EN 15692:2021
(Main)Ethanol as a blending component for gasoline - Determination of water content - Karl Fischer potentiometric titration method
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
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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 chemicals and reagents of recognized analytical grade.
5.1 Karl Fischer reagent, pyridine-free Karl Fischer (KF) reagent, containing iodine, sulfur dioxide
and an odourless amine and with a nominal water equivalent content of either 2 mg or 5 mg water per
ml equivalent.
The Karl Fisher reagent shall be standardized daily before use (see 8.1).
5.2 Titration solvent methanol, anhydrous methanol containing less than 0,05 % (m/m) of water.
5.3 Water, complying with grade 3 of EN ISO 3696.
6 Apparatus
6.1 Karl Fischer titrator, using a potentiometric end-point.
NOTE Karl Fischer titrators are commercially available and some of them automatically stop the titration at
the end-point. Instructions for operation of these devices are provided by the manufacturer and are not described
here. The method described in this document is using a titrator with a 5 ml burette.
6.2 Electrode platinum/platinum
6.3 Syringes
NOTE Needles with bores between 0,5 mm and 0,8 mm have been found suitable, such as syringe of single use
with Luer connection, 5 ml or 10 ml capacity.
6.3.1 Syringe, of approximately 10 μl capacity, fitted with a needle of sufficient length to enable the tip
to reach under the surface of the liquid in the titration vessel when inserted through the inlet-port
septum.
6.3.2 Syringe, of approximately 10 ml capacity, fitted with a needle of sufficient length to enable the
tip to reach under the surface of the liquid in the titration vessel when inserted through the inlet-port
septum.
6.4 Analytical balance, capable of weighing to the nearest 0,1 mg.
6.5 Automatic burette, of 5 ml or 10 ml capacity, protected from humidity by the use of a molecular
sieve (6.6) at the top.
Although it is recommended that an automatic burette connected to a reservoir containing the KF reagent
(5.1) is used, a burette, of approximately 5 ml capacity, fitted with a guard tube filled with molecular sieve
(6.6) to prevent the ingress of moisture, may also be used.
6.6 Molecular sieve, granulometry proximally 1,6 mm to 2,5 mm, pore size close to 1 nm.
If required to be dried it shall be placed in an oven at proximally 140 °C for about 8 hours, then cooled in
a desiccator to room temperature.
7 Sampling and sample handling
7.1 Samples shall be taken as described in EN ISO 3170.
7.2 Take care to minimize the uptake of atmospheric moisture during sampling and sample handling.
7.3 Samples shall be shaken before used.
7.4 Samples shall be stored capped at room temperature in a dry place to avoid modification of water
content.
NOTE The use of a glass bottle that can be sealed with a septum has been found suitable for sampling and
sample handling. In such a case, a test portion of the sample can be taken through the septum with a syringe fitted
with a needle.
8 Procedure
8.1 Standardization of the Karl Fischer reagent
8.1.1 Add sufficient of the titration solvent (5.2) to the clean, dry titration vessel (6.1) to cover the
electrodes. Seal all openings to the vessel, start the magnetic stirrer and adjust for smooth stirring action.
Turn on the indication circuit and add KF reagent (5.1) from the burette until the end point is reached.
Swirl the titration vessel to dry inside walls. Add more KF reagent if needed until a steady end point is
reached and maintained for at least 15 s.
Repeat these swirling and titration steps until the vessels walls are dry.
8.1.2 Fill a 10 µl syringe (6.3.1) with pure water, taking care to eliminate air bubble
...
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