METHODEN UND REAGENZIEN ZUR QUANTITATIVEN BESTIMMUNG VON ASCORBINSÄURE

摘要

The present invention relates to a method for the quantitative determination of ascorbic acid in a sample using ascorbate oxidase which catalyzes the reaction of reduced form of ascorbic acid with oxygen to form oxidized ascorbic acid and hydrogen peroxide (hereinafter the enzyme is referred to as ASOD), wherein the reaction of reduced ascorbic acid with oxygen in the presence of ASOD to form oxidized ascorbic acid and hydrogen peroxide and the reaction of the formed hydrogen peroxide with a chromogen in the presence of peroxidase to form a pigment are carried out in an aqueous medium in the same reaction system, and then the formed pigment is determined. The present invention also relates to a method for the determination of total ascorbic acid, wherein the enzyme reactions are carried out in the presence of a reducing agent which is capable of converting oxidized ascorbic acid into reduced ascorbic acid in said aqueous medium. The method enables the determination of total ascorbic acid at a low concentration. The present invention further relates to a method for the determination of total ascorbic acid, wherein oxidized ascorbic acid in said sample is reduced by the use of a reducing agent which is capable of converting oxidized ascorbic acid into reduced ascorbic acid, and then the enzyme reactions are carried out in the presence of a compound which is capable of deactivating the reducing agent. Furthermore, the present invention relates to a reagent and a kit for the determination of ascorbic acid suitable for use in the above methods. The method of the present invention is a simple method for the determination of ascorbic acid which is applicable to screening in clinical assays and which is capable of analyzing a large number of samples at the same time.