ISO 17947-1

• Abstract:

  This document specifies the methods for the chemical analysis of fine silicon nitride powders used as the raw material for fine ceramics. It stipulates the determination methods of total silicon, total nitrogen, aluminium, iron, calcium, oxygen, carbon, fluorine, and chlorine in fine silicon nitride powders.

• Status: Not Published
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: ISO/TC 206 - Fine ceramics
• Drafting Committee: ISO/TC 206/WG 3 - Chemical analysis
• Current Stage: 6000 - International Standard under publication
• Start Date: 11-Sep-2026
• Completion Date: 19-Sep-2026

• Consolidates: prEN ISO 17947-1 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Methods for chemical analysis of silicon nitride powders - Part 1: Wet chemical methods, X-ray fluorescence (XRF) using the fused cast-bead method, carrier-gas hot extraction (CGHE) and combustion methods (ISO/DIS 17947-1:2025)
• Effective Date: 12-Feb-2026
• Consolidates: ISO/IEC 17549-2:2020 - Information technology — User interface guidelines on menu navigation — Part 2: Navigation with 4-direction devices
• Effective Date: 18-Nov-2023
• Revises: ISO 17947:2014 - Fine ceramics (advanced ceramics, advanced technical ceramics) — Methods for chemical analysis of fine silicon nitride powders
• Effective Date: 18-Nov-2023

Overview

ISO 17947-1: Fine ceramics (advanced ceramics, advanced technical ceramics) - Methods for chemical analysis of silicon nitride powders - Part 1: Wet chemical methods, X-ray fluorescence (XRF) using the fused cast-bead method, carrier-gas hot extraction (CGHE) and combustion methods is an international standard developed by ISO for the reliable chemical analysis of silicon nitride powders. These powders serve as essential raw materials for fine ceramics and advanced technical ceramics. This standard specifies methods to determine the content of critical elements and compounds, including total silicon, total nitrogen, aluminium, iron, calcium, oxygen, carbon, fluorine, and chlorine, ensuring high-quality material characterization and process control in ceramic manufacturing.

Key Topics

• Sample Preparation: Guidelines for sampling, drying, weighing, and handling of silicon nitride powder in accordance with ISO 8656-1.
• Chemical Analysis Methods: Covers wet chemical methods, XRF using the fused cast-bead method, CGHE, and combustion techniques for a comprehensive analysis.
• Analyte Determination: Procedures for accurate quantification of silicon, nitrogen, aluminium, iron, calcium, oxygen, carbon, fluorine, and chlorine with defined measurement ranges.
  • Silicon (30%-70%)
  • Nitrogen (30%-45%)
  • Aluminium, Iron (0.001%-0.6%)
  • Calcium (0.001%-0.03%)
  • Oxygen (0.05%-5%)
  • Carbon (0.01%-6%)
  • Fluorine, Chlorine (0.001%-0.2%)
• Calibration and Blank Testing: Emphasizes the need for regular calibration and blank tests to minimize and correct analytical errors.
• Quality and Reporting: Details on how to evaluate, express, and report analytical values, including guidance for test report preparation.

Applications

ISO 17947-1 offers practical value for a broad range of stakeholders in the ceramics industry:

• Ceramic Manufacturers: Ensures the consistent chemical quality of silicon nitride powders, which directly impacts the mechanical and chemical performance of advanced ceramic products.
• R&D Laboratories: Enables detailed material characterization, leading to improved product development and innovation in fine ceramics.
• Quality Assurance and Control: Assists laboratories and production facilities in verifying compliance with internal and external specifications for raw materials.
• Material Suppliers: Provides a recognized reference for the chemical specifications of silicon nitride powders, supporting transparent trade and procurement processes.
• Accreditation and Certification: Forms a basis for laboratory accreditation and audit processes linked to advanced ceramics and powder metallurgy.

Key industries benefiting from the use of this standard include electronics, automotive, aerospace, and energy, where silicon nitride ceramics are valued for their strength, thermal stability, and resistance to wear and corrosion.

Related Standards

For a comprehensive approach to the chemical analysis of ceramic powders and related materials, users may also refer to:

• ISO 21068-2 and ISO 21068-3: Chemical analysis of raw materials and refractory products containing silicon-carbide, silicon-nitride, silicon-oxynitride, and sialon.
• ISO 2828: Determination of fluorine content in aluminium oxide.
• ISO 3696: Water quality for laboratory use.
• ISO 6353 series: Requirements for reagents in chemical analysis.
• ISO 8656-1: Sampling of raw materials for refractory products.
• ISO 26845: General requirements for wet chemical, atomic absorption spectrometry (AAS), and ICP-AES methods.

Summary

Implementing ISO 17947-1 helps organizations achieve precise and reproducible chemical analysis of silicon nitride powders, underpinning the integrity and performance of fine and advanced ceramics. Adhering to these standardized methods supports global trade, regulatory compliance, material development, and quality assurance in critical manufacturing sectors.

International
Standard
First edition
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Methods for chemical analysis of
silicon nitride powders —
Part 1:
Wet chemical methods, X-ray
fluorescence (XRF) using the fused
cast-bead method, carrier-gas hot
extraction (CGHE) and combustion
methods
Céramiques techniques — Méthodes pour l’analyse chimique de
poudres de nitrure de silicium —
Partie 1: Méthodes chimiques par voie humide, fluorescence de
rayons X (XRF) utilisant la méthode de la perle fondue, extraction
à chaud sous gaz vecteur (CGHE) et méthodes de combustion
PROOF/ÉPREUVE
Reference number
© ISO 2026
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or ISO’s member body in the country of the requester.
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Published in Switzerland
PROOF/ÉPREUVE
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Analytes and ranges . 2
5 Preparation of test sample . 2
5.1 General .2
5.2 Sampling .2
5.3 Drying .2
5.4 Weighing .3
6 Apparatus and reagents . 3
7 Blank test . 3
8 Determination of silicon . 3
8.1 Classification of determination methods .3
8.2 Fusion-dehydration/insolubilization separation-gravimetry and ICP-OES .3
8.2.1 Principle .3
8.2.2 Reagents .3
8.2.3 Apparatus and instruments .4
8.2.4 Procedure .4
8.2.5 Blank test .5
8.2.6 Calibration . . .5
8.2.7 Calculation .5
8.3 XRF using fused cast-bead method .5
9 Determination of nitrogen . 6
9.1 Classification of determination methods .6
9.2 Acid pressure decomposition-distillation separation-acidimetric titration method .6
9.2.1 Principle .6
9.2.2 Reagents .6
9.2.3 Apparatus .7
9.2.4 Procedure .10
9.2.5 Recovery measurement.11
9.2.6 Calculation .11
9.3 Inert gas fusion-thermal conductivity method .11
9.4 Fusion-ammonia separation-acidimetric titration method .14
10 Determination of aluminium, iron, and calcium . 14
10.1 Principle .14
10.2 Reagents .14
10.3 Apparatus .14
10.4 Procedure . 15
10.5 Blank test . 15
10.6 Calibration . 15
10.7 Calculation . 15
11 Determination of oxygen. 16
11.1 Principle .16
11.2 Reagents .16
11.3 Apparatus .16
11.4 Instrument .16
11.5 Procedure .16
11.6 Blank test .16
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iii
11.7 Calculation of calibration coefficient .17
11.8 Calculation .17
12 Determination of carbon . 17
12.1 Classification of determination methods .17
12.2 Combustion (induction furnace)-IR absorption spectrometry .18
12.2.1 Principle .18
12.2.2 Reagents .18
12.2.3 Apparatus .18
12.2.4 Instrument .18
12.2.5 Procedure .19
12.2.6 Blank test .19
12.2.7 Calculation of calibration coefficient .19
12.2.8 Calculation . 20
12.3 Combustion (resistance furnace)-coulometry . 20
12.4 Combustion (resistance furnace)-thermal conductivity. 20
13 Determination of fluorine and chlorine.20
13.1 Principle . 20
13.2 Reagents . 20
13.3 Apparatus .21
13.4 Procedure .21
13.4.1 Extraction of fluorine and chlorine from the sample .21
13.4.2 Determination of fluorine and chlorine .21
13.5 Blank test . 22
13.6 Calibration . 22
13.7 Calculation . 22
14 Reporting analytical values .23
14.1 Number of analyses . 23
14.2 Evaluation of analytical values . 23
14.3 Expression of analytical values . 23
15 Test report .23
Annex A (informative) List of commercial certified reference materials .25
Annex B (informative) Analytical results obtained from a round robin test .26
Annex C (informative) Spectral lines for ICP-OES .30
Bibliography .31
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iv
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 206, Fine ceramics, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 184, Advanced technical
ceramics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
This first edition of ISO 17947-1 cancels and replaces ISO 17947:2014, which has been technically revised.
A list of all parts in the ISO 17947 series can be found on the ISO website.
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.
PROOF/ÉPREUVE
v
Introduction
[1]
This document has been developed from Japanese Industrial Standard JIS R 1603:2007 with reference to
[2] [3]
CEN ENV 14226:2002 and ASTM C1494-01:2007 , and is applicable to the chemical analysis of silicon
nitride raw powders for fine ceramics use. This document covers both major and minor constituents, such as
silicon, nitrogen, and some trace metallic and non-metallic elements.
PROOF/ÉPREUVE
vi
International Standard ISO 17947-1:2026(en)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Methods for chemical analysis of silicon nitride
powders —
Part 1:
Wet chemical methods, X-ray fluorescence (XRF) using the
fused cast-bead method, carrier-gas hot extraction (CGHE)
and combustion methods
1 Scope
This document specifies methods for the determination of silicon, nitrogen, aluminium, iron, calcium,
oxygen, carbon, fluorine, and chlorine in silicon nitride powders.
This document is applicable for the chemical analysis of silicon nitride powders used as raw material for fine
ceramics.
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 2828, Aluminium oxide primarily used for the production of aluminium — Determination of fluorine content
— Alizarin complexone and lanthanum chloride spectrophotometric method
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 6353-1, Reagents for chemical analysis — Part 1: General test methods
ISO 6353-2, Reagents for chemical analysis — Part 2: Specifications — First series
ISO 6353-3, Reagents for chemical analysis — Part 3: Specifications — Second series
ISO 8656-1, Refractory products — Sampling of raw materials and unshaped products — Part 1: Sampling
scheme
ISO 21068-2:2024, Chemical analysis of raw materials and refractory products containing silicon-carbide,
silicon-nitride, silicon-oxynitride and sialon — Part 2: Determination of volatile components, total carbon, free
carbon, silicon carbide, total and free silicon, free and surface silica
ISO 21068-3:2024, Chemical analysis of raw materials and refractory products containing silicon-carbide,
silicon-nitride, silicon-oxynitride and sialon — Part 3: Determination of nitrogen, oxygen and metallic and oxidic
constituents
ISO 21438-2, Workplace atmospheres — Determination of inorganic acids by ion chromatography — Part 2:
Volatile acids, except hydrofluoric acid (hydrochloric acid, hydrobromic acid and nitric acid)
ISO 21438-3, Workplace atmospheres — Determination of inorganic acids by ion chromatography — Part 3:
Hydrofluoric acid and particulate fluorides
PROOF/ÉPREUVE
ISO 26845:2008, Chemical analysis of refractories — General requirements for wet chemical analysis, atomic
absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES)
methods
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 Analytes and ranges
Analytes and ranges specified in this document shall be as follows.
a) Silicon (Si), range of 30 % to 70 % (mass fraction)
b) Nitrogen (N), range of 30 % to 45 % (mass fraction)
c) Aluminium (Al), range of 0,001 % to 0,6 % (mass fraction)
d) Iron (Fe), range of 0,001 % to 0,6 % (mass fraction)
e) Calcium (Ca), range of 0,001 % to 0,03 % (mass fraction)
f) Oxygen (O), range of 0,05 % to 5 % (mass fraction)
g) Carbon (C), range of 0,01 % to 6 % (mass fraction)
h) Fluorine (F), range of 0,001 % to 0,2 % (mass fraction)
i) Chlorine (Cl), range of 0,001 % to 0,2 % (mass fraction)
NOTE The results of an interlaboratory test conducted using three silicon nitride powder samples are listed in
Annex B.
5 Preparation of test sample
5.1 General
The method of preparing samples shall be in accordance with ISO 8656-1 unless otherwise mutually agreed
upon between the analyser and the customer.
5.2 Sampling
Sampling shall be in accordance with ISO 8656-1.
5.3 Drying
The following procedure shall be used: Take about 10 g of the sample into a flat-type weighing bottle
(60 mm × 30 mm) and spread it uniformly over the bottom of the bottle. Place the bottle in a drying oven
at 110 °C ± 5 °C for 2 h without a lid, and then cool in a desiccator (desiccant: magnesium perchlorate for
drying) with a lid for 1 h.
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5.4 Weighing
The required quantity of the sample shall be weighed to the nearest 0,1 mg using a balance.
6 Apparatus and reagents
Unless otherwise specified for each determination, ordinary laboratory apparatus for chemical analysis as
listed in ISO 26845:2008, Clause 4 may be used. Reagents shall conform to the requirements of ISO 6353-1,
ISO 6353-2, and ISO 6353-3. Unless otherwise specified for each determination, reagents of analytical grade
listed in ISO 26845:2008, Clause 5, shall be used.
7 Blank test
Blank test shall be carried out without the sample by using identical quantities of reagents, conditions, and
procedures throughout each determination to correct the analytical values obtained.
8 Determination of silicon
8.1 Classification of determination methods
Silicon shall be determined by either of the following methods. If analytical results with four figures are
required, use the method A. If analytical results with two or three figures are required, the method B can be
used.
— Method A: Fusion–dehydration/insolubilization separation–gravimetry and inductively coupled plasma
optical emission spectrometry (ICP-OES)
— Method B: XRF using fused cast-bead method
8.2 Fusion-dehydration/insolubilization separation-gravimetry and ICP-OES
8.2.1 Principle
A sample is fused with alkaline carbonate and the melt is treated with an acid to separate into two parts of
silicon, insoluble silicon and soluble silicon, by filtration. Insoluble silicon is determined gravimetrically as
silicon dioxide after ignition of the insoluble residue, whereas soluble silicon is determined in the filtrate
using ICP-OES. The sum of them represents the content of silicon in the sample.
8.2.2 Reagents
Reagents of analytical grade shall be used. Reagent solutions shall be preserved in plastic bottles.
8.2.2.1 Water, of grade 1 or superior specified in ISO 3696.
8.2.2.2 Sodium carbonate, Na CO , anhydrous, specified in ISO 6353-3 or that of higher grade.
2 3
8.2.2.3 Hydrochloric acid (1+1), (1+4), (1+50), HCl, concentrated hydrochloric acid (c(HCl) = 32 %, mass
fraction) diluted (1+1), (1+4) and (1+50) by volume with water (8.2.2.1).
8.2.2.4 Sulfuric acid (1+1), (1+4), H SO , concentrated sulfuric acid (c(H SO ) = 96 %, mass fraction)
2 4 2 4
diluted (1+1) and (1+4) by volume with water (8.2.2.1).
8.2.2.5 Cellulose powder.
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8.2.2.6 Polyethylene glycol (PEG) solution, (C H O) H O, 0,05 % mass fraction of PEG, prepared by
2 4 n 2
dissolving solid PEG in water (8.2.2.1).
8.2.2.7 Hydrofluoric acid, HF, c(HF) = 48 %, mass fraction.
8.2.3 Apparatus and instruments
Ordinary laboratory apparatus and instruments for chemical analysis in accordance with ISO 26845:2008,
4 may be used.
8.2.3.1 Platinum dish.
8.2.3.2 Platinum crucible.
8.2.3.3 Burner, capable of heating at 1 100 °C.
8.2.3.4 Muffle furnace, capable of being operated at 1 100 °C.
8.2.3.5 Balance, readable to 0,1 mg.
8.2.3.6 Inductively coupled plasma optical emission spectrometer (ICP-OES).
8.2.4 Procedure
8.2.4.1 General
The procedure shall be as follows. The procedure described in ISO 21068-2:2024, Clause 8 may be
alternatively used.
8.2.4.2 Fusion of sample
The following procedure shall be used: Weigh 0,30 g of the sample and 2,0 g of sodium carbonate, anhydrous,
into a platinum dish and mix well. Start to heat carefully and increase the temperature gradually to 1 000 °C
to completely fuse the sample using a burner or a muffle furnace.
8.2.4.3 Separation of silicon
The following procedure shall be used: Add 20 ml of hydrochloric acid (1+1) to dissolve the melt on a hot
plate. Silicon dioxide will appear to be jellified and precipitated at this stage. There are two methods to
separate the precipitated silicon dioxide.
a) Dehydrate carefully the precipitate to dryness in order to prevent it from spattering and add 5 ml of
hydrochloric acid (1+1) and 20 ml of water to dissolve hydrochloric acid soluble components of the
precipitate. Filtrate the precipitate with a filter paper and wash with hot hydrochloric acid (1+50) several
times and then with hot water sufficiently until it contains no salt. Collect the filtrate and washings
together in a volumetric flask and dilute to volume with water. Preserve this precipitate for gravimetry
of insoluble silicon and the solution for the ICP-OES determination of soluble silicon, respectively.
b) After formation of jellified silicon dioxide, add 0,05 g of cellulose powder and 10 ml of PEG solution
(8.2.2.6) to agglomerate silicon dioxide for easy filtration. Filtrate and wash using the same procedure
as described in a), and then preserve this precipitate for gravimetry of insoluble silicon and the solution
for the ICP-OES determination of soluble silicon, respectively.
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8.2.4.4 Gravimetry for insoluble silicon
The following procedure shall be used: Transfer the filter paper with the precipitate to a platinum crucible.
Heat the platinum crucible slowly using a burner (8.2.3.3) or a muffle furnace (8.2.3.4) until complete ashing
of the filter paper and then calcine the residue at 1 100 °C. Place the platinum crucible in a desiccator to
cool to room temperature. Weigh the platinum crucible. Moisten the residue in the platinum crucible with
a few drops of water (8.2.2.1) and sulfuric acid (1+1) (8.2.2.4) and add 10 ml of hydrofluoric acid (8.2.2.7).
Then evaporate to dryness on a hot plate to remove all silicon dioxide, calcine the residue at 1 100 °C using
a burner or in a muffle furnace and place the platinum crucible in a desiccator to cool to room temperature.
Weigh the platinum crucible again. The loss of mass after hydrofluoric acid treatment corresponds to the
amount of insoluble silicon dioxide.
8.2.4.5 ICP-OES for soluble silicon
The following procedure shall be used: Nebulize the test solution obtained in 8.2.4.3 into the plasma of an
ICP-OES to determine soluble silicon in the sample.
NOTE An example for a suited silicon emission line is listed in Annex C.
8.2.5 Blank test
Blank determinations shall be performed according to 8.2.4.2 to 8.2.4.5 without the sample.
8.2.6 Calibration
For ICP-OES, calibration solutions shall be prepared to span the range of concentration of silicon in the test
solution. Each calibration solution shall have a similar matrix to the test solution.
With those calibration solutions, the calibration function for soluble silicon shall be created to establish the
relation between the emission intensity measured with the test solution and the concentration of silicon in
the test solution.
8.2.7 Calculation
With the amount of insoluble silicon (8.2.4.4), soluble silicon (8.2.4.5) and the blank test (8.2.5), the content
of silicon shall be calculated according to Formula (1).
 VAA 

w  mm 0,4674 (1)
 
Si 10
m
 
 
where
w is the mass fraction of silicon in the sample, in percent;
Si
m is the mass of insoluble silicon dioxide in the sample (8.2.4.4), in grams;
m is the mass of insoluble silicon dioxide in the blank test (8.2.5), in grams;
A is the concentration of soluble silicon in the test solution (8.2.4.3), in milligrams per litre;
A is the concentration of soluble silicon in the blank solution (8.2.5), in milligrams per litre;
V is the volume of the test and blank solution, in millilitres;
m is the mass of the sample (8.2.4.2), in grams.
8.3 XRF using fused cast-bead method
The procedure shall be in accordance with ISO 21068-3:2024, 8.2.
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9 Determination of nitrogen
9.1 Classification of determination methods
Nitrogen shall be determined by either of the following methods. Methods A and C provide a higher precision
than method B.
NOTE Based on practical experience, methods A and C provide a precision of two valid decimal places. Method B
usually provides a precision of one valid decimal place.
— Method A: Acid pressure decomposition–distillation separation–acidimetric titration method
— Method B: Inert gas fusion–thermal conductivity method
— Method C: Fusion–ammonia separation–acidimetric titration method
9.2 Acid pressure decomposition-distillation separation-acidimetric titration method
9.2.1 Principle
The sample is decomposed in a pressure decomposition vessel with a mixture of hydrofluoric acid and
sulfuric acid to convert nitrogen into ammonia. Boric acid is added and the solution is transferred into a
distillation flask. After addition of sodium hydroxide, the ammonia is separated by steam distillation
and the distillate is collected in a receiving vessel containing a known amount of amidosulfuric acid. The
distilled ammonia reacts with amidosulfuric acid and the excess of amidosulfuric acid is back-titrated with
a standardized sodium hydroxide solution.
9.2.2 Reagents
Reagents of analytical grade shall be used. Reagent solutions shall be preserved in plastic bottles.
9.2.2.1 Water, of grade 1 or superior specified in ISO 3696.
9.2.2.2 Hydrofluoric acid, HF, c(HF) = 48 %, mass fraction.
9.2.2.3 Sulfuric acid (1+1), H SO , concentrated sulfuric acid (c(H SO ) = 96 %, mass fraction) diluted
2 4 2 4
(1+1) by volume with water (9.2.2.1).
9.2.2.4 Sodium hydroxide, NaOH, more than 97,0 % (mass fraction) of purity.
9.2.2.5 Sodium hydroxide solution (500 g/l), prepared by dissolving sodium hydroxide (9.2.2.4) in
water (9.2.2.1).
9.2.2.6 Amidosulfuric acid, H NO S, more than 99,0 % (mass fraction) of purity.
3 3
9.2.2.7 0,1mol/l amidosulfuric acid solution, prepared by dissolving amidosulfuric acid (9.2.2.6) in
water (9.2.2.1). Weigh 10,0 g of amidosulfuric acid into a 1 000 ml volumetric flask, dissolve in approximately
PROOF/ÉPREUVE
200 ml water, dilute with water to volume and mix well. The factor of this solution shall be calculated
according to Formula (2).
F = m × P/(9,709 5 × 100) (2)
where
F is the factor of the 0,1 mol/l amidosulfuric acid solution;
m is the mass of amidosulfuric acid, g;
P is the purity of amidosulfuric acid, % (mass fraction).
9.2.2.8 0,1 mol/l sodium hydroxide solution, prepared by dissolving sodium hydroxide (9.2.2.4) in
water (9.2.2.1). Weigh 4,0 g of sodium hydroxide into a 1 000 ml volumetric flask, dissolve in approximately
200 ml water, dilute with water to volume and mix well.
The factor of this solution shall be determined using the following procedure: Pour exactly 50 ml of the
0,1 mol/l amidosulfuric acid solution into a beaker (200 ml) and dilute with water to about 100 ml. Titrate
this solution with the 0,1 mol/l sodium hydroxide solution using a pH meter. Take the end point as pH 5,5
and determine the volume of the titrant consumed. The factor of this solution shall be calculated according
to Formula (3).
F = F × 50,00/V (3)
where
F is the factor of the 0,1 mol/l sodium hydroxide solution;
F is the factor of the 0,1 mol/l amidosulfuric acid solution;
V is the titration volume of the 0,1 mol/l sodium hydroxide solution, ml.
9.2.2.9 Boric acid, H BO .
3 3
9.2.2.10 Ammonium sulfate, (NH ) SO , more than 99,9 % (mass fraction) of purity.
4 2 4
9.2.3 Apparatus
Ordinary laboratory apparatus for chemical analysis shall be used and the following.
9.2.3.1 Platinum crucible.
9.2.3.2 Pressure decomposition vessel, commercially available.
An example is shown in Figure 1. Since hydrofluoric acid under high temperature and pressure is used
for sample decomposition, polytetrafluoroethylene (PTFE) shall be used for vessel and cap (see Figure 1).
Instead of PTFE, caps and vessels made of perfluoroalkoxy (PFA) may be used. The vessels shall be
exclusively used for the determination of nitrogen according to method A (9.1) to avoid cross-contamination
by nitrogen. If vessels are used that have ever come into contact with nitric acid, lower values of nitrogen
can be obtained.
9.2.3.3 Drying Oven, capable of heating at 160 °C ± 5 °C.
9.2.3.4 Steam distillation apparatus, consisting of the components listed below. An example of the
apparatus is shown in Figure 2. Each component shall be made of hard glass coupled by common ground
joints and fixed by springs or clamps.
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Dimensions in millimetres
Key
1 centre screw
2 screw cap
3 top plate
4 polytetrafluoroethylene (PTFE) cap
5 pressure vessel
6 PTFE vessel
7 bottom plate
Figure 1 — An example of sealed decomposition vessel
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Dimensions in millimetres
Key
a flask (2,5 l) for generation of steam
b trap (500 ml)
c sphere and tube
d distillation flask (750 ml)
e graham condenser
f receiver
1 funnel
2 ball joint
3 dumet wire
4 funnel with stopcock
5 rubber tube
6 13 to15 coils
7 small holes
8 electric heater
9 connection of rubber tube with pinchcock
10 jack
Figure 2 — An example of steam distillation apparatus
PROOF/ÉPREUVE
9.2.3.5 Steam generation flask (2,5 l), equipped with a funnel with a cock, an immersion heater (with
1 kW Nichrome wire), and a steam outlet tube.
9.2.3.6 Trap, the bottom of a bulb shall be connected to a rubber tube with a pinch cock for a drain.
The tip of steam leading-out tube shall have several small holes.
9.2.3.7 Bulb, equipped with a steam leading-in tube, a funnel with a cock, a splash-proof trap, etc.
The steam leading-in tube shall be cut in the middle enabling the exchange of the tip by connecting to a
rubber tube.
9.2.3.8 Distillation flask (750 ml).
9.2.3.9 Coiled condenser.
9.2.3.10 Receiver, a tall beaker (300 ml) shall be used.
9.2.3.11 pH meter, readable to the smallest value of 0,1 equipped with a glass electrode.
9.2.4 Procedure
The following procedures shall be used:
a) Acid pressure decomposition of the sample. Weigh 0,15 g of the sample into a platinum crucible
(20 ml) and add 5 ml of sulfuric acid (1+1) and 5 ml of hydrofluoric acid. Place the crucible into a
pressure decomposition vessel and close the vessel according to the manufacturer’s instructions. If an
antistatic device is available during weighing, the sample may be directly weighed into the PTFE vessel
(see Figure 1). Place the vessel into a drying oven and heat at 160 °C ± 5 °C for 16 h. Acid pressure
decomposition under microwave irradiation may be performed if available. For microwave sample
decomposition the sample shall be weighed into a PTFE crucible or directly into the PTFE vessel of the
decomposition system (see Figure 1).
b) Preparation of the sample solution. After cooling, disassemble the vessel. Transfer the solution into
a 100 ml plastic beaker, thoroughly rinse the crucible or the PTFE vessel with water and add the rinse
water to the beaker. Add 5 g of boric acid and mix well.
c) Preparation of steam distillation apparatus. After transferring the sample solution into the
distillation flask, assemble the distillation apparatus and add exactly 50 ml of the 0,1 mol/l amidosulfuric
acid solution to the receiver. Fix the coiled condenser so that the tip is immersed in the solution of the
receiver. Pour 50 ml of the sodium hydroxide solution (500 g/l) through the funnel into the distillation
flask, rinse the funnel with water until the volume of the solution in the distillation flask reaches about
150 ml and close the funnel cock.
d) Steam distillation. Perform the steam distillation with a steam flow of 4,5 ml/min to 5,0 ml/min. When
the distillate reaches about 170 ml, lower the receiver to expose the tip of the condenser above the liquid
surface and continue distillation until the distillate reaches about 200 ml. Wash the outside of the tip
with a small amount of water. When using a new distillation apparatus or an apparatus which has not
been used for a long time, wash the inside of the apparatus by steam distillation for 2 h to 3 h.
e) Titration. Titrate the distillate with the 0,1 mol/l sodium hydroxide solution using the pH meter. Take
the end point as pH 5,5 and record the volume of the titrant.
PROOF/ÉPREUVE
9.2.5 Recovery measurement
The following procedure shall be used: Weigh 0,280 g of ammonium sulfate to the nearest 0,1 mg into a
platinum crucible (20 ml), perform operations of 9.2.4 and calculate the recovery according to Formula (4).
The recovery shall be not less than 99 %.
R = [{(50,00 × F) – (V × F )} × 0,001 400 7/(m × 0,212 0)] × 100 (4)
where
R is the recovery, %;
F is the factor of the 0,1 mol/l amidosulfuric acid solution;
V is the titration volume of the 0,1 mol/l sodium hydroxide solution, ml;
F is the factor of the 0,1 mol/l sodium hydroxide solution;
m is the mass of ammonium sulphate, g.
9.2.6 Calculation
The content of nitrogen in the sample shall be calculated according to Formula (5).
w = [{[(50,00 × F) – (V × F )] × [(0,001 400 7 × 100/R)]}/m] × 100 (5)
N 1
where
w is the content of nitrogen in the sample, % (mass fraction);
N
F is the factor of the 0,1 mol/l amidosulfuric acid solution;
V is the titration volume of the 0,1 mol/l sodium hydroxide solution, ml;
F is the factor of the 0,1 mol/l sodium hydroxide solution;
R is the recovery (%) in 9.2.5;
m is the mass of the sample, g.
9.3 Inert gas fusion-thermal conductivity method
9.3.1 Principle
A sample is fused together with a flux in a graphite crucibl
...

ISO TC 206/SC/PRF 17947-1
ISO/TC 206
Date: 2015-11-04
Secretariat: JISC
Date: 2026-08-13
Fine ceramics (advanced ceramics, advanced technical ceramics) —
Methods for chemical analysis of silicon nitride powders – —
Part 1:
Wet chemical methods, X-ray fluorescence (XRF) using the fused cast-
bead method, carrier-gas hot extraction (CGHE) and combustion
methods
Céramiques techniques — Méthodes pour l'analysel’analyse chimique de poudres de nitrure de silicium —
Partie 1: Méthodes chimiques par voie humide, fluorescence de rayons X (XRF) utilisant la méthode de la perle
fondue, extraction à chaud sous gaz vecteur (CGHE) et méthodes de combustion
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PROOF
ISO/DISPRF 17947-1:20252026(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
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CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.orgwww.iso.org
Published in Switzerland
iii
ISO/PRF 17947-1:2026(en)
Contents Page
Foreword . viii
Introduction . ix
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Analytes and ranges . 2
5 Preparation of test sample . 2
5.1 General . 2
5.2 Sampling . 2
5.3 Drying . 3
5.4 Weighing . 3
6 Apparatus and reagents . 3
7 Blank test . 3
8 Determination of silicon . 3
8.1 Classification of determination methods . 3
8.2 Fusion‑dehydration/insolubilization separation‑gravimetry and ICP-OES . 3
8.3 XRF using fused cast-bead method . 6
9 Determination of nitrogen . 6
9.1 Classification of determination methods . 6
9.2 Acid pressure decomposition‑distillation separation‑acidimetric titration method . 6
9.3 Inert gas fusion‑thermal conductivity method . 13
9.4 Fusion‑ammonia separation‑acidimetric titration method . 16
10 Determination of aluminium, iron, and calcium . 16
10.1 Principle . 16
10.2 Reagents . 16
10.3 Apparatus . 17
10.4 Procedure . 17
10.5 Blank test . 18
10.6 Calibration . 18
10.7 Calculation . 18
11 Determination of oxygen . 19
11.1 Principle . 19
11.2 Reagents . 19
11.3 Apparatus . 19
11.4 Instrument . 19
11.5 Procedure . 19
11.6 Blank test . 19
11.7 Calculation of calibration coefficient . 19
11.8 Calculation . 20
12 Determination of carbon . 20
12.1 Classification of determination methods . 20
12.2 Combustion (induction furnace)‑IR absorption spectrometry . 21
iv
ISO/DISPRF 17947-1:20252026(en)
12.3 Combustion (resistance furnace)‑coulometry . 23
12.4 Combustion (resistance furnace)‑thermal conductivity . 23
13 Determination of fluorine and chlorine . 23
13.1 Principle . 23
13.2 Reagents . 23
13.3 Apparatus . 24
13.4 Procedure . 25
13.5 Blank test . 25
13.6 Calibration . 26
13.7 Calculation . 26
14 Reporting analytical values . 27
14.1 Number of analyses . 27
14.2 Evaluation of analytical values . 27
14.3 Expression of analytical values . 27
15 Test report . 27
Annex A (informative) List of commercial certified reference materials . 28
Annex B (informative) Analytical results obtained from a round robin test . 29
Annex C (informative) Spectral lines for ICP-OES . 34
Bibliography . 35

Foreword . vi
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Analytes and ranges . 2
5 Preparation of test sample . 2
5.1 General . 2
5.2 Sampling . 2
5.3 Drying . 2
5.4 Weighing . 2
6 Apparatus and reagents . 3
7 Blank test . 3
8 Determination of silicon . 3
8.1 Classification of determination methods . 3
8.2 Fusion-dehydration/insolubilization separation-gravimetry and ICP-OES . 3
8.2.1 Principle . 3
8.2.2 Reagents . 3
8.2.3 Apparatus and instruments . 4
8.2.4 Procedure . 4
8.2.5 Blank test . 5
8.2.6 Calibration . 5
8.2.7 Calculation . 5
8.3 XRF using fused cast-bead method . 6
9 Determination of nitrogen . 6
v
ISO/PRF 17947-1:2026(en)
9.1 Classification of determination methods . 6
9.2 Acid pressure decomposition-distillation separation-acidimetric titration method . 6
9.2.1 Principle . 6
9.2.2 Reagents . 7
9.2.3 Apparatus . 7
9.2.4 Procedure . 10
9.2.5 Recovery measurement . 10
9.2.6 Calculation . 10
9.3 Inert gas fusion-thermal conductivity method . 11
9.3.1 Principle . 11
9.3.2 Reagents . 11
9.3.3 Apparatus . 11
9.3.4 Instrument . 11
9.3.5 Procedure . 12
9.3.6 Blank test . 13
9.3.7 Calculation of calibration coefficient . 13
9.3.8 Calculation . 13
9.4 Fusion-ammonia separation-acidimetric titration method . 14
10 Determination of aluminium, iron, and calcium . 14
10.1 Principle . 14
10.2 Reagents . 14
10.3 Apparatus and instrument . 14
10.4 Procedure . 15
10.5 Blank test . 15
10.6 Calibration . 15
10.7 Calculation . 15
11 Determination of oxygen . 17
11.1 Principle . 17
11.2 Reagents . 17
11.3 Apparatus . 17
11.4 Instrument . 17
11.5 Procedure . 17
11.6 Blank test . 17
11.7 Calculation of calibration coefficient . 17
11.8 Calculation . 18
12 Determination of carbon . 18
12.1 Classification of determination methods . 18
12.2 Combustion (induction furnace)-IR absorption spectrometry . 19
12.2.1 Principle . 19
12.2.2 Reagents . 19
12.2.3 Apparatus . 19
12.2.4 Instrument . 19
12.2.5 Procedure . 20
12.2.6 Blank test . 20
12.2.7 Calculation of calibration coefficient . 20
12.2.8 Calculation . 21
12.3 Combustion (resistance furnace)-coulometry . 21
12.4 Combustion (resistance furnace)-thermal conductivity . 21
13 Determination of fluorine and chlorine . 21
vi
ISO/DISPRF 17947-1:20252026(en)
13.1 Principle . 21
13.2 Reagents . 21
13.3 Apparatus and instruments . 22
13.4 Procedure . 22
13.4.1 Extraction of fluorine and chlorine from the sample . 22
13.4.2 Determination of fluorine and chlorine . 22
13.5 Blank test . 23
13.6 Calibration . 23
13.7 Calculation . 23
14 Reporting analytical values . 24
14.1 Number of analyses . 24
14.2 Evaluation of analytical values . 25
14.3 Expression of analytical values . 25
15 Test report . 25
Annex A (informative) List of commercial certified reference materials . 27
Annex B (informative) Analytical results obtained from a round robin test . 28
Annex C (informative) Spectral lines for ICP-OES . 33
Bibliography . 34

vii
ISO/PRF 17947-1:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO 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.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.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 206, Fine ceramics, in collaboration with the
European Committee for Standardization (CEN) Technical Committee CEN/TC 184, Advanced technical
ceramics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
This documentfirst edition of ISO 17947-1 cancels and replaces ISO 17947:2014 and EN ISO 17947:2023.
For this document, each clause of ISO 17947:2014 was comprehensively revised, both editorially and, which
has been technically. Clause 3 was added, noting that no terms or definitions are to be added to the document.
revised.
A list of all parts in the ISO 17947 series can be found on the ISO website.
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.htmlwww.iso.org/members.html.

viii
ISO/DISPRF 17947-1:20252026(en)
Introduction
[1]
This document has been developed from Japanese Industrial Standard JIS R 1603:2007 [1] with reference
[2] [3]
to CEN ENV 14226:2002 [2] and ASTM C1494-01:2007 ,[3], and is applicable to the chemical analysis of
silicon nitride raw powders for fine ceramics use. This document covers both major and minor constituents,
such as silicon, nitrogen, and some of trace metallic and non-metallic elements.
ix
DRAFT International Standard ISO/DIS 17947-1:2025(en)

Fine ceramics (advanced ceramics, advanced technical ceramics) —
Methods for chemical analysis of silicon nitride powders – —
Part 1:
Wet chemical methods, X-ray fluorescence (XRF) using the fused cast-
bead method, carrier-gas hot extraction (CGHE) and combustion
methods
1 Scope
This document specifies methods for the determination of silicon, nitrogen, aluminium, iron, calcium, oxygen,
carbon, fluorine, and chlorine in silicon nitride powders.
This document is applicable for the chemical analysis of silicon nitride powders used as raw material for fine
ceramics.
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 2828, Aluminium oxide primarily used for the production of aluminium — Determination of fluorine content
— Alizarin complexone and lanthanum chloride spectrophotometric method
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 6353--1, Reagents for chemical analysis — Part 1: General test methods
ISO 6353--2, Reagents for chemical analysis — Part 2: Specifications — First series
ISO 6353--3, Reagents for chemical analysis — Part 3: Specifications — Second series
ISO 8656--1, Refractory products — Sampling of raw materials and unshaped products — Part 1: Sampling
scheme
ISO 21068--2:2024, Chemical analysis of raw materials and refractory products containing silicon-carbide,
silicon-nitride, silicon-oxynitride and sialon — Part 2: Determination of volatile components, total carbon, free
carbon, silicon carbide, total and free silicon, free and surface silica
ISO 21068--3:2024, Chemical analysis of raw materials and refractory products containing silicon-carbide,
silicon-nitride, silicon-oxynitride and sialon — Part 3: Determination of nitrogen, oxygen and metallic and oxidic
constituents
ISO 21438--2, Workplace atmospheres — Determination of inorganic acids by ion chromatography — Part 2:
Volatile acids, except hydrofluoric acid (hydrochloric acid, hydrobromic acid and nitric acid)
ISO/PRF 17947-1:2026(en)
ISO 21438--3, Workplace atmospheres — Determination of inorganic acids by ion chromatography — Part 3:
Hydrofluoric acid and particulate fluorides
ISO 26845:2008, Chemical analysis of refractories — General requirements for wet chemical analysis, atomic
absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) methods
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/obphttps://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
4 Analytes and ranges
Analytes and ranges specified in this International Standarddocument shall be as follows.
a) a) Silicon (Si), range of 30 % to 70 % (mass fraction)
b) b) Nitrogen (N), range of 30 % to 45 % (mass fraction)
c) c) Aluminium (Al), range of 0,001 % to 0,6 % (mass fraction)
d) d) Iron (Fe), range of 0,001 % to 0,6 % (mass fraction)
e) e) Calcium (Ca), range of 0,001 % to 0,03 % (mass fraction)
f) f) Oxygen (O), range of 0,05 % to 5 % (mass fraction)
g) g) Carbon (C), range of 0,01 % to 6 % (mass fraction)
h) h) Fluorine (F), range of 0,001 % to 0,2 % (mass fraction)
i) i) Chlorine (Cl), range of 0,001 % to 0,2 % (mass fraction)
NOTE The results of an interlaboratory test conducted using three silicon nitride powder samples are listed in Annex
B.Annex B.
5 Preparation of test sample
5.1 General
The method of preparing samples shall be in accordance with ISO 8656--1 unless otherwise mutually agreed
upon between the analyser and the customer.
5.2 Sampling
Sampling shall be in accordance with ISO 8656--1.
ISO/DISPRF 17947-1:20252026(en)
5.3 Drying
The following procedure shall be used: Take about 10 g of the sample into a flat-type weighing bottle (60 mm
× 30 mm) and spread it uniformly over the bottom of the bottle. Place the bottle in a drying oven at
110 °C ± 5 °C for 2 h without a lid, and then cool in a desiccator (desiccant: magnesium perchlorate for drying)
with a lid for 1 h.
5.4 Weighing
The required quantity of the sample shall be weighed to the nearest 0,1 mg using a balance.
6 Apparatus and reagents
Unless otherwise specified for each determination, ordinary laboratory apparatus for chemical analysis as
listed in ISO 26845:2008, Clause 4 may be used. Reagents shall conform to the requirements of ISO 6353--1,
ISO 6353--2, and ISO 6353--3. Unless otherwise specified for each determination, reagents of analytical grade
listed in ISO 26845:2008, Clause 5, shall be used.
7 Blank test
Blank test shall be carried out without the sample by using identical quantities of reagents, conditions, and
procedures throughout each determination to correct the analytical values obtained.
8 Determination of silicon
8.1 Classification of determination methods
Silicon shall be determined by either of the following methods. If analytical results with four figures are
required, use the method A. If analytical results with two or three figures are required, the method B can be
used.
— — Method A: Fusion–dehydration/insolubilization separation–gravimetry and inductively coupled
plasma optical emission spectrometry (ICP-OES)
— — Method B: XRF using fused cast-bead method
8.2 Fusion-‑dehydration/insolubilization separation-‑gravimetry and ICP-OES
8.2.1 Principle
A sample is fused with alkaline carbonate and the melt is treated with an acid to separate into two parts of
silicon, insoluble silicon and soluble silicon, by filtration. Insoluble silicon is determined gravimetrically as
silicon dioxide after ignition of the insoluble residue, whereas soluble silicon is determined in the filtrate using
ICP-OES. The sum of them represents the content of silicon in the sample.
8.2.2 Reagents
Reagents of analytical grade shall be used. Reagent solutions shall be preserved in plastic bottles.
8.2.2.1 8.2.2.1 Water, of grade 1 or superior specified in ISO 3696.
8.2.2.2 8.2.2.2 Sodium carbonate, Na CO , anhydrous, specified in ISO 6353--3 or that of
2 3
higher grade.
8.2.2.3 8.2.2.3 Hydrochloric acid (1+1), (1+4), (1+50), HCl, concentrated hydrochloric acid
(c(HCl) = 32 %, mass fraction) diluted (1+1), (1+4) and (1+50) by volume with water (8.2.2.1).(8.2.2.1).
ISO/PRF 17947-1:2026(en)
8.2.2.4 8.2.2.4 Sulfuric acid (1+1), (1+4), H SO , concentrated sulfuric acid (c(H SO ) = 96 %,
2 4 2 4
mass fraction) diluted (1+1) and (1+4) by volume with water (8.2.2.1).(8.2.2.1).
8.2.2.5 8.2.2.5 Cellulose powder.
8.2.2.6 8.2.2.6 Polyethylene glycol (PEG) solution, (C H O) H O, 0,05 % mass fraction of
2 4 n 2
PEG, prepared by dissolving solid PEG in water (8.2.2.1).(8.2.2.1).
8.2.2.7 8.2.2.7 Hydrofluoric acid, HF, c(HF) = 48 %, mass fraction.
8.2.3 Apparatus and instruments
Ordinary laboratory apparatus and instruments for chemical analysis in accordance with ISO 26845:2008, 4
may be used.
8.2.3.1 8.2.3.1 Platinum dish.
8.2.3.2 8.2.3.2 Platinum crucible.
8.2.3.3 8.2.3.3 Burner, capable of heating at 1 100 °C.
8.2.3.4 8.2.3.4 Muffle furnace, capable of being operated at 1 100 °C.
8.2.3.5 8.2.3.5 Balance, readable to 0,1 mg.
8.2.3.6 8.2.3.6 Inductively coupled plasma optical emission spectrometer (ICP-OES).
8.2.4 Procedure
8.2.4.1 General
The procedure shall be as follows. The procedure described in ISO 21068--2:2024, Clause 8 may be
alternatively used.
8.2.4.2 Fusion of sample
The following procedure shall be used: Weigh 0,30 g of the sample and 2,0 g of sodium carbonate, anhydrous,
into a platinum dish and mix well. Start to heat carefully and increase the temperature gradually to 1 000 °C
to completely fuse the sample using a burner or a muffle furnace.
8.2.4.3 Separation of silicon
The following procedure shall be used: Add 20 ml of hydrochloric acid (1+1) to dissolve the melt on a hot
plate. Silicon dioxide will appear to be jellified and precipitated at this stage. There are two methods to
separate the precipitated silicon dioxide.
a) a) Dehydrate carefully the precipitate to dryness in order to prevent it from spattering and add
5 ml of hydrochloric acid (1+1) and 20 ml of water to dissolve hydrochloric acid soluble components of
the precipitate. Filtrate the precipitate with a filter paper and wash with hot hydrochloric acid (1+50)
several times and then with hot water sufficiently until it contains no salt. Collect the filtrate and washings
together in a volumetric flask and dilute to volume with water. Preserve this precipitate for gravimetry of
insoluble silicon and the solution for the ICP-OES determination of soluble silicon, respectively.
ISO/DISPRF 17947-1:20252026(en)
b) b) After formation of jellified silicon dioxide, add 0,05 g of cellulose powder and 10 ml of PEG
solution (8.2.2.6)(8.2.2.6) to agglomerate silicon dioxide for easy filtration. Filtrate and wash using the
same procedure as described in a), and then preserve this precipitate for gravimetry of insoluble silicon
and the solution for the ICP-OES determination of soluble silicon, respectively.
8.2.4.4 Gravimetry for insoluble silicon
The following procedure shall be used: Transfer the filter paper with the precipitate to a platinum crucible.
Heat the platinum crucible slowly using a burner (8.2.3.3)(8.2.3.3) or a muffle furnace (8.2.3.4)(8.2.3.4) until
complete ashing of the filter paper and then calcine the residue at 1 100 °C. Place the platinum crucible in a
desiccator to cool to room temperature. Weigh the platinum crucible. Moisten the residue in the platinum
crucible with a few drops of water (8.2.2.1)(8.2.2.1) and sulfuric acid (1+1) (8.2.2.4)(8.2.2.4) and add 10 ml of
hydrofluoric acid (8.2.2.7).(8.2.2.7). Then evaporate to dryness on a hot plate to remove all silicon dioxide,
calcine the residue at 1 100 °C using a burner or in a muffle furnace and place the platinum crucible in a
desiccator to cool to room temperature. Weigh the platinum crucible again. The loss of mass after hydrofluoric
acid treatment corresponds to the amount of insoluble silicon dioxide.
8.2.4.5 ICP-OES for soluble silicon
The following procedure shall be used: Nebulize the test solution obtained in 8.2.4.38.2.4.3 into the plasma of
an ICP-OES to determine soluble silicon in the sample.
NOTE An example for a suited silicon emission line is listed in Annex C.Annex C.
8.2.5 Blank test
Blank determinations shall be performed according to 8.2.4.28.2.4.2 to 8.2.4.58.2.4.5 without the sample.
8.2.6 Calibration
For ICP-OES, calibration solutions shall be prepared to span the range of concentration of silicon in the test
solution. Each calibration solution shall have a similar matrix to the test solution.
With those calibration solutions, the calibration function for soluble silicon shall be created to establish the
relation between the emission intensity measured with the test solution and the concentration of silicon in
the test solution.
8.2.7 Calculation
With the amount of insoluble silicon (8.2.4.4),(Error! Reference source not found.), soluble silicon
(8.2.4.5)(Error! Reference source not found.) and the blank test (8.2.5),(Error! Reference source not
found.), the content of silicon shall be calculated according to Formula (1).Error! Reference source not
found.
(1)
100 𝑉×(𝐴 −𝐴 )
1 0
𝑤 = ×[(𝑚 −𝑚 )×0,4674+ ]
𝑆𝑖 1 0
𝑚 10
(1)
where
w is the mass fraction of silicon in the sample, in percent;
Si
m is the mass of insoluble silicon dioxide in the sample (8.2.4.4),(8.2.4.4), in grams;
ISO/PRF 17947-1:2026(en)
m is the mass of insoluble silicon dioxide in the blank test (8.2.5),(8.2.5), in grams;
A is the concentration of soluble silicon in the test solution (8.2.4.3),(8.2.4.3), in milligrams per litre;
A is the concentration of soluble silicon in the blank solution (8.2.5),(8.2.5), in milligrams per litre;
V is the volume of the test and blank solution, in millilitres;
m is the mass of the sample (8.2.4.2),(8.2.4.2), in grams.
8.3 XRF using fused cast-bead method
The procedure shall be in accordance with ISO 21068-3:2024, 8.2.
9 Determination of nitrogen
9.1 Classification of determination methods
Nitrogen shall be determined by either of the following methods. Methods A and C provide a higher precision
than method B.
NOTE Based on practical experience, methods A and C provide a precision of two valid decimal places. Method B
usually provides a precision of one valid decimal place.
— — Method A: Acid pressure decomposition–distillation separation–acidimetric titration method
— — Method B: Inert gas fusion–thermal conductivity method
— — Method C: Fusion–ammonia separation–acidimetric titration method
9.2 Acid pressure decomposition-‑distillation separation-‑acidimetric titration method
9.2.1 9.2.1 Principle
The sample is decomposed in a pressure decomposition vessel with a mixture of hydrofluoric acid and sulfuric
acid to convert nitrogen into ammonia. Boric acid is added and the solution is transferred into
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