Determination of ascorbic acid by iodate using iodine cyanide end point; indirect determination of vanadium, and colorimetric determination of ascorbic acid

Abstract

Two methods for the determination of ascorbic acid are described. The first employs titration with iodate in presence of cyanide and hydrochloric acid and starch indicator with two end points, corresponding to the formation of iodine after reduction to iodide and conversion of iodine to iodine cyanide respectively. The titration is applied to the indirect determination of vanadium(V). In the second method ascorbic acid is treated with excess ferric solution and the ferrous iron formed is determined colorimetrically by ortho-phenanthroline. © 1964 Springer-Verlag.