SIST EN ISO 3884:2025
(Main)Solid recovered fuels - Methods for the determination of the content of elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
Solid recovered fuels - Methods for the determination of the content of elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
This document specifies methods for the determination of major and minor element concentrations in solid recovered fuels after digestion by the use of different acid mixtures and by addition of a fluxing agent for solid recovered fuel (SRF) ash.
a) Method A: Microwave assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (6 ml HCl; 2 ml HNO3; 2 ml HF) followed by boric acid complexation;
b) Method AT: Microwave assisted digestion with hydrochloric, nitric and tetrafluoroboric acid mixture (6 ml HCl; 2 ml HNO3; 4 ml HBF4);
c) Method B: Microwave assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (0,5 ml HCl; 6 ml HNO3; 1 ml HF) followed by boric acid complexation;
d) Method BT: Microwave assisted digestion with hydrochloric, nitric and tetrafluoroboric acid mixture (0,5 ml HCl; 6 ml HNO3; 2 ml HBF4);
e) Method C: Microwave assisted digestion with nitric acid, hydrogen peroxide and hydrofluoric acid mixture (2,5 ml H2O2; 5 ml HNO3; 0,4 ml HF) and optional boric acid complexation;
f) Method CT: Microwave assisted digestion with nitric acid, hydrogen peroxide and tetrafluoroboric acid mixture (2,5 ml H2O2; 5 ml HNO3; 0,8 ml HBF4);
g) Method D: Digestion of the ashed SRF sample with fluxing agent lithium metaborate in an oven at 1 050 °C.
This document is applicable for the following major and minor/trace elements:
— Major elements: aluminium (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), sodium (Na), phosphorus (P), sulfur (S), silicon (Si) and titanium (Ti).
— Minor/trace elements: arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), molybdenum (Mo), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), tin (Sn), thallium (Tl), vanadium (V) and zinc (Zn).
Method A is applicable for general use for SRF and ashed SRFs, but the amount of the test portion can be very low in case of high concentration of organic matter. Method AT can be used if an alternative to HF is necessary.
Method B with a higher volume of nitric acid is applicable for SRFs with high organic matter (e.g. suitable for high plastic content) that can be difficult to digest with less nitric acid or as a substitute for method A if appropriate equipment is not available. Method BT can be used if an alternative to HF is necessary.
Method C with combination of nitric acid and hydrogen peroxide and addition of hydrofluoric acid is applicable for wood based SRFs (e.g. demolition wood) or when there is a need for comparability to solid biofuel standards. Method CT can be used if an alternative to HF is necessary.
Method D is specifically applicable for determination of major elements in ashed SRF samples.
XRF can be used for the analysis of major elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti) after ashing (815 °C) of the samples and several major and minor/trace elements in SRF can be analysed by XRF after suitable calibration provided that the concentration levels are above instrumental detection limits of the XRF instrumentation and after proper preliminary testing and validation.
Digestion methods with HF and subsequent boric acid complexation or application of method D are applicable for determination of Si and Ti (better digestion efficiency).
Alternative digestion methods can be applied, if their performance is proved to be comparable with those of the methods described in this document.
Feste Sekundärbrennstoffe - Verfahren zur Bestimmung des Gehaltes an Elementen (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
Combustibles solides de récupération - Méthodes de détermination de la teneur en éléments (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
Le présent document spécifie les méthodes pour la détermination des concentrations en éléments majeurs et mineurs dans les combustibles solides de récupération après digestion par l'utilisation de différents mélanges d'acides et par l'ajout d'un fondant pour la cendre de combustible solide de récupération (CSR).
a) Méthode A: Digestion assistée par micro-ondes avec un mélange d'acides chlorhydrique, nitrique et fluorhydrique (6 ml de HCl, 2 ml de HNO3 et 2 ml de HF) suivie d'une complexation de l'acide borique.
b) Méthode AT: Digestion assistée par micro-ondes avec un mélange d'acides chlorhydrique, nitrique et tétrafluoroborique (6 ml de HCl, 2 ml de HNO3 et 4 ml de HBF4).
c) Méthode B: Digestion assistée par micro-ondes avec un mélange d'acides chlorhydrique, nitrique et fluorhydrique (0,5 ml de HCl, 6 ml de HNO3 et 1 ml de HF) suivie d'une complexation de l'acide borique.
d) Méthode BT: Digestion assistée par micro-ondes avec un mélange d'acides chlorhydrique, nitrique et tétrafluoroborique (0,5 ml de HCl, 6 ml de HNO3 et 2 ml de HBF4).
e) Méthode C: Digestion assistée par micro-ondes avec un mélange d'acide nitrique, de peroxyde d'hydrogène et d'acide fluorhydrique (2,5 ml de H2O2, 5 ml de HNO3 et 0,4 ml de HF) et d'une complexation optionnelle de l'acide borique.
f) Méthode CT: Digestion assistée par micro-ondes avec un mélange d'acide nitrique, de peroxyde d'hydrogène et d'acide tétrafluoroborique (2,5 ml de H2O2, 5 ml de HNO3 et 0,8 ml de HBF4).
g) Méthode D: Digestion de l'échantillon de CSR réduit à l'état de cendres avec un fondant de type métaborate de lithium dans un four à 1 050 °C.
Le présent document s'applique aux éléments majeurs et mineurs/traces suivants:
— éléments majeurs: aluminium (Al), calcium (Ca), fer (Fe), potassium (K), magnésium (mg), sodium (Na), phosphore (P), soufre (S), silicium (Si) et titane (Ti);
— éléments mineurs/traces: arsenic (As), baryum (Ba), béryllium (Be), cadmium (Cd), cobalt (Co), chrome (Cr), cuivre (Cu), mercure (Hg), molybdène (Mo), manganèse (Mn), nickel (Ni), plomb (Pb), antimoine (Sb), sélénium (Se), étain (Sn), thallium (Tl), vanadium (V) et zinc (Zn).
La méthode A est applicable pour une utilisation générale pour les CSR et les CSR réduits à l'état de cendres, mais la quantité de la prise d'essai peut être très faible en cas de forte concentration de matière organique. La méthode AT peut être utilisée si une alternative au HF est nécessaire.
La méthode B, avec un volume d'acide nitrique plus important, est applicable pour les CSR à forte teneur en matière organique (teneur élevée en matières plastiques par exemple) qui peuvent être difficiles à digérer avec moins d'acide nitrique, ou comme substitut à la méthode A si l'équipement approprié n'est pas disponible. La méthode BT peut être utilisée si une alternative au HF est nécessaire.
La méthode C, une combinaison d'acide nitrique et de peroxyde d'hydrogène avec ajout d'acide fluorhydrique, est applicable pour les CSR à base de bois (bois de démolition, par exemple) ou lorsqu'il est nécessaire de les comparer aux normes relatives aux biocarburants solides. La méthode CT peut être utilisée si une alternative au HF est nécessaire.
La méthode D est applicable spécifiquement à la détermination des éléments majeurs dans les échantillons de CSR réduits à l'état de cendres.
La fluorescence de rayons X (XRF)peut être utilisée pour l'analyse des éléments majeurs (Al, Ca, Fe, K, Mg, Na, P, S
Trdna alternativna goriva - Metode za določanje glavnih elementov (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
Ta dokument določa metode za določanje koncentracij glavnih in stranskih elementov v trdnih alternativnih gorivih po razklopu z uporabo različnih kislinskih mešanic in z dodajanjem talila za pepel trdnih alternativnih goriv (SRF). a) Metoda A: razklop s pomočjo mikrovalovne pečice z mešanico klorovodikove, dušikove in fluorovodikove kisline (6 ml HCl; 2 ml HNO3; 2 ml HF), čemur sledi kompleksiranje z borovo kislino; b) metoda AT: razklop s pomočjo mikrovalovne pečice z mešanico klorovodikove, dušikove in tetrafluoroborove kisline (6 ml HCl; 2 ml HNO3; 4 ml HBF4); c) metoda B: razklop s pomočjo mikrovalovne pečice z mešanico klorovodikove, dušikove in fluorovodikove kisline (0,5 ml HCl; 6 ml HNO3; 1 ml HF), čemur sledi kompleksiranje z borovo kislino; d) metoda BT: razklop s pomočjo mikrovalovne pečice z mešanico klorovodikove, dušikove in tetrafluoroborove kisline (0,5 ml HCl; 6 ml HNO3; 2 ml HBF4); e) metoda C: razklop s pomočjo mikrovalovne pečice z mešanico dušikove kisline, vodikovega peroksida in fluorovodikove kisline (2,5 ml H2O2; 5 ml HNO3; 0,4 ml HF) ter izbirno kompleksiranje z borovo kislino; f) metoda CT: razklop s pomočjo mikrovalovne pečice z mešanico dušikove kisline, vodikovega peroksida in tetrafluoroborove kisline (2,5 ml H2O2; 5 ml HNO3; 0,8 ml HBF4); g) metoda D: razklop vzorca pepela trdnega alternativnega goriva s topilom – litijevim metaboratom v pečici pri 1050 °C. Ta dokument se uporablja za naslednje glavne in stranske elemente/elemente v sledovih: – glavni elementi: aluminij (Al), kalcij (Ca), železo (Fe), kalij (K), magnezij (Mg), natrij (Na), fosfor (P), žveplo (S), silicij (Si) in titan (Ti); – stranski elementi/elementi v sledovih: arzen (As), barij (Ba), berilij (Be), kadmij (Cd), kobalt (Co), krom (Cr), baker (Cu), živo srebro (Hg), molibden (Mo), mangan (Mn), nikelj (Ni), svinec (Pb), antimon (Sb), selen (Se), kositer (Sn), talij (Tl), vanadij (V) in cink (Zn). Metoda A je namenjena za splošno uporabo trdnih alternativnih goriv in pepela trdnih alternativnih goriv, vendar je lahko v primeru visoke koncentracije organskih snovi količina preskusnega deleža zelo nizka. Metodo AT je mogoče uporabiti, če je potrebna alternativa za vodikov fluorid. Metoda B z večjo količino dušikove kisline se uporablja za trdna alternativna goriva z visoko vsebnostjo organskih snovi (npr. primerna je za visoko vsebnost plastike), ki jih je težko razklopiti z manjšo količino dušikove kisline, ali kot nadomestek za metodo A, če ustrezna oprema ni na voljo. Metodo BT je mogoče uporabiti, če je potrebna alternativa za vodikov fluorid. Metoda C s kombinacijo dušikove kisline in vodikovega peroksida ter z dodajanjem fluorovodikove kisline se uporablja za trdna alternativna goriva na osnovi lesa (npr. odpadni gradbeni les) ali kadar je potrebna primerljivost s standardi za trdna biogoriva. Metodo CT je mogoče uporabiti, če je potrebna alternativa za vodikov fluorid. Metoda D se uporablja posebej za določanje glavnih elementov v vzorcih pepela trdnih alternativnih goriv. Rentgensko fluorescenčno spektroskopijo (XRF) je mogoče uporabiti za analizo glavnih elementov (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti) po sežiganju (815 °C) vzorcev, več glavnih in stranskih elementov/elementov v sledovih v trdnih alternativnih gorivih pa je mogoče analizirati z rentgensko fluorescenčno spektroskopijo po ustreznem umerjanju, pri čemer morajo biti ravni koncentracije nad mejami detekcije instrumentov za rentgensko fluorescenčno spektroskopijo, ter po ustreznem predhodnem preskušanju in potrjevanju. Za določanje elementov Si in Ti se uporabljajo metode razklopa z vodikovim fluorom in naknadnim kompleksiranjem z borovo kislino ali z uporabo metode D (boljša učinkovitost razklopa). Alternativne metode razklopa je mogoče uporabiti, če se izkaže, da je njihova učinkovitost primerljiva z učinkovitostjo metod, opisanih v tem dokumentu.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2025
Nadomešča:
SIST EN 15411:2011
Trdna alternativna goriva - Metode za določanje glavnih elementov (Al, Ca, Fe, K,
Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V,
Zn) (ISO 3884:2025)
Solid recovered fuels - Methods for the determination of the content of elements (Al, Ca,
Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn,
Tl, V, Zn) (ISO 3884:2025)
Feste Sekundärbrennstoffe - Verfahren zur Bestimmung des Gehaltes an Elementen (Al,
Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se,
Sn, Tl, V, Zn) (ISO 3884:2025)
Combustibles solides de récupération - Méthodes de détermination de la teneur en
éléments (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni,
Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
Ta slovenski standard je istoveten z: EN ISO 3884:2025
ICS:
75.160.10 Trda goriva Solid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 3884
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2025
EUROPÄISCHE NORM
ICS 75.160.10 Supersedes EN 15410:2011, EN 15411:2011
English Version
Solid recovered fuels - Methods for the determination of
the content of elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As,
Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V,
Zn) (ISO 3884:2025)
Combustibles solides de récupération - Méthodes de Feste Sekundärbrennstoffe - Verfahren zur
détermination de la teneur en éléments (Al, Ca, Fe, K, Bestimmung des Gehaltes an Elementen (Al, Ca, Fe, K,
Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn,
Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025) Ni, Pb, Sb, Se, Sn, Tl, V, Zn) (ISO 3884:2025)
This European Standard was approved by CEN on 18 April 2025.
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,
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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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3884:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 3884:2025) has been prepared by Technical Committee ISO/TC 300 " Solid
recovered materials, including solid recovered fuels " in collaboration with Technical Committee
CEN/TC 343 “Solid recovered materials, including solid recovered fuels” the secretariat of which is held
by SFS.
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 2025, and conflicting national standards shall
be withdrawn at the latest by October 2025.
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 15410:2011 and EN 15411:2011.
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 3884:2025 has been approved by CEN as EN ISO 3884:2025 without any modification.
International
Standard
ISO 3884
First edition
Solid recovered fuels — Methods for
2025-04
the determination of the content of
elements (Al, Ca, Fe, K, Mg, Na, P, S,
Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg,
Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn)
Combustibles solides de récupération — Méthodes de
détermination de la teneur en éléments (Al, Ca, Fe, K, Mg, Na, P, S, Si,
Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn)
Reference number
ISO 3884:2025(en) © ISO 2025
ISO 3884:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
ISO 3884:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols and abbreviations . 2
5 Safety remarks . 5
6 Principle . 5
7 Reagents . 5
8 Apparatus . 6
9 Interferences and sources of errors . 7
9.1 General information.7
9.2 Closed vessel system for microwave digestion .8
10 Preparation of the test sample. 8
11 Procedure . 8
11.1 General .8
11.2 Blank test .8
11.3 Method A (general method for SRF and major elements in ashed SRF) - Microwave
assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (6 ml HCl;
2 ml HNO ; 2 ml HF) .9
11.4 Method AT (method for SRF and major elements in ashed SRF) - Microwave assisted
digestion with hydrochloric, nitric and tetrafluoroboric acid mixture (6 ml HCl; 2 ml
HNO ; 4 ml HBF ) .11
3 4
11.5 Method B (e.g. plastic based SRF and others if method A cannot be applied) - Microwave
assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (0,5 ml HCl;
6 ml HNO ; 1 ml HF) .11
11.6 Method BT (e.g. plastic based SRF and others) - Microwave assisted digestion with
hydrochloric, nitric and tetrafluoroboric acid mixture (0,5 ml HCl; 6 ml HNO ; 2 ml
HBF ) . 12
11.7 Method C (e.g. wood based SRFs) - Microwave assisted digestion with nitric acid,
hydrogen peroxide and hydrofluoric acid mixture (2,5 ml H O ; 5 ml HNO ; 0,4 ml HF) . 13
2 2 3
11.8 Method CT (e.g. wood based SRFs) - Microwave assisted digestion with nitric acid,
hydrogen peroxide and tetrafluoroboric acid mixture (2,5 ml H O ; 5 ml HNO ; 0,8 ml
2 2 3
HBF ) .14
11.9 Method D (major elements in SRF ash) – digestion of ashed SRF with fluxing agent
lithium metaborate (fused bead) .14
12 Analysis . .15
12.1 Preparation of the solution for analysis . 15
12.2 Analytical step . 15
12.3 XRF analysis on ashed samples – sample preparation (major elements only) . 15
13 Calculations .16
14 Quality control .16
15 Performance characteristics . 16
16 Test report .16
Annex A (informative) Calibration of the power adjustment .18
Annex B (informative) Validation and performance data (SRF22ERI) . 19
iii
ISO 3884:2025(en)
Annex C (informative) Performance data (QUOVADIS) .65
Annex D (informative) Results of ruggedness testing (QUOVADIS) .78
Bibliography .82
iv
ISO 3884:2025(en)
Foreword
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This document was prepared by Technical Committee ISO/TC 300, Solid recovered materials, including
solid recovered fuels, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 343, Solid recovered materials, including solid recovered fuels, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
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
ISO 3884:2025(en)
Introduction
Accurate determination of the element content in solid recovered fuels is important for environmental and
technical reasons both in the production and combustion stage. Some of the elements determined by the
[1]
application of one of the methods in this document are included in ISO 21640 while other elements can
have environmental implications both for emissions and for the bottom and fly ashes disposal or recovery.
Furthermore, the determination of elements such as Al, Ca, Fe, Mg, P, K, Si, Na and Ti can be helpful to predict
the melting behaviour and slagging of the ash.
The methods described in this document provide multi-element digestions for a wide range of solid
recovered fuels. The elements that are extractable and determined by these procedures can in many
instances be described as ‘total element contents’, although this will be matrix dependent. After digestion,
a number of analytical techniques can be used for the accurate determination of major and minor element
contents, e.g. inductively coupled plasma with optical or mass detection (ICP-OES, ICP-MS), graphite furnace
atomic absorption spectrometry (GF-AAS) and specific direct methods (e.g. for mercury, sulfur).
Alternatively, X-ray fluorescence can be used as a fast method for a qualitative overview of ash forming
elements and impurities of solid recovered fuels. After suitable calibration, X-ray fluorescence is very
useful for determining major elements or even minor elements (except mercury and beryllium) in solid
recovered fuels according to ISO 22940. For calibration of X-ray fluorescence, it is important to use several
solid recovered fuel reference materials or solid recovered fuel samples that were carefully characterized
after total digestion and measurement by ICP-OES, ICP-MS, GF-AAS or by other techniques such as elemental
[2]
analysis using combustion technology on sulfur (see ISO 21663 ).
After ashing of solid recovered fuels, X-ray fluorescence allows the simultaneous determination of major
elements (Al, Ca, Fe, Mg, P, K, Si, Na, Ti) in the ashes after matrix-based calibration (procedures for this are
described in ISO 22940 and EN 15309).
vi
International Standard ISO 3884:2025(en)
Solid recovered fuels — Methods for the determination of the
content of elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be,
Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn)
1 Scope
This document specifies methods for the determination of major and minor element concentrations in solid
recovered fuels after digestion by the use of different acid mixtures and by addition of a fluxing agent for
solid recovered fuel (SRF) ash.
a) Method A: Microwave assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (6 ml
HCl; 2 ml HNO ; 2 ml HF) followed by boric acid complexation;
b) Method AT: Microwave assisted digestion with hydrochloric, nitric and tetrafluoroboric acid mixture
(6 ml HCl; 2 ml HNO ; 4 ml HBF );
3 4
c) Method B: Microwave assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (0,5 ml
HCl; 6 ml HNO ; 1 ml HF) followed by boric acid complexation;
d) Method BT: Microwave assisted digestion with hydrochloric, nitric and tetrafluoroboric acid mixture
(0,5 ml HCl; 6 ml HNO ; 2 ml HBF );
3 4
e) Method C: Microwave assisted digestion with nitric acid, hydrogen peroxide and hydrofluoric acid
mixture (2,5 ml H O ; 5 ml HNO ; 0,4 ml HF) and optional boric acid complexation;
2 2 3
f) Method CT: Microwave assisted digestion with nitric acid, hydrogen peroxide and tetrafluoroboric acid
mixture (2,5 ml H O ; 5 ml HNO ; 0,8 ml HBF );
2 2 3 4
g) Method D: Digestion of the ashed SRF sample with fluxing agent lithium metaborate in an oven at
1 050 °C.
This document is applicable for the following major and minor/trace elements:
— Major elements: aluminium (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), sodium (Na),
phosphorus (P), sulfur (S), silicon (Si) and titanium (Ti).
— Minor/trace elements: arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), cobalt (Co), chromium
(Cr), copper (Cu), mercury (Hg), molybdenum (Mo), manganese (Mn), nickel (Ni), lead (Pb), antimony
(Sb), selenium (Se), tin (Sn), thallium (Tl), vanadium (V) and zinc (Zn).
Method A is applicable for general use for SRF and ashed SRFs, but the amount of the test portion can be
very low in case of high concentration of organic matter. Method AT can be used if an alternative to HF is
necessary.
Method B with a higher volume of nitric acid is applicable for SRFs with high organic matter (e.g. suitable
for high plastic content) that can be difficult to digest with less nitric acid or as a substitute for method A if
appropriate equipment is not available. Method BT can be used if an alternative to HF is necessary.
Method C with combination of nitric acid and hydrogen peroxide and addition of hydrofluoric acid is
applicable for wood based SRFs (e.g. demolition wood) or when there is a need for comparability to solid
biofuel standards. Method CT can be used if an alternative to HF is necessary.
Method D is specifically applicable for determination of major elements in ashed SRF samples.
ISO 3884:2025(en)
XRF can be used for the analysis of major elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti) after ashing (815 °C)
of the samples and several major and minor/trace elements in SRF can be analysed by XRF after suitable
calibration provided that the concentration levels are above instrumental detection limits of the XRF
instrumentation and after proper preliminary testing and validation.
Digestion methods with HF and subsequent boric acid complexation or application of method D are applicable
for determination of Si and Ti (better digestion efficiency).
Alternative digestion methods can be applied, if their performance is proved to be comparable with those of
the methods described in this document.
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 21637, Solid recovered fuels — Vocabulary
ISO 21660-3, Solid recovered fuels — Determination of moisture content using the oven dry method — Part 3:
Moisture in general analysis sample
ISO 22940:2021, Solid recovered fuels — Determination of elemental composition by X-ray fluorescence
EN 15309:2007, Characterization of waste and soil — Determination of elemental composition by X-ray
fluorescence
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21637 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
digestion
mineralization of the organic matter of a sample and dissolution of its mineral part, more or less completely,
when reacted with a reagent mixture
3.2
microwave unit
whole microwave digestion system (oven and associated equipment)
4 Symbols and abbreviations
A ash content at 815 °C on a dry basis (A_DB)
db
Al aluminium (AL)
Al aluminium in ashed SRF (ALASH)
ash
Ca calcium (CA)
Ca calcium in ashed SRF (CAASH)
ash
DM dry mass (DM)
ISO 3884:2025(en)
Fe iron (FE)
Fe iron in ashed SRF (FEASH)
ash
K potassium (K)
K potassium in ashed SRF (KASH)
ash
Mg magnesium (MG)
Mg magnesium in ashed SRF (MGASH)
ash
Na sodium (NA)
Na sodium in ashed SRF (NAASH)
ash
P phosphorus (P)
P phosphorus in ashed SRF (PASH)
ash
S sulfur (S)
S sulfur in ashed SRF (SASH)
ash
Si silicon (SI)
Si silicon in ashed SRF (SIASH)
ash
Ti titanium (TI)
Ti titanium in ashed SRF (TIASH)
ash
As arsenic (AS)
Ba barium (BA)
Be beryllium (BE)
Cd cadmium (CD)
Co cobalt (CO)
Cr chromium (CR)
Cu copper (CU)
Hg mercury (HG)
Mo molybdenum (MO)
Mn manganese (MN)
Ni nickel (NI)
Pb lead (PB)
Sb antimony (SB)
Se selenium (SE)
Sn tin (SN)
ISO 3884:2025(en)
Tl thallium (TL)
V vanadium (V)
Zn zinc (ZN)
GF-AAS Graphite Furnace-Atomic Absorption Spectrometry
HG-AAS Hydride Generation-Atomic Absorption Spectrometry
CV-AAS Cold Vapour-Atomic Absorption Spectrometry
ICP-OES Inductively coupled plasma-Optical Emission Spectrometry
ICP-MS Inductively coupled plasma-Mass Spectrometry
PTFE polytetrafluorethylene
PFA perfluoroalkoxy (e.g. PFA liner)
TFM tetrafluoroethylene, modified (e.g. TFM liner)
XRF X-ray fluorescence
SRF Solid recovered fuels
CRM certified reference material
RM reference material
(d) dry basis
l number of laboratories after outlier rejection (Annex C: number of outlier-free indi-
vidual analytical values per level)
n number of individual test results after outlier rejection (Annex C: number of labora-
tories after outlier elimination)
o percentage of outliers (Annex C: percentage of outliers from the replicate determi-
nation)
Mean(REF) mean value (reference laboratories)
Mean overall mean of results (without outliers)
Recovery rate recovery rate calculated by division of the overall mean value of results (without
outliers) by the mean value of reference laboratories, multiplied by 100 %
η recovery rate (Annex C)
s reproducibility standard deviation
R
C coefficient of variation of reproducibility
V,R
s repeatability standard deviation
r
C coefficient of variation of repeatability
V,r
RSD relative standard deviation (Annex C)
CV Coefficient of variation (Annex D)
ISO 3884:2025(en)
HCl hydrochloric acid
HNO nitric acid
HBF Tetrafluoroboric acid
H O hydrogen peroxide
2 2
HF hydrofluoric acid
5 Safety remarks
Safety when handling potentially hazardous material is dealt with by the applicable (inter-)national
regulations.
In addition, the following information is given:
— Only experienced personnel can use the microwave apparatus, following the operating and safety
instructions described in the manufacturer manual;
— The microwave unit cavity shall be built in a way that even in case of leakage or explosion of the vessels
the safety of the operators can be guaranteed. Household instruments are not suitable for laboratory use.
— Most of the reagents used within this document are strongly corrosive and toxic. Safety precautions are
absolutely necessary due to strong corrosive reagents, high temperature and high pressure;
— All procedures have to be performed in a hood or in closed force-ventilated equipment. By the use of
strong oxidising reagents, the formation of explosive intermediates is possible, especially when dealing
with samples with a high organic content. Do not open pressurised vessels before they have cooled down.
Avoid contact with the chemicals and the gaseous reaction products.
6 Principle
The test portion is digested using one of the proposed methods with a suitable acid mixture or by addition
of a fluxing agent (ashed SRF). The digested sample is then analysed by the most appropriate spectrometric
technique, such as inductively coupled plasma with optical or mass detection (ICP-OES, ICP-MS) or atomic
absorption (GF-AAS, CV-AAS, HG-AAS). Alternatively, specific direct methods can be applied after validation
(e.g. for determination of mercury or sulfur or for direct determination of elements by XRF).
[3]
For XRF analysis of major elements in the ashed SRF, the sample is ashed at 815 °C (ISO 21656 ) and the
ash is homogenized in a ball mill to obtain a uniform size dimension of the particles. The ash is then pressed
in the form of pellets (ISO 22940, EN 15309) or fused with lithium metaborate (EN 15309). Both techniques
are suitable for the analysis by XRF. Coal ash and other ashes of various origins can be used for instrument
calibration.
7 Reagents
7.1 General
All reagents and acids used shall be of recognized analytical grade or verify the content of the elements to be
analysed to avoid high blank values for subsequent analytical measurements. Throughout the procedure, a test
blank solution shall be used applying all steps with the same amount of acids or reagents, but without a sample.
7.2 Water, < 0,055 µS/cm, (e.g. deionized water)
7.3 Nitric acid (HNO ), approximately 15 mol/l, 65 % to 70 % (mass/mass).
ISO 3884:2025(en)
7.4 Hydrofluoric acid (HF), approximately 23 mol/l, 40 % to 45 % (w/w).
7.5 Hydrochloric acid (HCl), approximately 12 mol/l, 35 % to 37 % (w/w).
7.6 Diluted Hydrochloric acid (HCl), approximately 2 mol/l. Dissolve 166,5 ml of HCl 37 % (7.5) in water
and dilute to 1 l with water (7.2).
7.7 Boric acid (H BO ), solid.
3 3
7.8 Boric acid (H BO ) solution, e.g. 4 % (w/w). Dissolve 40 g of boric acid (7.7) in water and dilute to 1 l
3 3
of water (7.2).
7.9 Hydrogen peroxide (H O ), 30 % (w/w).
2 2
7.10 Lithium metaborate (LiBO ), solid.
7.11 Tetrafluoroboric acid (HBF ), approximately 6 mol/l, 38 % to 50 % (w/w).
8 Apparatus
8.1 General
Usual laboratory apparatus along with the following shall be used. All volumetric flasks and digestion vessels
shall be adequately cleaned and stored in order to avoid any contamination, particularly with respect to low
concentration of the elements of interest.
8.2 Microwave unit, temperature and/or power-controlled, closed vessels
8.2.1 Digestion vessels, for pressurized microwave digestion of appropriate volume, reagent-,
temperature- and pressure-resistant and capable of containing the mixture of sample and digest solution.
The vessel shall be suitable for the safe application in the temperature and pressure range applied, capable
of withstanding pressures of at least 3 000 kPa.
Digestion vessels made of modified polytetrafluorethene (PTFE), e.g. TFM or PFA liner, and equipped with a
safety pressure releasing system to avoid explosion of the vessel shall be used. The inner wall of the vessel
shall be inert and shall not release contaminations to the digest solutions.
NOTE It can be necessary to periodically clean the digestion vessels with a suitable surfactant to remove
persistent deposits.
8.2.2 Microwave unit, temperature-controlled, corrosion resistant and well ventilated.
All electronics shall be protected against corrosion for safe operation. Use a laboratory-grade microwave
oven with temperature feedback control mechanisms.
The microwave digestion system shall be able to control the temperature with an accuracy of at least ±5 °C
and automatically adjust the microwave field output power within 2 s of sensing. Temperature sensors shall
be accurate to ±2 °C, including the final reaction temperature of 190 °C ± 10 °C. Temperature feedback control
provides the primary performance mechanism for the method. Due to the variability in sample matrix types
and microwave digestion equipment (i.e. different vessel types and microwave designs), control of the
temperature during digestion is important for reproducible microwave heating and comparable data.
The accuracy of the temperature measurement system shall be periodically tested at an elevated
temperature according to the manufacturers’ instructions. If the temperature deviates by more than
2 °C from the temperature measured by an external, calibrated temperature measurement system, the
microwave temperature measurement system shall be re-calibrated.
ISO 3884:2025(en)
8.2.3 Microwave unit, power-controlled, corrosion resistant and well ventilated.
All electronics shall be protected against corrosion for safe operation. A laboratory-grade microwave oven
with temperature feedback control mechanisms shall be used.
The microwave unit shall be able to provide programmable power which can be programmed to within
±10 W of the required power. Typical units provide a nominal power of 600 W to 1 200 W. If necessary
(referring to manufacturers’ specifications), calibration of the microwave unit shall be performed (see
Annex A).
The microwave unit shall be designed in a way that guarantees homogeneous heating of the samples.
The microwave unit shall include a temperature and/or pressure control system.
8.3 Sample containers, plastic containers or glass containers (when no free hydrofluoric acid is
present)
8.4 Filter, usually with a pore size of 0,45 µm and resistant to the employed acid mixture and of
adequate purity
8.5 Centrifuge, minimum 3 000 r/min
8.6 Volumetric flasks, usually of nominal capacity of 50 ml (microwave digestion) or 100 ml, or 250 ml
(fluxing agent)
8.7 Magnetic stirrer with heating function and PTFE stirring bone
8.8 Press, in accordance with ISO 22940:2021, 7.2 or EN 15309:2007, 6.3
8.9 Analytical balance, with an accuracy of 0,1 mg or better
8.10 Muffle furnace for temperatures of 1 050 °C
8.11 Platinum crucible, e.g. Pt/Au (5 % (mass/mass))
8.12 Inductively coupled plasma. Normal commercial instrumentation with optical or mass spectrometric
detector (ICP-OES, ICP-MS).
8.13 X-ray fluorescence Spectrometer. Energy or wavelength dispersion system suitable for qualitative
and (semi-)quantitative analysis of the elements listed in this document (with the exception of Beryllium
and Mercury).
8.14 Atomic Absorption Spectrometer. Normal commercial instrumentation, equipped with graphite
furnace or hydride generation systems or cold vapour (GF-AAS, HG-AAS, CV-AAS).
9 Interferences and sources of errors
9.1 General information
The use of glassware shall be excluded when free hydrofluoric acid is present.
In the case of filtration of the digested solution, it is necessary to take care that the filtration procedure does
not introduce contaminants.
Ensure that the entire test portion is brought into contact with the acid mixture in the digestion vessel.
ISO 3884:2025(en)
Some elements of interest can be lost due to precipitation with ions present in the digest solutions, e.g. low
soluble chlorides, fluorides and sulphates.
9.2 Closed vessel system for microwave digestion
The upper limits of mass of the test portion according to the manufacturer’s specifications shall be taken
into account.
Very reactive or volatile materials that can create high pressures when heated can cause a venting of the
vessels with potential loss of sample and analytes.
After digestion, the vessels shall be cooled to room temperature before opening.
10 Preparation of the test sample
The sample preparation for heterogeneous materials as SRF is critical. The test sample is the general analysis
[4]
test sample with a nominal top size of 0,5 mm or less, following the procedure according to IS0 21646 and
shall be selected in a way that it is representative for the laboratory sample.
Depending on the used digestion method, the amount of test portion ranges between 0,2 g and 0,5 g SRF-
sample or 0,1 g ashed SRF-sample.
NOTE A nominal top size of 1 mm or less can be sufficient, when a significantly higher amount of sample intake
for the digestion step is feasible (at least 1 g).
Determine the moisture content of separate portions of the general analysis test sample of SRF in accordance
with ISO 21660-3 at 105 °C. Whereas the determination is carried out on a dry basis (as for ashed SRF-
samples), the moisture content shall be determined during the drying step in accordance with ISO 21660-3
at 105 °C.
11 Procedure
11.1 General
The mass of the test portion for a single digestion and the set temperature or pressure-programme shall
comply with the specifications of the manufacturer of the digestion unit. Use TFM and PFA liners (after
a cleaning run) for total digestion and check the power and temperature calibration of the microwave
digestion unit regularly to ensure functionality and reproducible results.
If the required amount of representative test portion exceeds the manufacturer’s specifications, the test
portion shall be divided into smaller quantities and digested separately. The individual digests shall be
combined prior to analysis.
When hydrofluoric acid has been used for digestion, a subsequent complexation run can be necessary to
complex free fluorides.
Addition of 11 ml cold-saturated boric acid solution (approx. 4 % H BO ) per ml used hydrofluoric acid is
3 3
recommended.
11.2 Blank test
A reagent blank test digestion shall be carried out in parallel with the samples, using the same procedure
and the same quantities of all the reagents as in the determination of the samples, but omitting the test
portion. The laboratory shall define acceptable limits.
NOTE The measurement of a blank solution is needed to determine the contribution of the digestion acid mixture,
digestion vessels and filter used to the measured value.
ISO 3884:2025(en)
11.3 Method A (general method for SRF and major elements in ashed SRF) - Microwave
assisted digestion with hydrochloric, nitric and hydrofluoric acid mixture (6 ml HCl; 2 ml
HNO; 2 ml HF)
a) Weigh between 0,2 g to 0,5 g of the SRF sample or 0,1 g of ashed SRF sample, to the nearest of 0,1 mg,
prepared according to Clause 10 and transfer it into the vessel (8.2.1). If necessary, the sample can be
moistened with a minimum amount of water (7.2).
The amount of the test sample depends on the amount of organic matter. The maximum amount of
organic carbon shall not exceed 0,15 g when 8 ml of HCl and HNO is used. Per additional 0,1 g organic
carbon (more than this 0,15 g), 1 ml of additional concentrated HNO (7.3) shall be added before the
digestion process is started.
Referring to the manufacturer’s instructions, the upper limits of mass of the test portion shall be taken
into account.
b) Add (6,0 ± 0,1) ml hydrochloric acid (7.5) followed by (2,0 ± 0,1) ml nitric acid (7.3) and (2,0 ± 0,1) ml
hydrofluoric acid (7.4).
If a vigorous reaction occurs, allow the reaction to cease before capping the vessel.
c) Cap the digestion vessel according to the manufacturer’s instructions. Place samples in all available
positions in the microwave for sample vessels.
If a lower number of samples are available compared to the vessel positions, use vessels filled with the
same amount of the acid mixture without sample to fill all the available vessel slots. This is to ensure
the same microwave energy absorption occurs during each digestion procedure. This method is an
operationally defined method, designed to achieve consistent digestion of samples by specific reaction
conditions.
Temperature profile for temperature- or power-controlled microwave unit, closed vessels:
Microwave heating (acid digestion):
— Step 1: Ramp to 190 °C over 15 min to 20 min;
— Step 2: Hold for 20 min at 190 °C;
— Step 3: Cool down (20 min).
NOTE 1 The stated temperature refers to the digestion solution. The high temperature serves to accelerate the
digestion reaction and therefore results in a better digestion efficiency.
1) Microwave unit, temperature-controlled, closed vessels: The temperature of the digestion mixture in
each vessel shall be raised with a heating rate of approximately 10 °C/min to 15 °C/min to (190 ± 10) °C
and remain at (190 ± 10) °C for (20 ± 1) min. Afterwards cool down to room temperature.
2) Microwave unit, power-controlled, closed vessels: According to the manufacturers’ manual a suitable
power programme is selected for the numbers of vessels and adjusted to ensure consistent reaction
conditions to reach at least 190 °C in 15 until 20 min and to remain at maximum temperature for at least
(20 ± 1) min. Afterwards, cool down to room temperature.
WARNING — A too high temperature increase in the microwave assisted digestion can cause a
vigorous, exothermic reaction in the digestion solution with high pressure increase and blow-
off of the security valve. Losses of analytes are then possible. Therefore, it is mandatory to follow
manufacturer’s instructions.
If necessary due to manufacturer’s instruction, the maximum temperature can be decreased and the
programme has to be adjusted (e.g. longer hold time when a lower maximum temperature must be set).
ISO 3884:2025(en)
A temperature increase of 10 °C leads to a halving of the reaction time, at the same time a higher temperature
also leads to an increase in the oxidation potential of the acid mixtures, which has a positive effect on the
digestion efficiency.
d) Verify the different kind of condition for the effectiveness of digestion for SRF samples and for (certified)
reference material/quality control samples by comparison of the results with another laboratory that
works according to the conditions listed above. Alternative kinds of digestion methods can be applied, if
their performance is proved to be comparable with those of the methods described in this document.
e) At the end of the microw
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