C3H5NaO2
96.1 -- 137-40-6
Action and use
Antifungal
DEFINITION
Sodium propionate
Content
99.0 per cent to 101.0 per cent Sodium propionate (dried substance).
CHARACTERS
Appearance
Colourless crystals or, white or almost white powder, slightly hygroscopic.
Solubility
Freely soluble in water, sparingly soluble in alcohol, practically insoluble in
methylene chloride.
IDENTIFICATION
First identification A, D.
Second identification B, C, D.
A. Infrared
absorption spectrophotometry.
Comparison reference spectrum of sodium
propionate.
B. Dissolve 0.1 g in a mixture of 2 ml of copper sulphate solution
and 2 ml of methylene chloride. Shake vigorously and allow to stand. Both the upper
and the lower layer show a blue colour.
C. To 5 ml of solution S add 2 ml of 0.1
M silver nitrate. A white precipitate is formed.
D. Solution S gives reaction of
sodium.
TESTS
Solution S
Dissolve 10 g Sodium propionate in carbon dioxide-free water
prepared from distilled water and dilute to 100 ml with the same solvent.
Appearance of solution
Solution S is clear and colourless.
pH
7.8 to 9.2
Dilute 1 ml of solution S to 5 ml with water.
Related substances
Liquid chromatography.
Test solution: Dissolve 0.250 g of the substance to be
examined in water and dilute to 100 ml with the same solvent.
Reference solution
(a) Dissolve 10 mg of the substance to be examined and 10 mg of sodium acetate
in water and dilute to 100 ml with the same solvent.
Reference solution (b)
Dilute 1.0 ml of the test solution to 100 ml with water.
Column: ı
ı— size: l
= 0.25 m, Ø = 4.6 mm;
ı— stationary phase: octadecylsilyl silica gel for
chromatography (5μm).
Mobile phase Dilute 1 ml of phosphoric acid R to 1000 ml
with water.
Flow rateı1 ml/min.
Detection Spectrophotometer at 210
nm.
Injectionı20 μl.
System suitability Reference solution (a):
ı—
resolution: minimum 5 between the peaks due to sodium acetate and sodium
propionate.
Limits:
ı— any impurity: not more than 0.1 times the area of the principal
peak in the chromatogram obtained with reference solution (b) (0.1 per cent);
ı—
total: not more than half the area of the principal peak in the chromatogram
obtained with reference solution (b) (0.5 per cent);
ı— disregard limit: 0.05
times the area of the principal peak in the chromatogram obtained with reference
solution (b) (0.05 per cent).
Readily oxidizable substancesI
n a ground-glass-stoppered conical flask introduce 10 g of the substance ( Sodium
propionate.) to be examined.
Add 100 ml of water R and stir to dissolve. Add 25
ml of sodium hypobromite solution and 10 ml of a 200 g/l solution of sodium acetate,
stopper the flask and allow to stand for 15 min. Add 10 ml of potassium iodide
solution and 20 ml of hydrochloric acid while cooling.
Titrate with 0.2 M sodium thiosulphate, adding 2 ml of starch solution R towards the
end of the titration. Carry out a blank titration. The difference between the
volumes used in the 2 titrations is not greater than 2.2 ml.
Iron
Maximum 10 ppm.
10 ml of solution S complies with the limit test for iron.
Heavy metals
Maximum 10 ppm.
12 ml of solution S complies with limit test A. Prepare the
standard using lead standard solution (1 ppm Pb).
Loss on drying
Maximum 0.5 per cent, determined on 1.000 g by heating in an oven at 105C for 3
h.
ASSAY
Dissolve 80.0 mg Sodium propionate in 30 ml of anhydrous acetic acid R. Titrate with
0.1 M perchloric acid, determining the end-point potentiometrically.
1 ml of 0.1 M perchloric acid is equivalent to 9.61 mg of C3H5NaO2.
Sodium Propionate
C3H5NaO2·xH2O
Propanoic acid, sodium salt, hydrate.
Sodium propionate hydrate [6700-17-0]
Anhydrous 96.06 [137-40-6]
Sodium
Propionate, dried at 105 for 2 hours, contains not less than 99.0 percent and not
more than 100.5 percent of C3H5NaO2.
Identification—
A: Infrared Absorption 197K , on un-dried specimen.
B: A solution (1 in 20)
responds to the tests for Sodium.
Alkalinity— Dissolve 2.0 g in 20 mL of water, and add phenolphthalein TS: if
a pink color is produced, it is discharged by 0.60 mL of 0.10 N sulfuric acid.
Water: not more than 1.0%.
Heavy metals— Dissolve 2 g in 1 mL of 1 N acetic acid and sufficient water to
make 25 mL: the limit is 0.001%.
Organic volatile impurities: meets the requirements.
(Official until July
1, 2007)
Assay— Dissolve about 200 mg of Sodium Propionate, previously dried at 105
for 2 hours and accurately weighed, in 50 mL of glacial acetic acid. Add 1 drop of
crystal violet TS, and titrate with 0.1 N perchloric acid VS to a green endpoint.
Perform a blank determination, and make any necessary correction. Each mL of 0.1 N
perchloric acid is equivalent to 9.606 mg of C3H5NaO2.
Sodium Propionate
C3H5NaO2·xH2O
Propanoic acid, sodium salt, hydrate.
Sodium propionate hydrate [6700-17-0]
Anhydrous 96.06 [137-40-6]
Sodium
Propionate, dried at 105 for 2 hours, contains not less than 99.0 percent and not
more than 100.5 percent of C3H5NaO2.
Identification—
A: Infrared Absorption 197K , on un-dried specimen.
B: A solution (1 in 20)
responds to the tests for Sodium.
Alkalinity— Dissolve 2.0 g in 20 mL of water, and add phenolphthalein TS: if
a pink color is produced, it is discharged by 0.60 mL of 0.10 N sulfuric acid.
Water: not more than 1.0%.
Heavy metals— Dissolve 2 g in 1 mL of 1 N acetic acid and sufficient water to
make 25 mL: the limit is 0.001%.
Organic volatile impurities: meets the requirements.
(Official until July
1, 2007)
Assay— Dissolve about 200 mg of Sodium Propionate, previously dried at 105
for 2 hours and accurately weighed, in 50 mL of glacial acetic acid. Add 1 drop of
crystal violet TS, and titrate with 0.1 N perchloric acid VS to a green endpoint.
Perform a blank determination, and make any necessary correction. Each mL of 0.1 N
perchloric acid is equivalent to 9.606 mg of C3H5NaO2.
