This method describes the procedure for the ion chromatographic determination of the total amount of each of the individual chelating agents EDTA, HEDTA, and DTPA in fertilizers containing one or more of these substances. The method allows the identification and the determination of the total water soluble fraction of each of these chelating agents. It does not allow to distinguish between the free form and the metal bound form of the chelating agents.
NOTE EDTA, HEDTA and DTPA are abbreviations used in the standard for the sake of simplicity. For complete names see annex A.
This method applies to fertilizers containing chelates of one or more of the following micro-nutrients: cobalt, copper, iron, manganese, zinc and with a mass fraction of at least 0,1 %.