Prepared at the 49th JECFA (1997)
superseding specifications prepared at the 44th JECFA (1995),
published in FNP 52 Addendum 3 (1995)
SYNONYMS |
Calcium propanoate, INS No. 282 |
DEFINITION |
|
Chemical name |
Calcium propionate |
C.A.S. number |
4075-81-4 |
Chemical formula |
C6H10CaO4 |
Structural formula |
(CH3CH2COO-)2 Ca++ |
Formula weight |
186.22 |
Assay |
Not less than 98,0% on the dried basis |
DESCRIPTION |
White crystals, powder or granules with not more than a faint odour of propionic acid |
FUNCTIONAL USES |
Preservative, antimould and antirope agent |
CHARACTERISTICS |
|
IDENTIFICATION |
|
Solubility |
Freely soluble in water, soluble in ethanol |
Positive test for calcium |
Passes test |
Positive test for propionate | |
|
Warm the sample with sulfuric acid. The propionic acid evolved may be recognized by its odour. |
Positive test for alkali salt of organic acid | |
|
Ignite the sample at a relatively low temperature. The alkaline organic acid residue effervesces with acid. |
PURITY |
|
Loss on drying |
Not more than 4% (105°. 2h) |
pH |
7.5 - 10.5 (1 in 10 soln) |
Water insoluble matter |
Not more than 0.3% |
Fluoride |
Not more than 30 mg/kg |
Iron |
Not more than 50 mg/kg |
Lead |
Not more than 5 mg/kg |
TESTS |
|
PURITY TESTS |
|
Water-insoluble matter |
Weigh 5 g of the sample to the nearest mg, transfer into a 100-ml beaker and add 50 ml of water. Stir until all the sample appears to be completely dissolved. Filter through a Gooch crucible, tared to an accuracy of ± 0.2 mg. Rinse the beaker with 20 ml of water. Dry the crucible with its contents in a 60°-oven to constant weight. Cool in a desiccator, weigh, and calculate as percentage. |
METHOD OF ASSAY |
Dissolve in a beaker 2.5 g of the sample, weighed to the nearest mg, in 5 ml of hot dilute hydrochloric acid TS. Cool, transfer to a 250-ml volumetric flask, dilute to volume with water, and mix. Transfer 50 ml of the solution to a 400-ml beaker, add 100 ml of water, 25 ml of sodium hydroxide TS, 40 mg of murexide indicator preparation and 3 ml of naphthol green TS. An alternative indicator is hydroxynaphthol blue, of which 0.25 g is used. In this case the naphthol green TS is omitted. Titrate with 0.05 M disodium ethylenediaminetetraacetate until the solution is deep blue in colour. Each ml of 0.05 M disodium ethylenediaminetetraacetate is equivalent to 9.311 mg of C6H10CaO4. |