. Dehydroascorbate is unstable but is more fat soluble than ascorbate and is taken up 10-20 times more rapidly by erythrocytes, where it will be reduced back to ascorbate by NADPH from the hexose monophosphate shunt; thus mechanisms exist to recycle vitamin C in human organism [29]. Therefore it is important to consider the contribution of ascorbic acid in the antioxidant activity of C. uvifera fruit.…”

Influence of novel bioactive compounds from selected fruit by-products and plant materials on the quality and storability of microwave-assisted cooked poultry meat wafer during ambient temperature storage

“…Make the volume up to 5 mL with ethanol and stored at À20 C for analysis. The samples were evaluated for total phenolic contents (Yuan, Bone, & Carrington, 2005), flavonoids (Earnsworth, Berderka, and Moses (1974), total b-carotene , gallic acid (Gonzalez, Guzman, Rudyk, Romano, & Molina, 2003), a-tocopherol (Prieto, Pineda, & Aguilar, 1999) and Vita-C (Shrivas, Agrawal, & Patel, 2005). The details of methodology of each individual compound are given as underFor determination of total phenolics, 100 mL of extract was mixed with 1.9 mL of Na 2 CO 3 buffer (2.0 g/100 mL) and incubated at 27 ± 2 C for 5 min.…”