EN ISO 16968:2015

Solid biofuels - Determination of minor elements (ISO 16968:2015)

ISO 16968:2015 is intended for the determination of the minor elements Arsenic, Cadmium, Cobalt, Chromium, Copper, Mercury, Manganese, Molybdenum, Nickel, Lead, Antimony, Vanadium, and Zinc in all solid biofuels. Further, it describes methods for sample decomposition and suggests suitable instrumental methods for the determination of the elements of interest in the digests. The determination of other elements such as Selenium, Tin, and Thallium is also possible with the method described in this International Standard.

Biogene Festbrennstoffe - Bestimmung von Spurenelementen (ISO 16968:2015)

Diese Internationale Norm dient der Bestimmung der Spurenelemente Arsen, Cadmium, Cobalt, Chrom, Kupfer, Quecksilber, Mangan, Molybdän, Nickel, Blei, Antimon, Vanadium und Zink in allen biogenen Festbrennstoffen. Außerdem sind Verfahren für den Probenaufschluss beschrieben und es werden geeignete instrumentelle Verfahren für die Bestimmung der interessierenden Elemente in den Aufschlussprodukten vorgeschlagen. Die Bestimmung von anderen Elementen, wie z. B. Selen, Zinn und Thallium, ist mit dem in dieser Internationalen Norm beschriebenen Verfahren auch möglich.

Biocombustibles solides - Détermination des éléments mineurs (ISO 16968:2015)

L'ISO 16968:2015 est applicable au dosage des éléments mineurs suivants dans tous les biocombustibles solides: arsenic, cadmium, cobalt, chrome, cuivre, mercure, manganèse, molybdène, nickel, plomb, antimoine, vanadium et zinc. De plus, elle décrit des méthodes de décomposition des échantillons et suggère des méthodes instrumentales appropriées pour le dosage des éléments à étudier dans les minéralisats. La méthode décrite dans l'ISO 16968:2015 peut également être utilisée pour le dosage d'autres éléments tels que le sélénium (Se), l'étain (Sn) et le thallium (TI).

Trdna biogoriva - Določevanje mikro elementov (ISO 16968:2015)

Ta mednarodni standard je namenjen določanju stranskih elementov As, Ca, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, V in Zn v vseh trdnih biogorivih. Nadalje opisuje metode za razkrajanje vzorcev in predlaga primerne instrumentalne metode za določanje elementov, ki so predmet zanimanja pri razkrajanju. Z uporabo metode, opisane v tem mednarodnem standardu, je možno tudi določanje drugih elementov, kot na primer Se, Ti in Th.

General Information

• Status: Published
• Publication Date: 26-May-2015
• Withdrawal Date: 29-Nov-2015
• ICS: 75.160.10 - Solid fuels
• ICS: 75.160.40 - Biofuels
• Technical Committee: CEN/TC 335 - Solid biofuels
• Drafting Committee: CEN/TC 335 - Solid biofuels
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 27-May-2015
• Completion Date: 27-May-2015
• Directive: 2000/76/EC - Directive 2000/76/EC of the European Parliament and of the Council of 4 December 2000 on the incineration of waste
• Mandate: M/298 - Mandate to CEN for standardisation in the field of solid biofuels
• Ref Project: SIST EN ISO 16968:2015 - Solid biofuels - Determination of minor elements (ISO 16968:2015)

Relations

• Replaces: EN 15297:2011 - Solid biofuels - Determination of minor elements - As, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, V and Zn
• Effective Date: 08-Jun-2015

Overview

EN ISO 16968:2015 - Solid biofuels: Determination of minor elements specifies wet-chemical and instrumental approaches for measuring trace or minor elements in all solid biofuels. It covers the determination of As, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, V, Zn and notes that Se, Sn, Tl can also be measured using the described methods. The standard describes sample decomposition (closed‑vessel digestion with HNO3, H2O2 and HF) and recommends suitable instrumental techniques for analysis.

Key topics and requirements

• Scope of elements: Arsenic, Cadmium, Cobalt, Chromium, Copper, Mercury, Manganese, Molybdenum, Nickel, Lead, Antimony, Vanadium, Zinc; other elements (Se, Sn, Tl) possible.
• Sample decomposition: Closed‑vessel digestion (fluoropolymer vessels) using nitric acid, hydrogen peroxide and hydrofluoric acid, heated in a microwave oven or resistance heating block.
• Analytical methods suggested: ICP‑OES, ICP‑MS, GF‑AAS, CV‑AAS, HG‑AAS; alternative methods (XRF, direct mercury analysers) may be used if validated with appropriate biomass reference materials.
• Quality assurance:
  • Use of Certified Reference Materials (CRM/SRM) to check accuracy and calibration.
  • If reagent blanks exceed ~30% of measured value, investigate ultra‑pure reagents and contamination control.
  • Calibration with multiple CRMs may be required to address matrix effects or concentration-range limitations.
• Safety note: Hydrofluoric acid (HF) is hazardous - appropriate safety and handling procedures are mandatory.
• Supporting procedures: Includes guidance on digestion, detection, calibration, blank testing, calculations, and reporting; performance characteristics and example data are provided in informative annexes.

Applications and users

EN ISO 16968:2015 is practical for:

• Laboratories performing trace element analysis of biomass and solid biofuels.
• Biomass fuel producers and power plants needing fuel quality control, combustion performance and ash management data.
• Environmental and regulatory bodies monitoring toxic element content (e.g., cadmium, mercury) for compliance and safe ash recycling (fertiliser use).
• Research groups studying element uptake in energy crops, pollution transfer, and lifecycle/environmental impacts.

Benefits include improved data comparability, robust QA/QC using CRMs, and methods suitable for low‑level trace element detection in complex biomass matrices.

Related standards (selection)

• ISO 11885 - ICP‑OES methods
• ISO 17294‑2 - ICP‑MS application
• ISO 17378‑2 - HG‑AAS for As and Sb
• ISO 16559 - Solid biofuels terminology
• ISO 16993 - Conversion of analytical results between bases
• EN 14780 - Sample preparation for solid biofuels
• ISO 17225‑1 - Typical concentrations in solid biofuels

Keywords: EN ISO 16968:2015, solid biofuels, minor elements, trace elements, microwave digestion, ICP‑MS, ICP‑OES, certified reference material, mercury, arsenic, cadmium.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2015
1DGRPHãþD
SIST EN 15297:2011
7UGQDELRJRULYD'RORþHYDQMHPLNURHOHPHQWRY,62
Solid biofuels - Determination of minor elements (ISO 16968:2015)
Biogene Festbrennstoffe - Bestimmung von Spurenelementen (ISO 16968:2015)
Biocombustibles solides - Détermination des éléments mineurs (ISO 16968:2015)
Ta slovenski standard je istoveten z: EN ISO 16968:2015
ICS:
27.190 Biološki viri in drugi Biological sources and
alternativni viri energije alternative sources of energy
75.160.10 Trda goriva Solid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 16968
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2015
ICS 75.160.10 Supersedes EN 15297:2011
English Version
Solid biofuels - Determination of minor elements (ISO
16968:2015)
Biocombustibles solides - Détermination des éléments Biogene Festbrennstoffe - Bestimmung von
mineurs (ISO 16968:2015) Spurenelementen (ISO 16968:2015)
This European Standard was approved by CEN on 14 February 2015.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16968:2015 E
worldwide for CEN national Members.

Contents
Page
Foreword .3

Foreword
This document (EN ISO 16968:2015) has been prepared by Technical Committee ISO/TC 238 “Solid biofuels”
in collaboration with Technical Committee CEN/TC 335 “Solid biofuels” the secretariat of which is held by SIS.
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 November 2015, and conflicting national standards shall be withdrawn
at the latest by November 2015.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 15297:2011.
This document has been prepared under a mandate given to CENELEC by the European Commission and
the European Free Trade Association.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 16968:2015 has been approved by CEN as EN ISO 16968:2015 without any modification.
INTERNATIONAL ISO
STANDARD 16968
First edition
2015-05-15
Solid biofuels — Determination of
minor elements
Biocombustibles solides — Détermination des éléments mineurs
Reference number
ISO 16968:2015(E)
©
ISO 2015
ISO 16968:2015(E)
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
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Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

ISO 16968:2015(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
4.1 Symbols . 2
4.2 Abbreviated terms . 2
5 Principle . 3
6 Reagents . 3
7 Apparatus . 4
8 Preparation of the test sample . 4
9 Procedure. 4
9.1 Digestion. 4
9.2 Detection methods . 5
9.3 Calibration of the apparatus . 5
9.4 Analysis of the digests . 5
9.5 Blank test . 5
10 Calculations. 6
11 Performance characteristics . 6
12 Test report . 6
Annex A (informative) Performance data . 7
Bibliography .11
ISO 16968:2015(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT), see the following URL: Foreword — Supplementary information.
ISO 16968 was prepared by the European Committee for Standardization (CEN) in collaboration
with Technical Committee ISO/TC 238, Solid biofuels, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
iv © ISO 2015 – All rights reserved

ISO 16968:2015(E)
Introduction
The minor elements present in solid biofuels can, in some cases, be of environmental concern, e.g. it
has been shown that certain energy crops will concentrate cadmium and, in polluted areas, other toxic
elements may be found at elevated concentrations in the biofuels. This can be a problem if, for example,
the ash from the combustion is to be put back in the forest as a fertilizer. Trace elements in biofuels are
often present at very low concentrations requiring great care to avoid contamination in the sample
preparation and decomposition steps. The typical concentrations of minor elements in solid biofuels can
be found in ISO 17225-1. In this International Standard, wet chemical methods are described. Alternative
methods such as X-ray fluorescence (XRF) or direct mercury analysers may be used when validated
with suitable materials (biomass reference materials).
INTERNATIONAL STANDARD ISO 16968:2015(E)
Solid biofuels — Determination of minor elements
1 Scope
This International Standard is intended for the determination of the minor elements Arsenic, Cadmium,
Cobalt, Chromium, Copper, Mercury, Manganese, Molybdenum, Nickel, Lead, Antimony, Vanadium, and
Zinc in all solid biofuels. Further, it describes methods for sample decomposition and suggests suitable
instrumental methods for the determination of the elements of interest in the digests. The determination
of other elements such as Selenium, Tin, and Thallium is also possible with the method described in this
International Standard.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 11885, Water quality — Determination of selected elements by inductively coupled plasma optical
emission spectrometry (ICP-OES)
ISO 16559, Solid biofuels — Terminology, definitions and descriptions
ISO 16993, Solid biofuels — Conversion of analytical results from one basis to another
ISO 17294-2, Water quality — Application of inductively coupled plasma mass spectrometry (ICP-MS) —
Part 2: Determination of 62 elements
ISO 17378-2:2014, Water quality — Determination of arsenic and antimony — Part 2: Method using hydride
generation atomic absorption spectrometry (HG-AAS)
1)
ISO 18134-3 , Solid biofuels — Determination of moisture content — Oven dry method — Part 3: Moisture
in general analysis simple
EN 14780, Solid Biofuels — Sample preparation
EN 12338, Water quality — Determination of mercury — Enrichment methods by amalgamation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16559 and the following apply.
3.1
reference material
RM
one or more material or substance of which property values are sufficiently homogeneous and well
established to be used for the calibration of an apparatus, assessment of a measurement method, or
assignment of values to materials
1) To be published.
ISO 16968:2015(E)
3.2
certified reference material
CRM
reference material, accompanied by a certificate, one or more of which property values are certified
by a procedure that establishes traceability to an accurate realisation of the unit in which the property
values are expressed, and for which each certified value is accompanied by an uncertainty at a stated
level of confidence
3.3
NIST standard reference material
SRM
CRM issued by NIST that also meets additional NIST-specific certification criteria and is issued with
a certificate or certificate of analysis that reports the results of its characterisations and provides
information regarding the appropriate use(s) of the material
4 Symbols and abbreviated terms
4.1 Symbols
As Arsenic
Cd Cadmium
Co Cobalt
Cr Chromium
Cu Copper
...