
Cryolite, natural and artificial — Determination of calcium content — Flame atomic absorption method
NORMA vydaná dňa 1.9.1976
Označenie normy: ISO 3391:1976
Dátum vydania normy: 1.9.1976
Počet strán: 4
Približná hmotnosť: 12 g (0.03 libier)
Krajina: Medzinárodná technická norma
Kategória: Technické normy ISO
Description / Abstract: Describes the preparation of the calibration graph and the dissolution of a test portion in concentrated sulphuric acid and heating on a hot-plate until the hydrofluoric acid has evaporated. Treatment of the residue with concentrated hydrochloric acid. Aspiration of the solution into an acetylene/dinitrogen monoxide flame and spectrophotometric measurement of the absorption of the 422.7-nm line emitted by a calcium hollow cathode lamp.