ISO 984:1974
Withdrawn
Sodium hydroxide for industrial use — Determination of silica content — Reduced silico-molybdic complex photometric method
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English, French
12-01-1974
02-26-2019
The method is applicable to products having silica contents exceeding 10 mg/kg. The principle is based on the formation of yellow oxidized silico-molybdic complex in a strongly acid medium, in the presence of boric acid to suppress interference by fluorides. Selective reduction of this complex with a mixture of aminonaphtholsulphonic acid (4-amino-3-hydroxynaphthalene-1-sulphonic acid), sodium metabisulphite and sodium sulphite, in the presence of oxalic acid and in a strongly acid medium so as to suppress interference by phosphates. Photometric measurement of the blue-coloured complex at a wavelength of about 795 nm.
| Committee |
ISO/TC 47
|
| DevelopmentNote |
Also numbered as BS 6075-4(1981) (09/2005)
|
| DocumentType |
Standard
|
| Pages |
3
|
| PublisherName |
International Organization for Standardization
|
| Status |
Withdrawn
|
| Standards | Relationship |
| NFT 20 424 : 76 FD | Identical |
| NBN T 03 126 : 1980 | Identical |
| UNE 55605:1978 | Not Equivalent |
| UNE 55605:1978 | Identical |
| BS 6075-11:1981 | Methods of sampling and test for sodium hydroxide for industrial use Determination of mercury content (flameless atomic absorption method) |
| BS 6075-8:1981 | Methods of sampling and test for sodium hydroxide for industrial use Determination of sulphate content |
| BS 6075-9:1981 | Methods of sampling and test for sodium hydroxide for industrial use Determination of calcium and magnesium contents |
| BS 6075-10:1981 | Methods of sampling and test for sodium hydroxide for industrial use Determination of mercury content (photometric method) |