National Food Safety Standard Determination of Vitamin C in Foods for Infants and Young Children, Milk and Milk Products
1 Scope
This Standard specifies the method for the determination of vitamin C in foods for infants and young children, milk and milk products.
This standard is applicable to the determination of vitamin C in foods for infants and young children, milk and milk products. The determination results indicate the total content of reduction-type and oxidation-type vitamin C.
2 Normative Reference
The following documents are indispensable for the application of this Standard. For dated references, only the dated edition applies. For undated references, the latest edition (including all the amendments) of the normative document applies.
3 Principle
Vitamin C (Ascorbic acid) is oxidized to be dehydroascorbic acid in the presence of activated carbon. The dehydroascorbic acid then reacts with o-phenylenediamine to generate fluorescent substances. The fluorescent spectrophotometer then is applied to determine the fluorescence intensity of the fluorescent substances generated. The fluorescence intensity is proportional to the concentration of ascorbic acid. And the external standard method is used for ration.
4 Reagents and Materials
Unless otherwise specified, the reagents used in the method are the ones of analytically pure, and the water used is the Level 3 water regulated in GB/T 6682.
4.1 Amylase: enzyme activity is of 1.5U/mg, the dosage shall be adjusted in accordance with the size of the activity unit.
