FCCV标准-Sodium Acid Pyrophosphate酸性焦磷酸钠.pdf

400/Sodium Acetate/ Monographs
FCCV
Sodium Acetate
Sodium Acid Pyrophosphate
C2H3NaO2
Formula wt, anhydrous 82.03 Disodium Pyrophosphate; Disodium Dihydrogen
C2H3Na023H20
Formula wt, trihydrate 136.08 Pyrophosphate; Disodium Dihydrogen Diphosphate; Acid
INS:262(i)
CAS: anhydrous [127-09-3]
Sodium Pyrophosphate
CAS: trihydrate 16131-90-41 Na2H2P2O7
Formula wt 221.94
i:450()
cAS:7758-16-91
DESCRIPTION
Sodium Acetate occurs as colorless, transparent crystals or DESCRIPTION
as a granular, crystalline or white powder. The anhydrous Sodium Acid Pyrophosphate occurs as a white, crystalline
form is hygroscopic; the trihydrate effloresces in warm, dry
air. One gram of the anhydrous form dissolves in about 2 mL
powder or granules. It is soluble in water. The pH of a 1: 100
100
of water; 1 g of the trihydrate dissolves in about 0.8 mL of
water and in about 19 mL of alcohol.
num and/or calcium salt to control the rate of reaction in
eavening systems.
Function Buffer
Function Buffer; emulsifier; leavening agent; sequestrant.
REQUIREMEnTS
REQUIREMENTS
Identification A 1: 20 aqueous solution gives positive tests
for Sodium and for Acetate, Appendix IIIA
Identification
Assay Not less than 99.0% and not more than 101.0% of
A. 1: 20 aqueous solution gives positive tests for Sodium,
npend
C2H3NaO2 after drying.
Appendix IlIA
Alkalinity Anhydrous: Not more than 0.2%; Trihydrate: Not
B. Dissolve 100 mg of sample in 100 mL of 1.7 N nitric
more than 0.05%
acid. Add 0.5 mL of this solution to 30 mL of quimociac TS
Lead Not more than 2 mgk
A yellow precipitate does not form. Heat the remaining portion
Loss on Drying Anhydrous: Not more than 1.0%; Trihy-
of the sample solution for10 min at95°, and add0.5mlof
d41
drate: Between 36.0% and 41.0%.
it to 30 mL of quimociac TS. A yellow precipitate forms
ound
Potassium Compounds Passes test.
immediately.
Assay Not less than 93.0% and not more than 100.5% of
TESTS
Na2H2P2O7.
Arsenic Not more than 3 mg/kg.
Assay Accurately weigh about 400 mg of the dried sample Fluoride Not more than 0.005%
obtained in the test for Loss on Drying (below), and dissolve Insoluble Substances Not more than 1%.
it in 40 mL of glacial acetic acid, add 2 drops of crystal violet Lead Not more than 2 mg/kg.
TS, and titrate with 0.1 N perchloric acid in glacial acetic acid.
Caution: Handle perchloric acid in an appropriate
TESTS
fume hood.
Assay Dissolve about 500 mg of sample, accurately
Perform a blank determination (see General Provisions) and weighed, in 100 mL of water contained in a 400-mL beaker.
make any necessary correction. Each
chloric acid is equivalent to
C2H3Na vwater, sulfate (125 g of ZnSO 7H20 dissolved in water, diluted to
hydrochloric acid, then add 50 mL of a 1: 8 solution of zinc
and add 3 drops of phenolphthalein TS. If a pink colo
opears. 1000 mL, filtered, and adjusted to 3.8 with hydrochloric
mL of 0.1 N sulfuric acid is acid), and allow the mixture to stand for min. Titrate the
required to disch
rous and trihydrate, liberated
until a pH of 3.8
respectively
.I N sodium hydrox-

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