Kinetic Spectrophotometric Determination of Ascorbic Acid by Using Phenanthroline Agent in Eruca sativa

Ascorbic acid is used for treatment in hypovitaminosis, nutritional deficiency, scurvy, gingivitis, Barlow and Basedow diseases. In this study, a simple and sensitive kinetic spectrophotometric method was developed for the determination of ascorbic acid in Eruca sativa. The rate of formation of the product formed as a result of the reaction of ascorbic acid with iron (III) sulfate and phenanthroline reagents was determined by measuring the absorbance at 510 nm wavelength at 5 minute intervals for 60 minutes. The measurement curve prepared from standard ascorbic acid solution is linear in the concentration range of 4.0-6.0 mg/mL. The regression equation obtained from the graph of logarithms of molar concentrations versus logarithms of slopes was found as log (rate) = 2.5721 logC - 9.461 (r=0.9999) according to the initial rate method. The developed method was applied to Eruca sativa samples and the amount of ascorbic acid in fresh leaves was found to be 72.80 mg/100 g.