ISO 1952:2025
(Main)Coal — Determination of extractable metals in dilute hydrochloric acid
Coal — Determination of extractable metals in dilute hydrochloric acid
This document describes the extraction from coal by dilute hydrochloric acid and determination of extractable sodium, potassium, calcium, iron and magnesium.
Charbon — Détermination des métaux extractibles dans l'acide chlorhydrique dilué
General Information
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Buy Standard
Standards Content (Sample)
International
Standard
ISO 1952
Third edition
Coal — Determination of
2025-07
extractable metals in dilute
hydrochloric acid
Charbon — Détermination des métaux extractibles dans l'acide
chlorhydrique dilué
Reference number
© ISO 2025
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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents and materials . 2
6 Apparatus . 4
7 Preparation of the test sample. 4
8 Procedure . 4
8.1 Preparation of test portion .4
8.2 Preparation of test solution .4
8.3 Analysis of test solutions .5
9 Expression of results . 6
10 Precision . 6
10.1 Repeatability .6
10.2 Reproducibility .6
11 Test report . 7
Bibliography . 8
iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 27, Coal and coke, Subcommittee SC 5, Methods
of analysis.
This third edition cancels and replaces the second edition (ISO 1952:2008), which has been technically
revised.
The main changes are as follows:
— the title and scope has been modified to specifically refer to coal;
— the normative references have been updated;
— the mandatory terms and definitions clause (Clause 3) has been added; subsequent clauses have been
renumbered;
— Formula (1) has been modified;
— the test report has been modified.
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.
iv
Introduction
Sodium, potassium, calcium, iron and magnesium are commonly present in coal. They can contribute
significantly to coal-utilization problems, such as boiler-tube fouling and ash disposal; they also affect
product quality and gaseous emissions from combustion processes.
Research indicates that the amounts of alkaline and earth-alkaline metals extractable with dilute
hydrochloric acid are more closely related to the fouling/slagging properties of coal than are the total
amounts of the metals.
v
International Standard ISO 1952:2025(en)
Coal — Determination of extractable metals in dilute
hydrochloric acid
1 Scope
This document describes the extraction from coal by dilute hydrochloric acid and determination of
extractable sodium, potassium, calcium, iron and magnesium.
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 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 5068-2, Brown coals and lignites — Determination of moisture — Part 2: Indirect gravimetric method for
moisture in the analysis sample
ISO 11722, Solid mineral fuels — Hard coal — Determination of moisture in the general analysis test sample by
drying in nitrogen
ISO 13909-4, Coal and coke — Mechanical sampling — Part 4: Preparation of test samples of coal
ISO 18283, Coal and coke — Manual sampling
3 Terms and definitions
No terms and definitions are listed in this document.
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/
4 Principle
A portion of the sample is extracted with hot, dilute hydrochloric acid after wetting of the coal with alcohol.
All forms of sodium, potassium, magnesium, calcium, iron that are exchangeable or extractable with the
hydrochloric acid are extracted from the coal. After removal of the residual solid mineral fuel by filtration,
the concentrations of the elements in the filtrate are determined by atomic absorption spectrometry.
The mass concentrations of the elements may also be determined by inductively coupled plasma optical
emission spectrometry (ICP-OES) if the instrument has been validated for the quantification in an
appropriate manner.
5 Reagents and materials
Use analytical reagent grade chemicals. Other grades can be used, provided it is documented that the reagent
is of sufficiently high purity to permit its use without adversely affecting the accuracy of the determination.
The subscript “20” represents 20 °C.
5.1 Water, high-purity deionized water in accordance with ISO 3696, or as defined by the equivalent
national standard.
5.2 Ethanol.
5.3 Hydrochloric acid, concentrated, ρ = 1,19 g/ml.
5.4 Hydrochloric acid solution, prepared by mixing 1 part concentrated hydrochloric acid (5.3) with
1 part water (5.1).
DANGER — The addition of the strong acid, HCl, to water liberates a significant amount of heat and
can cause a violent reaction.
5.5 Nitric acid (HNO ), concentrated, ρ = 1,42 g/ml.
3 20
5.6 Lanthanum oxide (La O ).
2 3
5.7 Lanthanum solution.
Dissolve 23,4 g of La O (5.6) in 350 ml of water (5.1). Slowly add 50 ml of concentrated nitric acid. Stir until
2 3
solution is completely mixed, transfer to a 1 l volumetric flask, dilute to the mark with water.
DANGER — The addition of the strong acid, HNO, to water liberates a significant amount of heat and
can cause a violent reaction.
NOTE The lanthanum solution is used as an ionization suppressant during calcium determination. It is possible to
use other commonly used ionization suppressants, e.g. cesium, as an alternative.
5.8 Magnesium perchlorate, anhydrous, 2,0 mm ± 0,7 mm, used as a desiccant.
DANGER — Regeneration of magnesium perchlorate by oven drying shall not be attempted because
of the risk of explosion. Magnesium perchlorate is a strong oxidant, and shall be kept away from
organic materials such as oils, greases and organic solvents.
5.9 Stock solutions
5.9.1 Sodium chloride (NaCl).
5.9.2 Sodium solution, 1 000 mg/l.
Dissolve 2,542 g of sodium chloride (5.9.1) (previously dried at 110 °C for 1 h) in 200 ml of water (5.1), stir
until solution is completely mixed, transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.3 Potassium chloride (KCl).
5.9.4 Potassium solution, 1 000 mg/l.
Dissolve 1,907 g of potassium chloride (5.9.3) (previously dried at 110 °C for 1 h) in 200 ml of water (5.1),
transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.5 Calcium carbonate (CaCO ).
5.9.6 Calcium carbonate solution, 1 000 mg/l.
Dissolve 2,497 g of calcium carbonate (5.9.5) (previously dried at 110 °C for 1 h) in a solution containing
10 ml of concentrated hydrochloric acid (5.3) and 200 ml of water (5.1), stir until solution is completely
mixed. Bring to a gentle boil to remove excess carbon dioxide. Cool the solution, transfer to a 1 l volumetric
flask, dilute to the mark with water.
5.9.7 Magnesium oxide.
5.9.8 Magnesium solution, 1 000 mg/l.
Place 1,658 g of magnesium oxide (5.9.7) (previously heated at 1 000 °C for 1 h) in solution containing 10 ml
of concentrated hydrochloric acid (5.3) and 200 ml of water (5.1), stir until solution is completely mixed.
Warm until dissolved, cool, transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.9 Iron, minimum purity 99,8 % Fe.
5.9.10 Iron solution, 1 000 mg/l.
Place 1,000 g of pure iron (5.9.9) in a solution containing 20 ml of concentrated hydrochloric acid (5.3) and
20 ml of water (5.1), stir until solution is completely mixed. Heat to boiling and gently simmer until dissolved.
Cool, transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.11 Commercial stock solutions, opti
...
FINAL DRAFT
International
Standard
ISO/FDIS 1952
ISO/TC 27/SC 5
Coal — Determination of
Secretariat: SA
extractable metals in dilute
Voting begins on:
hydrochloric acid
2025-03-31
Voting terminates on:
2025-05-26
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 1952:2025(en) © ISO 2025
FINAL DRAFT
ISO/FDIS 1952:2025(en)
International
Standard
ISO/FDIS 1952
ISO/TC 27/SC 5
Coal — Determination of
Secretariat: SA
extractable metals in dilute
Voting begins on:
hydrochloric acid
Voting terminates on:
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 1952:2025(en) © ISO 2025
ii
ISO/FDIS 1952:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents and materials . 2
6 Apparatus . 4
7 Preparation of the test sample. 4
8 Procedure . 4
8.1 Preparation of test portion .4
8.2 Preparation of test solution .4
8.3 Analysis of test solutions .5
9 Expression of results . 5
10 Precision . 6
10.1 Repeatability .6
10.2 Reproducibility .6
11 Test report . 6
Bibliography . 7
iii
ISO/FDIS 1952:2025(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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 27, Coal and coke, Subcommittee SC 5, Methods
of analysis.
This third edition cancels and replaces the second edition (ISO 1952:2008), which has been technically
revised.
The main changes are as follows:
— the title and scope has been modified to specifically refer to coal;
— the normative references have been updated;
— the mandatory terms and definitions clause (Clause 3) has been added; subsequent clauses have been
renumbered;
— Formula (1) has been modified;
— the test report has been modified.
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.
iv
ISO/FDIS 1952:2025(en)
Introduction
Sodium, potassium, calcium, iron and magnesium are commonly present in coal. They can contribute
significantly to coal-utilization problems, such as boiler-tube fouling and ash disposal; they also affect
product quality and gaseous emissions from combustion processes.
Research indicates that the amounts of alkaline and earth-alkaline metals extractable with dilute
hydrochloric acid are more closely related to the fouling/slagging properties of coal than are the total
amounts of the metals.
v
FINAL DRAFT International Standard ISO/FDIS 1952:2025(en)
Coal — Determination of extractable metals in dilute
hydrochloric acid
1 Scope
This document describes the extraction from coal by dilute hydrochloric acid and determination of
extractable sodium, potassium, calcium, iron and magnesium.
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 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 5068-2, Brown coals and lignites — Determination of moisture — Part 2: Indirect gravimetric method for
moisture in the analysis sample
ISO 11722, Solid mineral fuels — Hard coal — Determination of moisture in the general analysis test sample by
drying in nitrogen
ISO 13909-4, Hard coal and coke — Mechanical sampling — Part 4: Preparation of test samples of coal
ISO 18283, Coal and coke — Manual sampling
3 Terms and definitions
No terms and definitions are listed in this document.
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/
4 Principle
A portion of the sample is extracted with hot, dilute hydrochloric acid after wetting of the coal with alcohol.
All forms of sodium, potassium, magnesium, calcium, iron that are exchangeable or extractable with the
hydrochloric acid are extracted from the coal. After removal of the residual solid mineral fuel by filtration,
the concentrations of the elements in the filtrate are determined by atomic absorption spectrometry.
The mass concentrations of the elements may also be determined by inductively coupled plasma optical
emission spectrometry (ICP-OES) if the instrument has been validated for the quantification in an
appropriate manner.
ISO/FDIS 1952:2025(en)
5 Reagents and materials
Use analytical reagent grade chemicals. Other grades can be used, provided it is documented that the reagent
is of sufficiently high purity to permit its use without adversely affecting the accuracy of the determination.
The subscript “20” represents 20 °C.
5.1 Water, high-purity deionized water in accordance with ISO 3696, or as defined by the equivalent
national standard.
5.2 Ethanol.
5.3 Hydrochloric acid, concentrated, ρ = 1,19 g/ml.
5.4 Hydrochloric acid solution, prepared by mixing 1 part concentrated hydrochloric acid (5.3) with
1 part water (5.1).
DANGER — The addition of the strong acid, HCl, to water liberates a significant amount of heat and
can cause a violent reaction.
5.5 Nitric acid (HNO ), concentrated, ρ = 1,42 g/ml.
3 20
5.6 Lanthanum oxide (La O ).
2 3
5.7 Lanthanum solution.
Dissolve 23,4 g of La O (5.6) in 350 ml of water (5.1). Slowly add 50 ml of concentrated nitric acid. Stir until
2 3
solution is completely mixed, transfer to a 1 l volumetric flask, dilute to the mark with water.
DANGER — The addition of the strong acid, HNO, to water liberates a significant amount of heat and
can cause a violent reaction.
NOTE The lanthanum solution is used as an ionization suppressant during calcium determination. It is possible to
use other commonly used ionization suppressants, e.g. cesium, as an alternative.
5.8 Magnesium perchlorate, anhydrous, 2,0 mm ± 0,7 mm, used as a desiccant.
DANGER — Regeneration of magnesium perchlorate by oven drying shall not be attempted because
of the risk of explosion. Magnesium perchlorate is a strong oxidant, and shall be kept away from
organic materials such as oils, greases and organic solvents.
5.9 Stock solutions
5.9.1 Sodium chloride (NaCl).
5.9.2 Sodium solution, 1 000 mg/l.
Dissolve 2,542 g of sodium chloride (5.9.1) (previously dried at 110 °C for 1 h) in 200 ml of water (5.1), stir
until solution is completely mixed, transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.3 Potassium chloride (KCl).
5.9.4 Potassium solution, 1 000 mg/l.
Dissolve 1,907 g of potassium chloride (5.9.3) (previously dried at 110 °C for 1 h) in 200 ml of water (5.1),
transfer to a 1 l volumetric flask, dilute to the mark with water.
...
2025-02-14
ISO/FDIS 1952:2025(en)
ISO/TC 27/SC 05/WG 08 5
Secretariat: SA
Date: 2025-03-14
Coal — Determination of extractable metals in dilute hydrochloric
acid
Combustibles minéraux solides — Détermination des métaux extractibles dans l'acide chlorhydrique dilué
FDIS stage
ISO/FDIS 1952:2025(en)
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: + 41 22 749 01 11
Fax: +41 22 749 09 47
EmailE-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland
iii
ISO/FDIS 1952:2025(en)
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents and materials . 2
6 Apparatus . 4
7 Preparation of the test sample . 4
8 Procedure . 4
8.1 Preparation of test portion . 4
8.2 Preparation of test solution . 5
8.3 Analysis of test solutions . 5
9 Expression of results . 6
10 Precision . 6
10.1 Repeatability . 6
10.2 Reproducibility . 6
11 Test report . 7
Bibliography . 8
iv
ISO/FDIS 1952:2025(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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 27, Coal and coke, Subcommittee SC 5, Methods
of analysis.
This third edition cancels and replaces the second edition (ISO 1952:2008), which has been technically
revised.
The main changes are as follows:
— — the title and scope has been modified to specifically refer to coal;
— — the normative references have been updated;
— — the mandatory terms and definitions clause (Clause 3(Clause 3)) has been added; subsequent clauses
have been renumbered;
— Formula (1)— Formula (1) has been modified;
— — the test report has been modified.
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/FDIS 1952:2025(en)
Introduction
Sodium, potassium, calcium, iron and magnesium are commonly present in coal. They can contribute
significantly to coal-utilization problems, such as boiler-tube fouling and ash disposal; they also affect product
quality and gaseous emissions from combustion processes.
Research indicates that the amounts of alkaline and earth-alkaline metals extractable with dilute hydrochloric
acid are more closely related to the fouling/slagging properties of coal than are the total amounts of the metals.
vi
DRAFT INTERNATIONAL STANDARD ISO/FDIS 1952:2025(en)
Coal and coke — Determination of extractable metals in dilute
hydrochloric acid
1 Scope
This document describes the extraction from coal by dilute hydrochloric acid and determination of extractable
sodium, potassium, calcium, iron and magnesium.
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 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 5068--2, Brown coals and lignites — Determination of moisture — Part 2: Indirect gravimetric method for
moisture in the analysis sample
ISO 18283, Coal and coke — Manual sampling
ISO 11722, Solid mineral fuels — Hard coal — Determination of moisture in the general analysis test sample by
drying in nitrogen
ISO 13909--4, Hard coal and coke — Mechanical sampling — Part 4: Coal — Preparation of test samples of coal
ISO 18283, Coal and coke — Manual sampling
3 Terms and definitions
No terms and definitions are listed in this document.
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/
4 Principle
A portion of the sample is extracted with hot, dilute hydrochloric acid after wetting of the coal with alcohol.
All forms of sodium, potassium, magnesium, calcium, iron that are exchangeable or extractable with the
hydrochloric acid are extracted from the coal. After removal of the residual solid mineral fuel by filtration, the
concentrations of the elements in the filtrate are determined by atomic absorption spectrometry.
ISO/FDIS 1952:2025(en)
The mass concentrations of the elements may also be determined by inductively coupled plasma optical
emission spectrometry (ICP-OES) if the instrument has been validated for the quantification in an appropriate
manner.
5 Reagents and materials
Use analytical reagent grade chemicals. Other grades can be used, provided it is documented that the reagent
is of sufficiently high purity to permit its use without adversely affecting the accuracy of the determination.
The subscript “20” represents 20 °C.
5.1 5.1 Water, high-purity deionized water as defined in accordance with ISO 3696, or as defined
by the equivalent national standard.
5.2 5.2 Ethanol.
5.3 5.3 Hydrochloric acid, concentrated, ρ = 1,19 g/ml.
5.4 5.4 Hydrochloric acid solution, prepared by mixing 1 part concentrated hydrochloric acid
(5.3(5.3)) with 1 part water (5.1(5.1).).
DANGER — The addition of the strong acid, HCl, to water liberates a significant amount of heat and can
cause a violent reaction.
5.5 5.5 Nitric acid (HNO ), concentrated, ρ = 1,42 g/ml.
3 20
5.6 5.6 Lanthanum oxide (La O ).
2 3
5.7 5.7 Lanthanum solution.
Dissolve 23,4 g of La O (5.6(5.6)) in 350 ml of water (5.1(5.1).). Slowly add 50 ml of concentrated nitric acid.
2 3
Stir until solution is completely mixed, transfer to a 1 l volumetric flask, dilute to the mark with water.
DANGER — The addition of the strong acid, HNO , to water liberates a significant amount of heat and
can cause a violent reaction.
NOTE The lanthanum solution is used as an ionization suppressant during calcium determination. It is possible to
use other commonly used ionization suppressants, e.g. cesium, as an alternative.
5.8 5.8 Magnesium perchlorate, anhydrous, 2,0 mm ± 0,7 mm, used as a desiccant.
DANGER — Regeneration of magnesium perchlorate by oven drying shall not be attempted because of
the risk of explosion. Magnesium perchlorate is a strong oxidant, and shall be kept away from organic
materials such as oils, greases and organic solvents.
5.9 5.9 Stock solutions
5.9.1 5.9.1 Sodium chloride (NaCl).
5.9.2 5.9.2 Sodium solution, 1 000 mg/l.
Dissolve 2,542 g of sodium chloride (5.9.1(5.9.1)) (previously dried at 110 °C for 1 h) in 200 ml of water
(5.1(5.1),), stir until solution is completely mixed, transfer to a 1 l volumetric flask, dilute to the mark with
water.
5.9.3 5.9.3 Potassium chloride (KCl).
5.9.4 5.9.4 Potassium solution, 1 000 mg/l.
ISO/FDIS 1952:2025(en)
Dissolve 1,907 g of potassium chloride (5.9.3(5.9.3)) (previously dried at 110 °C for 1 h) in 200 ml of water
(5.1(5.1),), transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.5 5.9.5 Calcium carbonate (CaCO ).
5.9.6 5.9.6 Calcium carbonate solution, 1 000 mg/l.
Dissolve 2,497 g of calcium carbonate (5.9.5(5.9.5)) (previously dried at 110 °C for 1 h) in a solution
containing 10 ml of concentrated hydrochloric acid (5.3(5.3)) and 200 ml of water (5.1(5.1),), stir until
solution is completely mixed. Bring to a gentle boil to remove excess carbon dioxide. Cool the solution, transfer
to a 1 l volumetric flask, dilute to the mark with water.
5.9.7 5.9.7 Magnesium oxide.
5.9.8 5.9.8 Magnesium solution, 1 000 mg/l.
Place 1,658 g of magnesium oxide (5.9.7(5.9.7)) (previously heated at 1 000 °C for 1 h) in solution containing
10 ml of concentrated hydrochloric acid (5.3(5.3)) and 200 ml of water (5.1(5.1),), stir until solution is
completely mixed. Warm until dissolved, cool, transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.9 5.9.9 Iron, minimum purity 99,8 % Fe.
5.9.10 5.9.10 Iron solution, 1 000 mg/l.
Place 1,000 g of pure iron (5.9.9(5.9.9)) in a solution containing 20 ml of concentrated hydrochloric acid
(5.3(5.3)) and 20 ml of water (5.1(5.1),), stir until solution is completely mixed. Heat to boiling and gently
simmer until dissolved. Cool, transfer to a 1 l volumetric flask, dilute to the mark with water.
5.9.11 5.9.11 Commercial stock solutions, optional, certified stock solutions with a concentration of the
ion of interest of 1 000 mg/l that can be used as an alternative to preparing stock solutions.
5.10 5.10 Calibration solutions, prepared with the volumes of reagents given in Table 1Table 1.
Prepare calibration solution A, by adding 40 ml of lanthanum solution (5.7(5.7)) and 32 ml of hydrochloric
acid solution (5.4(5.4)) to a 1 l volumetric flask. Add 1 ml of each stock solution and stir until the solution is
completely mixed. Dilute to the mark with water.
Prepare calibration solutions B, C, D, E and the calibration BLANK in the sa
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