ISO 3198:1975
Sodium hydroxide for industrial use — Determination of sulphur compounds — Method by reduction and titrimetry
OVERVIEW
Applicable to products the content of which, expressed as sulphate, is equal or more than 5 mg/kg. The principle consists in the reduction of the sulphur compounds to hydrogen sulphide by heating with a mixture of hydriodic acid and hypophosphorous acid. Distillation of the hydrogen sulphide by a current of oxygen-free nitrogen in a mixture of sodium hydroxide and acetone. Titration of the sulphide with standard volumetric mercury(II) nitrate solution in the presence of dithizone as indicator.
COMMENTS
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PRODUCT DETAILS
| Status | Withdrawn - 06 Jan 2026 |
|---|---|
| Edition | 1975 |
| No. of Pages | 6 |
| ICS Classification | 71.060.40 Bases |
| Committee | ISO/TC 47 |
| Available for Purchase | For sale in Singapore only |
| Adoption | ISO |