SIST EN 12946:2024
(Main)Liming materials - Determination of the calcium content and magnesium content - Complexometric method
Liming materials - Determination of the calcium content and magnesium content - Complexometric method
This European Standard 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% (m/m) 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 Calcium- und des Magnesiumgehaltes von Kalkdüngern fest.
Es gilt nicht für Produkte mit unter 2 % Massenanteil Magnesium, für Produkte mit über 1 % Massenanteil P2O5 und 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
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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 magnesium.
This method can be performed manually or alternatively by means of an automatic titrator as far as
equivalence is proved.
5 Reagents
5.1 General
In principle, commercially available standard solutions may be used instead of standard solutions
produced on-site in the laboratory. Variations in concentration shall be taken into account for the
calculation of the results.
5.2 Hydrochloric acid solution
Density at 20 °C ρ = 1,09 g/ml
Add 1 part by volume of hydrochloric acid (ρ = 1,18 g/ml) to 1 part by volume of water.
5.3 Hydrochloric acid solution
Substance concentration c(HCl) = 1 mol/l approximately.
5.4 Hydrochloric acid solution
c(HCl) = 0,5 mol/l approximately.
5.5 Standard calcium solution, containing 2,004 g of calcium per litre
Weigh 5,004 g of dry calcium carbonate into a 500 ml beaker and add 100 ml of water.
Under continuous stirring, slowly add 120 ml of hydrochloric acid solution (5.3).
Drive off the carbon dioxide by boiling, cool and transfer the solution quantitatively into a 1 000 ml
volumetric flask and dilute to the mark with water.
Check the standard strength of the solution by titration with the EDTA standard solution (5.7)
according to 8.3.
1 ml of this solution should contain 2,004 mg of Ca (2,804 mg of CaO) and should correspond to 1 ml of
the EDTA standard solution (5.7).
5.6 Standard magnesium solution, containing 1,216 g of magnesium per litre
5.6.1 Weigh 1,232 g of magnesium sulfate (MgSO ⋅ 7H O) into a 100 ml volumetric flask, dissolve in
4 2
hydrochloric acid solution (5.4) and dilute to the mark with the same solution.
or
5.6.2 Calcined magnesium oxide (MgO) at 600 °C for 2 h.
Weigh 2,016 g of the freshly calcined MgO into a 500 ml beaker, dissolve in 100 ml of water and 120 ml
of hydrochloric acid solution (5.3). Transfer the solution into a 1 000 ml volumetric flask and dilute to
the mark with water.
1 ml of this solution should contain 1,216 mg Mg (2,016 mg of MgO/ml).
Before use check the Mg content of each standard solution after preparation.
5.7 Ethylenediamine tetraacetic acid (EDTA) standard solution, c(EDTA) = 0,05 mol/l
Weigh 18,61 g of ethylenediamine tetraacetic acid dihydrate disodium salt (EDTA;
C H N Na O ⋅ 2H O) into a 1 000 ml volumetric flask and dilute to the mark with water.
10 14 2 2 8 2
Check the standard strength of the solution by titration of 20 ml of the standard solution 5.6 a
...
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