EN 15962:2011

• Abstract:

  This European Standard specifies a general method for the determination of the micronutrients complexed by complexing agents in fertilizers. The method allows the determination of the total concentration of each complexed micronutrient in complexes after subtraction of the chelated micro-nutrients content, but it does not identify the individual complexing agents.; This procedure concerns EC-fertilizers which contain complexed micro-nutrients covered by Regulation (EC) No 2003/2003 [1]. The method is applicable to a mass fraction of the metal complexed of at least 0,07 %, 0,006 % and 0,035 % of Fe, Mn and Zn respectively (see [2]). A lower limit of quantification has not been established for Cu and Co.

• Status: Published
• Publication Date: 18-Jan-2011
• ICS: 65.080 - Fertilizers
• ICS: 65.120 - Animal feeding stuffs
• 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: 27-Apr-2022
• Completion Date: 08-Jul-2026
• Directive: Not Harmonized2003/2003 - Regulation (EC) N° 2003/2003 of the European Parlament and of the council of 13 October 2003 relating to fertilisers
• Directive:

  ---

  Harmonized Standard2019/1009 - Regulation (EU) 2019/1009 of the European Parliament and of the Council of 5 June 2019 laying down rules on the making available on the market of EU fertilising products and amending Regulations (EC) No 1069/2009 and (EC) No 1107/2009 and repealing Regulation (EC) No 2003/2003 (Text with EEA relevance)
• Mandate: M/335 - Standardization Mandate assigned to the CEN concerning the modernisation of the methods of anylysis of Fertilizers
• Ref Project: SIST EN 15962:2011 - Fertilizers - Determination of the complexed micro-nutrient content and of the complexed fraction of micro-nutrients

• Refers: EN ISO 3696:1995 - Water for analytical laboratory use - Specification and test methods (ISO 3696:1987)
• Effective Date: 28-Jan-2026
• Refers: EN 1482-2:2024 - Fertilizers, liming materials and inhibitors - Sampling and sample preparation - Part 2: General sample preparation provisions
• Effective Date: 28-Jan-2026
• Referred By: CEN/TS 17791:2022 - Inorganic fertilizers - Determination of chelating and complexing agents
• Effective Date: 28-Jan-2026
• Referred By: 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
• Effective Date: 28-Jan-2026
• Referred By: CEN/TS 17783:2022 - Fertilizing products - Determination of the stability of fertilizing products containing micronutrient complexes
• Effective Date: 28-Jan-2026

Overview

EN 15962:2011 (CEN) specifies a general analytical method for determining the amount of micronutrients that are complexed by complexing agents in fertilizers. The method quantifies the total concentration of each complexed micro‑nutrient (Fe, Mn, Zn, Cu, Co) remaining in solution after precipitation of inorganic forms at pH 9, and calculates the complexed fraction relative to the water‑soluble content. It applies to EC‑fertilizers covered by Regulation (EC) No 2003/2003 and includes procedural, precision and reporting requirements. The method does not identify individual complexing agents (e.g., lignosulfonates, EDTA).

Key topics and technical requirements

• Principle: precipitate inorganic metal forms at pH 9 so complexed forms remain in solution; separate by filtration/centrifugation and determine by spectrometry.
• Analytical techniques: atomic absorption spectrometry (AAS) or inductively coupled plasma emission spectrometry (ICP‑ES).
• Sample preparation: extract fertilizer samples in water (sample size and extract volume depend on declared metal content); follow EN 1482 sampling/preparation guidance.
• Precipitation step: raise pH to 9 rapidly, control pH for 18–24 h, then readjust, dilute and filter (0.45 µm).
• Calculations: convert measured filtrate concentrations to mass fraction of complexed element and compute complexed fraction (%) vs water‑soluble content.
• Applicability limits: method applicable for minimum mass fractions of complexed Fe, Mn and Zn (≈ 0.07 %, 0.006 % and 0.035 %, respectively); no lower quantification limit established for Cu and Co.
• Interferences: chelating agents and other compounds that form soluble complexes at pH 9 can affect results - chelated fraction should be identified and subtracted using appropriate methods.
• Quality and precision: includes inter‑laboratory test data with repeatability and reproducibility limits for tested matrices; specifies use of clean glassware and grade‑1 water (EN ISO 3696).

Practical applications

• Compliance testing for manufacturers and importers of EC‑fertilizers containing complexed micronutrients.
• Routine laboratory analysis to report complexed micro‑nutrient content and complexed fraction on product declarations.
• Regulatory and conformity assessment where accurate partitioning of micronutrients (complexed vs soluble) affects labeling, agronomic value and regulatory compliance.
• Product development and quality control for fertilizer formulators using complexing agents (e.g., lignosulfonates).

Who should use this standard

• Analytical and testing laboratories, fertilizer manufacturers, conformity assessment bodies, regulatory authorities, and R&D teams focused on micronutrient formulations.

Related standards and references

• EN 1482-2 - Sampling and sample preparation for fertilizers
• EN ISO 3696 - Water for analytical laboratory use
• Regulation (EC) No 2003/2003 - Fertilizer product regulation in the EU

Keywords: EN 15962:2011, fertilizers, complexed micro‑nutrient content, complexed fraction, CEN, EC‑fertilizers, Fe Mn Zn Cu Co, AAS, ICP‑ES, precipitation pH 9.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.PLNURKUDQLODüngemittel - Bestimmung des Gehalts an komplexgebundenen Mikronährstoffionen und der komplexgebundenen Fraktion von MikronährstoffenEngrais - Détermination des micro-nutriments ironique quels sont complexe manié et de fraction complexe manié des micro-nutrimentsFertilizers - Determination of the complexed micro-nutrient content and of the complexed fraction of micro-nutrients65.080GnojilaFertilizersICS:Ta slovenski standard je istoveten z:EN 15962:2011SIST EN 15962:2011en,fr,de01-oktober-2011SIST EN 15962:2011SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 15962
January 2011 ICS 65.080 English Version
Fertilizers - Determination of the complexed micro-nutrient content and of the complexed fraction of micro-nutrients
Engrais - Dosage de la teneur en oligo-élément complexé et de la fraction complexée des oligo-éléments
Düngemittel - Bestimmung des Gehalts an komplexgebundenen Spurennährstoffionen und der komplexgebundenen Fraktion von Spurennährstoffen This European Standard was approved by CEN on 3 December 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15962:2011: ESIST EN 15962:2011

Results of the inter-laboratory test . 10A.1Test samples . 10A.2Inter-laboratory test procedure . 10A.3Results and statistical interpretation. 10Bibliography . 14 SIST EN 15962:2011
...