EN 15692:2021

Ethanol as a blending component for gasoline - Determination of water content - Karl Fischer potentiometric titration method

This document specifies a method for the direct determination of water in ethanol to be used as a blending component for petrol, as well as in automotive ethanol (E85) fuel.
This method is applicable in the range 0,05 % (m/m) to 0,54 % (m/m).
NOTE For the purposes of this document, the term “% (m/m)” is used to represent the mass fraction.
WARNING — Use of this document might involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Ethanol zur Verwendung als Blendkomponente in Ottokraftstoff - Bestimmung des Wassergehaltes - Potentiometrische Titration nach Karl Fischer

Dieses Dokument legt ein direktes Bestimmungsverfahren für den Wassergehalt von Ethanol zur Verwendung als Blendkomponente in Ottokraftstoff sowie in Ethanolkraftstoff (E85) fest.
Dieses Verfahren ist anwendbar im Bereich von 0,05 % (m/m) bis 0,54 % (m/m).
ANMERKUNG Für die Zwecke dieses Dokuments wird zur Angabe des Massenanteils einer Substanz der Ausdruck „% (m/m)“ verwendet.
WARNUNG — Die Anwendung dieses Dokuments kann die Anwendung gefährlicher Stoffe, Arbeitsgänge und Geräte mit sich bringen. Dieses Dokument beansprucht nicht, alle damit verbundenen Sicherheitsprobleme zu behandeln. Es liegt in der Verantwortung des Anwenders dieses Dokuments, geeignete Maßnahmen für die Sicherheit und den Gesundheitsschutz zu ergreifen und vor der Anwendung die Geltung behördlicher Einschränkungen zu prüfen.

Ethanol comme base de mélange à l'essence - Détermination de la teneur en eau - Méthode de Karl Fischer par titrage potentiométrique

Le présent document prescrit une méthode de détermination directe de la teneur en eau dans l’éthanol utilisé comme constituant d’essence pour automobiles, ainsi que dans le carburant éthanol (E85).
Cette méthode s’applique à une plage de teneur en eau comprise entre 0,05 % (m/m) et 0,54 % (m/m).
NOTE Pour les besoins du présent document, le terme “% (m/m) ” représente la fraction massique.
AVERTISSEMENT — L'utilisation du présent document peut impliquer l'intervention de produits, d'opérations et d'équipements à caractère dangereux. Le présent document n'est pas censé aborder tous
les problèmes de sécurité concernés par son usage. Il est de la responsabilité de l'utilisateur de ce document de consulter et d'établir des règles de sécurité et d'hygiène appropriées et de déterminer l'applicabilité des restrictions réglementaires avant utilisation.

Etanol kot komponenta za dodajanje motornemu bencinu - Določevanje vode - Metoda potenciometrične titracije po Karlu Fischerju

General Information

• Status: Published
• Publication Date: 20-Jul-2021
• Withdrawal Date: 30-Jan-2022
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: CEN/TC 19 - Petroleum products, lubricants and related products
• Drafting Committee: CEN/TC 19 - Petroleum products, lubricants and related products
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 21-Jul-2021
• Due Date: 13-Aug-2022
• Completion Date: 21-Jul-2021
• Ref Project: SIST EN 15692:2021 - Ethanol as a blending component for gasoline - Determination of water content - Karl Fischer potentiometric titration method

Relations

• Replaces: EN 15692:2009 - Ethanol as a blending component for petrol - Determination of water content - Karl Fischer potentiometric titration method
• Effective Date: 08-Jun-2022

Overview

EN 15692:2021 is a European standard developed by CEN for determining water content in ethanol used as a blending component for gasoline, including automotive ethanol (E85) fuel. The standard specifies a precise and reliable method using Karl Fischer potentiometric titration, which directly measures the water fraction in ethanol. Applicable within a range from 0.05% to 0.54% mass fraction water content, this method ensures accurate quality control critical for fuel performance and regulatory compliance.

This method replaces the earlier EN 15692:2009, providing enhanced precision and updated procedural details consistent with industry best practices. It is essential for laboratories and fuel producers to adhere to this standard to maintain consistent ethanol quality and prevent engine or environmental issues caused by water contamination.

Key Topics

• Scope and Application
  Defines the direct determination of water in ethanol for blending in petrol and automotive fuel (E85) within a specified mass fraction range (0.05%–0.54%).

• Principle of Karl Fischer Titration
  Based on the redox reaction where one mole of iodine reacts with one mole of water, quantified potentiometrically for water content determination.

• Reagents and Equipment Requirements
  Utilizes pyridine-free Karl Fischer reagents, anhydrous methanol as solvent, platinum electrodes, automated burettes, syringes, molecular sieves, and analytical balances.

• Sampling and Handling
  Emphasizes minimizing atmospheric moisture uptake, using sealed glass bottles with septa, and storing samples at room temperature in dry conditions to avoid water content alteration.

• Procedure Essentials
  Standardizing Karl Fischer reagent daily, carefully titrating sample portions without shaking post-addition, and precise volume and mass measurements to ensure reliability.

• Calculation and Reporting
  Water content is calculated by correlating titrant volume, reagent water equivalence, and sample mass, with results expressed to two decimal places as % (m/m).

• Precision and Validation
  Precision values obtained from extensive interlaboratory studies confirm method repeatability and reproducibility suited for diverse ethanol sources including bio-based ethanol.

• Safety Considerations
  Users must observe appropriate safety measures as the process involves hazardous chemicals and apparatus. Regulatory compliance on handling chemicals and operations is the user’s responsibility.

Applications

EN 15692:2021 is vital for several practical applications in fuel production and quality control, including:

• Fuel Blending Operations
  Ensuring ethanol blended in gasoline meets strict water content limits to prevent phase separation, corrosion, or engine performance issues.

• Automotive Fuel Quality Testing
  Routine quality checks of E85 fuel to verify water content is within permissible levels for optimal combustion and emissions compliance.

• Regulatory Compliance
  Meeting European regulatory standards on fuel quality, facilitating market access and certification for ethanol-blended fuels.

• Research and Development
  Supporting development of bioethanol and fuel formulations by providing a standardized and validated water content measurement.

• Proficiency and Interlaboratory Testing
  Establishing benchmark procedures to support laboratory accreditation, proficiency testing programs, and consistent global fuel quality assessment.

Related Standards

• EN ISO 3170 – Manual sampling of petroleum liquids: Provides guidelines for sampling fuels consistent with EN 15692 sample handling recommendations.

• EN ISO 3696 – Water for analytical laboratory use: Specifies water purity levels essential for reagent preparation in Karl Fischer titration.

• EN 15489 – Alternative water content determination methods in ethanol: EN 15692 provides a more industry-prevalent method complementing this standard.

• ISO 760 – General Karl Fischer titration for water content: The foundational method upon which EN 15692’s technical approach is based.

• EN ISO 4259-1 – Precision data for petroleum-related tests: Used for statistical validation of precision in EN 15692 interlaboratory comparisons.

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Keywords: EN 15692:2021, ethanol water content, Karl Fischer titration, gasoline blending, E85 fuel, water determination method, potentiometric titration, fuel quality control, automotive ethanol, CEN standard, analytical balance, reagent standardization, ethanol sampling, precision testing, European fuel standard.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2021
Nadomešča:
SIST EN 15692:2009
Etanol kot komponenta za dodajanje motornemu bencinu - Določevanje vode -
Metoda potenciometrične titracije po Karlu Fischerju
Ethanol as a blending component for gasoline - Determination of water content - Karl
Fischer potentiometric titration method
Ethanol zur Verwendung als Blendkomponente in Ottokraftstoff - Bestimmung des
Wassergehaltes - Potentiometrische Titration nach Karl Fischer
Ethanol comme base de mélange à l'essence - Détermination de la teneur en eau -
Méthode de Karl Fischer par titrage potentiométrique
Ta slovenski standard je istoveten z: EN 15692:2021
ICS:
71.080.60 Alkoholi. Etri Alcohols. Ethers
75.160.20 Tekoča goriva Liquid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 15692
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2021
EUROPÄISCHE NORM
ICS 75.160.20 Supersedes EN 15692:2009
English Version
Ethanol as a blending component for gasoline -
Determination of water content - Karl Fischer
potentiometric titration method
Ethanol comme base de mélange à l'essence - Ethanol zur Verwendung als Blendkomponente in
Détermination de la teneur en eau - Méthode de Karl Ottokraftstoff - Bestimmung des Wassergehaltes -
Fischer par titrage potentiométrique Potentiometrische Titration nach Karl Fischer
This European Standard was approved by CEN on 14 June 2021.

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, Turkey 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15692:2021 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 and materials . 5
6 Apparatus . 5
7 Sampling and sample handling . 6
8 Procedure . 6
8.1 Standardization of the Karl Fischer reagent . 6
8.2 Analysis . 7
9 Calculation . 8
10 Expression of results . 8
11 Precision . 8
11.1 General. 8
11.2 Repeatability, r . 8
11.3 Reproducibility, R . 8
12 Test report . 9
Bibliography . 10

European foreword
This document (EN 15692:2021) has been prepared by Technical Committee CEN/TC 19 “Gaseous and
liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat
of which is held by NEN.
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 January 2022, and conflicting national standards shall
be withdrawn at the latest by January 2022.
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 15692:2009.
In comparison with the previous edition, the following technical modifications have been made:
— The original document was prepared by CEN/TC 19’s Ethanol Task Force under its Working Group
21 and is based on ISO 760 [1]. It is developed as an alternative to EN 15489 [2], delivering a method
more widely used in the alcohol and beverage industry environment.
— The test method has been revised in terms of its precision and scope. A second interlaboratory study
(ILS) in 2010 [5] confirmed the application to automotive ethanol (E85) fuel. Use of the method over
time, especially in proficiency testing programmes, gave questions around whether the precision in
the original document. When CEN/TC 19/WG 36 was requested to study the ILS reports, the
recalculated precision results did not reflect the published precision.
— The newly calculated precision is lower than the one published and the statistics allow introducing a
constant reproducibility for the determination of water content in ethanol. The test method lower
limit could remain at 0,05 % (whereas the lowest sample mean was 0,02 %). So the scope range has
not been changed, but the precision calculations have.
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, Turkey and the United
Kingdom.
1 Scope
This document specifies a method for the direct determination of water in ethanol to be used as a
blending component for petrol, as well as in automotive ethanol (E85) fuel.
This method is applicable in the range 0,05 % (m/m) to 0,54 % (m/m).
NOTE For the purposes of this document, the term “% (m/m)” is used to represent the mass fraction.
WARNING — Use of this document might involve hazardous materials, operations and equipment. This
document does not purport to address all of the safety problems associated with its use. It is the
responsibility of the user of this document to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use.
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 ISO 3170, Petroleum liquids - Manual sampling (ISO 3170)
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696)
3 Terms and definitions
For the purposes of this document, the following term and definition apply.
ISO and IEC maintain terminological 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
3.1
water content
content of water determined by potentiometric Karl Fischer procedure as given in this document
4 Principle
A weighed test portion is injected into the titration vessel of a potentiometric Karl Fischer apparatus. The
water present is titrated to a potentiometric end point using Karl Fischer reagent. Iodine (I ), with
presence of anhydride sulfur (SO ), of methanol (CH OH) and of an appropriate nitrogen base (RN), is
2 3
introduced for the Karl Fischer reaction. Based on the stoichiometry of the reaction, one mole of iodine
reacts with one mole of water.
The reaction can be expressed as follows:
CH OH + SO + RN → [RNH]SO CH
3 2 3 3
H O +I + [RNH]SO CH + 2RN → [RNH]SO CH +2[RNH]I
2 2 3 3 4 3
5 Reagents and materials
Use only chemic
...