SIST EN ISO 15512:2014

Plastics - Determination of water content (ISO 15512:2014)

1.1 This International Standard specifies methods for the determination of the water content of plastics
in the form of powder, granules, and finished articles. These methods do not test for water absorption
(kinetics and equilibrium) of plastics as measured by ISO 62.
Method A is suitable for the determination of water content as low as 0,1 % with an accuracy of 0,1 %.
Method B and Method C are suitable for the determination of water content as low as 0,01 % with an
accuracy of 0,01 %.
Water content is an important parameter for processing materials and has to remain below the level
specified in the appropriate material standard.
1.2 Four alternative methods are specified in this International Standard.
— Method A is an extraction method using anhydrous methanol followed by a Karl Fischer titration
of the extracted water. It can be used for all plastics and is applicable to granules smaller than
4 mm × 4 mm × 3 mm. The method can also be used for, e.g. prepolymer materials in the form of a
powder that are insoluble in methanol.
— Method B1 is a vaporization method using a tube oven. The water contained in the test portion is
vaporized and carried to the titration cell by a dry air or nitrogen carrier gas, followed by a Karl
Fischer titration of the collected water. It can be used for all plastics and is applicable to granules
smaller than 4 mm × 4 mm × 3 mm.
— Method B2 is a vaporization method using a heated sample vial. The water contained in the test
portion is vaporized and carried to the titration cell by a dry air or nitrogen carrier gas, followed
by a Karl Fischer titration of the collected water. It can be used for all plastics and is applicable to
granules smaller than 4 mm × 4 mm × 3 mm.
— Method C is a manometric method. The water content is determined from the increase in pressure,
which results when the water is evaporated under a vacuum. This method is not applicable to plastic
samples containing volatile compounds, other than water, in amounts contributing significantly
to the vapour pressure at room temperature. Checks for the presence of large amounts of volatile
compounds are to be carried out periodically, for example by gas chromatography. Such checks are
particularly required for new types or grades of material.

Kunststoffe - Bestimmung des Wassergehaltes (ISO 15512:2014)

1.1   Diese Internationale Norm legt Verfahren zur Bestimmung des Wassergehalts von Kunststoffen fest, die als Pulver, Granulat oder Fertigerzeugnis vorliegen. Bei diesen Verfahren wird nicht, wie nach ISO 62, die Wasseraufnahme (Kinetik und Gleichgewicht) von Kunststoffen geprüft. Diese Verfahren sind zur Bestimmung von Wassergehalten bis zu 0,01 % oder besser vorgesehen:
Der Wassergehalt ist ein wichtiger Parameter bei der Verarbeitung von Werkstoffen und sollte stets unter dem in den entsprechenden Werkstoffnormen festgelegten Wert bleiben.
1.2   In dieser Internationalen Norm sind vier alternative Verfahren festgelegt:
a)   Verfahren A ist ein Extraktionsverfahren mit wasserfreiem Methanol und anschließender Titration des Wassers nach dem Karl Fischer Verfahren. Es kann für alle Kunststoffe verwendet werden und ist auf Granulate mit einer Korngröße kleiner als 4 mm  4 mm  3 mm anwendbar. Das Verfahren kann auch z. B. auf Vorpolymer Pulvermaterialien angewendet werden, die in Methanol unlöslich sind.
ANMERKUNG   Bei der nächsten Überarbeitung dieser Norm darf die Beschreibung des Verfahrens A in dieser Norm entfallen oder in einen informativen Anhang aufgenommen werden.
b)   Verfahren B1 ist ein Verdampfungsverfahren unter Anwendung eines Rohrofens. Das in der Analysenmenge enthaltene Wasser wird verdampft und durch trockene Luft oder Stickstoff als Trägergas in die Titrationszelle überführt, in der anschließend die Titration des gesammelten Wassers nach dem Karl Fischer Verfahren erfolgt. Es kann für sämtliche Kunststoffe und Granulate angewendet werden, die kleiner als 4 mm  4 mm  3 mm sind.
ANMERKUNG   Bei der nächsten Überarbeitung dieser Norm darf die Beschreibung des Verfahrens B.1 in dieser Norm entfallen oder in einen informativen Anhang aufgenommen werden.
c)   Verfahren B2 ist ein Verdampfungsverfahren unter Anwendung eines erhitzten Probenfläschchens. Das in der Analysenmenge enthaltene Wasser wird verdampft und durch trockene Luft oder Stickstoff als Trägergas in die Titrationszelle überführt, in der anschließend die Titration des gesammelten Wassers nach dem Karl Fischer Verfahren erfolgt. Es kann für sämtliche Kunststoffe und Granulate angewendet werden, die kleiner als 4 mm  4 mm  3 mm sind.
d)   Verfahren C ist ein manometrisches Verfahren. Der Wassergehalt wird aus dem Druckanstieg nach dem Verdampfen des Wassers unter Vakuum bestimmt. Das Verfahren kann nicht auf Kunststoffproben angewendet werden, die andere flüchtige Bestandteile als Wasser in solchen Mengen enthalten, dass diese signifikant zum Dampfdruck bei Raumtemperatur beisteuern. In regelmäßigen Abständen sollte, z. B. durch Gaschromatographie, die Anwesenheit großer Mengen an flüchtigen Bestandteilen überprüft werden. Diese Überprüfungen sind besonders bei neuen Typen oder Klassen von Werk¬stoffen notwendig.

Plastiques - Dosage de l'eau (ISO 15512:2014)

L'ISO 15512:2014 spécifie des méthodes pour le dosage de l'eau dans les plastiques sous forme de poudre, de granulés et d'articles finis. Ces méthodes ne contrôlent pas l'absorption d'eau (cinétique et équilibre) des plastiques, cet aspect étant traité dans l'ISO 62.
La Méthode A est applicable au dosage de l'eau à des niveaux aussi faibles que 0,1 % avec une précision de 0,1 %. La Méthode B et la Méthode C sont applicables au dosage de l'eau à des niveaux aussi faibles que 0,01 % avec une précision de 0,01 %.

Polimerni materiali - Določevanje vode (ISO 15512:2014)

1.1 Ta mednarodni standard določa metode za določevanje vode v polimernih materialih v obliki praškov, granul in dokončanih izdelkov. Te metode ne preskušajo absorpcije vode (kinetika in ravnovesje) polimernih materialov, kot se meri v skladu s standardom ISO 62.
Metoda A je primerna za določevanje vsebnosti vode, ki dosega komaj 0,1 %, z natančnostjo 0,1 %. Metoda B in metoda C sta primerni za določevanje vsebnosti vode, ki dosega komaj 0,01 %, z natančnostjo 0,01 %.
Vsebnost vode je pomemben parameter za obdelavo materialov in mora ostati pod ravnjo, določeno v ustreznem standardu za materiale.
1.2 V tem mednarodnem standardu so določene štiri alternativne metode.
– Metoda A je metoda ekstrakcije z brezvodnim metanolom, ki mu sledi titracija ekstrahirane vode po Karlu Fischerju. Uporablja se lahko za vse polimerne elemente in velja za granule, manjše od 4 mm × 4 mm × 3 mm. Metoda se lahko uporablja tudi za npr. predpolimerne materiale v obliki praška, ki niso topni v metanolu.
– Metoda B1 je metoda izparevanja s cevasto pečjo. Voda v preskusni količini izpari in se prenese v titracijsko celico prek nosilnega plina (suh zrak ali dušik), čemur sledi titracija zbrane vode po Karlu Fischerju. Uporablja se lahko za vse polimerne elemente in velja za granule, manjše od 4 mm × 4 mm × 3 mm.
– Metoda B je metoda izparevanja z ogrevano preskusno stekleničko. Voda v preskusni količini izpari in se prenese v titracijsko celico prek nosilnega plina (suh zrak ali dušik), čemur sledi titracija zbrane vode po Karlu Fischerju. Uporablja se lahko za vse polimerne elemente in velja za granule, manjše od 4 mm × 4 mm × 3 mm.
– Metoda C je manometrska metoda. Vsebnost vode se določi na podlagi povečanja tlaka, do katerega pride, ko voda izhlapi v vakuumu. Ta metoda se ne uporablja za vzorce polimernih materialov, ki vsebujejo hlapne spojine, ki niso voda, v količinah, ki znatno prispevajo k parnemu tlaku pri sobni temperaturi. Redno je treba preverjati prisotnost velikih količin hlapnih spojin, na primer s plinsko kromatografijo. Tako preverjanje je zlasti potrebno za nove tipe ali razrede materiala.

General Information

• Status: Withdrawn
• Publication Date: 21-Oct-2014
• Withdrawal Date: 17-Nov-2016
• ICS: 83.080.01 - Plastics in general
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 18-Nov-2016
• Due Date: 11-Dec-2016
• Completion Date: 18-Nov-2016
• Ref Project: EN ISO 15512:2014 - Plastics - Determination of water content (ISO 15512:2014)

Relations

• Replaced By: SIST EN ISO 15512:2017 - Plastics - Determination of water content (ISO 15512:2016)
• Effective Date: 16-Nov-2016
• Replaces: SIST EN ISO 15512:2009 - Plastics - Determination of water content (ISO 15512:2008)
• Effective Date: 01-Dec-2014
• Revised: SIST EN ISO 15512:2017 - Plastics - Determination of water content (ISO 15512:2016)
• Effective Date: 11-Nov-2015

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 15512:2014
01-december-2014
1DGRPHãþD
SIST EN ISO 15512:2009
3ROLPHUQLPDWHULDOL'RORþHYDQMHYRGH,62
Plastics - Determination of water content (ISO 15512:2014)
Kunststoffe - Bestimmung des Wassergehaltes (ISO 15512:2014)
Plastiques - Dosage de l'eau (ISO 15512:2014)
Ta slovenski standard je istoveten z: EN ISO 15512:2014
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
SIST EN ISO 15512:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 15512:2014

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SIST EN ISO 15512:2014

EUROPEAN STANDARD
EN ISO 15512

NORME EUROPÉENNE

EUROPÄISCHE NORM
September 2014
ICS 83.080.01 Supersedes EN ISO 15512:2009
English Version
Plastics - Determination of water content (ISO 15512:2014)
Plastiques - Dosage de l'eau (ISO 15512:2014) Kunststoffe - Bestimmung des Wassergehaltes (ISO
15512:2014)
This European Standard was approved by CEN on 6 September 2014.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15512:2014 E
worldwide for CEN national Members.

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SIST EN ISO 15512:2014
EN ISO 15512:2014 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 15512:2014
EN ISO 15512:2014 (E)
Foreword
This document (EN ISO 15512:2014) has been prepared by Technical Committee ISO/TC 61 ” Plastics ” in
collaboration with Technical Committee CEN/TC 249 “Plastics” 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 March 2015, and conflicting national standards shall be withdrawn at
the latest by March 2015.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 15512:2009.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 15512:2014 has been approved by CEN as EN ISO 15512:2014 without any modification.

3

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SIST EN ISO 15512:2014

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SIST EN ISO 15512:2014
INTERNATIONAL ISO
STANDARD 15512
Third edition
2014-09-15
Plastics — Determination of water
content
Plastiques — Dosage de l’eau
Reference number
ISO 15512:2014(E)
©
ISO 2014

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SIST EN ISO 15512:2014
ISO 15512:2014(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved

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SIST EN ISO 15512:2014
ISO 15512:2014(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Method A — Extraction with anhydrous methanol . 1
3.1 Principle . 1
3.2 Reagents. 2
3.3 Apparatus . 2
3.4 Preparation of test sample . 2
3.5 Procedure . 3
3.6 Expression of results . 3
3.7 Precision . 4
4 Method B1 — Water vaporization using a heating tube oven . 4
4.1 Principle . 4
4.2 Reagents. 4
4.3 Apparatus . 5
4.4 Preparation of test sample . 7
4.5 Procedure . 7
4.6 Expression of results . 8
4.7 Precision . 8
5 Method B2 — Water vaporization using a heated sample vial . 9
5.1 Principle . 9
5.2 Reagents. 9
5.3 Apparatus . 9
5.4 Preparation of test sample .11
5.5 Procedure .12
5.6 Expression of results .14
5.7 Precision .14
6 Method C — Manometric method .15
6.1 Principle .15
6.2 Reagents.15
6.3 Apparatus .15
6.4 Preparation of test sample .16
6.5 Procedure .16
6.6 Expression of results .20
6.7 Precision .20
7 Test report .20
Annex A (informative) Alternative sample preparation methods and titration methods .21
Annex B (informative) Selection of the optimum heating temperature for the water
content determination .22
Annex C (normative) Determination of the water content of a water standard .24
Bibliography .25
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SIST EN ISO 15512:2014
ISO 15512:2014(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
This third edition cancels and replaces the second edition (ISO 15512:2008), which has been technically
revised with the following changes:
a) the Introduction has been revised;
b) the Scope has been revised, i.e. four alternative methods are specified for the determination of
water content;
c) the apparatus in use for Method A has been updated;
d) a precision statement for Method A has been added;
e) a new Method B2 has been added (Clause 5);
f) Method C has been revised (Clause 6);
g) a new informative annex on alternative sample preparation methods and titration methods has
been added (Annex A);
h) a new normative annex on the determination of the water content of a water standard has been
added (Annex C).
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SIST EN ISO 15512:2014
ISO 15512:2014(E)

Introduction
The interlaboratory comparability of the water content determination of plastics is often low. Major
causes for this are the sample packaging, sample handling, and differences between equipment and
settings. Samples have to, e.g. be packed in special glass containers or water barrier sealed bags.
Sample handling is preferably to be carried out in a dry nitrogen or air environment. For improving
the repeatability and reproducibility, the prescribed procedure in this International Standard has to be
followed strictly.
The temperature settings for the vaporization method are not specified in this International Standard.
For the manometric method, a temperature of 200 °C is often used. However, for some condensation
materials, this might be too high and could, e.g. cause generation of water due to a condensation reaction.
The heating temperature has to be optimized concerning the material to be tested, the equipment in use,
and the practical circumstances. If the temperature is too low, the total amount of water in the material
to be tested will not be evaporated completely, whereas too high temperatures cause water generation
due to effects like degradation and condensation reactions.
In this International Standard, a procedure is included for optimization of the heating temperature
in order to choose the correct temperature for the water content determination and to improve the
interlaboratory comparability.
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SIST EN ISO 15512:2014

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SIST EN ISO 15512:2014
INTERNATIONAL STANDARD ISO 15512:2014(E)
Plastics — Determination of water content
1 Scope
1.1 This International Standard specifies methods for the determination of the water content of plastics
in the form of powder, granules, and finished articles. These methods do not test for water absorption
(kinetics and equilibrium) of plastics as measured by ISO 62.
Method A is suitable for the determination of water content as low as 0,1 % with an accuracy of 0,1 %.
Method B and Method C are suitable for the determination of water content as low as 0,01 % with an
accuracy of 0,01 %.
Water content is an important parameter for processing materials and has to remain below the level
specified in the appropriate material standard.
1.2 Four alternative methods are specified in this International Standard.
— Method A is an extraction method using anhydrous methanol followed by a Karl Fischer titration
of the extracted water. It can be used for all plastics and is applicable to granules smaller than
4 mm × 4 mm × 3 mm. The method can also be used for, e.g. prepolymer materials in the form of a
powder that are insoluble in methanol.
— Method B1 is a vaporization method using a tube oven. The water contained in the test portion is
vaporized and carried to the titration cell by a dry air or nitrogen carrier gas, followed by a Karl
Fischer titration of the collected water. It can be used for all plastics and is applicable to granules
smaller than 4 mm × 4 mm × 3 mm.
— Method B2 is a vaporization method using a heated sample vial. The water contained in the test
portion is vaporized and carried to the titration cell by a dry air or nitrogen carrier gas, followed
by a Karl Fischer titration of the collected water. It can be used for all plastics and is applicable to
granules smaller than 4 mm × 4 mm × 3 mm.
— Method C is a manometric method. The water content is determined from the increase in pressure,
which results when the water is evaporated under a vacuum. This method is not applicable to plastic
samples containing volatile compounds, other than water, in amounts contributing significantly
to the vapour pressure at room temperature. Checks for the presence of large amounts of volatile
compounds are to be carried out periodically, for example by gas chromatography. Such checks are
particularly required for new types or grades of material.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 760, Determination of water — Karl Fischer method (General method)
3 Method A — Extraction with anhydrous methanol
3.1 Principle
A test portion is extracted with anhydrous methanol and the extracted water determined by titration
using the Karl Fischer method.
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SIST EN ISO 15512:2014
ISO 15512:2014(E)

3.2 Reagents
During the analysis, use only reagents of recognized analytical grade.
3.2.1 Titration medium, methanol anhydrous, having a water content less than 0,1 % by mass. Other
solvents can be used if shown to be comparable.
3.2.2 Karl Fischer reagent, with an equivalence factor of approximately 3 mg/ml to 5 mg/ml of water.
When the reagent is prepared, check its equivalence factor as specified in ISO 760.
3.3 Apparatus
Ordinary laboratory apparatus and the following:
3.3.1 Glass flasks, approximately 250 ml capacity, provided with a suitable cap preventing moisture
uptake or release.
3.3.2 Conical titration flasks, approximately 150 ml capacity, with standard ground necks and
provided with ground-glass stoppers.
3.3.3 Reflux condensers, with ground neck capable of being fitted on to the flasks (3.3.2) and on to the
tubes (3.3.4).
3.3.4 Water-absorption tubes with ground joints, containing calcium chloride or other suitable
drying agent.
3.3.5 Heaters, suitable for the conical titration flasks (3.3.2).
3.3.6 Desiccator, containing a suitable desiccant.
3.3.7 Analytical balance, accurate to 0,2 mg.
3.3.8 Karl Fischer apparatus, for determining water content in accordance with ISO 760.
3.4 Preparation of test sample
3.4.1 Granules or powder
Take a representative sample of approximately 100 g. Put the sample into a pre-dried glass flask (3.3.1)
and immediately close it with a stopper.
NOTE It is desirable to pre-dry the container in an oven and then cool it over a suitable desiccant.
3.4.2 Finished articles
Cut or saw the sample into pieces of appropriate size, i.e. having a maximum size of 4 mm × 4 mm × 3 mm.
Proceed quickly to minimize moisture absorption.
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SIST EN ISO 15512:2014
ISO 15512:2014(E)

3.5 Procedure
3.5.1 Precautions
Due to the low quantities of water measured, maximum care shall be exercised at all times to avoid
contaminating the sample with water from the sample container, the atmosphere, or transfer equipment.
Hygroscopic resin samples shall be protected from the atmosphere.
3.5.2 Preparation of test portions
Conduct the test on two test portions from the same sample. Use test portions containing 10 mg to
20 mg of water based on the estimated water content of the sample.
Using modern coulometric Karl Fischer titration instruments test portions containing less than 10 mg
can be applied if the same level of accuracy of results can be achieved.
3.5.3 Determination
Carefully dry the apparatus.
Weigh each test portion to the nearest 1 mg into a conical titration flask (3.3.2) fitted with a ground-
glass stopper. Pipette 50 ml of anhydrous methanol (3.2.1) into the conical flask containing the test
portion. At the same time, pipette 50 ml of anhydrous methanol to another conical flask for a blank test.
Stopper the flasks. Keep the stoppered flasks in the desiccator (3.3.6) pending continuation of the test.
Unstopper the flasks and quickly attach them to reflux condensers (3.3.3) fitted with calcium chloride
tubes (3.3.4). Reflux the contents of the conical flasks for 3 h, then leave them for 45 min to cool to
room temperature. Separate the flasks from the condensers, quickly stopper them, and place them in
the desiccator.
Use the Karl Fischer apparatus (3.3.8) to titrate the contents of each flask with Karl Fischer reagent
(3.2.2).
NOTE Alternative sample preparation methods and titration methods are given in Annex A.
3.6 Expression of results
The water content, w, expressed as a percentage by mass, for each of the two determinations is given by
Formula (1):
VV− ×T
()
12
w= ×100 (1)
m
where
V is the volume, expressed in millilitres, of Karl Fischer reagent used for the determination;
1
V is the volume, expressed in millilitres, of Karl Fischer reagent used for the blank test;
2
T is the water equivalent, expressed in grams of water per millilitre of reagent, of Karl Fischer
reagent;
m is the mass, in grams, of the test portion.
NOTE For some equipment, V might not be available separately but only used for internal calculation of
2
V - V . In this case, the numerator in the formula simplifies to V × T.
1 2
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SIST EN ISO 15512:2014
ISO 15512:2014(E)

The two values for the water content shall not differ by more than 10 % relative or 0,02 % absolute,
whichever is the greater. If the difference is greater, repeat the measurements until acceptable
consecutive values are obtained and discard all unacceptable results.
The result is expressed as the average of these two determinations, rounded to the nearest 0,01 % by
mass.
3.7 Precision
The precision of this test method is not known because interlaboratory data are not available. If and
when interlaboratory data are obtained, a precision statement will be added to a subsequent revision.
For comparison of data between two laboratories, special care needs to be taken on sample packing and
sample handling.
4 Method B1 — Water vaporization using a heating tube oven
4.1 Principle
The sample is weighed then placed in an oven. The water contained in the test portion is vaporized and
carried to the titration cell by a dry nitrogen carrier gas. The water is then titrated using the coulometric
Karl Fischer method. This method is based on the reduction of iodine by sulfur dioxide in the presence of
water to form sulfur trioxide and hydroiodic acid as follows:
I + SO + H O → 2HI + SO
2 2 2 3
Unlike the conventional Karl Fischer reagents that include iodine, the coulometric technique generates
the iodine electrolytically from iodide:
− −
2I → I + 2e
2
with 10,71 C of generating current corresponding to 1 mg of water in accordance with Faraday’s Law.
4.2 Reagents
During the analysis, use only reagents of recognized analytical grade.
4.2.1 Anode solution, containing iodide ions to generate iodine in the reaction mixture, in accordance
with the equipment manufacturer’s instructions.
4.2.2 Cathode solution, containing a suitable salt in methanol (or another suitable organic solvent),
prepared in accordance with the equipment manufacturer’s instructions.
4.2.3 Universal single anode reagent, containing iodide ions to generate iodine in the reaction
mixture, in accordance with the equipment manufacturer’s instructions, for use in a diaphragm-free cell.
NOTE A universal single anode coulometric reagent is applied in diaphragm-free titration cells. Titration
cells with diaphragm require the use of a separate anode and cathode solution.
4.2.4 Neutralization solution, consisting of approximately 4 mg/ml of water in propylene carbonate,
ethylene glycol monomethyl ether (2-methoxyethanol), or methyl cellosolve.
4.2.5 Nitrogen gas (N ), containing less than 5 μg/g of water.
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SIST EN ISO 15512:2014
ISO 15512:2014(E)

4.3 Apparatus
Ordinary laboratory apparatus and the following:
4.3.1 Coulometric Karl Fischer titrator, consisting of a control unit and a titration-cell assembly
equipped with a generator cell, with or without diaphragm, dual platinum sensing electrodes, and a
magnetic stirrer (see Figure 1).
The instrument is designed to coulometrically generate iodine that reacts stoichiometrically with the
water present in the cell. The coulombs of electricity required to generate the reagent are converted to
micrograms of water and is given as a direct digital readout.
NOTE A diaphragm-free cell is accurate enough for many applications. However, check with the equipment
supplier to verify whether your applications require a diaphragm. A cell with a diaphragm is recommended if the
best possible accuracy is required.
4.3.2 Water vaporizer, consisting of an oven capable of heating the sample to at least 300 °C, a heating
tube (see Figure 2), a temperature control unit, a carrier-gas flow meter, and carrier-gas drying tubes
containing desiccant.
4.3.3 Microsyringe, with capacity of 10 μl, calibrated.
4.3.4 Sample boat.
Aluminium foil can be used to hand-fashion a disposable boat large enough to contain the sample and
small enough to fit into the heating tube.
4.3.5 Suitable desiccant, for the carrier-gas drying tubes (4.3.2).
4.3.6 Molecular sieve, pore size 0,3 nm, desiccant for carrier gas.
4.3.7 P
...