Specifications of Sodium Citrate BP Grade Ph Eur Grade
Trisodium Citrate Ph Eur.
C6H5Na3O7,2H2O -- 294.1 -- CAS 6132-04-3

DEFINITION
Trisodium 2-hydroxypropane-1,2,3-tricarboxylate dihydrate.
Content: 99.0 per cent to 101.0 per cent (anhydrous substance).

CHARACTERS
Appearance: White or almost white, crystalline powder or white or almost white, granular crystals, slightly deliquescent in moist air.
Solubility: Freely soluble in water, practically insoluble in ethanol (96 per cent).

IDENTIFICATION
A. To 1 ml of solution S (see Tests) add 4 ml of water. The solution gives the reaction of citrates.
B. 1 ml of solution S gives reaction of sodium.

TESTS
Solution S: Dissolve 10.0 g in carbon dioxide-free water R prepared from distilled water R and dilute to 100 ml with the same solvent.
Appearance of solution: Solution S is clear and colourless.
Acidity or alkalinity: To 10 ml of solution S add 0.1 ml of PhPh solution. Not more than 0.2 ml of 0.1M hydrochloric acid or 0.1 M sodium hydroxide is required to change the colour of the indicator.
Readily carbonizable substances: To 0.20 g of the powdered substance to be examined add 10 ml of sulphuric acid and heat in a water-bath at 90 ± 1 °C for 60 min. Cool rapidly. The solution is not more intensely coloured than reference solution.
Chlorides: Maximum 50 ppm.
Oxalates: Maximum 300 ppm.
Sulphates: Maximum 150 ppm.
Heavy metals: Maximum 10 ppm.
Water: 11.0 per cent to 13.0 per cent, determined on 0.300 g. After adding the substance to be examined, stir for 15 min before titrating.

IDENTIFICATION
A. To 1 ml of solution S (see Tests) add 4 ml of water. The solution gives the reaction of citrates.
B. 1 ml of solution S gives reaction of sodium.