ISO/R 852:1968
Sodium tripolyphosphate and sodium pyrophosphate for industrial use — Determination of iron content — 2,2'- Bipyridyl spectrophotometric method
Reference number
ISO/R 852:1968
Edition 1
1968-10
Withdrawn
w
ISO/R 852:1968
5227
Withdrawn (Edition 1, 1968)

Abstract

Applicable to products having Fe contents of more than 0.001 % (m/m). Preliminary hydrolysis of polyphophates by prolonged boiling in the presence of hydrochloric acid. Reduction of iron(III) by means of hydroxylammonium chloride. Formation of the iron(II)-2,2'-dipyridyl complex in the presence of ammonium acetate at pH of 3.1 and a temperature of 75 °C (under the test conditions the phosphate ions do not interfere). Spectrophotometric measurement of the coloured complex at a wavelength of about 522 nm.

General information

  •  : Withdrawn
     : 1968-10
    : Withdrawal of International Standard [95.99]
  •  : 1
     : 4
  • ISO/TC 47
    71.060.50 
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