Ascorbic Acid(Vitamin C) - Langen Suzhou Co.,Ltd.

DESCRIPTION

Ascorbic Acid occurs as white or slightly yellow crystals or as powder. It melts at about 190°. It gradually darkens on exposure to light, is reasonably stable in air when dry, but rapidly deteriorates in solution in the presence of air. One gram is soluble in about 3 mL of water and in about 30 mL of alcohol. It is insoluble in chloroform and in ether.

Function Antioxidant; meat-curing aid; nutrient.

REQUIREMENTS

Identification

A. A 1:50 aqueous solution slowly reduces alkaline cupric tartrate TS at 25°, but more readily upon heating.

B. The infrared absorption spectrum of a potassium bromide dispersion of the sample exhibits maxima at the same wavelengths as those of a similar preparation of USP Ascorbic Acid Reference Standard.

Assay Not less than 99.0% and not more than 100.5% of C6H8O6.

Lead Not more than 2 mg/kg.

Optical (Specific) Rotation [ï¿½]D^25°: Between +20.5° and +21.5°.

Residue on Ignition Not more than 0.1%.

TESTS

Assay Dissolve about 400 mg of sample, accurately weighed, in a mixture of 100 mL of water, recently boiled and cooled, and 25 mL of 2 N sulfuric acid. Titrate the solution immediately with 0.1 N iodine, adding starch TS near the endpoint. Each milliliter of 0.1 N iodine is equivalent to 8.806 mg of C6H8O6.

Lead Determine as directed in the Flame Atomic Absorption Spectrophotometric Method under Lead Limit Test, Appendix IIIB, using a 10-g sample.

Optical (Specific) Rotation Determine as directed under Optical (Specific) Rotation, Appendix IIB, using a solution containing 1 g of sample in 10 mL of carbon dioxide-free water.

Residue on Ignition Determine as directed under Residue on Ignition, Appendix IIC, igniting a 2-g sample.

Packaging and Storage Store in tight, light-resistant containers.