SIST EN ISO 10058-2:2009

SLOVENSKI STANDARD
SIST EN ISO 10058-2:2009
01-marec-2009
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SIST EN ISO 10058:1998
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Chemical analysis of magnesite and dolomite refractory products (alternative to the X-ray
fluorescence method) - Part 2: Wet chemical analysis (ISO 10058-2:2008)
Chemische Analyse von feuerfesten Erzeugnissen aus Magnesit und Dolomit
(Alternative zur Röntgenfluoreszenzanalyse) - Teil 2: Nasschemische Analyse (ISO
10058-2:2008)
Analyse chimique des produits de magnésie et de dolomie (méthode alternative a la
méthode par fluorescence de rayons X) - Partie 2: Méthodes d'analyse chimique par voie
humide(ISO 10058-2:2008)
Ta slovenski standard je istoveten z: EN ISO 10058-2:2008
ICS:
71.040.40 Kemijska analiza Chemical analysis
73.080 Nekovinske rudnine Non-metalliferous minerals
81.080 Ognjevzdržni materiali Refractories
SIST EN ISO 10058-2:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 10058-2:2009

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SIST EN ISO 10058-2:2009
EUROPEAN STANDARD
EN ISO 10058-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2008
ICS 73.080 Supersedes EN ISO 10058:1996
English Version
Chemical analysis of magnesite and dolomite refractory
products (alternative to the X-ray fluorescence method) - Part 2:
Wet chemical analysis (ISO 10058-2:2008)
Analyse chimique des produits de magnésie et de dolomie Chemische Analyse von feuerfesten Erzeugnissen aus
(méthode alternative à la méthode par fluorescence de Magnesit und Dolomit (Alternative zur
rayons X) - Partie 2: Méthodes d'analyse chimique par voie Röntgenfluoreszenzanalyse) - Teil 2: Nasschemische
humide (ISO 10058-2:2008) Analyse (ISO 10058-2:2008)
This European Standard was approved by CEN on 1 November 2008.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10058-2:2008: E
worldwide for CEN national Members.

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SIST EN ISO 10058-2:2009
EN ISO 10058-2:2008 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 10058-2:2009
EN ISO 10058-2:2008 (E)
Foreword
This document (EN ISO 10058-2:2008) has been prepared by Technical Committee ISO/TC 33 "Refractories"
in collaboration with Technical Committee CEN/TC 187 “Refractory products and materials” the secretariat of
which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2009, and conflicting national standards shall be withdrawn at
the latest by June 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 10058:1996.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 10058-2:2008 has been approved by CEN as a EN ISO 10058-2:2008 without any
modification.

3

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SIST EN ISO 10058-2:2009

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SIST EN ISO 10058-2:2009

INTERNATIONAL ISO
STANDARD 10058-2
First edition
2008-12-01


Chemical analysis of magnesite and
dolomite refractory products (alternative
to the X-ray fluorescence method) —
Part 2:
Wet chemical analysis
Analyse chimique des produits de magnésie et de dolomie (méthode
alternative à la méthode par fluorescence de rayons X) —
Partie 2: Méthodes d'analyse chimique par voie humide





Reference number
ISO 10058-2:2008(E)
©
ISO 2008

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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
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ii © ISO 2008 – All rights reserved

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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
Contents Page
Foreword .iv
1 Scope.1
2 Normative references.1
3 Determination of silicon(IV) oxide .2
4 Determination of aluminium oxide .4
5 Determination of iron(III) oxide .6
6 Determination of titanium(IV) oxide.7
7 Determination of manganese(II) oxide .8
8 Determination of calcium oxide .9
9 Determination of magnesium oxide .10
10 Determination of sodium oxide by flame photometry .11
11 Determination of potassium oxide by flame spectrophotometry.13
12 Determination of chromium(III) oxide.14
13 Determination of zirconium oxide by xylenol orange absorption spectroscopy .17
14 Determination of phosphorus(V) oxide by molybdenum blue method .18
15 Test report.19

© ISO 2008 – All rights reserved iii

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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 10058-2 was prepared by Technical Committee ISO/TC 33, Refractories.
This first edition of ISO 10058-2, together with ISO 10058-1 and ISO 10058-3, cancels and replaces
ISO 10058:1992 which has been technically revised to include the increasing use of flame atomic absorption
spectrophotometry (FAAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) methods
as well some improvements in the wet chemical analyses procedures developed in Japan.
ISO 10058 consists of the following parts, under the general title Chemical analysis of magnesite and dolomite
refractory products (alternative to the X-ray fluorescence method):
⎯ Part 1: Apparatus, reagents, dissolution and determination of gravimetric silica
⎯ Part 2: Wet chemical analysis
⎯ Part 3: Flame atomic absorption spectrophotometry (FAAS) and inductively coupled plasma atomic
emission spectrometry (ICP-AES)

iv © ISO 2008 – All rights reserved

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SIST EN ISO 10058-2:2009
INTERNATIONAL STANDARD ISO 10058-2:2008(E)

Chemical analysis of magnesite and dolomite refractory
products (alternative to the X-ray fluorescence method) —
Part 2:
Wet chemical analysis
1 Scope
This part of ISO 10058 specifies traditional (“wet process”) methods for the chemical analysis of magnesite
and dolomite refractory products and raw materials.
It is applicable to components within the ranges of determination given in Table 1.
Table 1 — Range of determination (percentage by mass)
Component Range Component Range
SiO 0,1 to 10 MgO 30 to 99,9
2
Al O 0,05 to 10 Na O 0,01 to 1
2 3 2
Fe O 0,01 to 10 K O 0,01 to 1
2 3 2
TiO 0,01 to 1 Cr O 0,01 to 3
2 2 3
MnO 0,01 to 1 ZrO 0,01 to 1
2
CaO 0,01 to 60 P O 0,01 to 5
2 5
LOI 0,01 to 60 — —
NOTE These values are after the loss on ignition (LOI) has been taken into account.
2 Normative references
The following referenced documents are indispensable for the application 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 10058-1:2008, Chemical analysis of magnesite and dolomite refractory products (alternative to the X-ray
fluorescence method) — Part 1: Apparatus, reagents, dissolution and determination of gravimetric silica
ISO 10058-3:2008, Chemical analysis of magnesite and dolomite refractory products (alternative to the X-ray
fluorescence method) — Part 3: Flame atomic absorption spectrophotometry (FAAS) and inductively coupled
atomic plasma emission spectrometry (ICP-AES)
ISO 26845, Chemical analysis of refractories — General requirements for wet chemical analysis, atomic
absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES)
methods
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
3 Determination of silicon(IV) oxide
3.1 General
The determination of silicon(IV) oxide is carried out using one of the following methods.
a) Combined use of the dehydration or the coagulation and molybdenum blue methods
This method is applied to samples consisting of more than 4 % by mass of silicon(IV) oxide (see 3.2).
b) Molybdenum blue method
This method is applied to samples consisting of less than 10 % by mass of silicon(IV) oxide (see 3.3).
3.2 Combined use of the coagulation and molybdenum blue methods
3.2.1 Principle
An aliquot portion of the stock solution (S1) (see ISO 10058-1:2008, Annex A), after pH adjustment, is treated
with ammonium molybdate and the silicomolybdate is reduced to yield molybdenum blue, the absorbance of
which is measured.
The sum of this residual silicon(IV) oxide in solution plus the mass of silicon (IV) oxide (m − m ) calculated in
1 2
accordance with ISO 10058-1:2008, 8.2.2.3.3, gives the total silicon(IV) oxide content.
3.2.2 Procedure
This determination should be commenced with little delay after the stock solution (S1) is prepared, as
prolonged standing may allow polymerization of silica to occur leading to low results.
Transfer 10 ml of stock solution (S1) (see ISO 10058-1:2008, Annex A) to a 100 ml plastic beaker, add 2 ml of
hydrofluoric acid (1+9) and mix with a plastic rod. Allow to stand for 10 min and add 50 ml of boric acid
solution. Add 2 ml of ammonium molybdate solution while mixing at a temperature of 25 °C and allow to stand
for 10 min. Add 5 ml of L (+)-tartaric acid solution while stirring and, after 1 min, add 2 ml of L (+)-ascorbic acid
solution. Transfer the solution to a 100 ml volumetric flask, dilute to the mark with water, mix and allow to
stand for 60 min.
Measure the absorbance of the solution in a 10 mm cell at a wavelength of 650 nm using water as reference.
3.2.3 Plotting the calibration graph
Transfer 0 ml, 2 ml, 4 ml, 6 ml, 8 ml and 10 ml aliquot portions [0 mg to 0,4 mg as silicon(IV) oxide] of dilute
standard silicon(IV) oxide solution (SiO 0,04 mg/ml) to separate 100 ml plastic beakers and add to each
2
10 ml of blank solution (B1) (see ISO 10058-1:2008, Annex A). Treat these solutions and measure the
absorbance as given in 3.2.2, and plot the absorbances against the amounts of silicon(IV) oxide. Prepare the
calibration graph by adjusting the curve so that it passes through the point of origin.
3.2.4 Blank test
Using the blank solution (B1) (see ISO 10058-1:2008, Annex A), carry out the procedure given in 3.2.2.
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
3.2.5 Calculation
Calculate the mass fraction of silicon(IV) oxide, w , expressed as a percentage, using Equation (1), with
SiO
2
the absorbances obtained by the procedures given in 3.2.2 and 3.2.4 and the calibration graph plotted in 3.2.3.
250
mm−+m−m×
()()
12 s b
10
w=×100 (1)
SiO
2
m
where
m is the mass from ISO 10058-1:2008, 8.2.2.3.3, in grams (g);
1
m is the mass from ISO 10058-12008, 8.2.2.3.3, in grams (g);
2
m is the mass of silicon(IV) oxide in the aliquot portion of stock solution (S1) as applicable, in grams (g);
s
m is the mass of silicon(IV) oxide in the aliquot portion of blank solution (B1) as applicable, in grams (g);
b
m is the mass of the test portion calculated in accordance with ISO 10058-1:2008, 8.2.2.3.1, in grams (g).
3.3 Molybdenum blue method
3.3.1 Principle
An aliquot portion of the stock solution (S′1) (see ISO 10058-1:2008, Annex A), after pH adjustment, is treated
with ammonium molybdate and the silicomolybdate is reduced to yield molybdenum blue, the absorbance of
which is measured.
3.3.2 Procedure
Transfer precisely an aliquot portion of stock solution (S′1) (see ISO 10058-1:2008, Annex A) to two 100 ml
plastic beakers and add to each an aliquot portion of blank solution (B′1) (see ISO 10058-1:2008, Annex A).
Add to each 2 ml of hydrofluoric acid (1+9), mix with a plastics rod and allow to stand for 10 min. Add 50 ml of
boric acid solution, dilute to 80 ml with water. Add 5 ml of ammonium molybdate solution while mixing at a
temperature of 25 °C and allow to stand for 10 min. Add 5 ml of L (+)-tartaric acid solution while stirring and,
after 1 min, add to 10 ml of L (+)-ascorbic acid solution. Transfer each solution to a 200 ml volumetric flask,
dilute to the mark with water and mix. Allow to stand for 60 min and measure the absorbance of the solutions
in a 10 mm cell at a wavelength of 650 nm against water as a reference. Average the two measurements.
NOTE Aliquot volumes of stock solution (S′1) and blank solution (B′1) corresponding to the mass fraction of
silicon(IV) oxide in the sample are shown in Table 2.
If the difference of the two absorbance measurements is greater than 0,005, repeat the procedure given in
3.3.2 and ISO 10058-1:2008, 8.2.3.3. When measurements of the same sample with around 1,0 absorbance
are repeated, it is necessary for the spectrophotometer to show the differences within 0,002.
Table 2 — Aliquot volumes of stock solution (S′1) and blank solution (B′1)
Mass fraction Aliquot volume Aliquot volume
of silicon(IV) oxide of stock solution (S′1) of blank solution (B′1)
% ml ml
< 2 20 0
W 2, < 4 10 10
W 4, u 10 5 15
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
3.3.3 Blank test
Carry out a blank determination by treating the blank solution (B1) (see ISO 10058-1:2008, Annex A) and
following the procedure described into 3.3.2. The volume of the aliquot portion of blank solution is the same as
those for the corresponding “S” solution.
3.3.4 Plotting of calibration graph
Transfer 0 ml, 5 ml, 10 ml, 15 ml, 20 ml and 25 ml aliquot portions [0 mg to 1 mg as silicon(IV) oxide] of dilute
standard silicon(IV) oxide solution (SiO 0,04 mg/ml) to separate 100 ml plastic beakers and add to each
2
20 ml of blank solution (B′1) (see ISO 10058-1:2008, Annex A). Treat these solutions and measure the
absorbance in accordance with the procedure from the addition of hydrofluoric acid (1+9) in 3.3.2. Plot the
absorbance against the amounts of silicon(IV) oxide and prepare the calibration graph by adjusting the curve
so that it passes through the point of origin.
3.3.5 Calculation
Calculate the mass fraction of silicon(IV) oxide, w , expressed as a percentage, using Equation (2), with
SiO
2
the amount of silicon(IV) oxide derived from the absorbance measurements obtained in 3.3.2 and 3.3.3 and
the calibration in 3.3.4.
mm− 250
sb
w =× ×100 (2)
SiO
2
mV
where
m is the mass of silicon(IV) oxide in the aliquot portion of stock solution (S′1), in grams (g);
s
m is the mass of silicon(IV) oxide in the aliquot portion of blank solution (B′1), in grams (g);
b
V is the aliquot portion volume of stock solution (S′1), in millilitres (ml);
m is the mass of the test portion in ISO 10058-1:2008, 8.2.3.3, in grams (g).
4 Determination of aluminium oxide
4.1 Principle
An aliquot portion of stock solution (S1) or (S′1) (see ISO 10058-1:2008, Annex A) is transferred. Excess
standard volumetric CyDTA solution is added to an aliquot portion of stock solution. A chelate compound of
aluminium CyDTA is formed by adjusting the pH with ammonia water. The pH is further adjusted by addition of
hexamethylenetetramine. The amount of remaining standard volumetric CyDTA is determined by back-titration
with standard volumetric zinc solution using xylenol orange as an indicator. The content of aluminium oxide is
calculated by allowing for the content of iron(III) oxide determined by the method given in Clause 5.
4.2 Procedure
4.2.1 Transfer precisely 50 ml of stock solution (S1), or stock solution (S′1), to a 300 ml beaker. Precisely

add an adequate amount of standard volumetric CyDTA solution [c(CyDTA) = 0,01 mol/l ] and dilute to 100 ml
with water.
The volume of standard volumetric CyDTA solution to be added depends on the percentage of aluminium
oxide and iron(III) oxide as shown in Table 3.
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
Table 3 — Volumes of standard volumetric CyDTA solution
Mass fraction of aluminium oxide and iron(III) oxide Volume of standard volumetric CyDTA solution
% ml
< 1 5
W 1, < 2 10
W 2, < 4 20
W 4, < 7 30
W 7 40
4.2.2 Add 1 g of hexamethylenetetramine and a drop of methyl orange solution as an indicator. Using drops,
add ammonia water (1+1) and ammonia water (1+9) of up to pH 3 until the solution indicates a slightly orange
colour. Allow to stand for 5 min.
If ammonia water (1+9) is added excessively, the pH can be adjusted to less than 3, showing a red colour, by
adding hydrochloric acid (1+1), before repeating the procedure in above paragraph.
4.2.3 Add 5 g of hexamethylenetetramine of up to pH 5,5 to pH 5,8, add 4 or 5 drops of xylenol orange

solution as an indicator and titrate with standard volumetric zinc solution [c(Zn) = 0,01 mol/l ]. Carry out the
titration gently while mixing. Record the end point of the titration when the colour changes from yellow to the
first appearance of a permanent reddish colour.
4.3 Blank test
Using a 50 ml aliquot portion of blank solution (B1), or blank solution (B′1) (see ISO 10058-1:2008, Annex A),
carry out the procedure in accordance with 4.2. Ensure that CyDTA standard volumetric solution is the same
as that used for the corresponding stock solution.
4.4 Calculation
Calculate the mass fraction of aluminium oxide, w , expressed as a percentage, using Equation (3).
Al O
23
(VV−×)F× 0,001 019 6
250
21
w=××100
Al O
23
m 50
(3)
−+[ww ×0,638 +w×0,719+w×0,414]
()
Fe O TiO MnO ZrO
23 2 2
where
V is the volume of standard volumetric zinc solution in 4.2.3, in millilitres (ml);
1
V is the volume of standard volumetric zinc solution in 4.3, in millilitres (ml);
2
F is the factor of standard volumetric zinc solution;
m is the mass of the weighed sample in ISO 10058-1:2008, 8.2.2.3.1 or 8.2.3.3, in grams (g);
w is the mass fraction of iron(III) oxide determined in 5.5 or in ISO 10058-3:2008, 3.2.6, expressed
Fe O
23
as a percentage;
w is the mass fraction of titanium(IV) oxide determined in 6.5 or in ISO 10058-3:2008, 3.2.6,
TiO
2
expressed as a percentage;
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
w is the mass fraction of manganese oxide determined in 7.5 or in ISO 10058-3:2008, 3.2.6 or
MnO
4.1.6, expressed as a percentage;
w is the mass fraction of zirconium oxide determined in 13.5 or in ISO 10058-3:2008, 3.2.6,
ZrO
2
expressed as a percentage.
5 Determination of iron(III) oxide
5.1 Principle
Stock solution (S1) or (S′1) (see ISO 10058-1:2008, Annex A) is transferred and iron is reduced with
L (+)-ascorbic acid. 1,10-Phenanthrolinium chloride is added, the pH is adjusted by adding ammonium acetate
and the iron coloured complex with phenanthrolinium is developed. The absorbance is measured.
5.2 Procedure
5.2.1 Transfer an aliquot portion, determined in accordance with Table 4, of either stock solution (S1) or
(S′1), to a 100 ml volumetric flask.
NOTE The aliquot portion volumes of stock solutions (S1) or (S′1) shown in Table 4 correspond to the content of
iron(III) oxide in the sample.
Table 4 — Aliquot volumes of stock solution (S1) or (S′1)
Mass fraction of iron(III) oxide Aliquot volume of stock solution (S1) or (S′1)
% ml
< 0,5 25
W 0,5, < 1,5 10
W 1,5, < 5 5

a
W 5 2
a
Alternatively, transfer precisely 20 ml of the stock solution to a 100 ml volumetric flask and dilute to the
mark with water. An aliquot portion of 10 ml may be used instead of the 2 ml of the stock solution.
5.2.2 Dilute to about 60 ml with water and, while mixing, add 5 ml of L (+)-tartaric acid solution and 2 ml of
L (+)-ascorbic acid solution. Add 10 ml of 1,10-phenanthrolinium chloride solution and 10 ml of ammonium
acetate solution. Dilute to the mark with water and allow to stand for 30 min. Measure the absorbance of the
solution in a 10 mm cell at a wavelength of 510 nm against water.
5.3 Blank test
Using an aliquot portion of blank solution (B1) or blank solution (B′1) (see ISO 10058-1:2008, Annex A), carry
out the procedure in accordance with 5.2. Use the same volume of aliquot portion for the blank solution as
used for the corresponding stock solution.
5.4 Plotting of calibration graph
Transfer 0 ml (as reference), 5 ml, 10 ml and 15 ml aliquot portions [0 mg to 0,6 mg as iron(III) oxide] of the
dilute standard iron(III) oxide solution (Fe O 0,04 mg/ml) to separate 100 ml volumetric flasks. Treat these
2 3
solutions in accordance with 5.2.2 and measure the absorbance against the reference solution. Plot the
relation between the absorbance measurements and mass of iron(III) oxide. Prepare the calibration graph by
adjusting the curve so that it passes through the point of origin.
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
5.5 Calculation
Calculate the mass fraction of iron(III), w , expressed as a percentage, using Equation (4). Use the
Fe O
23
amount of iron(III) oxide derived from the absorbance in 5.2 and 5.3, and the calibration in 5.4.
mm− 250
sb
w 100=× × (4)
Fe O
23
mV
where
m is the mass of iron(III) oxide in the aliquot portion of stock solution (S1) or (S′1), in grams (g);
s
m is the mass of iron(III) oxide in the aliquot portion of blank solution (B1) or (B′1), in grams (g);
b
m is the mass of the test portion in ISO 10058-1:2008, 8.2.2.3.1 or 8.2.3.3, in grams (g);
V is the volume of the aliquot portion taken from stock solution (S1) or (S′1) in 5.2.1, in millilitres (ml).
6 Determination of titanium(IV) oxide
6.1 Principle
Sample solution (S1) or (S′1) (see ISO 10058-1:2008, Annex A) is transferred. After the adjustment of acidity,
iron is reduced with the addition of L (+)-ascorbic acid. The titanium is coloured by the di-antipyrylmethane
(DAM) and the absorbance is measured.
6.2 Procedure
6.2.1 Transfer an aliquot portion, determined using Table 5, of either stock solution (S1) or (S′1)
(see ISO 10058-1:2008, Annex A), to a 50 ml volumetric flask.
NOTE The aliquot portions taken from stock solution (S1) or (S′1) shown in Table 5 correspond to the content of
titanium(IV) oxide in the sample.
Table 5 — Aliquot volumes taken from stock solution (S1) or (S′1)
Mass fraction of titanium(IV) oxide Aliquot volume taken of (S1) or (S′1)
% ml
< 0,5 25
W 0,5, < 1,5 10
W 1,5 5
6.2.2 Add 5 ml of hydrochloric acid (1+1), 2 ml of L (+)-ascorbic acid and allow to stand for 1 min. Add 15 ml
of DAM solution, dilute to the mark with water and allow to stand for 90 min. Measure the absorbance of the
solution in a 10 mm cell at a wavelength of 390 nm against water.
6.3 Blank test
Using the same aliquot portion of stock solution used in blank test solution (B1) or (B′1)
(see ISO 10058-1:2008, Annex A), carry out the procedure in 6.2.
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SIST EN ISO 10058-2:2009
ISO 10058-2:2008(E)
6.4 Plotting of calibration graph
Transfer 0 ml (as reference), 5 ml, 10 ml, 15 ml and 20 ml aliquot portions [0 mg to 0,20 mg as titanium(IV)
oxide] of the dilute standard titanium(IV) oxide solution (TiO 0,01 mg/ml) to separate 50 ml volumetric flasks
2
and treat these solutions in accordance with 6.2. Measure the absorbance against the reference solution. Plot
the relation between the absorbance and the amount of titanium(IV) oxide. Prepare the calibration graph by
adjusting the curve so that it passes through the point of origin.
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