Calcium Ascorbate
C12H14CaO12·2H2O
426.34
426.34» Calcium Ascorbate contains not less than 98.0 percent and not more than 101.0 percent of C12H14CaO12·2H2O, calculated on the as-is basis.
Packaging and storage—
Preserve in tight, light-resistant containers.
Identification—
A:
A solution (1 in 10) responds to the tests for Calcium 
191
.
191.
B:
A solution (1 in 10) decolorizes a solution of dichlorophenol-indophenol (1 in 10).
Specific rotation 781S:
between +95
and +97, from optical rotation measurements made immediately following the preparation of the Test solution.
781S:
between +95 and +97, from optical rotation measurements made immediately following the preparation of the Test solution.
Test solution:
50 mg per mL, in carbon dioxide-free water.
pH 791:
between 6.8 and 7.4 in a solution (1 in 10).
791:
between 6.8 and 7.4 in a solution (1 in 10).
Loss on drying 731—
Dry an accurately weighed quantity of about 3 g of it at 105 for 2 hours: it loses not more than 0.1% of its weight.
731—
Dry an accurately weighed quantity of about 3 g of it at 105 for 2 hours: it loses not more than 0.1% of its weight.
Arsenic, Method I 211:
3 µg per g.
211:
3 µg per g.
Heavy metals, Method II 231:
0.001%.
231:
0.001%.
Limit of fluoride—
Proceed as directed in the test for Limit of fluoride under Dibasic Calcium Phosphate: the limit is 10 ppm.
Assay—
Transfer an accurately weighed quantity of about 300 mg of Calcium Ascorbate to a 250-mL conical flask. Add 50 mL of water, mix to dissolve, and immediately titrate with 0.1 N iodine VS, adding 3 mL of starch TS as the endpoint is approached. Each mL of 0.1 N iodine is equivalent to 10.66 mg of C12H14CaO12·2H2O.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
| Monograph | Curtis Phinney
1-301-816-8345 |
(DSN05) Dietary Supplements - Non-Botanicals |
| Reference Standards | Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org |
USP32–NF27 Page 1754
Pharmacopeial Forum: Volume No. 27(6) Page 3255