C4H4Na2O6-2H2O --- 230.08
Disodium L-tartrate.
Disodium (+)-2,3-dihydroxybutanedioic acid [868-18-8].
Sodium Tartrate contains not less than 99.0 percent and not more than 100.5 percent of C4H4Na2O6.2H2O, calculated on the dried basis.
Identification:
A: Responds to the tests for Sodium .
B: Responds to the tests for Tartrate.
pH: between 7 and 9 (1 in 10 solution).
Loss on drying: Dry it at 150 for 3 hours: it loses between 14.0% and 17.0% of its weight.
Heavy metals: 0.002%.
Limit of oxalate: Dissolve 1.0 g of Sodium Tartrate in 10 mL of water, then add 5 drops of diluted acetic acid and 2 mL of calcium chloride: no turbidity develops within 1 hour. Not more than 0.1% is found.
Assay: Transfer about 250 mg of Sodium Tartrate, accurately weighed and previously dried at 150 for 3 hours, to a 250-mL beaker, and dissolve by stirring and heating to near the boiling point in 150 mL of acetic acid. Cool the solution to room temperature. Titrate with 0.1 N perchloric acid VS (in glacial acetic acid), determining the endpoint potentiometrically. Perform a blank determination, and make any necessary adjustments. Each mL of 0.1 N perchloric acid is equivalent to 9.703 mg of C4H4Na2O6.
Disodium Tartrate; Disodium L-Tartrate
NaOOCCH(OH)CH(OH)COONa-2H2O or C4H4Na2O6-2H2O
Formula wt 230.08
INS: 335 CAS: [868-18-8]
DESCRIPTION
Sodium Tartrate occurs as transparent, colorless crystals. It is the disodium salt of L(+)-tartaric acid. One gram dissolves in 3 mL of water. It is insoluble in alcohol. The pH of a 1:20 aqueous solution is between 7 and 9. Upon ignition, it emits the odor of burning sugar and leaves a residue that is alkaline to litmus and that effervesces with acids.
Function: Sequestrant.
REQUIREMENTS
Identification: A sample gives positive tests for Sodium and for Tartrate.
Assay: Not less than 99.0% and not more than 100.5% of C4H4Na2O6 after drying.
Lead: Not more than 2 mg/kg.
Loss on Drying: Between 14.0% and 17.0%.
Oxalate: Passes test (limit about 0.1%).
