The method consists in precipitating of potassium ions by an excess of sodium tetraphenylborate (NaTPB) in a weakly alkaline medium, filtrating and determing of the unused NaTPB by back titration with cetyltrimethylammoniumbromide solution. The test solution shall be prepared as specified in ISO 5317 or ISO 7407.

General information

  • Status :  Withdrawn
    Publication date : 1986-12
  • Edition : 1
    Number of pages : 4
  • :
    ISO/TC 134
    Fertilizers, soil conditioners and beneficial substances
  • 65.080

Got a question?

Check out our FAQs

Customer care
+41 22 749 08 88

Opening hours:
Monday to Friday - 09:00-12:00, 14:00-17:00 (UTC+1)

Keep up to date with ISO

Sign up to our newsletter for the latest news, views and product information.