Sodium Ascorbate
(soe' dee um a skor' bate).
DEFINITION
Sodium Ascorbate contains NLT 99.0% and NMT 101.0% of sodium ascorbate (C6H7NaO6), calculated on the dried basis.
IDENTIFICATION
• A. Infrared Absorption 197M
Sample:
Use undried Sodium Ascorbate.
Acceptance criteria:
Meets the requirements
• B. Reducing capacity
Sample solution:
20 mg/mL
Analysis:
Add 1 mL of 0.1 N hydrochloric acid to 4 mL of the Sample solution, and add alkaline cupric tartrate TS.
Acceptance criteria:
The solution reduces alkaline cupric tartrate TS slowly at room temperature, but more readily upon heating.
• C. Identification TestsGeneral, Sodium 191:
A 20-mg/mL solution meets the requirements.
ASSAY
• Procedure
Sample:
400 mg of Sodium Ascorbate
Blank:
100 mL of carbon dioxide-free water and 25 mL of 2 N sulfuric acid
Titrimetric system
(See Titrimetry 541.)
Mode:
Direct titration
Titrant:
0.1 N iodine VS
Endpoint detection:
Visual
Analysis:
Dissolve the Sample in a mixture of 100 mL of carbon dioxide-free water and 25 mL of 2 N sulfuric acid. Titrate immediately with the Titrant, and add 3 mL of starch TS as the endpoint is approached. Perform the Blank determination.
Calculate the percentage of sodium ascorbate (C6H7NaO6) in the portion of Sodium Ascorbate taken:
Result = {[(VS VB) × N × F]/W} × 100
Acceptance criteria:
99.0%101.0% on the dried basis
IMPURITIES
• Heavy Metals, Method II 231:
NMT 20 ppm
SPECIFIC TESTS
• Optical Rotation, Specific Rotation 781S
Sample solution:
100 mg/mL in carbon dioxide-free water. Use the solution immediately after preparation.
Acceptance criteria:
+103 to +108
• Loss on Drying 731:
Dry a sample in a suitable vacuum drying tube, using phosphorus pentoxide as the desiccant, at 60 for 4 h: it loses NMT 0.25% of its weight.
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight, light-resistant containers.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 4646
|