Prepared at the 53rd JECFA (1999) and published in FNP 52 Add 7 (1999), superseding specifications prepared at the 21st JECFA (1977), published in NMRS 57 (1977) and in FNP 52 (1992). No ADI allocated at the 21st JECFA in 1977. | |
SYNONYMS |
dl-Tartaric acid |
DEFINITION |
|
Chemical names |
DL-Tartaric acid, 2,3-dihydroxybutanedioic acid; 2,3-dihydroxysuccinic acid |
C.A.S. number |
133-37-9 |
Chemical formula |
C4H6O6 |
Structural formula |
|
Formula weight |
150.09 |
Assay |
Not less than 99.5% on the dried basis |
DESCRIPTION |
Colourless or translucent crystals, or a white crystalline powder; odourless |
FUNCTIONAL USES |
Synergist for antioxidants, acid, emulsifier, sequestrant, flavouring agent (see "Table of specifications of flavouring agents") |
CHARACTERISTICS |
|
IDENTIFICATION |
|
Solubility (FNP 5) |
Freely soluble in water; sparingly soluble in ethanol |
Optical rotation (FNP 5) |
A 1 in 10 solution has no optical activity |
Test for tartrate (FNP 5) |
Passes test |
PURITY |
|
Loss on drying (FNP 5) |
Not more than 0.5% (over P2O5, 3 h) |
Melting range (FNP 5) |
200 - 206� with decomposition when heated rapidly in a sealed capillary-tube |
Sulfated ash (FNP 5) |
Not more than 0.1% |
Readily oxidizable substances |
Dissolve 1 g of the sample in 25 ml dilute sulfuric acid TS. Add 4 ml of 0.1 N potassium permanganate while keeping the solution at 20�. The colour of the solution does not disappear within 3 min. |
Sulfates (FNP 5) |
Not more than 0.05% |
Lead (FNP 5) |
Not more than 2 mg/kg |
METHOD OF ASSAY |
Weigh accurately about 2 g of the dried sample, dissolve it in 40 ml of water, add phenolphthalein TS, and titrate with 1 N sodium hydroxide. Each ml of 1 N sodium hydroxide is equivalent to 75.04 mg of C4H6O6. |