ISO/TS TECHNICAL SPECIFICATION 24672 First edition 2023-11 Nanotechnologies Guidance on the measurement of nanoparticle number concentration Nanotechnologies - Conseils pour la mesure de la concentration en nombre de nanoparticules Reference number IS0/TS24672:2023(E) Tso IS02023 IS0/TS 24672:2023(E) COPYRIGHT PROTECTED DOCUMENT @IS02023 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 or IsoO'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: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2023 - All rights reserved IS0/TS 24672:2023(E) @ Contents Page Foreword ..V Introduction. vi 1 Scope. .1 2 Normative references .1 3 Terms and definitions ..1 4 Abbreviated terms ..4 5 Overview. .5 5.1 General .5 5.2 Comparison of different techniques. .5 5.3 Considerations when selecting a technique 8 5.3.1 General ..8 5.3.2 Type of particles. 8 5.3.3 Number concentration range 9 5.3.4 Accuracy and precision. .9 5.3.5 Otherfactors 10 5.4 Unit for nanoparticle number concentration 10 6 Ensemble techniques. .11 6.1 Differential centrifugal sedimentation. 11 6.1.1 General 11 6.1.2 Sample specifications. 12 6.1.3 Technical aspects. 12 6.1.4 Sources of uncertainty and challenges 14 6.1.5 Outlook 15 6.2 Multi-angle dynamic light scattering 15 6.2.1 General 15 6.2.2 Sample specifications. .15 6.2.3 Technical aspects. 16 6.2.4 Sources of uncertainty and challenges 17 6.2.5 Outlook 17 6.3 Small-angle X-ray scattering 17 6.3.1 General 17 6.3.2 Sample specifications. 18 6.3.3 Technical aspects. 18 6.3.4 Sources of uncertainty and challenges 20 6.3.5 Outlook 20 6.4 Ultraviolet-visible spectroscopy 20 6.4.1 General 20 6.4.2 Sample specifications. 21 6.4.3 Technical aspects 21 6.4.4 Sources of uncertainty and challenges 22 6.4.5 Outlook 23 7 Particle counting techniques. .23 7.1 Particle tracking analysis .23 7.1.1 General 23 7.1.2 Sample specifications. 23 7.1.3 Technical aspects. 24 7.1.4 Sources of uncertainty and challenges. 24 7.1.5 Outlook 25 7.2 Resistive pulse sensing 25 7.2.1 General 25 7.2.2 Sample specifications. 26 7.2.3 Technical aspects. .27 @ IS0 2023 - All rights reserved iii IS0/TS 24672:2023(E) 7.2.4 Sources of uncertainty and challenges 28 7.2.5 Outlook 28 7.3 Single particle inductively coupled plasma mass spectrometry 28 7.3.1 General 28 7.3.2 Sample specifications. 29 7.3.3 Technical aspects. 29 7.3.4 Sources of uncertainty and challenges 33 7.3.5 Outlook 33 7.4 Condensation particle counter and differential mobility analysing system 34 7.4.1 General 34 7.4.2 Sample specifications. 34 7.4.3 Technicalaspects. 35 7.4.4 Sources of uncertainty and challenges 37 7.4.5 Outlook. 38 Annex A (informative) Summary of VAMAS international interlaboratory studies 40 Annex B (informative) General guidance on sample preparation for suspensions containing nanoparticles. 43 Bibliography 46 iv @ IS0 2023 - All rights reserved IS0/TS24672:2023(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 par