Dried Aluminium Hydroxide Gel
|
SL. NO
|
TESTS
|
STANDARDS
|
||
|
1
|
Characters
|
|||
|
A
|
Description |
A white, light, amorphous powder containing some aggregates;
odourless; tasteless. |
||
|
B
|
Solubility |
Insoluble in water and in ethanol (95%). It dissolves
in dilute mineral acids and in excess of caustic alkali solutions. |
||
|
2
|
Identification
|
|||
|
A
|
Reaction of Aluminium salts | |||
|
i
|
Reaction A
|
Gelatinous white precipitate should re-appear.
|
||
|
ii
|
Reaction B
|
An intense purple colour should be formed.
|
||
|
iii
|
Reaction C
|
A reddish violet colour should be formed.
|
||
|
3
|
pH
|
Not more than 10.0
|
||
|
4
|
Arsenic
|
Not more than 5 ppm. | ||
|
5
|
Heavy Metals
|
Not more than 60 ppm
|
||
|
6
|
Chloride
|
Not more than 1.25%
|
||
|
7
|
Sulphate
|
Not more than 1.2%
|
||
|
8
|
Neutralising Capacity
|
Not more than 35 ml of 0.1M sodium hydroxide should
be required and the pH of the solution at 37 degree Centigrade at no time should be more than 4.5 |
||
|
9
|
Microbial limit
|
1 g should be free from Escherichia coli.
|
||
|
10
|
Assay
|
Between 47.0% and 60.0% (of Al2O3)
|
||