SIST-TS CEN/TS 17685-2:2025

Earthworks - Chemical tests - Part 2: Determination of organic matter content by potassium permanganate method

This document describes a method for the determination of the oxidizable organic matter content of a soil, which is mainly composed of fresh organic matter and fulvic and humic acids, by back titration with potassium permanganate.
The result obtained with this technical specification is not comparable with those obtained by EN 17685-1:2023 (loss on ignition).

Erdarbeiten - Chemische Laborversuche - Teil 2: Bestimmung der organischen Anteile durch das Kaliumpermanganat-Verfahren

Dieses Dokument beschreibt ein Verfahren zur Bestimmung des Gehalts an organischen Stoffen eines Bodens, die hauptsächlich aus frischen organischen Stoffen und Fulvosäuren und Huminsäuren bestehen, durch Rücktitration mit Kaliumpermanganat.
Die mit dieser technischen Spezifikation erzielten Ergebnisse sind nicht mit denen vergleichbar, die mit EN 17685 1:2023 (Glühverlust) erzielt werden.

Terrassements - Essais chimiques - Partie 2 : Détermination de la teneur en matière organique par méthode au permanganate de potassium

Zemeljska dela - Kemijski preskusi - 2. del: Določanje vsebnosti organskih snovi z metodo kalijevega permanganata

General Information

• Status: Published
• Publication Date: 30-Dec-2024
• ICS: 13.080.99 - Other standards related to soil quality
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: ZEM - Earthworks
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 11-Nov-2024
• Due Date: 16-Jan-2025
• Completion Date: 31-Dec-2024
• Ref Project: CEN/TS 17685-2:2024 - Earthworks - Chemical tests - Part 2: Determination of organic matter content by potassium permanganate method

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2025
Zemeljska dela - Kemijski preskusi - 2. del: Določanje vsebnosti organskih snovi z
metodo kalijevega permanganata
Earthworks - Chemical tests - Part 2: Determination of organic matter content by
potassium permanganate method
Erdarbeiten - Chemische Laborversuche - Teil 2: Bestimmung der organischen Anteile
durch das Kaliumpermanganat-Verfahren
Terrassements - Essais chimiques - Partie 2 : Détermination de la teneur en matière
organique par méthode au permanganate de potassium
Ta slovenski standard je istoveten z: CEN/TS 17685-2:2024
ICS:
13.080.99 Drugi standardi v zvezi s Other standards related to
kakovostjo tal soil quality
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 17685-2
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
October 2024
TECHNISCHE SPEZIFIKATION
ICS 13.080.99; 93.020
English Version
Earthworks - Chemical tests - Part 2: Determination of
organic matter content by potassium permanganate
method
Terrassements - Essais chimiques - Partie 2 : Erdarbeiten - Chemische Laborversuche - Teil 2:
Détermination de la teneur en matière organique par Bestimmung der organischen Anteile durch das
méthode au permanganate de potassium Kaliumpermanganat-Verfahren
This Technical Specification (CEN/TS) was approved by CEN on 5 August 2024 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 17685-2:2024 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 Abbreviations and symbols . 5
5 Apparatus . 6
6 Preparation of solutions and determination of normality factors . 7
6.1 Normality factor of potassium permanganate . 7
6.2 Normality factor of oxalic acid . 8
7 Test procedure . 8
7.1 Sample preparation . 8
7.2 Test procedure . 9
8 Expression of results and determination of the organic matter content . 9
Annex A (informative) Example of a test data sheet . 11
Bibliography . 12

European foreword
This document (CEN/TS 17685-2:2024) has been prepared by Technical Committee CEN/TC 396
“Earthworks”, the secretariat of which is held by AFNOR.
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.
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 announce this Technical Specification: 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
This document describes a method for the determination of the oxidizable organic matter content of a
soil, which is mainly composed of fresh organic matter and fulvic and humic acids, by means of a chemical
back titration with potassium permanganate.
This method is an alternative to loss on ignition (LOI) method for the determination of the organic matter
content, but not same results as with the LOI method.

1 Scope
This document describes a method for the determination of the oxidizable organic matter content of a
soil, which is mainly composed of fresh organic matter and fulvic and humic acids, by back titration with
potassium permanganate.
The result obtained with this technical specification is not comparable with those obtained by
EN 17685-1:2023 (loss on ignition).
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 1997-2, Eurocode 7 — Geotechnical design — Part 2: Ground investigation and testing
ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 3310-2, Test sieves — Technical requirements and testing — Part 2: Test sieves of perforated metal
plate
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology 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/
3.1
constant mass
successive weightings after drying at least 1h apart not differing by more than 0,1 %
4 Abbreviations and symbols
For the purposes of this document, the following abbreviations and symbols apply.

% C Organic matter content dimensionless (%)
OM
normality factor of 0,1 N permanganate solution dimensionless
f
KMnO
normality factor of 0,1 N oxalic acid solution dimensionless
f
HC O
2 2 4
m mass of oxalate portion i in the determination of the normality g
bi
factor of permanganate solution
V volume of permanganate solution spent in its titration with the ml
bi
oxalate portion i
V volume of permanganate solution spent in the titration of the ml
c
oxalic solution
m mass of the sample portion tested i g
i
V volume of permanganate solution spent with the sample portion ml
i
tested i
R fraction of soil particles greater than 5 mm that do not contain
5mm
carbonates
f fraction of soil sample passing through 5 mm sieve
5mm
5 Apparatus
— Drying oven, of the forced-draft type and capable of maintaining a temperature of (110 ± 5) °C
throughout the drying chamber. Any air circulation shall not be so strong that any transport of
particles can take place;
— Standard sample splitters;
— Mortar and pestle, or mill device for soil crushing;
— Test sieves, of 5 mm aperture conforming to ISO 3310-2 and of 0,40 mm aperture conforming to
ISO 3310-1;
— Closed desiccator;
— Analytical balance, with an accuracy of 0,001 mg;
— Thermometer, graduated between 0 °C and 100 °C (accuracy of 0,5 °C);
...