PD CEN/TS 17764:2022

Inorganic micronutrient fertilizers. Determination of the concentration of free, chelated or complexed micronutrients and the chelating and/or complexing agents present in compound inorganic micronutrient fertilizers. | Status: Current, Under review

1 Scope This document specifies the method for the determination of free, chelated or complexed micronutrients and chelating and/or complexing agents present in compound inorganic micronutrient fertilizers. This method applies to compound inorganic micronutrient fertilizers when micronutrients are chelated and/or complexed. The method is based on the determination of the following specific parameters1:

• — the water-soluble micronutrient concentration;
• — the fraction of chelated micronutrients in relation;
• — identification of chelating agents EDTA, DTPA, HEEDTA, IDHA, [S,S]–EDDS, [o,o] EDDHA, [o,o] EDDHMA, [o,p] EDDHA, HBED and EDDHSA;
• — the fraction of complexed micronutrients;
• — identification of complexing agents (lignosulfonates, heptagluconic acid (HGA)).

The method is based on

• — ICP (inductive coupled plasma) or FAAS (flame atomic absorption spectrometry) measurement of the concentration of water-soluble micronutrients according to EN 16963 or EN 16965 after extraction according to EN 16962;
• — LC (liquid chromatography) measurement of the chelating agents according to EN 15950, EN 13368‑1, EN 13368‑2, EN 13368‑3, EN 15451, EN 15452; and/or complexing agents according to EN 16109 and EN 16847;
• — determination of the concentration of chelated micronutrients by CEN/TS 17786‑1 and/or CEN/TS 17786‑2;
• — determination of the complexed micronutrients by EN 15962.

To avoid duplication of the analytical methods, CEN/TS 17786‑2 describes the determination of micronutrients and the identification and determination of chelating agents.