prEN ISO 11494

• Abstract:

  This document describes an analytical procedure for the determination of platinum in platinum alloys with a nominal content up to 990 ‰ (parts per thousand), including alloys according to ISO 9202.

• Status: Not Published
• Publication Date: 17-Jan-2028
• ICS: 39.060 - Jewellery
• Technical Committee: CEN/TC 410 - Project Committee - Consumer confidence and nomenclature in the diamond industry
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 30-Jul-2026
• Completion Date: 30-Jul-2026
• Ref Project: oSIST prEN ISO 11494:2026 - Jewellery and precious metals - Determination of platinum - ICP-OES method using an internal standard element (ISO/DIS 11494:2026)

• Revises: EN ISO 11494:2019 - Jewellery and precious metals - Determination of platinum in platinum alloys - ICP-OES method using an internal standard element (ISO 11494:2019)
• Effective Date: 18-Jun-2025

prEN ISO 11494 is a CEN and ISO document for determining platinum in jewellery and precious metals. It specifies an ICP-OES method using an internal standard element for homogeneous platinum alloys with nominal platinum content up to 990 ‰, including alloys according to ISO 9202.

What does prEN ISO 11494 specify?

prEN ISO 11494 specifies an analytical procedure for platinum in platinum alloys, with preferred applicability from 50 ‰ to 990 ‰ by mass. For fineness above 990.0 ‰, the document points to ISO 15093 for the difference method.

The standard is organized into clauses for scope, references, terms, principle, reagents, equipment, sampling, procedure, calculation and expression of results, repeatability, and test report.

Annex	What it covers
Annex A	Technical background for ICP-OES and instrument setup
Annex B	Interlaboratory testing data used to confirm performance

What are the key requirements of prEN ISO 11494?

prEN ISO 11494 requires a controlled ICP-OES comparison between sample solutions and calibration solutions, using an internal standard and bracketing. In practice, this means the laboratory must prepare matched solutions carefully, run them in a defined sequence, and calculate platinum from intensity ratios.

Sampling and sample preparation

Clause 7 calls for sampling in accordance with ISO 11596. Clause 8 requires at least two accurately weighed samples to be dissolved in aqua regia and brought to an exactly weighed mass, then mixed with a fixed amount of internal standard before measurement.

For alloys containing ruthenium, rhodium, iridium, or tungsten, the document calls for minor changes to the preparation. This matters because these elements can change dissolution behavior and spectral performance.

Reagents and equipment

Clause 5 limits the analysis to analytical-grade reagents and platinum-free water, except for platinum itself. Clause 6 requires an ICP-OES instrument able to measure platinum and the internal standard simultaneously with at least 0.02 nm optical resolution, plus a balance with 0.01 mg readability.

Calibration and measurement

Clause 8.2 uses two calibration standards for bracketing, while a set of at least three standards is recommended to check linearity. Clause 8.4 requires a preliminary calibration check with regression coefficient above 0.9999, at least 3 bracketing cycles, 60 s stabilization, at least 15 s integration, and at least three integrations per solution.

Internal standard handling

Clause 8.1 sets the internal standard solution at about 300 mg/l for In, Lu, or Ge, or about 100 mg/l for Sc or Y, with adjustment allowed for instrument sensitivity. This reduces drift and matrix effects, so the platinum result depends less on small instrument changes.

Calculation and acceptance

Clause 9 bases the result on corrected intensity quotients and the two calibration points nearest the sample. The mean of the three measuring cycles must have an RSD not larger than 0.30 %, and duplicate determinations must differ by less than 3 ‰ for platinum.

Test reporting

Clause 10 requires the report to identify the sample, sampling procedure, method reference, platinum content as single values and mean values, deviations, unusual features, test date, laboratory identification, and signatures. That gives traceability for purchasing, quality control, and dispute handling.

What terms does prEN ISO 11494 define?

• Calibration solution - A solution used to calibrate the instrument, prepared from stock solution or certified reference material with added acids, buffer, reference elements, and salt as needed.
• Bracketing - A measurement approach in which the sample signal is bracketed by two calibration solutions of neighboring concentrations.
• Laboratory sample - The sample intended for laboratory inspection or testing.
• Test portion - The portion taken from the laboratory sample for the actual analysis.
• Test sample solution - The solution prepared after extraction or digestion of the test sample.
• Internal standard - A fixed-added compound with similar behavior to the analyte, used to correct drift and matrix interference.
• Linearity - A straight-line relationship between mean measurement result and analyte concentration.
• Linear calibration curve - The expression of the relation between instrument indication and measured quantity value.

Who uses prEN ISO 11494?

prEN ISO 11494 is used by analytical laboratories, precious-metal assayers, and quality control teams in jewellery and precious metals. It supports platinum alloy verification, incoming material checks, process control, and reporting platinum content in parts per thousand by mass.

What changed in prEN ISO 11494 from the previous edition?

prEN ISO 11494 is described as the third edition and it cancels and replaces ISO 11494:2014. The stated changes include:

• removal of the definition of bracketing in Clause 3
• removal of recommended lines in Clause 4
• updated reagents and internal standard requirements
• changed preparation of the internal standard solution
• revised calibration and sample preparation, including removal of aliquot preparation
• added detail on acids for pressure dissolution
• added bracketing and recommended lines in 8.4
• adapted calculation formulae
• removal of emission line information from the test report
• editorial revision

Which standards are used with prEN ISO 11494?

• ISO 11596 - Provides the sampling procedure for precious metals and precious metal alloys.
• ISO 15093 - Gives the difference method used for platinum fineness above 990.0 ‰.
• ISO 19376-1 - Supplies the vocabulary for precious metals and units, including several terms used in this document.
• EN ISO 1042 - Supports the use of grade A one-mark volumetric flasks.

What does the prEN ISO 11494 document contain?

prEN ISO 11494 contains the full analytical workflow: principle, reagent list, equipment list, sampling, solution preparation, ICP-OES measurement, calculation, repeatability, and reporting. It also gives a recommended wavelength table for platinum and several internal standard elements, so the user can select lines and check spectral interference.

Annex A explains the ICP-OES instrument background, including the sample introduction system, plasma, optical system, detector, and viewing geometry. Annex B presents interlaboratory testing results that support the method’s repeatability and reproducibility claims.

SLOVENSKI STANDARD
01-oktober-2026
Nakit in plemenite kovine - Določanje platine - Metoda ICP-OES z uporabo
notranjega standardnega elementa (ISO/DIS 11494:2026)
Jewellery and precious metals - Determination of platinum - ICP-OES method using an
internal standard element (ISO/DIS 11494:2026)
Schmuck und Edelmetalle - Bestimmung von Platin - ICP-OES-Verfahren unter
Verwendung eines internen Standardelements (ISO/DIS 11494:2026)
Joaillerie, bijouterie et métaux précieux - Dosage du platine - Méthode par ICP-OES
utilisant un étalon interne (ISO/DIS 11494:2026)
Ta slovenski standard je istoveten z: prEN ISO 11494
ICS:
39.060 Nakit Jewellery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 11494
ISO/TC 174
Jewellery and precious metals —
Secretariat: DIN
Determination of platinum — ICP-
Voting begins on:
OES method using an internal
2026-07-28
standard element
Voting terminates on:
2026-10-20
Joaillerie, bijouterie et métaux précieux — Dosage du platine —
Méthode par ICP-OES utilisant un étalon interne
ICS: 39.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
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POTENTIAL TO BECOME STANDARDS TO
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NATIONAL REGULATIONS.
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NOTIFICATION OF ANY RELEVANT PATENT
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Reference number
ISO/DIS 11494:2026(en)
DRAFT
ISO/DIS 11494:2026(en)
International
Standard
ISO/DIS 11494
ISO/TC 174
Jewellery and precious metals —
Secretariat: DIN
Determination of platinum — ICP-
Voting begins on:
OES method using an internal
standard element
Voting terminates on:
Joaillerie, bijouterie et métaux précieux — Dosage du platine —
Méthode par ICP-OES utilisant un étalon interne
ICS: 39.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
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WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
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RECIPIENTS OF THIS DRAFT ARE INVITED
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TO SUBMIT, WITH THEIR COMMENTS,
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NOTIFICATION OF ANY RELEVANT PATENT
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 11494:2026(en)
ii
ISO/DIS 11494:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents . 2
6 Equipment . 3
7 Sampling . 3
8 Procedure . 3
8.1 Internal standard solution .3
8.2 Calibration solutions .3
8.3 Sample solutions .4
8.3.1 Preparation of the platinum alloy solution containing ruthenium, iridium or
tungsten .4
8.4 Measurement .4
9 Calculation and expression of results . 5
9.1 Calculation .5
9.2 Repeatability .7
10 Test report . 7
Annex A (informative) Technical background for ICP -OES (inductively coupled argon plasma
optical emission spectrometer) . . 8
Annex B (informative) Interlaboratory testing . 9
Bibliography .10

iii
ISO/DIS 11494:2026(en)
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/TC 410,
Jewellery and precious metals in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 11494:2014), which has been technically
revised.
The main changes compared to the previous edition are as follows:
a) the definition of bracketing in Clause 3 has been removed;
b) the recommended lines in Clause 4 have been removed;
c) reagents and the requirements about internal standard element have been updated;
d) the preparation of the internal standard solution in 8.1 has been changed;
e) the list of standards to be prepared and precisions about qualification of them by linearity as well as
way to choose the low and high standards in 8.2 have been changed;
f) the way of preparation by aliquots for both standard and sample solutions in 8.2 and 8.3 has been
removed;
g) the preparation of both standard and sample solutions in 8.2 and 8.3 has been changed;
h) precisions about quantity of acids to be used in case of dissolution under pressure have been added;
i) the definition of bracketing and recommended lines in 8.4 have been added;
j) the formulae in 9.1 after having removed the way of preparation by aliquots have been adapted;
k) the emission line as information to be mentioned in the test report in Clause 10 has been removed;
l) the document has been editorially revised.

iv
ISO/DIS 11494:2026(en)
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.

v
DRAFT International Standard ISO/DIS 11494:2026(en)
Jewellery and precious metals — Determination of platinum
— ICP-OES method using an internal standard element
1 Scope
This document specifies an analytical method for the determination of platinum on a material considered
homogeneous. The platinum content of the samples lies preferably between 50 ‰ (parts per thousand by
mass) and 990 ‰ (parts per thousand by mass). Fineness above 990,0 ‰ (parts per thousand by mass) can
be determined using a spectroscopy method by difference ISO 15093.
NOTE Lower contents of platinum can be analysed referring to this 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 11596, Jewellery and precious metals — Sampling of precious metals and precious metal alloys
ISO 15093, Jewellery and precious metals — Determination of high purity gold, platinum and palladium —
Difference method using ICP-OES
ISO 19376-1, Jewellery and precious metals — Vocabulary — Part 1: Precious metals and units
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
calibration solution
solution used to calibrate the instrument, prepared from stock solution or solution prepared with certified
reference material by adding acid, buffer, reference elements and salt as needed
3.2
bracketing
analytical method consisting of bracketing the measured emission line intensity of the sample between two
measurements made on calibration solutions of neighbouring concentrations within the optimum working
range
Note 1 to entry: Running of standards and samples in the following sequence: low standard – sample – high standard –
sample – low standard – sample – high standard …
[SOURCE: ISO 19376-1, 3.3.7]
3.3
laboratory sample
sample intended for laboratory inspection or testing

ISO/DIS 11494:2026(en)
3.4
test portion
portion of material, resulting from the laboratory sample by means of an appropriate method of sample
pretreatment, and having the size (volume/mass) necessary for the desired testing or analysis
[SOURCE: ISO 19376-1:2025, identical]
3.5
test sample solution
solution prepared after extraction or digestion of the test sample according to appropriate specification
3.6
internal standard
compound added to a sample in a fixed amount that has similar properties to the target analyte used to
correct for instrument drift and matrix interference
[SOURCE: ISO 19376-1, 3.3.8]
3.7
linearity
straight-line relationship between the mean result of measurement and the quantity (concentration) of the
analyte
3.8
linear calibration curve
expression of the relation between indication and corresponding measured quantity value
4 Principle
At least two accurately weighed samples are individually dissolved in aqua regia and made up to an exactly
weighed mass. These sample solutions are mixed with an exact amount of internal standard and made up to
the standard measuring volume.
Using ICP-OES, the platinum content of the sample solution is measured by comparison of the ratio intensities
of the spectral emission of platinum and appropriate internal standard line(s) with the ratio for solutions
containing known masses of platinum and internal standard using the bracketing method.
Minor modifications are required when the alloy contains ruthenium, rhodium, iridium, or tungsten.
5 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only
di
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