EN 12946:2023

Liming materials - Determination of the calcium content and magnesium content - Complexometric method

TThis document specifies a complexometric method for the determination of the calcium content and the magnesium content of liming materials.
It is not applicable to products with a mass fraction less than 2 % magnesium or those with a mass fraction more than 1 % P2O5 and is not applicable to silicate liming materials.

Kalkdünger - Bestimmung des Calcium- und Magnesiumgehaltes - Komplexometrisches Verfahren

Dieses Dokument legt ein komplexometrisches Verfahren zur Bestimmung des Calciumgehaltes und des Magnesiumgehaltes von Kalkdüngern fest.
Es ist nicht anwendbar für Produkte mit unter 2 % Massenanteil Magnesium, für Produkte mit über 1 % Massenanteil P2O5 und ist nicht anwendbar für Kalke aus Eisenhüttenschlacken.

Amendements minéraux basiques - Détermination de la teneur en calcium et de la teneur en magnésium - Méthode par complexométrie

Le présent document spécifie une méthode de détermination, par complexométrie, de la teneur en calcium et de la teneur en magnésium des amendements minéraux basiques.
Elle ne s'applique pas aux produits ayant une fraction massique inférieure à 2 % de magnésium, ni aux produits ayant une fraction massique supérieure à 1 % de P2O5, ni aux amendements minéraux basiques silicatés.

Sredstva za apnjenje - Določanje kalcija in magnezija - Kompleksometrijska metoda

Ta evropski standard določa kompleksometrijsko metodo za določanje kalcija in magnezija v sredstvih za apnjenje. Uporablja se za izdelke z masnim deležem manj kot 2 % (m/m) magnezija oziroma več kot 1 % P2O5. Ne uporablja se za silikatna sredstva za apnenje.

General Information

• Status: Published
• Publication Date: 13-Jun-2023
• ICS: 65.080 - Fertilizers
• Technical Committee: CEN/TC 260 - Fertilizers and liming materials
• Drafting Committee: CEN/TC 260/WG 3 - Liming materials
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 14-Jun-2023
• Due Date: 22-Aug-2023
• Completion Date: 14-Jun-2023
• Directive: 2019/1009 - 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
• 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
• Ref Project: SIST EN 12946:2024 - Liming materials - Determination of the calcium content and magnesium content - Complexometric method

Relations

• Replaces: EN 12946:2000/AC:2002 - Liming materials - Determination of calcium content and magnesium content - Complexometric method
• Effective Date: 03-Aug-2022
• Replaces: EN 12946:2000 - Liming materials - Determination of calcium content and magnesium content - Complexometric method
• Effective Date: 14-Jul-2021

Overview

EN 12946:2023, titled Liming materials - Determination of the calcium content and magnesium content - Complexometric method, is a European Standard developed by CEN/TC 260 focused on the precise analysis of calcium (Ca) and magnesium (Mg) concentrations in liming materials. This standard defines a complexometric titration procedure using EDTA as the titrant to accurately quantify these mineral contents. It supersedes previous versions EN 12946:2000 and EN 12946:2000/AC:2002 with updated normative references and methodological improvements, including provisions for automatic titration.

Key Topics

• Scope & Applicability
  The standard is applicable to liming materials except products with less than 2% Mg, more than 1% P₂O₅, or silicate liming materials. It ensures consistent calcium and magnesium measurement critical for fertilizer quality control.

• Principle of the Method
  The complexometric titration method involves extraction of test portions in boiling hydrochloric acid, followed by filtration and volumetric dilution. Separate titrations with EDTA, using specific indicators (calcein/thymolphthalein, calcon carbonic acid, eriochrome black T), allow determination of calcium and magnesium content.

• Reagents and Solutions
  Includes preparation and use of standardized hydrochloric acid solutions, standard calcium and magnesium solutions, EDTA titrant (0.05 mol/l), and three types of indicators to detect end points during titration.

• Apparatus and Sampling
  Specifies laboratory apparatus such as precision balances, test sieves (ISO 3310-1 compliant), pH meters, stirrers, and volumetric flasks. Sampling shall follow EN 1482 parts 1 and 3 to ensure representative and reproducible results.

• Test Procedure
  Sample preparation involves grinding and sieving to 250 µm, acid digestion with hydrochloric acid, and preparation of aliquots for titration. Titration must be carefully controlled, using pH adjustments to about 10.5, and verified for end-point accuracy through color change observation.

• Precision and Reporting
  The standard outlines criteria for repeatability and reproducibility of test results, ensuring laboratory consistency. Test reports should clearly document procedures, titration data, and calculated calcium and magnesium contents.

Applications

EN 12946:2023 provides a robust, standardized method for determining calcium and magnesium in liming materials. This is essential for:

• Agricultural Fertilizers
  Ensuring accurate nutrient content in liming products, critical for soil pH adjustment and crop yield optimization.

• Quality Control Laboratories
  Offering a validated approach that harmonizes testing procedures across European member states, facilitating compliance and trade.

• Environmental Monitoring
  Assessing liming material composition to manage ecological impact and regulatory reporting.

• Research and Development
  Supporting formulation and testing of novel liming materials with controlled mineral content.

Related Standards

• EN 1482-1 & EN 1482-3
  Standards for sampling and sample preparation of fertilizers and liming materials, ensuring consistency in test sample quality.

• EN 12944-3
  Provides vocabulary and terms related to liming materials, ensuring clarity and common understanding in the sector.

• ISO 3310-1
  Technical requirements for test sieves used during sample preparation to achieve consistent particle sizes.

• Other Fertilizer Testing Methods
  Complements other standards on nutrient content determination and product specifications, supporting integrated quality assurance systems.

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Keywords: EN 12946:2023, liming materials, calcium determination, magnesium determination, complexometric method, EDTA titration, fertilizers, laboratory testing, European Standard, CEN standard, soil amendment analysis, quality control, agricultural inputs.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2024
Nadomešča:
SIST EN 12946:2001
SIST EN 12946:2001/AC:2003
Sredstva za apnjenje - Določanje kalcija in magnezija - Kompleksometrijska
metoda
Liming materials - Determination of the calcium content and magnesium content -
Complexometric method
Kalkdünger - Bestimmung des Calcium- und Magnesiumgehaltes - Komplexometrisches
Verfahren
Amendements minéraux basiques - Détermination de la teneur en calcium et de la
teneur en magnésium - Méthode par complexométrie
Ta slovenski standard je istoveten z: EN 12946:2023
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12946
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2023
EUROPÄISCHE NORM
ICS 65.080 Supersedes EN 12946:2000, EN 12946:2000/AC:2002
English Version
Liming materials - Determination of the calcium content
and magnesium content - Complexometric method
Amendements minéraux basiques - Détermination de Kalkdünger - Bestimmung des Calcium- und
la teneur en calcium et de la teneur en magnésium - Magnesiumgehaltes - Komplexometrisches Verfahren
Méthode par complexométrie
This European Standard was approved by CEN on 14 May 2023.

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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12946:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Reagents . 5
5.1 General . 5
5.2 Hydrochloric acid solution . 5
5.3 Hydrochloric acid solution . 6
5.4 Hydrochloric acid solution . 6
5.5 Standard calcium solution, containing 2,004 g of calcium per litre . 6
5.6 Standard magnesium solution, containing 1,216 g of magnesium per litre . 6
5.7 Ethylenediamine tetraacetic acid (EDTA) standard solution, c(EDTA) = 0,05 mol/l . 6
5.8 Calcein thymolphthalein indicator . 6
5.9 Calcon carbonic acid indicator . 7
5.10 Eriochrome black T indicator . 7
5.11 Triethanolamine . 7
5.12 Buffer solution, pH 10,5 . 7
5.13 Sodium hydroxide solution . 7
6 Apparatus . 7
7 Sampling . 7
8 Procedure. 7
8.1 Preparation . 7
8.2 Determination . 8
8.3 Control test of the standard solutions . 9
9 Expression of results . 9
10 Precision . 9
10.1 General . 9
10.2 Repeatability . 10
10.3 Reproducibility . 10
11 Test report . 10
Bibliography . 11

European foreword
This document (EN 12946:2023) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2023, and conflicting national standards
shall be withdrawn at the latest by December 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12946:2000 and EN 12946:2000/AC:2002.
This document has been prepared under a standardization request given to CEN by the European
Commission and the European Free Trade Association.
The main changes compared to the previous edition are listed below:
a) Normative references updated and added;
b) Reference to EN 12944-3 added in Clause 3;
c) Principle (Clause 4) updated to recognize the possibility to use automatic titration;
d) Reference updated in Clause 7;
e) Bibliography updated.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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 the
United Kingdom.
Introduction
The complexometric method for the determination of calcium content and magnesium content in liming
materials is based on a method, which is described in VDLUFA, Manual II of analysing methods for
fertilizers [1].
1 Scope
This document specifies a complexometric method for the determination of the calcium content and the
magnesium content of liming materials.
It is not applicable to products with a mass fraction less than 2 % magnesium or those with a mass
fraction more than 1 % P O and is not applicable to silicate liming materials.
2 5
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 1482-1, Fertilizers and liming materials - Sampling and sample preparation - Part 1: Sampling
EN 1482-3, Fertilizers and liming materials - Sampling and sample preparation - Part 3: Sampling of
static heaps
EN 12944-3, Fertilizers and liming materials - Vocabulary - Part 3: Terms relating to liming materials
ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12944-3 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
4 Principle
A test portion is extracted with boiling hydrochloric acid solution. After filtration and dilution, an
aliquot portion is titrated against EDTA solution with calcein/thymolphthalein or calcon carbonic acid
as indicator in order to measure calcium. A second aliquot portion is titrated against EDTA with
eriochrome black T as indicator in order to measure calcium and magnesiu
...