Recommended Best Practice for the Analysis of Potassium Content in Potassium Chloride (KCl) Fertilizers

This best practice recommendation was researched and prepared by the IFA Working Group on the Harmonization of Fertilizer Sampling and Methods of Analysis. The IFA Expert Working Group evaluated analytical methods used globally for the quality testing of potassium content in potassium chloride (KCl) fertilizers. The global peer review process indicates that the tetraphenylboron method, in its two variations (gravimetric and titrimetric), is the preferred – or best practice – methodology for use in international fertilizer trade.