oSIST prEN ISO 21813:2026

SLOVENSKI STANDARD
01-oktober-2026
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Metode za
kemijsko analizo praškov barijevega titanata visoke čistosti (ISO/DIS 21813:2026)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Methods for
chemical analysis of high purity barium titanate powders (ISO/DIS 21813:2026)
Hochleistungskeramik - Verfahren zur chemischen Analyse von hochreinen
Bariumtitanatpulvern (ISO/DIS 21813:2026)
Céramiques techniques (céramiques techniques avancées) - Méthodes d’analyse
chimique des poudres de titanate de baryum de haute pureté (ISO/DIS 21813:2026)
Ta slovenski standard je istoveten z: prEN ISO 21813
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 21813
ISO/TC 206
Fine ceramics (advanced ceramics,
Secretariat: JISC
advanced technical ceramics) —
Voting begins on:
Methods for chemical analysis
2026-07-20
of high purity barium titanate
Voting terminates on:
powders
2026-10-12
Céramiques techniques (céramiques techniques avancées) —
Méthodes d’analyse chimique des poudres de titanate de baryum
de haute pureté
ICS: 81.060.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
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Reference number
ISO/DIS 21813:2026(en)
DRAFT
ISO/DIS 21813:2026(en)
International
Standard
ISO/DIS 21813
ISO/TC 206
Fine ceramics (advanced ceramics,
Secretariat: JISC
advanced technical ceramics) —
Voting begins on:
Methods for chemical analysis
of high purity barium titanate
Voting terminates on:
powders
Céramiques techniques (céramiques techniques avancées) —
Méthodes d’analyse chimique des poudres de titanate de baryum
de haute pureté
ICS: 81.060.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
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Published in Switzerland Reference number
ISO/DIS 21813:2026(en)
ii
ISO/DIS 21813:2026(en)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Analytes and ranges . 1
5 Preparation of test sample . 2
5.1 General .2
5.2 Sampling .2
5.3 Drying .2
5.4 Weighing .2
6 Reporting the analytical values . . 3
6.1 Number of analyses .3
6.2 Blank value .3
6.3 Evaluation of the analytical values .3
6.4 Expression of the analytical values .3
7 Determination of the barium and titanium contents . 3
7.1 Classification of the determination methods .3
7.2 Acid decomposition-gravimetric method .4
7.2.1 Principle .4
7.2.2 Reagents .4
7.2.3 Apparatus .4
7.2.4 Procedure .5
7.2.5 Blank solution .5
7.2.6 Calculation .6
7.3 Acid decomposition-ICP-OES method .6
7.3.1 Principle .6
7.3.2 Reagents .6
7.3.3 Apparatus .6
7.3.4 Procedure .7
7.3.5 Blank solution .7
7.3.6 Calibration . . .7
7.3.7 Calculation .7
8 Determination of the trace element contents . 8
8.1 Principle .8
8.2 Reagents .8
8.3 Apparatus .8
8.4 Procedure .8
8.5 Blank solution .9
8.6 Calibration .9
8.7 Calculation .10
9 Determination of the total oxygen content. 10
9.1 Principle .10
9.2 Reagents .10
9.3 Apparatus .10
9.4 Instrument .10
9.5 Procedure .11
9.6 Blank value .11
9.7 Calculation of the calibration coefficient . 12
9.8 Calculation . 12
10 Determination of the total carbon content .12
10.1 Classification of the determination methods . 12

iii
ISO/DIS 21813:2026(en)
10.2 Combustion (resistance furnace)-IR absorption spectrometry . 12
10.2.1 Principle . 12
10.2.2 Reagents . 13
10.2.3 Apparatus . 13
10.2.4 Instrument . 13
10.2.5 Procedure .14
10.2.6 Blank value .14
10.2.7 Calculation of the calibration coefficient .14
10.2.8 Calculation . 15
10.3 Combustion (radio frequency heating furnace)-thermal conductometry . 15
10.3.1 Principle . 15
10.3.2 Reagents . 15
10.3.3 Apparatus . 15
10.3.4 Instrument .16
10.3.5 Procedure .16
10.3.6 Blank value .17
10.3.7 Calculation of the calibration coefficient .17
10.3.8 Calculation .17
10.4 Combustion (radio frequency heating furnace)-IR absorption spectrometry .17
10.4.1 Principle .17
10.4.2 Reagents .17
10.4.3 Apparatus .17
10.4.4 Instrument .17
10.4.5 Procedure .18
10.4.6 Blank value .19
10.4.7 Calculation of the calibration coefficient .19
10.4.8 Calculation .19
11 Test report . 19
Annex A (informative) Analytical results obtained from the round-robin test.20
Bibliography .22

iv
ISO/DIS 21813:2026(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
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of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
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Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
[1]
This document, which is based on, was prepared by Technical Committee ISO/TC 206, Fine ceramics.
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
DRAFT International Standard ISO/DIS 21813:2026(en)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Methods for chemical analysis of high purity
barium titanate powders
1 Scope
This document specifies methods for the chemical analysis of fine high purity barium titanate powders used
as the raw material for fine ceramics.
This document stipulates the determination methods of the barium, titanium, aluminium, cadmium,
calcium, cobalt, dysprosium, iron, lead, magnesium, manganese, nickel, niobium, potassium, silicon, sodium,
strontium, vanadium, zirconium, carbon and oxygen contents in high purity barium titanate powders.
The barium and titanium contents, the major elements, are determined by using an acid decomposition-
gravimetric method or an acid decomposition-inductively coupled plasma-optical emission spectrometry
(ICP-OES) method. The aluminium, cadmium, calcium, chromium, cobalt, dysprosium, iron, lead, magnesium,
manganese, nickel, potassium, silicon, strontium, vanadium and zinc contents are simultaneously
determined via an acid digestion-ICP-OES method. The oxygen content is determined via an inert gas fusion-
IR absorption spectrometry method. Finally, the carbon content is determined using a combustion-IR
absorption spectrometry method or a combustion-thermal conductometry method.
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 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
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological 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
a) Barium (Ba), range of 40 % to 60 % (mass fraction).
b) Titanium (Ti), range of 10 % to 30 % (mass fraction).

ISO/DIS 21813:2026(en)
c) Aluminium (Al), range of 0,001 % to 0,03 % (mass fraction).
d) Cadmium (Cd), range of 0,001 % to 0,03 % (mass fraction).
e) Calcium (Ca), range of 0,001 % to 0,03 % (mass fraction).
f) Cobalt (Co), range of 0,001 % to 0,03 % (mass fraction).
g) Dysprosium (Dy), range of 0,001 % to 0,03 % (mass fraction).
h) Iron (Fe), range of 0,001 % to 0,03 % (mass fraction).
i) Lead (Pb), range of 0,001 % to 0,03 % (mass fraction).
j) Magnesium (Mg), range of 0,001 % to 0,03 % (mass fraction).
k) Manganese (Mn), range of 0,001 % to 0,03 % (mass fraction).
l) Nickel (Ni), range of 0,001 % to 0,03 % (mass fraction).
m) Potassium (K), range of 0,001 % to 0,03 % (mass fraction).
n) Silicon (Si), range of 0,001 % to 0,03 % (mass fraction).
o) Sodium (Na), range of 0,001 % to 0,03 % (mass fraction).
p) Strontium (Sr), range of 0,001 % to 0,03 % (mass fraction).
q) Vanadium (V), range of 0,001 % to 0,03 % (mass fraction).
r) Zinc (Zn), range of 0,001 % to 0,03 % (mass fraction).
s) Oxygen (O), range of 10 % to 30 % (mass fraction).
t) Carbon (C), range of 0,01 % to 5 % (mass fraction).
5 Preparation of test sample
5.1 General
The sample preparation method shall be in accordance with ISO 8656-1, unless otherwise mutually agreed
upon by the analyser and customer.
5.2 Sampling
The sample shall be collected in accordance with ISO 8656-1.
5.3 Drying
Place a 10 g 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, uncovered, and cool in a
desiccator (desiccant: dried silica gel), covered, for 1 h.
5.4 Weighing
Weigh the sample to the nearest 0,1 mg using a balance.

ISO/DIS 21813:2026(en)
6 Reporting the analytical values
6.1 Number of analyses
Analyse the sample twice on different days.
6.2 Blank value
Determine the blank value for each analysis method described in this standard in order to correct the values
measured for the samples.
6.3 Evaluation of the analytical values
When the difference between the two analytical values does not exceed the tolerance value (Table 1),
the average value shall be reported. When the difference between the two analytical values exceeds the
tolerance value, perform two additional analyses. When the difference in these further two analyses does
not exceed the tolerance value, the average value thereof shall be reported. If the difference also exceeds the
tolerance value, the median of four analytical values shall be reported.
6.4 Expression of the analytical values
The analytical values shall be given in % (mass fraction), on a dry basis.
a) Barium, titanium and oxygen: express the results to two decimal places.
b) Others: express the results to three decimal places.
Table 1 — Tolerances for the analytical values
Units: % (mass fraction)
Al, Cd, Ca, Co, Dy, Fe, Pb, Mg, Mn, Ni,
Element Ba Ti O C
K, Si, Na, Sr, V, Zn
a a c
0,30 0,20 0,001
Tolerance 0,50 0,005
b b d
0,40 0,30 0,005
a
Acid decomposition-gravimetric method.
b
Acid decomposition-ICP-OES method.
c
Applicable to content of less than 0,01 % (mass fraction).
d
Applicable to content of not less than 0,01 % (mass fraction).
7 Determination of the barium and titanium contents
7.1 Classification of the determination methods
The barium and titanium contents shall be determined by either of the following methods:
— Method A, acid decomposition-gravimetric method;
— Method B, acid decomposition-ICP-OES method.
If analytical results with four significant figures are required, use method A; if two or three significant
figures are required, method B can be used.

ISO/DIS 21813:2026(en)
7.2 Acid decomposition-gravimetric method
7.2.1 Principle
A portion of the sample is decomposed using hydrogen peroxide and hydrochloric acid. The barium present
in the test solution is analysed by gravimetric analysis using sulfuric acid. The titanium in the test solution
is analysed by gravimetric analysis using ammonia solution.
7.2.2 Reagents
During the analysis, unless otherwise stated, only reagents of recognized analytical grade and only distilled
water or water of equivalent purity shall be used.
Reagents shall conform to the requirements of ISO 6353-1, ISO 6353-2 and ISO 6353-3 as appropriate.
Specific requirements for the reagents are given in the appropriate clause.
7.2.2.1 Ammonia water (NH ), (ISO 6353-2, R 3), 25 % (mass fraction).
7.2.2.2 Hydrogen peroxide (H O ), (ISO 6353-2, R 14), 30 % (mass fraction).
2 2
7.2.2.3 Hydrochloric acid (HCl), (ISO 6353-2, R 13), 35 % (mass fraction).
7.2.2.4 Sulfuric acid (H SO ), (ISO 6353-2, R 37), 95 % (mass fraction).
2 4
7.2.2.5 Hydrogen peroxide (1+10).
7.2.2.6 Hydrochloric acid (1+10).
7.2.2.7 Sulfuric acid (1+1).
7.2.2.8 Water, grade 1 or superior as specified in ISO 3696.
7.2.3 Apparatus
Ordinary laboratory apparatus together with the following:
7.2.3.1 PTFE beaker, 250 ml.
7.2.3.2 Burette, with a 0,1 ml scale and a maximum volume of 50 ml.
7.2.3.3 PTFE pipette, suitable for the transfer of each sample or standard solution.
7.2.3.4 Desiccator, containing dried silica gel as the drying agent.
7.2.3.5 Balance, capable of weighing to ±0,1 mg.
7.2.3.6 Electric furnace, for operation at (1 000 ± 50) °C.
7.2.3.7 Platinum crucible (30 ml).
7.2.3.8 PTFE beaker cover.
7.2.3.9 Volumetric flask (100 ml, 500 ml).

ISO/DIS 21813:2026(en)
7.2.3.10 Hot plate, with magnetic stirrer and magnetic bar.
7.2.4 Procedure
7.2.4.1 Weigh 0,30 g of the test sample and transfer it into a 250 ml PTFE beaker (7.2.3.1). Place the
magnetic bar in the PTFE beaker containing the test sample and carefully add 20 ml water, 10 ml hydrogen
peroxide (7.2.2.2) and 20 ml hydrochloric acid (7.2.2.3) to the beaker. Cover the beaker with a PTFE beaker
cover (7.2.3.8) and heat and stir the contents at (85 ± 5) °C using the hot plate (7.2.3.10) until the test sample
is completely dissolved. After cooling, transfer the solution to a 100 ml volumetric flask, dilute with water to
the mark and mix well.
The highly pure fine barium titanate powder sample completely decomposes in hydrochloric acid and
hydrogen peroxide. However, the presence of impurities or coarse grains in the sample may hinder the
decomposition process. If the sample is not completely decomposed by the acid decomposition method,
it is recommended that other decomposition methods are applied. These include the acid pressure
decomposition, fusion or acid microwave dissolution methods.
7.2.4.2 Transfer a 50 ml aliquot of the test solution (7.2.4.1) to a 250 ml PTFE beaker (7.2.3.1) and add
10 ml sulfuric acid (1+1) (7.2.2.7). After covering the beaker with a PTFE beaker cover (7.2.3.8), heat and stir
the contents at 200 °C for 1 h using the hot plate (7.2.3.10).
7.2.4.3 Filter the solution with ashless filter paper and wash the precipitate several times with hot water.
Keep the filtrate and washings in the beaker covered with the watch glass for the determination of the
titanium content.
7.2.4.4 Transfer the precipitate and the filter paper to a 30 ml platinum crucible. Heat the crucible in an
electric furnace at low temperature until the filter paper has been completely burned to ashes. Heat the
crucible and its contents in an electric furnace (1 000 ± 50) °C for 1 h. After cooling in a desiccator, weigh the
barium sulfate.
7.2.4.5 Add 50 ml ammonia water (7.2.2.1) to the filtrate (7.2.4.3). Filter the solution with ashless filter
paper and wash over the precipitate several times with hot water. Transfer the precipitate with filter paper
to a 30 ml platinum crucible. Heat the sample in an electric furnace at low temperature until ashing of the
filter paper is complete. Next, heat the crucible and its contents in an electric furnace at (1 000 ± 50) °C for
1 h. After cooling in a desiccator, weigh the titanium oxide.
7.2.5 Blank solution
Carry out the procedure described in 7.2.4 without the sample. Designate the final solution as the blank
solution.
ISO/DIS 21813:2026(en)
7.2.6 Calculation
Calculate the mass fractions of barium and titanium in the sample according to Formula (1).
100mm VF

21 1
w  (1)
mV
where
w is the mass fraction of barium or titanium in the sample, in percent;
m is the mass of the empty platinum crucible, in grams;
m is the mass of the platinum crucible after ignition (7.2.4.4 or 7.2.4.5), in grams;
m is the sample mass, in grams;
V is the volume of the sample solution (7.2.4.1), in millilitres;
V is the volume of the aliquot of the sample solution (7.2.4.2), in millilitres;
F is the element to compound mass ratio: 0,588 4 for barium in barium sulphate and 0,599 3 for
titanium in titanium dioxide.
7.3 Acid decomposition-ICP-OES method
7.3.1 Principle
A portion of the sample is decomposed in concentrated hydrogen peroxide and hydrochloric acid. The
barium and titanium present in the test solution are analysed by ICP-OES at selected emission lines.
7.3.2 Reagents
Use the reagents described in 7.2.2 together with the following:
7.3.2.1 Barium standard solution (Ba 10 mg/ml).
The SI traceable commercial standard solution is available.
7.3.2.2 Barium standard solution (Ba 1 mg/ml).
Transfer 10 ml barium standard solution (7.3.2.1) to a 100 ml volumetric flask, dilute with water to the mark
and mix well.
7.3.2.3 Titanium standard solution (Ti 10 mg/ml).
The SI traceable commercial standard solution is available.
7.3.2.4 Titanium standard solution (Ti 1 mg/ml).
Transfer 10 ml titanium standard solution (7.3.2.3) to a 100 ml volumetric flask, dilute with water to the
mark and mix well.
7.3.3 Apparatus
Use the apparatus described in 7.2.3 together with the following:
7.3.3.1 ICP-OES, consisting of a sample introduction system (pump, nebulizer, spray chamber), inductively
coupled plasma as excitation source, optical system, detector and computer with software for device control,
data acquisition and data evaluation.

ISO/DIS 21813:2026(en)
7.3.4 Procedure
7.3.4.1 Carry out the procedures described in 7.2.4.1.
7.3.4.2 After cooling, transfer a 10 ml aliquot of the solution into a 500 ml volumetric flask, dilute with
water to the mark and mix well. This solution is used as the test solution.
7.3.4.3 Spray a portion of the test solution into the argon plasma flame of the ICP-OES, then measure the
emission intensity for barium at 455,40 nm, 493,40 nm and 233,52 nm, and that for titanium at 334,94 nm,
336,12 nm and 337,27 nm. The measurements should be carried out using background correction.
NOTE To improve trueness and precision of the measurements the method of internal standard can be applied.
For this purpose, the ratio of intensities of the emission lines of analyte elements to the intensity of the emission line
of a reference element added to the test solutions is used to compensate for matrix effects and changed excitation
conditions in the plasma. The method of internal standard was not used by any of the laboratories participating in the
round-robin test (see Annex A).
7.3.5 Blank solution
Perform the operation described in 7.3.4 without using a sample. Designate the final solution as the blank
solution.
7.3.6 Calibration
Transfer 0 ml, 1 ml, 2 ml, 3 ml, 4 ml and 5 ml aliquots of the barium standard solution (7.3.2.2) and 0 ml,
0,5 ml, 1 ml, 1,5 ml, 2 ml and 2,5 ml of the titanium standard solution (7.3.2.4) to six separate 100 ml
volumetric flasks. To each flask, add 5 ml hydrochloric acid (1+10). Dilute with water to the mark and mix
well. The calibration functions are created by measurement of these six calibration solutions as described in
7.3.4.3. The measurements should be carried out using background correction.
NOTE 1 Based on practical experience, using less than six points for the calibration function usually has no impact
on the precision of the determination. It is recommended to use at least three points for the calibration function
including the zero point, for example, calibration solutions with a concentration of 0 mg/L, 25 mg/L and 50 mg/L for
barium and 0 mg/L, 12 mg/L and 25 mg/L for titanium.
NOTE 2 The calculation of the calibration functions is usually carried out as linear regression.
7.3.7 Calculation
Determine the barium and titanium concentrations in the test solution and blank solution from the
calibration function. Calculate the mass fraction of barium or titanium in the sample, w, according to
Formula (2).
CC VV

TB TS
w  (2)
10000Vm
A
where
w is the mass fraction of barium or titanium in the sample, in percent;
C is the measured barium or titanium concentration in the test solution (7.3.4.2), in milligrams
T
per litre;
C is the measured barium or titanium concentration in the blank test solution (7.3.5), in milligrams
B
per litre;
V is the volume of the test solution (7.3.4.2), in millilitres;
T
V is the volume of the sample solution (7.2.4.1), in millilitres;
S
V is the volume of the aliquot of the sample solution (7.2.4.1) used for preparation of the test
A
solution (7.3.4.2), in millilitres;
m is the mass of the test portion, in grams.

ISO/DIS 21813:2026(en)
8 Determination of the trace element contents
8.1 Principle
To prepare the test solution, the sample is decomposed in hydrochloric acid and hydrogen peroxide.
Aluminium, cadmium, calcium, chromium, cobalt, dysprosium, iron, lead, magnesium, manganese, nickel,
niobium, potassium, silicon, strontium, vanadium and zirconium are determined by ICP-OES at selected
emission lines.
8.2 Reagents
Use the reagents described in 7.2.2 together with the following:
8.2.1 Element standard solutions.
The SI traceable commercial standard solution is available for each of the following elements.
— aluminium standard solution (Al, 1 mg/ml);
— cadmium standard solution (Cd, 1 mg/ml);
— calcium standard solution (Ca, 1 mg/ml);
— cobalt standard solution (Co, 1 mg/ml);
— dysprosium standard solution (Dy, 1 mg/ml);
— iron standard solution (Fe, 1 mg /ml);
— lead standard solution (Pb, 1 mg/ml);
— magnesium standard solution (Mg, 1 mg/ml);
— manganese standard solution (Mn, 1 mg /ml);
— nickel standard solution (Ni, 1 mg/ml);
— potassium standard solution (K, 1 mg/ml);
— silicon standard solution (Si, 1 mg/ml);
— sodium standard solution (Na, 1 mg/ml);
— strontium standard solution (Sr, 1 mg/ml);
— vanadium standard solution (V, 1 mg/ml);
— zinc standard solution (Zn, 1 mg/ml).
8.2.2 Mixed standard solution (each element 50 mg/l), place 5 ml each of the element standard
solutions (8.2.1) in a 100 ml volumetric flask. Dilute with water to the mark and mix well. Attention shall be
paid to ensure that no precipitation occurs during the mixing. Prepare a fresh solution before use.
8.3 Apparatus
Use the apparatus described in 7.2.3.
8.4 Procedure
8.4.1 Carry out the procedures described in 7.2.4.1. This solution is designated as the test solution.

ISO/DIS 21813:2026(en)
8.4.2 Spray a portion of the test solution into the argon plasma flame of an ICP-OES and measure the
emission intensity at the appropriate wavelength (Table 2). Interferences may be encountered. Carefully
choose the optimum emission lines that are free from interferences. The measurements should be carried
out using background correction.
Table 2 — Recommended emission lines for each element
Wavelength 1 Wavelength 2
Element
nm nm
Al 396,15 308,21
Cd 228,80 214,44
Ca 317,93 315,88
Co 228,61 238,89
Dy 353,17 394,46
Fe 238,20 239,56
Pb 220,35 217,00
Mg 285,21 279,07
Mn 257,61 259,37
Ni 231,60 221,64
K 766,49 —
Si 251,61 212,41
Na 589,59 —
Sr 407,77 421,55
V 290,88 292,46
Zn 206,20 213,86
NOTE For spectrometers with Echelle optics, to mitigate spectral interferences and sensitivities higher-order emission lines
should be selected, if available.
8.5 Blank solution
Perform the operation described in 8.4 without taking a sample. Designate the final solution as the blank
solution.
8.6 Calibration
Pour 15 ml barium solution (7.3.2.1) and 6 ml titanium solution (7.3.2.3) separately into six 100 ml
volumetric flasks. Add 0 ml, 0,5 ml, 1 ml, 1,5 ml, 2 ml and 2,5 ml of the mix standard solution (8.2.2) stepwise
and precisely. Add 20 ml hydrochloric acid (7.2.2.3), dilute with water to the mark and mix well. Spray a
portion of each solution into the argon plasma flame of the ICP-OES and measure the emission intensity at
the appropriate wavelength. The measurements should be carried out using background correction.
NOTE 1 Based on practical experience, using less than six points for the calibration function usually has no impact
on the precision of the determination. It is recommended to use at least three points for the calibration function
including the zero point, for example, calibration solutions with a concentration of 0 mg/L, 0,6 mg/L and 1,25 mg/L for
each trace element.
NOTE 2 The calculation of the calibration functions is usually carried out as linear regression.

ISO/DIS 21813:2026(en)
8.7 Calculation
Determine the concentration of each element in the test solution and in the blank solution from the
calibration function. Calculate the mass fraction of each element in the sample, w , according to Formula (3).
i
CC V

iB T
w  (3)
i
10000m
where
w is the mass fraction of each element in the sample, in percent;
i
C is the measured concentration of each element in the test solution (7.2.4.1), in milligrams per
i
litre;
C is the measured concentration of each element in the blank test solution (8.5), in milligrams
B
per litre;
V is the volume of the test solution (7.2.4.1), in millilitres;
T
m is the mass of the test portion, in grams.
NOTE The analytical results obtained from the round-robin test are listed i
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