Prepared at the 49th JECFA (1997)
superseding specifications prepared at the 46th JECFA (1996),
published in FNP 52 Addendum 4 (1996)
SYNONYMS |
INS No. 330 |
DEFINITION |
|
Chemical name |
2-hydroxy-1,2,3-propanetricarboxylic acid |
C.A.S. number |
77-92-9 (anhydrous) |
Chemical formula |
C6H8O7 (anhydrous) |
Structural formula |
Figure Anhydrous |
Figure Monohydrate |
|
Formula weight |
192.13 (anhydrous) |
Assay |
Not less than 99.5% and not more than 100.5% on the anhydrous basis |
DESCRIPTION |
White or colourless, odourless, crystalline solid. The monohydrate form effloresces in dry air |
FUNCTIONAL USES |
Synergist for antioxidants, sequestrant, acidity regulator, flavouring agent |
CHARACTERISTICS |
|
IDENTIFICATION |
|
Solubility |
Very soluble in water; freely soluble in ethanol; slightly soluble in ether |
Positive Test for citrate |
Passes test |
PURITY |
|
Water |
Anhydrous: Not more than 0.5% (Karl Fischer method) |
Sulphated ash |
Not more than 0.05% |
Lead |
Not more than 0.5 mg/kg |
Oxalate |
Passes test |
Readily carbonizable substances |
|
|
Passes test |
TESTS |
|
PURITY TESTS |
|
Oxalate |
Neutralize 10 ml of a 10% solution of the sample with dilute ammonia TS. Add 5 drops of dilute acetic acid TS, cool and add 2 ml of calcium chloride TS. No turbidity should be produced. |
Readily carbonizable substances |
|
|
Heat 1.0 g of sample with 10 ml of 98% sulfuric acid in a water bath at 90±1° for 60 min. No colour darker than Matching Fluid K (25°) should be produced (not more than 0.5 absorbance units at 470 nm in a 10 mm cell). |
METHOD OF ASSAY |
Weigh, to the nearest mg, 2.5 g of the sample and place in a tared flask. Dissolve in 40 ml of water and titrate with IN sodium hydroxide, using phenolphthalein TS as the indicator. Each ml of IN sodium hydroxide is equivalent to 64.04 mg of C6H8O7. |