Aluminium powder

Prepared at the 49th JECFA (1997)
superseding specifications prepared at the 39th JECFA (1992),
published in FNP 52 Addendum 1 (1992)

SYNONYMS

CI Pigment Metal
CI (1975) No. 77000, INS No. 173

DEFINITION

Aluminium powder is produced by grinding aluminium in the presence of edible vegetable oils and/or food grade fatty acids.

Chemical name

Aluminium

C.A.S number

7429-90-5

Chemical formula

Al

Atomic weight

26.98

Assay

Not less than 99.0%

DESCRIPTION

A silvery grey powder

FUNCTIONAL USES

Colour, surface colourant

CHARACTERISTICS

IDENTIFICATION

Solubility

Insoluble in water
Insoluble in organic solvents
Soluble in dilute hydrochloric acid

Test for Aluminium

Passes test

PURITY

Loss on drying

Not more than 0.5% (105°)

Arsenic

Not more than 3 mg/kg

Lead

Not more than 20 mg/kg

Heavy metals

Not more than 40 mg/kg
Test 0.5 g of the sample as directed in the Limit Test (Method II)

METHOD OF ASSAY

Wash a small sample in hexane, repeating to remove traces of any associated oil or fatty acid. Transfer about 0.2 g of the sample, accurately weighed, to a 500-ml flask fitted with a rubber stopper carrying a 150-ml separating funnel, an inlet tube connected to a cylinder of carbon dioxide and an outlet tube dipping into a water-trap. Add 60 ml of freshly boiled and cooled water and disperse the sample; replace the air by carbon dioxide and add, by the separating funnel, 100 ml of a solution containing 56 g of ferric ammonium sulfate and 7.5 ml of sulfuric acid in freshly boiled and cooled water. While maintaining an atmosphere of carbon dioxide in the flask, heat to boiling and boil for 5 min. After the sample has dissolved, cool rapidly to 20°, and dilute to 250 ml with freshly boiled and cooled water. To 50 ml of this solution, add 15 ml of phosphoric acid and titrate with 0.1 N potassium permanganate. 1 ml of 0.1 N potassium permanganate = 0.8994 mg Al.

SYNONYMS	CI Pigment Metal CI (1975) No. 77000, INS No. 173
DEFINITION	Aluminium powder is produced by grinding aluminium in the presence of edible vegetable oils and/or food grade fatty acids.
Chemical name	Aluminium
C.A.S number	7429-90-5
Chemical formula	Al
Atomic weight	26.98
Assay	Not less than 99.0%
DESCRIPTION	A silvery grey powder
FUNCTIONAL USES	Colour, surface colourant
CHARACTERISTICS
IDENTIFICATION
Solubility	Insoluble in water Insoluble in organic solvents Soluble in dilute hydrochloric acid
Test for Aluminium	Passes test
PURITY
Loss on drying	Not more than 0.5% (105°)
Arsenic	Not more than 3 mg/kg
Lead	Not more than 20 mg/kg
Heavy metals	Not more than 40 mg/kg Test 0.5 g of the sample as directed in the Limit Test (Method II)
METHOD OF ASSAY	Wash a small sample in hexane, repeating to remove traces of any associated oil or fatty acid. Transfer about 0.2 g of the sample, accurately weighed, to a 500-ml flask fitted with a rubber stopper carrying a 150-ml separating funnel, an inlet tube connected to a cylinder of carbon dioxide and an outlet tube dipping into a water-trap. Add 60 ml of freshly boiled and cooled water and disperse the sample; replace the air by carbon dioxide and add, by the separating funnel, 100 ml of a solution containing 56 g of ferric ammonium sulfate and 7.5 ml of sulfuric acid in freshly boiled and cooled water. While maintaining an atmosphere of carbon dioxide in the flask, heat to boiling and boil for 5 min. After the sample has dissolved, cool rapidly to 20°, and dilute to 250 ml with freshly boiled and cooled water. To 50 ml of this solution, add 15 ml of phosphoric acid and titrate with 0.1 N potassium permanganate. 1 ml of 0.1 N potassium permanganate = 0.8994 mg Al.