ISO TS 13278:2011

Nanotechnologies - Determination of elemental impurities in samples of carbon nanotubes using inductively coupled plasma mass spectrometry

Nanotechnologies - Dosage des impuretés dans les nanotubes en carbone (CNTs) par spectroscopie de masse à plasma induit (ICP-MS)

General Information

• Status: Withdrawn
• Publication Date: 31-Oct-2011
• Withdrawal Date: 02-Feb-2022
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 07.030 - Physics. Chemistry
• Technical Committee: TC 113 - Nanotechnology for electrotechnical products and systems
• Drafting Committee: JWG 2 - TC 113/JWG 2
• Current Stage: PPUB - Publication issued
• Completion Date: 31-Oct-2011

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 13278
First edition
2011-11-01
Nanotechnologies — Determination of
elemental impurities in samples of carbon
nanotubes using inductively coupled
plasma mass spectrometry
Nanotechnologies — Dosage des impuretés dans les nanotubes en
carbone (CNTs) par spectroscopie de masse à plasma induit (ICP-MS)
Reference number
ISO/TS 13278:2011(E)
©
ISO 2011
ISO/TS 13278:2011(E)
COPYRIGHT PROTECTED DOCUMENT
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii    © ISO 2011 – All rights reserved

ISO/TS 13278:2011(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.
In other circumstances, particularly when there is an urgent market requirement for such documents, a technical
committee may decide to publish other types of document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further
three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed,
it is reviewed again after a further three years, at which time it must either be transformed into an International
Standard or be withdrawn.
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/TS 13278 was prepared by Technical Committee ISO/TC 229, Nanotechnologies.
ISO/TS 13278:2011(E)
Introduction
Inductively coupled plasma mass spectrometry (ICP-MS) is a well-established multi-element analytical
technique used for fast, precise and accurate determinations of trace elements. ICP-MS has many advantages
over other elemental analysis techniques such as atomic absorption and ICP atomic emission spectrometry
(ICP-AES). The ability to handle both simple and complex matrices with a minimum of matrix interferences
is due to the high temperature of the ICP source. ICP-MS also has high sensitivity and superior detection
capability.
Owing to their unusual physical and chemical properties, and potential applications in a number of areas,
interest in carbon nanotubes (CNTs) has shown tremendous growth in the past decade. Metal particle catalysts
[1][2][3]
are essential in the mass production of nanotubes by chemical vapour deposition (CVD) . Removal of
these residual catalysts (typically Fe, Co, and/or Ni) after CNT production is one of the key challenges for the
[4]
application of CNTs in many fields . After complicated purification steps, the concentration of such catalysts
is measured. It is of great concern that the results of toxicological and ecological impact studies of carbon
[5][6][7]
nanotubes could be misinterpreted due to the presence of impurities in the test materials and that the
metals could be released into the environment during disposal of the product by means of combustion or other
ways. Additionally, the actual desired performance of nanotube materials might depend on these impurities,
which is the reason why it is so crucial to use reliable techniques to determine their content in these materials.
Currently available methods for analysis of the purity of CNTs include neutron activation analysis (NAA),
transmission electron microscopy (TEM) with electron energy loss spectroscopy (EELS), scanning electron
microscopy (SEM) with energy dispersive X-ray analysis (EDX), Raman spectroscopy, X-ray photoelectron
[8][9][10][11]
spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray fluorescence (XRF) spectrometry
[12]
. A number of these techniques for the characterization of single-wall and/or multiwall carbon nanotubes are
1)
the subject of standardization within ISO/TC 229, including SEM (ISO/TS 10798), TEM (ISO/TS 10797 ), and
2)
measurement methods for the characterization of multiwall carbon nanotubes (ISO/TR 10929 ).
However, each method has its limitations for determination of elemental impurities. TGA can only provide a
gross estimation of metal content. NAA is a quantitative and qualitative method based on nuclear reactions
between neutrons and target nuclei. This method provides high efficiency for the precise and simultaneous
determination of a number of major, minor and trace elements in different types of samples in the parts per
−9 −6
billion (10 ) to parts per million (10 ) range. Moreover, due to the superior figures of merit, including high
accuracy, good precision and no matrix blank requirement, NAA is widely used in the certification of reference
materials. NAA is, however, not a technique that is readily available, being not only a highly specialised field of
analysis, but also requiring access to a nuclear reactor. ICP-MS, on the other hand, is also capable of providing
highly accurate and precise results, while being widely available in most commercial laboratories. However,
using conventional solution sample introduction ICP-MS, the sample has to be completely solubilised. Digestion
of some types of samples requires thorough pretreatment schemes. Standard sample preparation procedures
are available for routine matrix types, including soils, rocks and biological specimens. In the case of carbon
nanotubes, because of their extremely stable structure and possible encapsulation of metals in structural
defects, it is necessary that the materials go through special destructive pretreatments before analysis by ICP-
[12][13][14][15]
MS . ICP-MS offers better sensitivity than graphite furnace atomic absorption spectrometry with the
multi-element speed of ICP-AES.
The purpose of this Technical Specification is to provide guidelines for optimized sample pretreatment methods
for single-wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs) to enable accurate
and quantitative determinations of elemental impurities using ICP-MS. An example of the determination of
elemental impurities in commercially produced carbon nanotubes, using the methods described, is given in
Annex A.
1) Under preparation.
2) Under preparation.
iv    © ISO 2011 – All rights reserved

TECHNICAL SPECIFICATION  ISO/TS 13278:2011(E)
Nanotechnologies — Determination of elemental impurities in
samples of carbon nanotubes using inductively coupled plasma
mass spectrometry
1  Scope
This Technical Specification provides methods for the determination of residual elements other than carbon
in samples of single-wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs) using
inductively coupled plasma mass spectrometry (ICP-MS).
The purpose of this Technical Specification is to provide optimized digestion and preparation procedures
for SWCNT and MWCNT samples in order to enable accurate and quantitative determinations of elemental
impurities using ICP-MS.
2  Normative reference
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/TS 80004-3, Nanotechnologies — Vocabulary — Part 3: Carbon nano-objects
3  Terms, definitions, symbols and abbreviations
3.1  Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 80004-3 and the following apply.
3.1.1
inductively coupled plasma source
device used to generate a plasma sustained in argon gas at atmospheric pressure by radiofrequency
electromagnetic fields
3.1.2
ICP-MS
inductively coupled plasma mass spectrometry
analytical technique comprising a sample introduction system, an inductively coupled plasma source for
generation of ions of the material(s) under investigation, a plasma/vacuum interface, and a mass spectrometer
comprising an ion focusing, separation and detection system
NOTE ICP-MS permits quantitative determinations of trace, minor and major elements in samples pertaining to
almost every field of application of analytical chemistry.
3.1.3
elemental impurity
element other than carbon that is present in a sample and not in the form of carbon nanotubes
NOTE 1 Such impurities are primarily remnants of metal catalysts used during large-scale production of CNTs.
NOTE 2 Amorphous carbon can be considered another type of impurity in samples containing SWCNTs and MWCNTs,
but is outside the scope of this Technical Specification.
ISO/TS 13278:2011(E)
3.2  Symbols and abbreviations
CCT collision cell technology
c sensitivity coefficient for input quantity, x , defined as df/dx
i i i
CNT carbon nanotube
C expected concentration, in micrograms per litre, of spiked sample solution based on the added
s
spike
CVD chemical vapour deposition
DRC dynamic reaction cell
ICP-MS inductively coupled plasma mass spectrometry
ICP-AES inductively coupled plasma atomic emission spectrometry
k
coverage factor
I dilution factor of the analysed sample solution, accounting for all sample preparation steps
d
MWCNT multiwall carbon nanotube
M measured concentration, in micrograms per litre, of the analysed sample solution
c
M measured concentration, in micrograms per litre, in the spiked sample solution
s
NAA neutron activation analysis
OD outer diameter
PTFE polytetrafluoroethylene
S weight, in grams, of CNT sample
w
SWCNT single-wall carbon nanotube
U expanded uncertainty
u (y) combined standard uncertainty of the final result
c
u(x ) standard uncertainty associated with input quantity, x
i i
V volume, in litres, of the analysed sample solution
wt % weight percentage
4  Samples and reagents
4.1  General
CNT samples produced by various processes typically contain impurities consisting of amorphous carbon
and other elements if they are not specifically separated. ICP-MS allows the determination of major, minor
and trace elements, providing quantitative information important for the characterization of the relative purity
of CNT samples. By acquiring the mass spectrum of the plasma, data can be obtained for almost the entire
periodic table in just minutes, with detection limits below 0,1 µg/l for most elements.
4.2  Samples
Samples shall be used that contain either SWCNTs or MWCNTs, or both.
2    © ISO 2011 – All rights reserved

ISO/TS 13278:2011(E)
4.3  Reagents
4.3.1  General
All reagents should be prepared and stored in polytetrafluoroethylene (PTFE) containers precleaned by nitric
acid and ultrapure water. Precleaned containers made from polypropylene, quartz, or other materials may also
be suitable.
4.3.2  Purity of acids
Ultra high purity acids (e.g. HNO , guaranteed reagent or equivalent grade) shall be used for sample dissolution
and preparation of calibration standards.
4.3.3  Purity of reagents
Guaranteed grade chemicals (99,99 % or higher than 99,99 %) shall be used in all tests (e.g. H O , guaranteed
2 2
reagent or equivalent grade). Certified reference materials should be used whenever available.
4.3.4  Purity of water
Ultrapure water having a resistivity of at least 18 MΩ cm shall be used in all tests.
4.4  Stock solutions
4.4.1  General
Stock solutions may be obtained directly as multi-element standards from accredited commercial vendors or
national metrology institutes as certified reference materials. They may also be prepared from single element
standards or suitable starting materials in-house, although this can be difficult due to problems with cross-
contamination. The following stock solutions shall be available for calibration of the instrument. The purity of
starting materials should be assessed.
4.4.2  ICP-MS calibration standard stock solution No. 1
1 000 mg/l of each element (Ca, Ce, Gd, Ge, Hg, La, Li, Sb, Sm, Ti, W, Yb) in 10 vol% HNO (1,6 mol/l HNO )
3 3
in water.
4.4.3  ICP-MS calibration standard stock solution No. 2
100 mg/l of each element (As, B, Be, Fe, Se, Zn) in 1,6 mol/l HNO in water.
4.4.4  ICP-MS calibration standard stock solution No. 3
10 mg/l of each element (Ag, Al, Ba, Bi, Cd, Co, Cr, Cu, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sr, Te, Tl, U, V)
in 1,6 mol/l HNO in water.
NOTE The working standard should be prepared daily.
4.5  Stock spike solutions
4.5.1  General
Multi-element spike standards are available from commercial vendors and national metrology institutes.
Alternatively, stock solutions of multi-element spike standards may be prepared in-house giving due
consideration to the purity of water and acids. The following stock spike solutions shall be available.
ISO/TS 13278:2011(E)
4.5.2  Stock spike solution No. 1
10 mg/l each of As, Ca, Co, Cr, Cu, Fe, Mn, Ni, Se, V, and Zn in 1,6 mol/l HNO in wat
...

TECHNICAL ISO/TS
SPECIFICATION 13278
First edition
2011-11-01
Nanotechnologies — Determination of
elemental impurities in samples of carbon
nanotubes using inductively coupled
plasma mass spectrometry
Nanotechnologies — Dosage des impuretés dans les nanotubes en
carbone (CNTs) par spectroscopie de masse à plasma induit (ICP-MS)

Reference number
ISO/TS 13278:2011(E)
©
ISO 2011
ISO/TS 13278:2011(E)
COPYRIGHT PROTECTED DOCUMENT
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii    © ISO 2011 – All rights reserved

ISO/TS 13278:2011(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.
In other circumstances, particularly when there is an urgent market requirement for such documents, a technical
committee may decide to publish other types of document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further
three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed,
it is reviewed again after a further three years, at which time it must either be transformed into an International
Standard or be withdrawn.
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/TS 13278 was prepared by Technical Committee ISO/TC 229, Nanotechnologies.

ISO/TS 13278:2011(E)
Introduction
Induc tively coupled plasma mass spectrometry (ICP-MS) is a well-established multi-element analytical
technique used for fast, precise and accurate determinations of trace elements. ICP-MS has many advantages

over other elemental analysis techniques such as atomic absorption and ICP atomic emission spectrometry

(ICP-AES). The ability to handle both simple and complex matrices with a minimum of matrix interferences

is due to the high temperature of the ICP source. ICP-MS also has high sensitivity and superior detection

capability.
Owing to their unusual physical and chemical properties, and potential applications in a number of areas,

interest in carbon nanotubes (CNTs) has shown tremendous growth in the past decade. Metal particle catalysts

[1][2][3]
are essential in the mass production of nanotubes by chemical vapour deposition (CVD) . Removal of
these residual catalysts (typically Fe, Co, and/or Ni) after CNT production is one of the key challenges for the
[4]
application of CNTs in many fields . After complicated purification steps, the concentration of such catalysts
is measured. It is of great concern that the results of toxicological and ecological impact studies of carbon
[5][6][7]
nanotubes could be misinterpreted due to the presence of impurities in the test materials and that the
metals could be released into the environment during disposal of the product by means of combustion or other
ways. Additionally, the actual desired performance of nanotube materials might depend on these impurities,
which is the reason why it is so crucial to use reliable techniques to determine their content in these materials.
Currently available methods for analysis of the purity of CNTs include neutron activation analysis (NAA),
transmission electron microscopy (TEM) with electron energy loss spectroscopy (EELS), scanning electron
microscopy (SEM) with energy dispersive X-ray analysis (EDX), Raman spectroscopy, X-ray photoelectron
[8][9][10][11]
spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray fluorescence (XRF) spectrometry
[12]
. A number of these techniques for the characterization of single-wall and/or multiwall carbon nanotubes are
1)
the subject of standardization within ISO/TC 229, including SEM (ISO/TS 10798), TEM (ISO/TS 10797 ), and
2)
measurement methods for the characterization of multiwall carbon nanotubes (ISO/TR 10929 ).
However, each method has its limitations for determination of elemental impurities. TGA can only provide a
gross estimation of metal content. NAA is a quantitative and qualitative method based on nuclear reactions
between neutrons and target nuclei. This method provides high efficiency for the precise and simultaneous
determination of a number of major, minor and trace elements in different types of samples in the parts per
−9 −6
billion (10 ) to parts per million (10 ) range. Moreover, due to the superior figures of merit, including high
accuracy, good precision and no matrix blank requirement, NAA is widely used in the certification of reference
materials. NAA is, however, not a technique that is readily available, being not only a highly specialised field of
analysis, but also requiring access to a nuclear reactor. ICP-MS, on the other hand, is also capable of providing
highly accurate and precise results, while being widely available in most commercial laboratories. However,
using conventional solution sample introduction ICP-MS, the sample has to be completely solubilised. Digestion
of some types of samples requires thorough pretreatment schemes. Standard sample preparation procedures
are available for routine matrix types, including soils, rocks and biological specimens. In the case of carbon
nanotubes, because of their extremely stable structure and possible encapsulation of metals in structural
defects, it is necessary that the materials go through special destructive pretreatments before analysis by ICP-
[12][13][14][15]
MS . ICP-MS offers better sensitivity than graphite furnace atomic absorption spectrometry with the
multi-element speed of ICP-AES.
The purpose of this Technical Specification is to provide guidelines for optimized sample pretreatment methods
for single-wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs) to enable accurate
and quantitative determinations of elemental impurities using ICP-MS. An example of the determination of
elemental impurities in commercially produced carbon nanotubes, using the methods described, is given in
Annex A.
1) Under preparation.
2) Under preparation.
iv    © ISO 2011 – All rights reserved

TECHNICAL SPECIFICATION  ISO/TS 13278:2011(E)

Nanotechnologies — Determination of elemental impurities in

samples of carbon nanotubes using inductively coupled plasma

mass spectrometry
1  Scope
This Technical Specification provides methods for the determination of residual elements other than carbon
in samples of single-wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs) using
inductively coupled plasma mass spectrometry (ICP-MS).
The purpose of this Technical Specification is to provide optimized digestion and preparation procedures
for SWCNT and MWCNT samples in order to enable accurate and quantitative determinations of elemental
impurities using ICP-MS.
2  Normative reference
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/TS 80004-3, Nanotechnologies — Vocabulary — Part 3: Carbon nano-objects
3  Terms, definitions, symbols and abbreviations
3.1  Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 80004-3 and the following apply.
3.1.1
inductively coupled plasma source
device used to generate a plasma sustained in argon gas at atmospheric pressure by radiofrequency
electromagnetic fields
3.1.2
ICP-MS
inductively coupled plasma mass spectrometry
analytical technique comprising a sample introduction system, an inductively coupled plasma source for

generation of ions of the material(s) under investigation, a plasma/vacuum interface, and a mass spectrometer
comprising an ion focusing, separation and detection system
NOTE ICP-MS permits quantitative determinations of trace, minor and major elements in samples pertaining to
almost every field of application of analytical chemistry.
3.1.3
elemental impurity
element other than carbon that is present in a sample and not in the form of carbon nanotubes
NOTE 1 Such impurities are primarily remnants of metal catalysts used during large-scale production of CNTs.
NOTE 2 Amorphous carbon can be considered another type of impurity in samples containing SWCNTs and MWCNTs,
but is outside the scope of this Technical Specification.
ISO/TS 13278:2011(E)
3.2  Symbols and abbreviations

CCT collision cell technology
c sensitivity coefficient for input quantity, x , defined as df/dx
i i i
CNT carbon nanotube
C expected concentration, in micrograms per litre, of spiked sample solution based on the added
s
spike
CVD chemical vapour deposition

DRC dynamic reaction cell
ICP-MS inductively coupled plasma mass spectrometry
ICP-AES inductively coupled plasma atomic emission spectrometry
k
coverage factor
I dilution factor of the analysed sample solution, accounting for all sample preparation steps
d
MWCNT multiwall carbon nanotube
M measured concentration, in micrograms per litre, of the analysed sample solution
c
M measured concentration, in micrograms per litre, in the spiked sample solution
s
NAA neutron activation analysis
OD outer diameter
PTFE polytetrafluoroethylene
S weight, in grams, of CNT sample
w
SWCNT single-wall carbon nanotube
U expanded uncertainty
u (y) combined standard uncertainty of the final result
c
u(x ) standard uncertainty associated with input quantity, x
i i
V volume, in litres, of the analysed sample solution
wt % weight percentage
4  Samples and reagents
4.1  General
CNT samples produced by various processes typically contain impurities consisting of amorphous carbon
and other elements if they are not specifically separated. ICP-MS allows the determination of major, minor
and trace elements, providing quantitative information important for the characterization of the relative purity
of CNT samples. By acquiring the mass spectrum of the plasma, data can be obtained for almost the entire
periodic table in just minutes, with detection limits below 0,1 µg/l for most elements.
4.2  Samples
Samples shall be used that contain either SWCNTs or MWCNTs, or both.
2    © ISO 2011 – All rights reserved

ISO/TS 13278:2011(E)
4.3  Reagents
4.3.1  General
All reagents should be prepared and stored in polytetrafluoroethylene (PTFE) containers precleaned by nitric

acid and ultrapure water. Precleaned containers made from polypropylene, quartz, or other materials may also

be suitable.
4.3.2  Purity of acids
Ultra high purity acids (e.g. HNO , guaranteed reagent or equivalent grade) shall be used for sample dissolution
and preparation of calibration standards.
4.3.3  Purity of reagents
Guaranteed grade chemicals (99,99 % or higher than 99,99 %) shall be used in all tests (e.g. H O , guaranteed
2 2
reagent or equivalent grade). Certified reference materials should be used whenever available.
4.3.4  Purity of water
Ultrapure water having a resistivity of at least 18 MΩ cm shall be used in all tests.
4.4  Stock solutions
4.4.1  General
Stock solutions may be obtained directly as multi-element standards from accredited commercial vendors or
national metrology institutes as certified reference materials. They may also be prepared from single element
standards or suitable starting materials in-house, although this can be difficult due to problems with cross-
contamination. The following stock solutions shall be available for calibration of the instrument. The purity of
starting materials should be assessed.
4.4.2  ICP-MS calibration standard stock solution No. 1
1 000 mg/l of each element (Ca, Ce, Gd, Ge, Hg, La, Li, Sb, Sm, Ti, W, Yb) in 10 vol% HNO (1,6 mol/l HNO )
3 3
in water.
4.4.3  ICP-MS calibration standard stock solution No. 2
100 mg/l of each element (As, B, Be, Fe, Se, Zn) in 1,6 mol/l HNO in water.
4.4.4  ICP-MS calibration standard stock solution No. 3
10 mg/l of each element (Ag, Al, Ba, Bi, Cd, Co, Cr, Cu, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sr, Te, Tl, U, V)
in 1,6 mol/l HNO in water.
NOTE The working standard should be prepared daily.
4.5  Stock spike solutions
4.5.1  General
Multi-element spike standards are available from commercial vendors and national metrology institutes.
Alternatively, stock solutions of multi-element spike standards may be prepared in-house giving due
consideration to the purity of water and acids. The following stock spike solutions shall be available.
...

SPÉCIFICATION ISO/TS
TECHNIQUE 13278
Première édition
2011-11-01
Nanotechnologies — Dosage des
impuretés dans les nanotubes en
carbone (CNTs) par spectroscopie de
masse à plasma induit (ICP-MS)
Nanotechnologies — Determination of elemental impurities in
samples of carbon nanotubes using inductively coupled plasma mass
spectrometry
Numéro de référence
ISO/TS 13278:2011(F)
©
ISO 2011
ISO/TS 13278:2011(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l’accord écrit
de l’ISO à l’adresse ci-après ou du comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Publié en Suisse
ii    © ISO 2011 – Tous droits réservés

ISO/TS 13278:2011(F)
Sommaire  Page
Avant-propos .iv

Introduction .v

1  Domaine d’application .1

2  Références normatives .1

3  Termes et définitions, symboles et abréviations .1

3.1  Termes et définitions .1

3.2  Symboles et abréviations .2

4  Échantillons et réactifs .2
4.1  Généralités .2
4.2  Échantillons .3
4.3  Réactifs .3
4.4  Solutions mères .3
4.5  Solutions mères de dopage .4
4.6  Solutions mères d’étalon interne .4
4.7  Solutions étalons mères de réglage .4
5  Appareillage .5
6  Prétraitement de l’échantillon .5
6.1  Préparation de l’échantillon pour l’analyse par ICP-MS .5
6.2  Digestion par voie humide sous haute pression .6
6.3  Incinération par voie sèche et digestion acide combinées .6
6.4  Digestion par micro-ondes .7
7  Modes opératoires expérimentaux .8
7.1  ICP-MS .8
7.2  Interférences dans l’ICP-MS .8
7.3  Sélection des isotopes .9
7.4  Courbe d’étalonnage .9
7.5  Évaluation du taux de récupération des méthodes au moyen des ajouts d’étalons .9
7.6  Utilisation des étalons internes dans l’analyse ICP-MS .9
8  Analyse des données et interprétation des résultats .10
8.1  Calcul de la fraction massique des impuretés élémentaires dans l’échantillon d’essai .10
8.2  Calcul du taux de récupération de l’agent de dopage (méthode) .10
9  Estimation de l’incertitude .11
10  Rapport d’essai .11
Annexe A (informative) Exemple de détermination des impuretés élémentaires dans des nanotubes de

carbone .13
Bibliographie .19
ISO/TS 13278:2011(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes nationaux de
normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est en général confiée aux

comités techniques de l’ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du comité

technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales,

en liaison avec l’ISO participent également aux travaux. L’ISO collabore étroitement avec la Commission

électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.

Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,

Partie 2.
La tâche principale des comités techniques est d’élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l’approbation de 75 % au moins des comités membres
votants.
Dans d’autres circonstances, en particulier lorsqu’il existe une demande urgente du marché, un comité
technique peut décider de publier d’autres types de documents:
— une Spécification publiquement disponible ISO (ISO/PAS) représente un accord entre les experts dans un
groupe de travail ISO et est acceptée pour publication si elle est approuvée par plus de 50 % des membres
votants du comité dont relève le groupe de travail;
— une Spécification technique ISO (ISO/TS) représente un accord entre les membres d’un comité technique
et est acceptée pour publication si elle est approuvée par 2/3 des membres votants du comité.
Une ISO/PAS ou ISO/TS fait l’objet d’un examen après trois ans afin de décider si elle est confirmée pour trois
nouvelles années, révisée pour devenir une Norme internationale, ou annulée. Lorsqu’une ISO/PAS ou ISO/TS
a été confirmée, elle fait l’objet d’un nouvel examen après trois ans qui décidera soit de sa transformation en
Norme internationale soit de son annulation.
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de droits
de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable de ne pas avoir
identifié de tels droits de propriété et averti de leur existence.
L’ISO/TS 13278 a été élaborée par le comité technique ISO/TC 229, Nanotechnologies.

iv    © ISO 2011 – Tous droits réservés

ISO/TS 13278:2011(F)
Introduction
La spectrométrie de masse à plasma induit (ICP-MS) est une technique d’analyse multi-éléments utilisée
pour les déterminations rapides, précises et exactes des éléments à l’état de traces. L’ICP-MS présente de

nombreux avantages par rapport à d’autres techniques d’analyse élémentaire telles que l’absorption atomique

et la spectroscopie d’émission atomique à plasma induit (ICP-AES). La capacité de traiter des matrices simples

et complexes avec un minimum d’interférences de la matrice est liée à la haute température de la source ICP.

L’ICP-MS possède également une grande sensibilité ainsi qu’une capacité de détection supérieure.

Compte tenu de leurs propriétés physiques et chimiques inhabituelles et de leurs applications potentielles

dans bon nombre de domaines, les nanotubes de carbone (CNT) ont suscité un intérêt croissant et connu une

évolution remarquable au cours de la dernière décennie. Les catalyseurs constitués de particules métalliques
[1][2]
sont essentiels dans la production en masse de nanotubes par dépôt chimique en phase vapeur (CVD)
[3]
. Après production de CNT, la suppression de ces catalyseurs résiduels (généralement Fe, Co, et/ou Ni) est
[4]
l’un des principaux défis pour l’application des nanotubes de carbone dans de nombreux domaines . Après
des étapes de purification compliquées, la concentration de ces catalyseurs est mesurée. Il est préoccupant
de constater que les résultats des études d’impact toxicologique et écologique de nanotubes de carbone
[5][6][7]
pourraient être mal interprétés en raison de la présence d’impuretés dans les matériaux d’essai et que
les métaux pourraient être libérés dans l’environnement pendant la mise au rebut du produit au moyen de
combustion ou d’autres moyens. En outre, les performances réelles attendues des matériaux de nanotubes
pourraient dépendre de ces impuretés, raison pour laquelle il est si crucial d’utiliser des techniques fiables pour
déterminer leur teneur dans ces matériaux.
Les méthodes actuellement disponibles pour l’analyse de la pureté des CNT comprennent l’analyse par
activation neutronique (NAA), la microscopie électronique en transmission (MET) avec la spectroscopie
de perte d’énergie des électrons (EELS), la microscopie électronique à balayage (SEM) avec l’analyse en
dispersion d’énergie des rayons X (EDX), la spectroscopie Raman, la spectroscopie de photoélectrons par
[8][9]
rayons X (XPS), l’analyse thermogravimétrique (TGA) et la spectrométrie par fluorescence des rayons X
[10][11][12]
. Un certain nombre de ces techniques de caractérisation de nanotubes de carbone à paroi simple
et/ou à parois multiples fait l’objet de normalisation au sein de l’ISO/TC 229, y compris la SEM (ISO/TS 10798),
1)
la TEM (ISO/TS 10797 ) et les méthodes de mesure pour la caractérisation des nanotubes de carbone à
2)
parois multiples (ISO/TR 10929 ).
Cependant, chaque méthode a ses limites pour la détermination des impuretés élémentaires. La TGA ne peut
fournir qu’une estimation brute de la teneur en métaux. La NAA est une méthode quantitative et qualitative
fondée sur des réactions nucléaires entre des neutrons et des noyaux cibles. Cette méthode fournit un
rendement élevé pour la détermination précise et simultanée d’un certain nombre d’éléments majeurs, mineurs
-9
et à l’état de trace dans différents types d’échantillons situés dans la plage des parties par milliard (10 ) aux
-6
parties par million (10 ). Par ailleurs, en raison de ses indices de comparaison supérieurs, dont une grande
précision, une bonne fidélité et pas de blanc matrice exigé, la NAA est largement utilisée pour la certification
des matériaux de référence. La NAA n’est cependant pas une technique facilement disponible, car il s’agit
non seulement d’un domaine hautement spécialisé de l’analyse, mais elle nécessite également l’accès à un
réacteur nucléaire. D’autre part, l’ICP-MS permet également d’obtenir des résultats très précis et fidèl es, tout
en étant largement disponible dans la plupart des laboratoires du commerce. L’utilisation de l’ICP-MS avec
introduction conventionnelle d’échantillon en solution nécessite cependant une solubilisation complète de
l’échantillon. La digestion de certains types d’échantillons requiert des procédés de prétraitement approfondi.
Les procédures de préparation des échantillons étalons sont disponibles pour des types de matrice usuels, y
compris les sols, les roches et les spécimens biologiques. Toutefois, dans le cas des nanotubes de carbone,
du fait de leur structure extrêmement stable et de l’encapsulation éventuelle de métaux dans les défauts de
[12][13]
structure, les matériaux doivent subir des prétraitements destructifs spéciaux avant analyse par ICP-MS
[14][15]
. L’ICP-MS est plus sensible que la spectroscopie d’absorption atomique en four graphite, compte tenu
de la capacité multi-éléments de l’ICP-AES.
Le but de la présente Spécification technique est de fournir des lignes directrices destinées à optimiser les
méthodes de prétraitement d’échantillons de nanotubes de carbone à paroi simple (SWCNT) et de nanotubes
de carbone à parois multiples (MWCNT) pour permettre des dosages exacts et quantitatifs des impuretés
1) En cours d’élaboration.
2) En cours d’élaboration.
...