Reference number
ISO 5442:1980
ISO 5442:1980
Sodium hexafluorosilicate for industrial use — Determination of sulphur compounds content — Iodometric method after reduction
Edition 1
1980-10
Withdrawn
ISO 5442:1980
11487
Withdrawn (Edition 1, 1980)

Abstract

Applicable to products having contents, expressed as sulphate2- , between 0.03 % (m/m) and 0.5 % (m/m). Reduction of the compounds to hydrogen sulphide by heating with a mixture of hydriodic and hypophosphorus acids in the presence of hydrochloric acid. Entrainment of the hydrogen sulphide in a flow of nitrogen and absorption in an excess of ammoniacal cadmium acetate solution. Liberation of the absorbed hydrogen sulphide in the presence of an excess of standard volumetric iodate/iodide solution. Back-titration of the excess iodine with standard volumetric sodium thiosulphate solution using starch as the indicator. An apparatus for reduction, entrainment and absorption is shown in a figure. Has also been approved by the IUPAC.

General information

  •  : Withdrawn
     : 1980-10
    : Withdrawal of International Standard [95.99]
  •  : 1
     : 5
  • ISO/TC 47
    71.060.50 
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