Chemical Name: AMMONIUM ALUM??? ?????? RM Control No.:__________

PARAMETERS

USP

STANDARD

SAMPLE

REMARKS

Description

Large colourless crystals, or crystalline fragments, or a white powder. Is odourless, Its solutions are acid to litmus

Solubility

Freely soluble in water, very soluble in boiling water; freely but slowly soluble in glycerin. Insoluble in alcohol.

Identification

USP 23

A: a precipitate is formed and it dissolves in the excess of the reagent with the evolution of ammonia

B: responds to the test for aluminum and for sulfate <191>

Loss on drying <731>

It loses between 45.0% and 48.5% of its weight (dry at 300?to constant?weight )

Limit of alkalies and alkaline earths

The weight of the residue does not exceed

5 mg ( 0.5%)

Heavy metals method I <231>

The limit is 0.002%

Iron

No blue colour is produced immediately

Assay

Not less than 99.0% and not more than 100.5% of AlNH₄(SO₄)₂, calculated on the dried basis