SIST EN ISO 11426:2021
(Main)Jewellery and precious metals - Determination of gold - Cupellation method (fire assay) (ISO 11426:2021)
Jewellery and precious metals - Determination of gold - Cupellation method (fire assay) (ISO 11426:2021)
This document specifies a cupellation method (fire assay) for the determination of gold on a material
considered homogeneous. The gold content of the sample lies preferably between 100 and 999,5 parts
per thousand (‰) by weight. Fineness above 999,5 ‰ can be determined using a spectroscopy method
by difference (e.g. ISO 15093).
The procedure is applicable to most types of gold samples. Some modifications are indicated for specific
cases (presence of large amount of base metals, platinum or palladium, silver). It is not compatible with
the presence above trace levels of iridium, rhodium and ruthenium (more than 0,25 ‰ for the sum of
all three elements).
This method is also intended to be used as the recommended method for the determination of fineness
in jewellery alloys covered by ISO 9202.
Schmuck und Edelmetalle - Bestimmung von Gold - Dokimastisches Verfahren (ISO 11426:2021)
Dieses Dokument legt ein dokimastisches Verfahren (Kupellationsverfahren) zur Bestimmung von Gold in Materialien, die als homogen betrachtet werden, fest. Der Goldgehalt der Legierung sollte vorzugsweise zwischen 100 Promille und 999,5 Promille (‰) liegen. Feingehalte über 999,5 ‰ können durch eine spektroskopisches Differenzverfahren (z. B. ISO 15093) bestimmt werden.
Das Verfahren ist anwendbar für die meisten Arten von Goldproben. Einige Modifikationen sind für bestimmte Fälle angegeben (Vorhandensein einer großen Menge unedler Metalle, Platin oder Palladium, Silber). Es ist nicht kompatibel mit dem Vorhandensein von Iridium, Rhodium und Ruthenium über den Spuren (mehr als 0,25 ‰ für die Summe aller drei Elemente).
Dieses Verfahren ist als empfohlenes Verfahren zur Bestimmung der Feinheit von Schmucklegierungen nach ISO 9202 vorgesehen.
Joaillerie, bijouterie et métaux précieux - Dosage de l'or - Méthode de coupellation (essai au feu) (ISO 11426:2021)
Le présent document spécifie une méthode de coupellation (essai au feu) permettant le dosage de l’or dans un matériau considéré comme homogène. La teneur en or de l’échantillon se situe de préférence entre 100 millièmes et 999,5 millièmes (‰) en poids. Un titre supérieur à 999,5 ‰ peut être déterminé par spectroscopie selon la méthode par différence (par exemple, ISO 15093).
Ce mode opératoire s’applique à la plupart des types d’échantillons d’or. Des modifications sont indiquées en rapport avec des cas particuliers (teneur élevée en métaux communs, en platine ou palladium, en argent). Il est incompatible avec la présence d’iridium, de rhodium et de ruthénium à des teneurs supérieures aux niveaux traces (plus de 0,25 ‰ pour la somme des trois éléments).
La présente méthode est également destinée à servir de méthode recommandée pour la détermination du titre des alliages utilisés en joaillerie-bijouterie traités dans l'ISO 9202.
Nakit in plemenite kovine - Določevanje zlata - Odtopitev primesi v tekočem svincu (ISO 11426:2021)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11426:2021
01-junij-2021
Nadomešča:
SIST EN ISO 11426:2016
Nakit in plemenite kovine - Določevanje zlata - Odtopitev primesi v tekočem svincu
(ISO 11426:2021)
Jewellery and precious metals - Determination of gold - Cupellation method (fire assay)
(ISO 11426:2021)
Schmuck und Edelmetalle - Bestimmung von Gold - Dokimastisches Verfahren (ISO
11426:2021)
Joaillerie, bijouterie et métaux précieux - Dosage de l'or - Méthode de coupellation (essai
au feu) (ISO 11426:2021)
Ta slovenski standard je istoveten z: EN ISO 11426:2021
ICS:
39.060 Nakit Jewellery
SIST EN ISO 11426:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 11426:2021
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SIST EN ISO 11426:2021
EN ISO 11426
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 39.060 Supersedes EN ISO 11426:2016
English Version
Jewellery and precious metals - Determination of gold -
Cupellation method (fire assay) (ISO 11426:2021)
Joaillerie, bijouterie et métaux précieux - Dosage de l'or Schmuck und Edelmetalle - Bestimmung von Gold -
- Méthode de coupellation (essai au feu) (ISO Dokimastisches Verfahren (ISO 11426:2021)
11426:2021)
This European Standard was approved by CEN on 18 December 2020.
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 ISO 11426:2021 E
worldwide for CEN national Members.
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SIST EN ISO 11426:2021
EN ISO 11426:2021 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 11426:2021
EN ISO 11426:2021 (E)
European foreword
This document (EN ISO 11426:2021) has been prepared by Technical Committee ISO/TC 174 "Jewellery
and precious metals" in collaboration with CCMC.
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 September 2021, and conflicting national standards
shall be withdrawn at the latest by September 2021.
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 ISO 11426:2016.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 11426:2021 has been approved by CEN as EN ISO 11426:2021 without any modification.
3
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SIST EN ISO 11426:2021
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SIST EN ISO 11426:2021
INTERNATIONAL ISO
STANDARD 11426
Fourth edition
2021-03
Jewellery and precious metals —
Determination of gold — Cupellation
method (fire assay)
Joaillerie, bijouterie et métaux précieux — Dosage de l'or — Méthode
de coupellation (essai au feu)
Reference number
ISO 11426:2021(E)
©
ISO 2021
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SIST EN ISO 11426:2021
ISO 11426:2021(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
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SIST EN ISO 11426:2021
ISO 11426:2021(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents . 2
6 Apparatus . 2
7 Sampling . 3
8 Procedure. 3
8.1 Method selection . 3
8.2 General method . 3
8.2.1 Assay samples . 3
8.2.2 Proof samples . 4
8.2.3 Cupellation and treatment of precious metal buttons . 4
8.2.4 Parting of the silver/gold samples . 4
8.3 Sample with large amount of base metals. 5
8.4 Sample containing platinum or palladium. 5
8.5 Sample with a silver/gold ratio higher than 3 . 5
9 Calculation and expression of results . 5
9.1 Proof sample factor . 5
9.2 Calculation of gold content . 6
9.3 Repeatability . 6
10 Test report . 6
Annex A (informative) Concentration of other base metals, affecting the gold result .7
Bibliography . 8
© ISO 2021 – All rights reserved iii
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SIST EN ISO 11426:2021
ISO 11426:2021(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 174, Jewellery and precious metals, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
SS M21, Precious metals - Applications in jewellery and associated products, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 11426:2014), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— extension of the scope to cover determination of gold in multiple types of alloys, not only in
jewellery ones;
— purity of proof samples was re-defined in Clause 5;
— specific procedures are described in Clause 8 for samples with large amount of base metals,
containing platinum or palladium, or with a silver/gold ratio higher than 3;
— calculation was adapted to take into account the addition of pure gold and the fineness of the gold
used in the proof sample;
— repeatability requirements were changed;
— the use of scorification was removed.
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.
iv © ISO 2021 – All rights reserved
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SIST EN ISO 11426:2021
INTERNATIONAL STANDARD ISO 11426:2021(E)
Jewellery and precious metals — Determination of gold —
Cupellation method (fire assay)
1 Scope
This document specifies a cupellation method (fire assay) for the determination of gold on a material
considered homogeneous. The gold content of the sample lies preferably between 100 and 999,5 parts
per thousand (‰) by weight. Fineness above 999,5 ‰ can be determined using a spectroscopy method
by difference (e.g. ISO 15093).
The procedure is applicable to most types of gold samples. Some modifications are indicated for specific
cases (presence of large amount of base metals, platinum or palladium, silver). It is not compatible with
the presence above trace levels of iridium, rhodium and ruthenium (more than 0,25 ‰ for the sum of
all three elements).
This method is also intended to be used as the recommended method for the determination of fineness
in jewellery alloys covered by ISO 9202.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in s
...
SLOVENSKI STANDARD
oSIST prEN ISO 11426:2020
01-oktober-2020
Nakit in plemenite kovine - Določevanje zlata - Odtopitev primesi v tekočem svincu
(ISO/DIS 11426:2020)
Jewellery and precious metals - Determination of gold - Cupellation method (fire assay)
(ISO/DIS 11426:2020)
Schmuck und Edelmetalle - Bestimmung von Gold - Dokimastisches Verfahren (ISO/DIS
11426:2020)
Joaillerie, bijouterie et métaux précieux - Dosage de l'or - Méthode de coupellation (essai
au feu) (ISO/DIS 11426:2020)
Ta slovenski standard je istoveten z: prEN ISO 11426
ICS:
39.060 Nakit Jewellery
oSIST prEN ISO 11426:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 11426:2020
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oSIST prEN ISO 11426:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 11426
ISO/TC 174 Secretariat: DIN
Voting begins on: Voting terminates on:
2020-08-25 2020-11-17
Jewellery and precious metals — Determination of gold —
Cupellation method (fire assay)
ICS: 39.060
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 11426:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
---------------------- Page: 3 ----------------------
oSIST prEN ISO 11426:2020
ISO/DIS 11426:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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 2020 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 11426:2020
ISO/DIS 11426:2020(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents . 2
6 Apparatus . 2
7 Sampling . 3
8 Procedure. 3
8.1 Method selection . 3
8.2 General method . 3
8.2.1 Assay samples . 3
8.2.2 Proof samples . 4
8.2.3 Cupellation and treatment of precious metal buttons . 4
8.2.4 Parting of the silver/gold samples . 4
8.2.5 Parting in individual flasks. 4
8.2.6 Parting in a basket . 4
8.3 Sample with large amount of base metals. 5
8.4 Sample containing platinum or palladium. 5
8.5 Sample with a silver/gold ratio higher than 3 . 5
9 Calculation and expression of results . 6
9.1 Proof sample factor . 6
9.2 Calculation of gold content . 6
9.3 Repeatability . 6
10 Test report . 6
Annex A (informative) Concentration of other metals, affecting the gold result .8
Bibliography . 9
© ISO 2020 – All rights reserved iii
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oSIST prEN ISO 11426:2020
ISO/DIS 11426:2020(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 174, Jewellery and precious metals.
This fourth edition cancels and replaces the third edition (ISO 11426:2014), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Extension of the scope to cover determination of gold in multiple types of alloys, not only in
jewellery ones;
— Purity of proof samples was re-defined in 5;
— Specific procedures are described in 8 for samples with large amount of base metals, containing
platinum or palladium, or with a silver/gold ratio higher than 3;
— Calculation were adapted to take into account the addition of fine gold and the fineness of the gold
used in the proof;
— Repeatability requirements were changed;
— The use of scorification was removed.
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.
iv © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST prEN ISO 11426:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 11426:2020(E)
Jewellery and precious metals — Determination of gold —
Cupellation method (fire assay)
1 Scope
This document specifies a cupellation method (fire assay) for the determination of gold on a material
considered homogeneous. The gold content of the sample should preferably lie between 100 and
999,5 parts per thousand (‰). Finenesses above 999,5 ‰ can be determined using a spectroscopy
method by difference (e.g. ISO 15093).
The procedure is applicable to most types of gold samples. Some modifications are indicated for specific
cases (presence of large amount of base metals, platinum or palladium, silver). It is not compatible with
the presence above trace levels of iridium, rhodium and ruthenium (more than 0.25 ‰ for the sum of
all three elements).
This method is also intended to be used as the recommended method for the determination of fineness
in jewellery alloys covered by ISO 9202.
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 15093, Jewellery and precious metals — Determination of high purity gold, platinum and palladium —
Difference method using ICP-OES
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 http:// www .electropedia .org/
3.1
cornet
alloy of gold and precious metals shaped in a roll, prior the parting process
3.2
gold cornet
gold shaped in a roll, after the parting process
3.3
parting
separation of silver and other metals from gold by digestion of those metals with nitric acid, in a
chloride-free environment
3.4
proof sample
synthetic reference sample whose composition is as similar as possible to the sample; cupellation of the
proof sample is performed together with the sample, and its result is used to correct the final assay
© ISO 2020 – All rights reserved 1
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oSIST prEN ISO 11426:2020
ISO/DIS 11426:2020(E)
3.5
inquartation
addition of silver to gold alloys in a specific ratio in order to enable the parting of gold from silver by
means of nitric acid
4 Principle
The gold alloys are inquarted with silver, compounded with lead and cupelled in a cupellation furnace
until a
...
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