CEN/TS 17786-1:2022
(Main)Inorganic micronutrient fertilizers - Determination of the chelated micronutrient content and the chelated fraction of micronutrients - Part 1: Treatment with a cation exchange resin
General Information
- Abstract
This document specifies a method for the determination of the chelated iron content and the chelated fraction of iron, in UVCB chelats, EDDHA, EDDHMA, HBED, EDDHSA, in inorganic micronutrient fertilizers by the treatment with a cation exchange resin.
The limit of determination of the chelated iron content highly depends on the specific electrical conductivity of the sample, on the amount of nutrient present, and varies between 0,005 % in simple matrices with high amounts of micronutrient and 0,5 % in more complex cases (see 9.1).
- Status
- Published
- Publication Date
- 05-Apr-2022
- Technical Committee
- CEN/TC 260 - Fertilizers and liming materials
- Drafting Committee
- CEN/TC 260/WG 5 - Determination of chelating agents
- Current Stage
- 9093 - Decision to confirm - Review Enquiry
- Start Date
- 17-Feb-2026
- Completion Date
- 02-Sep-2026
Overview
CEN/TS 17786-1:2022 defines a laboratory method to determine the chelated iron content and the chelated fraction of iron in inorganic micronutrient fertilizers that contain Group‑2 chelating agents (UVCB chelates, EDDHA, EDDHMA, HBED, EDDHSA). The method uses a strong sulfonated cation exchange resin to separate chelated (neutral/negatively charged) iron species from non‑chelated (cationic) forms, followed by spectrometric quantification. This Technical Specification was approved for provisional application in April 2022 and supports compliance assessment under EU fertilizer regulation frameworks.
Key topics and technical requirements
- Scope: Applicable to inorganic micronutrient fertilizers containing Group‑2 chelants; intended to measure chelated iron content and express the chelated fraction as a percentage of water‑soluble iron.
- Principle: Water extraction → pH neutralization → ion‑exchange separation on PS‑DVB sulfonated cation resin (chelated forms pass through; non‑chelated retained) → spectrometric determination of iron in the collected fraction and of total water‑soluble iron.
- Analytical limits: Limit of determination varies with matrix and conductivity - typically 0.005% (simple matrices with high micronutrient) to 0.5% (complex matrices) - see clause 9.1.
- Reagents & resin: Use degassed water (EN ISO 3696), a polystyrene‑divinylbenzene (PS‑DVB) sulfonated cation exchange resin (free from Co, Cu, Fe, Mn, Zn), and standard acid/base solutions for resin preparation and CEC measurement.
- Apparatus & controls: Tumbling shaker, sieve sized for resin, conductivity meter (filtrate ≤ 1.5 mS/cm), pH‑meter, 0.45 μm membrane filters, volumetric glassware. Rapid processing is advised to avoid equilibrium shifts or precipitation.
- Interferences: Other complexing agents (amino acids, citrate, non‑target chelants) can prevent resin retention, biasing results. For statutory chelant identification, apply EN 13368‑1/2.
- Traceability: Spectrometric determination references include EN 16963 (ICP‑AES) and EN 16965 (FAAS).
Applications and users
- Fertilizer manufacturers - quality control of micronutrient formulations containing EDDHA/EDDHMA/HBED/EDDHSA and UVCB chelates.
- Accredited testing laboratories - routine analysis for product declarations and regulatory compliance.
- Regulators and conformity assessors - verifying compliance with EU product function categories (e.g., PFC 1(C)(II)(a) under Regulation (EU) 2019/1009).
- R&D and formulation teams - evaluating chelation efficiency, product stability, and speciation during development.
Related standards
- EN 12944‑1, EN 12944‑2 (fertilizer vocabulary)
- EN 16962 (extraction of water‑soluble micronutrients)
- EN 16963 (ICP‑AES iron determination)
- EN 16965 (FAAS iron determination)
- EN 13368‑1/2 (identification of chelating agents)
- EN 1482‑1/2 (sampling and sample preparation)
Keywords: CEN/TS 17786-1:2022, chelated micronutrient fertilizers, chelated iron content, chelated fraction, cation exchange resin, EDDHA, HBED, fertilizer testing, inorganic micronutrient fertilizers.
Relations
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Referred By
CEN/TS 17791:2022 - Inorganic fertilizers - Determination of chelating and complexing agents - Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
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Frequently Asked Questions
CEN/TS 17786-1:2022 is a technical specification published by the European Committee for Standardization (CEN). Its full title is "Inorganic micronutrient fertilizers - Determination of the chelated micronutrient content and the chelated fraction of micronutrients - Part 1: Treatment with a cation exchange resin". This standard covers: This document specifies a method for the determination of the chelated iron content and the chelated fraction of iron, in UVCB chelats, EDDHA, EDDHMA, HBED, EDDHSA, in inorganic micronutrient fertilizers by the treatment with a cation exchange resin. The limit of determination of the chelated iron content highly depends on the specific electrical conductivity of the sample, on the amount of nutrient present, and varies between 0,005 % in simple matrices with high amounts of micronutrient and 0,5 % in more complex cases (see 9.1).
This document specifies a method for the determination of the chelated iron content and the chelated fraction of iron, in UVCB chelats, EDDHA, EDDHMA, HBED, EDDHSA, in inorganic micronutrient fertilizers by the treatment with a cation exchange resin. The limit of determination of the chelated iron content highly depends on the specific electrical conductivity of the sample, on the amount of nutrient present, and varies between 0,005 % in simple matrices with high amounts of micronutrient and 0,5 % in more complex cases (see 9.1).
CEN/TS 17786-1:2022 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
CEN/TS 17786-1:2022 has the following relationships with other standards: It is inter standard links to EN 16965:2018, EN 12944-2:1999, EN 12944-1:1999, EN 16963:2018, EN 16962:2018, CEN/TS 17764:2022, CEN/TS 17783:2022, CEN/TS 17791:2022, CEN/TS 17782:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
CEN/TS 17786-1:2022 is associated with the following European legislation: EU Directives/Regulations: 2019/1009; Standardization Mandates: M/564. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
CEN/TS 17786-1:2022 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.