Abstract
The purpose of this study was to apply Roche method(Anal.Chem.28,1486,1953) to determination of viamin C in multivitamin preparations. The method was modified as follows : Diazo reagent : 0.1 ml of 2% sojium nitrite is added to 0.1 ml of the mixture of equal volume of glacial acetic acid containing 4% of 2-nitro-4-methoxyaniline and 10% hydrochloric acid. After brown color of amino compounds vanishes, 15 ml of alcohol is added to the solution. Determination : Diazo reagent is added to 1 ml of metaphosphoric acid-acetic acid solution containing about 1 mg of vitamin C in a 50 ml measuring flask, then the mixture is alkalized with 2 ml of 10% sodium hydroxide, and after 1 minute filled up to 50 ml. The vitamin C content is calculated from the color intensity of the solution measured at 570 mμ.
