prEN 17758

Fertilizers and liming materials - Determination of the chloride content by potentiometric titration

This document specifies a method for the determination of the chloride content in organic fertilizers, organo-mineral fertilizers, inorganic fertilizers and liming materials by potentiometric titration.
This document is applicable to fertilizing product blends, where a blend is a mix of at least two of the following components, fertilizers and liming materials, and where the following category, organic fertilizers, organo-mineral fertilizers, inorganic fertilizers or liming materials, is the highest % in the blend by mass or volume, or in the case of liquid form, by dry mass.
If organic fertilizers, organo-mineral fertilizers, inorganic fertilizers, or liming materials is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply.
NOTE   Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.

Düngemittel und Kalkdünger - Bestimmung des Chloridgehaltes mittels potentiometrischer Titration

Dieses Dokument legt ein Verfahren zur Bestimmung des Chloridgehalts in organischen Düngemitteln, organisch-mineralischen Düngemitteln, anorganischen Düngemitteln und Kalkdüngern mittels potentiometrischer Titration fest.
Dieses Dokument ist anwendbar auf Düngeproduktmischungen, bei denen eine Mischung aus mindestens zwei der folgenden Komponenten besteht: Düngemittel, Kalkdünger und wenn die Kategorie „organische Düngemittel, organisch-mineralische Düngemittel, anorganische Düngemittel oder Kalkdünger“ den höchsten Prozentsatz in der Mischung bezüglich Masse oder Volumen, oder im Falle von flüssigen Formen bezüglich Trockenmasse ausmacht.
Wenn organische Düngemittel, organisch-mineralische Düngemittel, anorganische Düngemittel oder Kalkdünger nicht den höchsten Prozentsatz in der Mischung ausmachen, gilt die Europäische Norm für den höchsten Prozentsatz der Mischung. Im Falle, dass die Düngeproduktmischung aus Komponenten gleicher Menge besteht, entscheidet der Anwender, welche Norm angewendet wird.
ANMERKUNG   Variationen in analytischen Verfahren für Düngeproduktmischungen können zu unterschiedlichen Ergebnissen führen, da einige Komponenten oder Matrixwechselwirkungen das Ergebnis beeinflussen können. Validierungen haben gezeigt, dass die entwickelten Standardverfahren robust und zuverlässig über unterschiedliche Produktzusammensetzungen hinweg sind. Jedoch sind mögliche Interferenzen und unerwartete Ergebnisse bei der Analyse von Düngeproduktmischungen möglich.

Engrais et amendements minéraux basiques - Détermination de la teneur en chlorures par titrage potentiométrique

Le présent document spécifie une méthode pour la détermination de la teneur en chlorures dans les engrais organiques, les engrais organo-minéraux, les engrais inorganiques et les amendements minéraux basiques par titrage potentiométrique.
Le présent document est applicable aux mélanges de fertilisants constitués d’au moins deux des composants suivants : engrais et amendements minéraux basiques, et dans lesquels la catégorie « engrais organiques, engrais organo-minéraux, engrais inorganiques ou amendements minéraux basiques » représente le pourcentage le plus élevé du mélange en masse ou en volume, ou dans le cas d’un liquide, en masse sèche.
Si les engrais organiques, les engrais organo-minéraux, les engrais inorganiques ou les amendements minéraux basiques ne représentent pas le pourcentage le plus élevé du mélange, la Norme européenne relative au composant représentant le pourcentage le plus élevé du mélange s’applique. Dans le cas où le mélange de produits fertilisants est constitué de composants en quantités égales, l’utilisateur décide quelle norme appliquer.
NOTE   Les variations dans les méthodes d’analyse des mélanges de fertilisants peuvent conduire à des résultats différents, car certaines interactions de composants ou de la matrice peuvent affecter le résultat. Les procédures de validation ont montré que les méthodes normalisées développées sont robustes et fiables pour diverses compositions de produits, mais que des interférences éventuelles et des résultats inattendus lors de l’analyse des mélanges de fertilisants sont possibles.

Gnojila in sredstva za apnjenje - Določanje klorida s potenciometrijsko titracijo

General Information

• Status: Not Published
• Publication Date: 28-Feb-2028
• ICS: 65.080 - Fertilizers
• Technical Committee: CEN/TC 260 - Fertilizers and liming materials
• Drafting Committee: CEN/TC 260/WG 7 - Chemical analysis
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 26-Feb-2026
• Due Date: 13-Oct-2026
• Completion Date: 26-Feb-2026
• Directive: Not Harmonized2019/1009 - 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/564 - Fertilising products in support of Regulation (EU) 2019/1009
• Mandate: M/564 AMD 1 - amending Implementing Decision C(2020) 612 as regards certain harmonised standards and standardisation deliverables, deadlines for their adoption and the duration of the validity of the standardisation request
• Mandate: M/564 AMD 2 - Commission Implementing decision amending Implementing Decision C(2020)612 as regards harmonised standards, the deadlines for the adoption of those standards and the duration of the validity of the standardisation request to the European Committee for Standardisation as regards the EU fertilising products in support of Regulation (EU) 2019/1009 of the European Parliament and of the Council
• Ref Project: oSIST prEN 17758:2026 - Fertilizers and liming materials - Determination of the chloride content by potentiometric titration

Relations

• Revises: CEN/TS 17758:2022 - Fertilizers and liming materials - Determination of the chloride content by potentiometric titration
• Effective Date: 01-May-2024

Overview

prEN 17758 is a draft European Standard developed by CEN that specifies a method for the determination of chloride content in fertilizers and liming materials using potentiometric titration. This method ensures accurate and consistent measurement of chloride, a key parameter for product quality and regulatory compliance in fertilizers and soil amendments.

The standard applies to a wide range of products, including:

• Organic fertilizers
• Organo-mineral fertilizers
• Inorganic fertilizers
• Liming materials

It also addresses the analysis of fertilizing product blends made by mixing at least two of these components. The methodology outlined accommodates solids and liquids, ensuring broad applicability for laboratory settings working with various product forms.

Key Topics

• Chloride determination: The standard describes a potentiometric titration process for precise chloride analysis, vital for assessing the nutrient balance and suitability of fertilizers and liming materials.
• Applicability to Blends: The procedure is applicable not only to individual product categories but also to blends, depending on which component is predominant by mass, volume, or dry mass for liquids.
• Method Robustness: The procedure has undergone inter-laboratory validation, demonstrating reliability across diverse compositions, though users are advised to consider possible interferences in complex blends.
• Comprehensive Reporting: Guidelines for reporting results are included, ensuring clarity on sample identification, methods used, test results, and any deviations or incidents during analysis.
• Precision and Validation: The standard includes detailed data on repeatability and reproducibility, supporting laboratories in producing consistent, comparable results.

Applications

prEN 17758 is valuable for:

• Analytical laboratories: Supporting routine quality control and regulatory testing for fertilizer producers and soil amendment suppliers.
• Fertilizer manufacturers: Ensuring that chloride levels are within targeted specifications for different fertilizer types, preventing crop toxicity or deficiency.
• Blending and formulation: Assisting in optimizing nutrient composition when creating custom blends or multi-component fertilizing products.
• Regulatory compliance: Meeting European and national requirements for declared nutrient content in agricultural products.
• Research and development: Facilitating innovation in fertilizer formulations by providing a reliable, standardized method for chloride analysis.

The standard’s guidance on handling blends assists users in selecting the appropriate test method based on the predominant component, maintaining consistency and compliance in complex scenarios.

Related Standards

For comprehensive fertilizer analysis and quality assurance, consider the following related standards:

• EN 1482-2: Fertilizers, liming materials and inhibitors - Sampling and sample preparation - General sample preparation provisions.
• EN 12944-1, -2, -3: Vocabulary for fertilizers, liming materials and inhibitors, covering general terms and category-specific terminology.
• EN 1482-1, EN 1482-3: Provisions for sampling and sample preparation, including guidance for bulk materials and static heaps.
• EN 16195: Alternative methods for chloride determination when organic materials are absent.
• ISO 5725 (Parts 2 and 3): Standards for assessing accuracy, repeatability, and reproducibility in measurement methods.

Practical Value

By following prEN 17758, laboratories and manufacturers can ensure that chloride content is determined accurately and reliably, supporting product quality, efficient nutrient management, and regulatory compliance throughout the European fertilizer industry. The standardized method is practical, well-validated, and adaptable to both individual products and complex blends, making it an essential reference for anyone involved in fertilizer testing and quality assurance.

Keywords: prEN 17758, chloride determination, potentiometric titration, fertilizer analysis, liming materials, CEN standard, fertilizer blends, laboratory testing, quality control, regulatory compliance.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2026
Gnojila in sredstva za apnjenje - Določanje klorida s potenciometrijsko titracijo
Fertilizers and liming materials - Determination of the chloride content by potentiometric
titration
Düngemittel und Kalkdünger - Bestimmung des Chloridgehaltes mittels
potentiometrischer Titration
Engrais et amendements minéraux basiques - Détermination de la teneur en chlorures
par titrage potentiométrique
Ta slovenski standard je istoveten z: prEN 17758
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2026
ICS 65.080 Will supersede CEN/TS 17758:2022
English Version
Fertilizers and liming materials - Determination of the
chloride content by potentiometric titration
Engrais et amendements minéraux basiques - Düngemittel und Kalkdünger - Bestimmung des
Détermination de la teneur en chlorures par titrage Chloridgehaltes mittels potentiometrischer Titration
potentiométrique
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 260.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17758:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents . 5
6 Apparatus and equipment . 5
7 Sampling and sample preparation . 6
7.1 Sampling . 6
7.2 Sample preparation . 6
8 Procedure . 6
8.1 Preparation of the test portion and the sample solution . 6
8.2 Calibration of the system (titre factor) . 6
8.3 Determination . 7
8.4 Control test . 7
9 Calculation and expression of the results . 7
10 Precision . 7
10.1 Inter-laboratory study . 7
10.2 Repeatability . 8
10.3 Reproducibility . 8
11 Test report . 9
Annex A (informative) Results of the inter-laboratory study . 10
Bibliography . 12

European foreword
This document (prEN 17758:2026) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This document is currently submitted to CEN Enquiry.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
CEN/TS 17758:2022:
— The CEN Technical Specification has been adopted as a European Standard;
— Scope (Clause 1) updated regarding the applicability to fertilizing product blends;
— Water as reagent has been included (5.1);
— The option to use a centrifuge for the preparation of test portion (8.1) of organic and organic-mineral
fertilizers added;
— The precision data (Clause 10) of the validation study included;
— Annex A including results of inter-laboratory study added;
— Normative references (Clause 2) and Bibliography revised.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
1 Scope
This document specifies a method for the determination of the chloride content in organic fertilizers,
organo-mineral fertilizers, inorganic fertilizers and liming materials by potentiometric titration.
This document is applicable to fertilizing product blends, where a blend is a mix of at least two of the
following components, fertilizers and liming materials, and where the following category, organic
fertilizers, organo-mineral fertilizers, inorganic fertilizers or liming materials, is the highest % in the
blend by mass or volume, or in the case of liquid form, by dry mass.
If organic fertilizers, organo-mineral fertilizers, inorganic fertilizers, or liming materials is not the highest
% in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product
blend is composed of components in equal quantity, the user decides which standard to apply.
NOTE Variations in analytical methods for fertilizing product blends can lead to differing results as some
components or matrix interactions can affect the outcome. Validation procedures have shown that developed
standard methods are robust and reliable across diverse product compositions, but possible interferences and
unexpected results when analysing fertilizing product blends are possible.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1482-2, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part 2:
General sample preparation provisions
EN 12944-1, Fertilizers, liming materials and inhibitors — Vocabulary — Part 1: General terms
EN 12944-2, Fertilizers, liming materials and inhibitors — Vocabulary — Part 2: Terms relating to
fertilizers
EN 12944-3, Fertilizers, liming materials and inhibitors — Vocabulary — Part 3: Terms relating to liming
materials
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12944-1, EN 12944-2 and
EN 12944-3 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
The chlorides, dissolved in water, are precipitated in an acidified medium by a standard solution of silver
nitrate. The chloride concentration in the samples is quantified by potentiometric determination. To
detect the end point, the voltage between a reference electrode on the one hand and the silver electrode
or an ion selective electrode on the other hand, is tracked. This voltage depends on the logarithm of the
chloride ion activity. If it is plotted, in mV, on the ordinate and the silver nitrate solution, in ml, on the

Under revision. Stage at the time of preparation: prEN 12944-1:2026
Under revision. Stage at the time of preparation: prEN 12944-2:2026
abscissa, the point of inflection of the curve obtained in this manner is the equivalence point. Equivalent
methods of evaluation are permitted [4, 6].
5 Reagents
Use only reagents of recognized analytical grade.
5.1 Water, distilled or demineralized with a specific conductivity not higher than 0,2 mS/m at 25 °C,
free from chloride.
5.2 Nitric acid, substance concentration c = 16 mol/l.
5.3 Nitric acid solu
...