(Ph. Eur. monograph 0707)
CaCl2, 6H2O 219.1 7774-34-7
DEFINITION
Content97.0 per cent to 103.0 per cent of CaCl2,6H2O.
CHARACTERS
Appearance
White or almost white, crystalline mass or colourless crystals.
Solubility
Very soluble in water, freely soluble in ethanol (96 per cent).
It solidifies at about 29 °C.
IDENTIFICATION
A. Solution S (see Tests) gives reaction (a) of chlorides (2.3.1).
B. It gives reaction (b) of calcium (2.3.1).
C. It complies with the limits of the assay.
TESTS
Solution S
Dissolve 15.0 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 (2.2.1) and not more intensely coloured than reference solution Y6 (2.2.2, Method II).
Acidity or alkalinity
To 10 mL of freshly prepared solution S add 0.1 mL of phenolphthalein solution R. If the solution is pink, not more than 0.2 mL of 0.01 M hydrochloric acid is required to discharge the colour and if the solution is colourless, not more than 0.2 mL of 0.01 M sodium hydroxide is required to turn it pink.
Sulfates (2.4.13)
Maximum 200 ppm.
Dilute 5 mL of solution S to 15 mL with distilled water R.
Aluminium
To 10 mL of solution S add 2 mL of ammonium chloride solution R and 1 mL of dilute ammonia R1. Heat to boiling. No turbidity or precipitate is formed.
If intended for use in the manufacture of dialysis solutions, the above test is replaced by the following test for aluminium (2.4.17): maximum 1 ppm.
Prescribed solution: Dissolve 6 g in 100 mL of water R and add 10 mL of acetate buffer solution pH 6.0 R.
Reference solution: Mix 2 mL of aluminium standard solution (2 ppm Al) R, 10 mL of acetate buffer solution pH 6.0 R and 98 mL of water R.
Blank solution: Mix 10 mL of acetate buffer solution pH 6.0 R and 100 mL of water R.
Iron (2.4.9)
Maximum 7 ppm, determined on solution S.
Magnesium and alkali metals
Maximum 0.3 per cent.
To a mixture of 20 mL of solution S and 80 mL of water R add 2 g of ammonium chloride R and 2 mL of dilute ammonia R1, heat to boiling and pour into the boiling solution a hot solution of 5 g of ammonium oxalate R in 75 mL of water R. Allow to stand for 4 h, dilute to 200 mL with water R and filter through a suitable filter. To 100 mL of the filtrate add 0.5 mL of sulfuric acid R. Evaporate to dryness on a water-bath and ignite to constant mass at 600 ± 50 °C. The residue weighs a maximum of 5 mg.
ASSAY
Dissolve 0.200 g in 100 mL of water R. Carry out the complexometric titration of calcium (2.5.11).
1 mL of 0.1 M sodium edetate is equivalent to 21.91 mg of CaCl2, 6H2O.
LABELLING
The label states, where applicable, that the substance is suitable for use in the manufacture of dialysis solutions.
