ISO 3180:2023

INTERNATIONAL ISO
STANDARD 3180
First edition
2023-07
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Methods for chemical analysis of
calcium-phosphate-based powders for
non-biomedical applications
Céramiques techniques — Méthodes d'analyse chimique des poudres à
base de phosphate de calcium pour applications non biomédicales
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Analytical 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 Reporting analytical values . 2
6.1 Number of analyses . 2
6.2 Blank test . 2
6.3 Evaluation of analytical results . 2
6.4 Expression of analytical results . 3
7 Decomposition of test sample .3
7.1 Reagents . 3
7.2 Apparatus . 3
7.3 Procedure . 3
7.3.1 Decomposition . . 3
7.3.2 Dilution . 3
7.4 Blank test . 3
8 Determination of phosphorus and calcium contents . 4
8.1 Classification of determination methods . 4
8.2 Precipitation and gravimetric method (for phosphorus) . 4
8.2.1 Principle . 4
8.2.2 Reagents . 4
8.2.3 Apparatus . 4
8.2.4 Procedure . 5
8.2.5 Blank test . 5
8.2.6 Calculation . 5
8.3 Titration method (for calcium) . 5
8.3.1 Principle . 5
8.3.2 Reagents . 5
8.3.3 Apparatus . 6
8.3.4 Procedure . 6
8.3.5 Blank test . 7
8.3.6 Calculation . 7
8.4 ICP–OES method (for calcium and phosphorus) . 7
8.4.1 Principle . 7
8.4.2 Reagents . 7
8.4.3 Apparatus . 8
8.4.4 Procedure . 8
8.4.5 Measurement . 9
8.4.6 Drawing of calibration curve . 9
8.4.7 Calculation . 10
9 Determination of impurity elements .11
9.1 Principle . 11
9.2 Reagents . 11
9.3 Apparatus .12
9.4 Procedure .12
iii
9.4.1 Preparation of sample test solutions .12
9.4.2 Preparation of calibration standard solutions .12
9.4.3 Preparation of blank test solution . 13
9.5 Measurement . 13
9.5.1 Set up of the instrument . 13
9.5.2 Measurement of sample test solution and calibration standard solutions .13
9.5.3 Measurement of blank test solution . 13
9.6 Drawing of the calibration curve . 14
9.7 Calculation . 14
10 Test report .14
Annex A (informative) Decomposition of insoluble precipitate using alkali fusion method .15
Annex B (informative) Interlaboratory chemical analysis of calcium-phosphate-based
powder .17
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.
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
INTERNATIONAL STANDARD ISO 3180:2023(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Methods for chemical analysis of calcium-
phosphate-based powders for non-biomedical applications
1 Scope
This document specifies wet chemical and inductively coupled plasma–optical emission spectrometry
(ICP–OES)-based methods for the chemical analysis of calcium-phosphate-based powders for non-
biomedical applications, such as those in the chemical industry, the treatment of air, water and soil
contamination.
It stipulates the methods used for the determination of major elements of calcium-phosphate-
based powders and their impurities. Calcium-phosphate-based powders are decomposed by acid
decomposition. The calcium content is determined using a titration method or an ICP–OES method. The
phosphorus content is determined using a precipitation and gravimetric method or an ICP–OES method.
Certain impurities, such as aluminium, barium, chromium, copper, iron, magnesium, manganese, nickel,
potassium, selenium, silicon, sodium, strontium, titanium and zinc contents, are determined by an ICP–
OES method.
This document does not include calcium-phosphate-based powders for biomedical applications.
The ISO 13779 series characterizes hydroxyapatite powders for biomedical applications using
various methods, such as atomic absorption spectrometry (AAS), inductively coupled plasma–mass
spectrometry (ICP–MS) and flame atomic absorption spectrometry (FAAS).
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 6353-2, Reagents for chemical analysis — Part 2: Specifications — First series
ISO 8656-1, Refractory products — Sampling of raw materials and unshaped products — Part 1: Sampling
scheme
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
calcium-phosphate-based powder
calcium phosphate powder with a small amount (not more than 1,0 % mass fraction) of each inorganic
element or impurity except calcium, phosphorous, oxygen and hydrogen
Note 1 to entry: Examples of calcium phosphate powders include tricalcium phosphate, octacalcium phosphate
and hydroxyapatite.
4 Analytical ranges
— Calcium (Ca), range of 30 % to 40 % (mass fraction).
— Phosphorus (P), range of 10 % to 20 % (mass fraction).
— Other analytes, range of 0,000 5 % to 1,0 % (mass fraction).
5 Preparation of test sample
5.1 General
Prepare the sample in accordance with ISO 8656-1, unless otherwise mutually agreed upon by the
analyst and customer.
5.2 Sampling
Collect the sample in accordance with ISO 8656-1.
5.3 Drying
Place 10 g of the sample into a flat-type weighing bottle and spread it uniformly at the bottom of
the bottle. Place the bottle for 2 h at 110 °C ± 5 °C, then cover the mouth of the bottle and cool it in a
desiccator for 1 h.
5.4 Weighing
Weigh the sample to the nearest 0,1 mg of the required quantity using a balance.
6 Reporting analytical values
6.1 Number of analyses
Prepare each sample twice and analyse them at intervals of time.
6.2 Blank test
Upon analysis, perform a blank test to correct the measured values. A double blank digestion is highly
recommended for the blank value determination.
6.3 Evaluation of analytical results
When the absolute difference between the two analytical results does not exceed the tolerance
(Table 1), the average value shall be reported. When the absolute difference between the two analytical
results exceeds the tolerance, perform two additional analyses. When the absolute difference of these
further two analyses does not exceed the tolerance, the average value thereof shall be reported. If the
difference also exceeds the tolerance, the median of four analytical results shall be reported.
Table 1 — Tolerances for two analytical results
Unit: % (mass fraction)
Analyte Range of results Tolerance
Ca, P – 0,1
Less than 0,01 % 0,001
Al, Ba, Cr, Cu, Fe, K, Mg, Mn,
Not less than 0,01 %, and less than 0,1 % 0,005
Na, Ni, Se, Si, Sr, Ti, Zn
Not less than 0,1 % 0,01
6.4 Expression of analytical results
Express the analytical results in % (mass fraction), in dryness.
a) Calcium and phosphorus: express the results to four significant digits, as required.
b) Others: express the results to four decimal places.
7 Decomposition of test sample
7.1 Reagents
It shall be ascertained that the reagents are of sufficiently high purity to permit their use without
compromising the accuracy of the determination.
7.1.1 Water, grade 1 or superior, as specified in ISO 3696.
7.1.2 Nitric acid (HNO ), 65 % min., as specified in ISO 6353-2 (R 19).
7.2 Apparatus
Use ordinary laboratory apparatus.
7.3 Procedure
7.3.1 Decomposition
Weigh 1,0 g of the test sample and transfer it to a 250 ml beaker. Add 10 ml of nitric acid (7.1.2) to the
beaker. Cover the beaker with a watch-glass and heat it at 180 °C ± 5 °C on a hot plate until the test
sample dissolves completely. Remove the beaker from the hot plate and cool it to room temperature.
If the precipitate falls out of the solution after the decomposition procedure, an additional process (e.g.
alkali fusion method) is necessary for decomposing the insoluble salt (see Annex A).
7.3.2 Dilution
After cooling, transfer the solution to a 250 ml volumetric flask. Rinse the inner wall of the beaker and
the watch-glass with a small quantity of water and put the washings into the flask. Dilute with water up
to the mark and mix well. This solution is designated the sample solution.
7.4 Blank test
Perform the operation described in 7.3 without sample. The resulting solution is designated as blank
solution.
8 Determination of phosphorus and calcium contents
8.1 Classification of determination methods
Method A: Precipitation and gravimetric method (for phosphorus).
Method B: Titration method (for calcium).
Method C: ICP–OES method (for phosphorus and calcium).
Analytical results of interlaboratory study for chemical analysis of calcium-phosphate-based powder
are described in Annex B.
8.2 Precipitation and gravimetric method (for phosphorus)
8.2.1 Principle
Phosphorus (P) in the sample solution is precipitated as quinoline phosphomolybdate
[(C H NH) PO · 12MoO ] by the addition of citromolybdate quinoline solution. After filtering, the mass
9 7 3 4 3
of the precipitate is measured. The content of phosphorus is calculated from the mass of the quinoline
phosphomolybdate.
8.2.2 Reagents
Use the reagents described in 7.1 together with the following.
8.2.2.1 Citromolybdate quinoline solution.
Dissolve 70 g of sodium molybdate dihydrate (Na MoO ·2H O) in 150 ml of water in a 250 ml beaker
2 4 2
(solution A).
Dissolve 60 g of citric acid monohydrate (C H O ·H O) in 150 ml of water in a 250 ml beaker, then add
6 8 7 2
85 ml of nitric acid (solution B).
Pour solution A and solution B into a 1 000 ml beaker and mix well (solution C).
Add 35 ml of nitric acid and 5 ml of recently distilled quinoline (C H N) to 100 ml of water in a 250 ml
9 7
beaker (solution D).
Pour solution C and solution D into a 1 000 ml beaker and mix well. Leave the solution undisturbed for
at least 12 h. Filter the solution using a filter paper. Add 280 ml of acetone (C H O) to the filtrate and
3 6
transfer it to a 1 000 ml volumetric flask. Dilute with water up to the mark and mix well.
Store the solution protected from light in a well-stoppered flask. Do not keep the solution for more than
1 week.
8.2.3 Apparatus
Use ordinary laboratory apparatus together with the following:
8.2.3.1 Sintered glass filter crucible, of porosity P10 (pore size between 4 μm and 10 μm).
Heat the filter crucible in an air bath controlled at 220 °C ± 20 °C and leave for 15 min after the
temperature stabilizes. Cool to room temperature in a desiccator containing silica gel.
8.2.3.2 Air bath, capable of heating at 250 °C ± 5 °C.
8.2.4 Procedure
Transfer 25,0 ml of the sample solution (7.3.2) into a 250 ml beaker. Add 100 ml of citromolybdate
quinoline solution (8.2.2.1) and heat the beaker on a hot plate at 75 °C ± 5 °C for 1 h. Remove the beaker
from the hot plate. Cool the solution to room temperature, stirring three or four times with a glass rod.
Decant the solution through the filter crucible (8.2.3.1). Store the filtrates and the washings for the
measurement of calcium content. This solution is designated the sample test solution for the titration
(8.3).
Wash the precipitate six times with approximately 30 ml of water each time. Place the filter crucible and
the precipitate in the air bath (8.2.3.2) at 85 °C ± 5 °C until completely dry. Cool to room temperature in
a desiccator and weigh to the nearest 0,1 mg.
8.2.5 Blank test
Perform the procedure described in 8.2.4 with the blank solution (7.4).
8.2.6 Calculation
Calculate phosphorus content, W , expressed as a percentage mass fraction, using Formula (1).
P
()mm−
SB
W = ××F ×100 (1)
P
m 25
where
W is the phosphorus content, in per cent (mass fraction);
P
m is the mass of the test sample (7.3), in g;
m is the mass of the precipitate in the sample test solution (8.2.4), in g;
S
m is the mass of the precipitate in the blank test solution (8.2.5), in g;
B
F is the conversion factor from quinoline phosphomolybdate [(C H NH) PO · 12MoO ] to
9 7 3 4 3
phosphorus (P) (= 0,014).
8.3 Titration method (for calcium)
8.3.1 Principle
Calcium (Ca) in the sample solution is precipitated as calcium oxalate (CaC O ) by the addition of
2 4
ammonium oxalate solution. After filtering, the solution is titrated with potassium permanganate. The
content of calcium is calculated from the volume of the titrant at the endpoint.
8.3.2 Reagents
It shall be ascertained that the reagents are of sufficiently high purity to permit their use without
compromising the accuracy of the determination.
8.3.2.1 Water, grade 1 or superior, as specified in ISO 3696.
8.3.2.2 Ammonium chloride (NH Cl), 99,5 % min., as specified in ISO 6353-2 (R 5).
8.3.2.3 Ammonia solution (NH OH), 25 % min., as specified in ISO 6353-2 (R 3).
8.3.2.4 Ammonium oxalate (C H N O ).
2 8 2 4
...