EN ISO 23157:2022
(Main)Determination of the silanol group content on the surface of fumed silica - Reaction gas chromatographic method (ISO 23157:2021)
Determination of the silanol group content on the surface of fumed silica - Reaction gas chromatographic method (ISO 23157:2021)
This document specifies a method for the determination of the silanol group content on the surface of fumed silica by reaction gas chromatographic method.
Bestimmung des Gehaltes an Silanolgruppen auf der Oberfläche von pyrogener Kieselsäure - Gaschromatographisches Verfahren (ISO 23157:2021)
Détermination de la teneur en groupes silanol à la surface de la silice pyrogénée - Méthode par analyse chromatographique en phase gazeuse des gaz de réaction (ISO 23157:2021)
Le présent document spécifie une méthode de détermination de la teneur en groupes silanol à la surface de la silice pyrogénée en recourant à l’analyse chromatographique en phase gazeuse des gaz de réaction.
Določevanje silanolnih skupin na površini pirogenega silicijevega dioksida (kremenčevega dima) - Metoda reakcijske plinske kromatografije (ISO 23157:2021)
Ta dokument določa metodo za določevanje silanolnih skupin na površini pirogenega silicijevega dioksida (kremenčevega dima) z metodo reakcijske plinske kromatografije.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 23157:2023
01-januar-2023
Določevanje silanolnih skupin na površini pirogenega silicijevega dioksida
(kremenčevega dima) - Metoda reakcijske plinske kromatografije (ISO 23157:2021)
Determination of the silanol group content on the surface of fumed silica - Reaction gas
chromatographic method (ISO 23157:2021)Bestimmung des Gehaltes an Silanolgruppen auf der Oberfläche von pyrogener
Kieselsäure - Gaschromatographisches Verfahren (ISO 23157:2021)
Détermination de la teneur en groupes silanol à la surface de la silice pyrogénée -
Méthode par analyse chromatographique en phase gazeuse des gaz de réaction (ISO23157:2021)
Ta slovenski standard je istoveten z: EN ISO 23157:2022
ICS:
87.060.10 Pigmenti in polnila Pigments and extenders
SIST EN ISO 23157:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------SIST EN ISO 23157:2023
---------------------- Page: 2 ----------------------
SIST EN ISO 23157:2023
EN ISO 23157
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2022
EUROPÄISCHE NORM
ICS 87.060.10
English Version
Determination of the silanol group content on the surface
of fumed silica - Reaction gas chromatographic method
(ISO 23157:2021)
Détermination de la teneur en groupes silanol à la Bestimmung des Gehaltes an Silanolgruppen auf der
surface de la silice pyrogénée - Méthode par analyse Oberfläche von pyrogener Kieselsäure -
chromatographique en phase gazeuse des gaz de Gaschromatographisches Verfahren (ISO 23157:2021)
réaction (ISO 23157:2021)This European Standard was approved by CEN on 9 October 2022.
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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23157:2022 E
worldwide for CEN national Members.---------------------- Page: 3 ----------------------
SIST EN ISO 23157:2023
EN ISO 23157:2022 (E)
Contents Page
European foreword ....................................................................................................................................................... 3
---------------------- Page: 4 ----------------------SIST EN ISO 23157:2023
EN ISO 23157:2022 (E)
European foreword
The text of ISO 23157:2021 has been prepared by Technical Committee ISO/TC 256 "Pigments,
dyestuffs and extenders” of the International Organization for Standardization (ISO) and has been taken
over as EN ISO 23157:2022 by Technical Committee CEN/TC 298 “Pigments and extenders” 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 April 2023, and conflicting national standards shall be
withdrawn at the latest by April 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.
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 organizations 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.Endorsement notice
The text of ISO 23157:2021 has been approved by CEN as EN ISO 23157:2022 without any modification.
---------------------- Page: 5 ----------------------SIST EN ISO 23157:2023
---------------------- Page: 6 ----------------------
SIST EN ISO 23157:2023
INTERNATIONAL ISO
STANDARD 23157
First edition
2021-07
Determination of the silanol group
content on the surface of fumed
silica — Reaction gas chromatographic
method
Reference number
ISO 23157:2021(E)
ISO 2021
---------------------- Page: 7 ----------------------
SIST EN ISO 23157:2023
ISO 23157:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 23157:2023
ISO 23157:2021(E)
Contents Page
Foreword ..........................................................................................................................................................................................................................................v
Introduction ................................................................................................................................................................................................................................vi
1 Scope ................................................................................................................................................................................................................................. 1
2 Normative references ...................................................................................................................................................................................... 1
3 Terms and definitions ..................................................................................................................................................................................... 1
4 Principle ........................................................................................................................................................................................................................ 1
5 Reagents ........................................................................................................................................................................................................................ 2
5.1 General ........................................................................................................................................................................................................... 2
5.2 Toluene .......................................................................................................................................................................................................... 2
5.3 Grignard reagent ................................................................................................................................................................................... 2
5.4 Reaction solution .................................................................................................................................................................................. 2
5.5 Carrier gas and diluent gas ........................................................................................................................................................... 2
5.6 Auxiliary gases ........................................................................................................................................................................................ 2
5.7 Calibration substance ........................................................................................................................................................................ 2
6 Apparatus ..................................................................................................................................................................................................................... 3
6.1 Gas chromatograph ............................................................................................................................................................................. 3
6.2 Headspace system ................................................................................................................................................................................ 3
6.3 Oven .................................................................................................................................................................................................................. 3
6.4 Capillary column.................................................................................................................................................................................... 3
6.5 Sample vials ............................................................................................................................................................................................... 4
6.6 Analytical balance................................................................................................................................................................................. 4
6.7 Gas collecting bag ................................................................................................................................................................................. 4
6.8 Syringe............................................................................................................................................................................................................ 4
7 Sample pre-treatment and reaction ................................................................................................................................................. 4
7.1 Sample pre-treatment ....................................................................................................................................................................... 4
7.1.1 Determination of matter volatile at 105 °C in fumed silica......................................................... 4
7.1.2 Preparation of the test sample ............................................................................................................................. 4
7.2 Blank test ..................................................................................................................................................................................................... 4
7.3 Reaction ........................................................................................................................................................................................................ 5
7.4 Analysis.......................................................................................................................................................................................................... 5
7.4.1 Headspace system conditions .............................................................................................................................. 5
7.4.2 Gas chromatographic conditions ....................................................................................................................... 5
7.4.3 Identification ....................................................................................................................................................................... 5
7.4.4 Calibration ............................................................................................................................................................................. 5
7.4.5 Measurement ...................................................................................................................................................................... 6
8 Calculation .................................................................................................................................................................................................................. 6
8.1 Calculation of the methane quantity produced in the vials ............................................................................. 6
8.2 Calculation of the silanol group content ........................................................................................................................... 7
8.2.1 Calculation of fumed silica volatile at 105 °C .......................................................................................... 7
8.2.2 Calculation of the silanol group content on the surface of fumed silica .......................... 7
9 Expression of results ........................................................................................................................................................................................ 7
10 Precision ....................................................................................................................................................................................................................... 7
10.1 General ........................................................................................................................................................................................................... 7
10.2 Repeatability limit, r ............................................................................................................................................................................7
10.3 Reproducibility limit, R .....................................................................................................................................................................8
11 Test report ................................................................................................................................................................................................................... 8
Annex A (informative) Representative chromatogram of methane ..................................................................................... 9
Annex B (informative) Information about precision ........................................................................................................................10
© ISO 2021 – All rights reserved iii---------------------- Page: 9 ----------------------
SIST EN ISO 23157:2023
ISO 23157:2021(E)
Bibliography .............................................................................................................................................................................................................................11
iv © ISO 2021 – All rights reserved---------------------- Page: 10 ----------------------
SIST EN ISO 23157:2023
ISO 23157:2021(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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 256, Pigments, dyestuffs and extenders.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.© ISO 2021 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 23157:2023
ISO 23157:2021(E)
Introduction
Fumed silica (pyrogenic silicon dioxide) has a relatively high concentration of silanol groups formed
during high-temperature flame hydrolysis and the following cooling process. This specified property
enables fumed silica to be widely used as a reinforcing filler, thickener, thixotropy-increasing and anti-
sagging additive in numerous industries, for example silicone rubber, coating materials, adhesives and
sealants.The determination of the silanol group content on the surface of fumed silica is essential for both
manufacturers and users to develop a high-performance, surface modified fumed silica and improve
existing products. Further, it also facilitates the communication among interested parties.
In practice, methods of titra...
SLOVENSKI STANDARD
oSIST prEN ISO 23157:2022
01-julij-2022
[Not translated]
Determination of the silanol group content on the surface of fumed silica - Reaction gas
chromatographic method (ISO 23157:2021)Bestimmung des Gehaltes an Silanolgruppen auf der Oberfläche von gefällter
Kieselsäure - Gaschromatographisches Verfahren (ISO 23157:2021)
Ta slovenski standard je istoveten z: prEN ISO 23157
ICS:
87.060.10 Pigmenti in polnila Pigments and extenders
oSIST prEN ISO 23157:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------oSIST prEN ISO 23157:2022
---------------------- Page: 2 ----------------------
oSIST prEN ISO 23157:2022
INTERNATIONAL ISO
STANDARD 23157
First edition
2021-07
Determination of the silanol group
content on the surface of fumed
silica — Reaction gas chromatographic
method
Reference number
ISO 23157:2021(E)
ISO 2021
---------------------- Page: 3 ----------------------
oSIST prEN ISO 23157:2022
ISO 23157:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 23157:2022
ISO 23157:2021(E)
Contents Page
Foreword ..........................................................................................................................................................................................................................................v
Introduction ................................................................................................................................................................................................................................vi
1 Scope ................................................................................................................................................................................................................................. 1
2 Normative references ...................................................................................................................................................................................... 1
3 Terms and definitions ..................................................................................................................................................................................... 1
4 Principle ........................................................................................................................................................................................................................ 1
5 Reagents ........................................................................................................................................................................................................................ 2
5.1 General ........................................................................................................................................................................................................... 2
5.2 Toluene .......................................................................................................................................................................................................... 2
5.3 Grignard reagent ................................................................................................................................................................................... 2
5.4 Reaction solution .................................................................................................................................................................................. 2
5.5 Carrier gas and diluent gas ........................................................................................................................................................... 2
5.6 Auxiliary gases ........................................................................................................................................................................................ 2
5.7 Calibration substance ........................................................................................................................................................................ 2
6 Apparatus ..................................................................................................................................................................................................................... 3
6.1 Gas chromatograph ............................................................................................................................................................................. 3
6.2 Headspace system ................................................................................................................................................................................ 3
6.3 Oven .................................................................................................................................................................................................................. 3
6.4 Capillary column.................................................................................................................................................................................... 3
6.5 Sample vials ............................................................................................................................................................................................... 4
6.6 Analytical balance................................................................................................................................................................................. 4
6.7 Gas collecting bag ................................................................................................................................................................................. 4
6.8 Syringe............................................................................................................................................................................................................ 4
7 Sample pre-treatment and reaction ................................................................................................................................................. 4
7.1 Sample pre-treatment ....................................................................................................................................................................... 4
7.1.1 Determination of matter volatile at 105 °C in fumed silica......................................................... 4
7.1.2 Preparation of the test sample ............................................................................................................................. 4
7.2 Blank test ..................................................................................................................................................................................................... 4
7.3 Reaction ........................................................................................................................................................................................................ 5
7.4 Analysis.......................................................................................................................................................................................................... 5
7.4.1 Headspace system conditions .............................................................................................................................. 5
7.4.2 Gas chromatographic conditions ....................................................................................................................... 5
7.4.3 Identification ....................................................................................................................................................................... 5
7.4.4 Calibration ............................................................................................................................................................................. 5
7.4.5 Measurement ...................................................................................................................................................................... 6
8 Calculation .................................................................................................................................................................................................................. 6
8.1 Calculation of the methane quantity produced in the vials ............................................................................. 6
8.2 Calculation of the silanol group content ........................................................................................................................... 7
8.2.1 Calculation of fumed silica volatile at 105 °C .......................................................................................... 7
8.2.2 Calculation of the silanol group content on the surface of fumed silica .......................... 7
9 Expression of results ........................................................................................................................................................................................ 7
10 Precision ....................................................................................................................................................................................................................... 7
10.1 General ........................................................................................................................................................................................................... 7
10.2 Repeatability limit, r ............................................................................................................................................................................7
10.3 Reproducibility limit, R .....................................................................................................................................................................8
11 Test report ................................................................................................................................................................................................................... 8
Annex A (informative) Representative chromatogram of methane ..................................................................................... 9
Annex B (informative) Information about precision ........................................................................................................................10
© ISO 2021 – All rights reserved iii---------------------- Page: 5 ----------------------
oSIST prEN ISO 23157:2022
ISO 23157:2021(E)
Bibliography .............................................................................................................................................................................................................................11
iv © ISO 2021 – All rights reserved---------------------- Page: 6 ----------------------
oSIST prEN ISO 23157:2022
ISO 23157:2021(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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 256, Pigments, dyestuffs and extenders.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.© ISO 2021 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST prEN ISO 23157:2022
ISO 23157:2021(E)
Introduction
Fumed silica (pyrogenic silicon dioxide) has a relatively high concentration of silanol groups formed
during high-temperature flame hydrolysis and the following cooling process. This specified property
enables fumed silica to be widely used as a reinforcing filler, thickener, thixotropy-increasing and anti-
sagging additive in numerous industries, for example silicone rubber, coating materials, adhesives and
sealants.The determination of the silanol group content on the surface of fumed silica is essential for both
manufacturers and users to develop a high-performance, surface modified fumed silica and improve
existing products. Further, it also facilitates the communication among interested parties.
In practice, methods of titration, thermogravimetry (TG), infrared spectroscopy (IR) and reaction gas
chromatography can be a choice for the determination of the silanol group content on the surface of
fumed silica. Among these methods, the method of reaction gas chromatography is preferred by users
due to the advantage of higher sensitivity and better reproducibility.This document provides a detailed procedure for how to conduct the testing of the silanol group content
on the surface of fumed silica by means of the reaction gas chromatographic method.
vi © ISO 2021 – All rights reserved---------------------- Page: 8 ----------------------
oSIST prEN ISO 23157:2022
INTERNATIONAL STANDARD ISO 23157:2021(E)
Determination of the silanol group content on the surface
of fumed silica — Reaction gas chromatographic method
SAFETY STATEMENT — Persons using this document should be familiar with usual laboratory
practice. This document does not purport to address all of the safety problems, if any, associated
with its use. It is the responsibility of the user to establish appropriate safety and health
practices and to determine applicability of any national regulatory conditions.IMPORTANT — It is absolutely essential that tests conducted in accordance to this document be
carried out by suitably qualified staff.1 Scope
This document specifies a method for the determination of the silanol group content on the surface of
fumed silica by reaction gas chromatographic method.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.
ISO 18451-1, Pigments, dyestuffs and extenders — Terminology — Part 1: General terms
3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 18451-1 and the following
apply.ISO and IEC maintain terminological 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
fumed silica
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.