EN ISO 11427:2024

Jewellery and precious metals - Determination of silver - Potentiometry using potassium bromide (ISO 11427:2024)

This document specifies a volumetric method for the determination of silver on a material considered homogeneous. The silver content of the sample lies preferably between (100 and 999,0) parts per thousand (‰) by mass. Fineness above 999,0 ‰ can be determined using a spectroscopy method by difference (e.g. ISO 15096).
This method is intended to be used as the reference method for the determination of fineness in alloys covered by ISO 9202.

Schmuck und Edelmetalle - Bestimmung von Silber - Potentiometrie unter Verwendung von Kaliumbromid (ISO 11427:2024)

Joaillerie, bijouterie et métaux précieux - Dosage de l’argent - Méthode potentiométrique utilisant le bromure de potassium (ISO 11427:2024)

Le présent document spécifie une méthode volumétrique de dosage de l'argent sur un matériau considéré comme homogène. La teneur en argent des échantillons est de préférence comprise entre 100 et 999,0 millièmes (‰) en masse. Les titres supérieurs à 999,0 ‰ peuvent être déterminés à l’aide d’une méthode de spectroscopie par différence (par exemple, ISO 15096).
Cette méthode est destinée à être utilisée comme méthode de référence pour la détermination du titre dans les alliages couverts par l’ISO 9202.

Nakit in plemenite kovine - Določevanje srebra v zlitinah srebra - Potenciometrična metoda z uporabo kalijevega bromida (ISO 11427:2024)

Ta dokument določa volumetrično metodo za določevanje srebra v materialu, ki se šteje za homogenega. Vsebnost srebra v vzorcu bi morala biti med 100 in 999,0 delov na tisoč (‰) glede na maso. Finost nad 999,0 ‰ je mogoče določiti z metodo spektroskopije glede na razlike (npr. ISO 15096).
Metoda je namenjena za uporabo kot referenčna metoda za določanje finosti v zlitinah, zajetih v standardu ISO 9202.

General Information

• Status: Published
• Publication Date: 16-Apr-2024
• ICS: 39.060 - Jewellery
• Technical Committee: CEN/TC 410 - Project Committee - Consumer confidence and nomenclature in the diamond industry
• Drafting Committee: CEN/SS M21 - Precious metals - Applications in jewellery and associated products
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 17-Apr-2024
• Completion Date: 17-Apr-2024
• Ref Project: SIST EN ISO 11427:2024 - Jewellery and precious metals - Determination of silver in silver alloys - Potentiometry using potassium bromide (ISO 11427:2024)

Relations

• Replaces: EN ISO 11427:2016 - Jewellery - Determination of silver in silver jewellery alloys - Volumetric (potentiometric) method using potassium bromide (ISO 11427:2014)
• Effective Date: 28-Jan-2023

Overview

EN ISO 11427:2024, titled Jewellery and precious metals - Determination of silver - Potentiometry using potassium bromide, is the latest international standard published by CEN for the precise volumetric analysis of silver content in homogeneous materials. This method is applicable for silver fineness ranging from 100 to 999 parts per thousand (‰) by mass. It replaces the 2016 edition, offering refinements such as extending the measurement scope and updating reagent purity requirements. The standard defines potentiometric titration using potassium bromide as the reference method for determining silver fineness in precious metal alloys, aligning with ISO 9202.

Key Topics

• Volumetric Determination Method
  The method involves dissolving the sample in dilute nitric acid followed by titration with a potassium bromide solution. The equivalence point is potentiometrically indicated using silver bromide-coated electrodes.

• Sample Scope
  Suitable for homogeneous materials containing silver from 100‰ up to 999‰ by mass. For fineness levels above 999‰, alternative spectroscopy-based methods, such as ISO 15096, are recommended.

• Reagents and Preparation
  Reagents include nitric acid with low halide content, a 0.1 mol/L potassium bromide standard solution, and disodium dimethylglyoxime for palladium precipitation. High purity reference silver (≥ 999.9‰, with oxygen < 100 mg/kg) is required for calibration.

• Apparatus Requirements
  The standard describes the use of motor-driven burettes linked to a potentiometer or automatic titrator capable of delivering 0.05 ml increments, combination silver electrodes, and high-accuracy analytical balances.

• Measurement Precision and Calculation
  The standard mandates precise determination of the potassium bromide solution factor with repeated titrations, ensuring repeatability within 0.05% relative difference. Results are calculated based on the volume of titrant at the equivalence point and the standard solution factor.

• Interference Management
  Palladium interference is eliminated by precipitation before titration. Other alloying elements do not affect the potentiometric determination.

Applications

EN ISO 11427:2024 is essential for:

• Jewellery and Precious Metals Industry
  Ensures accurate assessment of silver content in hallmarking, quality control, and certification processes within jewelry manufacturing and precious metals trading.

• Quality Assurance Laboratories
  Analytical labs measuring silver content in alloys and verifying compliance with commercial and regulatory fineness declarations.

• Regulatory Compliance
  Supports national and international standards compliance linked to silver fineness, contributing to consumer confidence and product traceability in precious metals markets.

• Research and Development
  Enables precise quantification of silver content during alloy development or when testing new production batches.

Related Standards

• ISO 15096 – Spectroscopic determination of fineness for silver above 999‰
  A complementary spectroscopy-based method recommended for determining silver fineness exceeding 999‰ when potentiometry is not suitable.

• ISO 9202 – Jewellery and precious metals – Fineness determination in alloys
  EN ISO 11427:2024 serves as the reference method for alloys covered under this standard.

• ISO 11596 – Sampling procedures for precious metals
  Specifies proper sampling methods to ensure representative analysis using the volumetric potentiometric technique.

Summary

EN ISO 11427:2024 is a critical standard for the reliable and repeatable determination of silver content in jewelry and precious metal alloys. By employing potentiometry with potassium bromide titration, it provides an accurate volumetric approach for silver fineness measurement up to 999‰. This method supports quality control, regulatory compliance, and industry transparency, making it an indispensable reference for laboratories and manufacturers working with precious metals. The standard’s integration with other ISO standards further strengthens its application across sampling, measurement, and specification of silver alloys.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2024
Nakit in plemenite kovine - Določevanje srebra v zlitinah srebra - Potenciometrična
metoda z uporabo kalijevega bromida (ISO 11427:2024)
Jewellery and precious metals - Determination of silver in silver alloys - Potentiometry
using potassium bromide (ISO 11427:2024)
Schmuck und Edelmetalle - Bestimmung von Silber in Silberlegierungen - Potentiometrie
unter Verwendung von Kaliumbromid (ISO 11427:2024)
Joaillerie, bijouterie et métaux précieux - Dosage de l’argent dans les alliages d’argent -
Méthode potentiométrique utilisant le bromure de potassium (ISO 11427:2024)
Ta slovenski standard je istoveten z: EN ISO 11427:2024
ICS:
39.060 Nakit Jewellery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11427
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2024
EUROPÄISCHE NORM
ICS 39.060 Supersedes EN ISO 11427:2016
English Version
Jewellery and precious metals - Determination of silver -
Potentiometry using potassium bromide (ISO
11427:2024)
Joaillerie, bijouterie et métaux précieux - Dosage de Schmuck und Edelmetalle - Bestimmung von Silber in
l'argent - Méthode potentiométrique utilisant le Silberlegierungen - Potentiometrie unter Verwendung
bromure de potassium (ISO 11427:2024) von Kaliumbromid (ISO 11427:2024)
This European Standard was approved by CEN on 7 July 2023.

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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11427:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11427:2024) has been prepared by Technical Committee ISO/TC 174 "Jewellery
and precious metals" in collaboration with Technical Committee CEN/TC 410 “Jewellery and precious
metals” 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 October 2024, and conflicting national standards shall
be withdrawn at the latest by October 2024.
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 11427:2016.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. 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 11427:2024 has been approved by CEN as EN ISO 11427:2024 without any modification.

International
Standard
ISO 11427
Third edition
Jewellery and precious
2024-04
metals — Determination of
silver — Potentiometry using
potassium bromide
Joaillerie, bijouterie et métaux précieux — Dosage de l’argent —
Méthode potentiométrique utilisant le bromure de potassium
Reference number
ISO 11427:2024(en) © ISO 2024
ISO 11427:2024(en)
© ISO 2024
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 11427:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 1
6 Apparatus . 2
7 Sampling . 2
8 Procedure . 2
8.1 Determination of potassium bromide solution factor .2
8.1.1 General .2
8.1.2 Preparation of silver standards .2
8.1.3 Titration of the standard silver solution .2
8.1.4 Calculation of the potassium bromide standard solution factor .3
8.2 Determination .3
8.2.1 Preparation of the sample solution .3
8.2.2 Elimination of palladium .3
8.2.3 Titration of the sample solution .3
9 Calculation and expression of results . 3
9.1 Calculation .3
9.2 Repeatability .4
10 Test report . 4
Bibliography . 5

iii
ISO 11427:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies).
...