ISO/TS 11251:2019

TECHNICAL ISO/TS
SPECIFICATION 11251
Second edition
2019-09
Nanotechnologies — Characterization
of volatile components in single-
wall carbon nanotube samples
using evolved gas analysis/gas
chromatograph-mass spectrometry
Nanotechnologies — Caractérisation des composés volatils dans les
nanotubes de carbone à simple paroi (SWCNT) utilisant l'analyse
des gaz émis par chromatographie en phase gazeuse couplée à la
spectrométrie de masse
Reference number
©
ISO 2019
© ISO 2019
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Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Sample preparation . 4
7 Measurement procedures for EGA/MS and EGA/GCMS. 4
7.1 General . 4
7.2 Measurement procedure of EGA/MS . 4
7.3 Measurement procedure of EGA/GCMS . 4
8 Data analysis and interpretations of results . 5
8.1 Qualitative analysis . 5
8.2 Mass loss analysis . 5
9 Accuracy and uncertainties . 5
10 Test report . 5
Annex A (informative) Case study. 7
Bibliography .12
Foreword
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This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies.
This second edition cancels and replaces the first edition (ISO/TS 11251:2010), which has been
technically revised.
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iv © ISO 2019 – All rights reserved

TECHNICAL SPECIFICATION ISO/TS 11251:2019(E)
Nanotechnologies — Characterization of volatile
components in single-wall carbon nanotube samples
using evolved gas analysis/gas chromatograph-mass
spectrometry
1 Scope
This document specifies a method for the characterization of evolved gas components in single-wall
carbon nanotube (SWCNT) samples using evolved gas analysis/gas chromatograph mass spectrometry
(EGA/GCMS).
NOTE Some difference could appear between qualitative and quantitative results of emitted gas and gas
content in the sample due to the heating and the possible presence of catalysts.
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/TS 80004-3, Nanotechnologies — Vocaburlary — Part 3: Carbon nano-objects
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 80004-3 and the
following apply.
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 http: //www .electropedia .org/
3.1
single-wall carbon nanotube
SWCNT
carbon nanotube consisting of cylindrical graphene layer
3.2
evolved gas analysis
EGA
technique in which the nature and/or amount of evolved gas product(s) released by a sample subjected
to a controlled temperature program is(are) determined
Note 1 to entry: The method of analysis should always be clearly stated (Reference [1] in the Bibliography).
3.3
EGA/MS
evolved gas analysis/mass spectrometry
technique using mass spectrometry to analyse gaseous components evolved from a sample as a function
of temperature
Note 1 to entry: Although the gases evolved at any particular temperature are detected simultaneously, it might
not be possible to uniquely identify the different components using MS alone.
3.4
EGA/GCMS
evolved gas analysis/gas chromatography coupled to mass spectrometry
technique combining a gas chromatograph and a mass spectrometer to identify the chemical
composition of gases evolved from a sample as a function of temperature
Note 1 to entry: The evolved gases are passed through a gas chromatograph (GC) to separate each component so
that it can be identified in the MS unit.
3.5
volatile compounds
compounds that are evolved from a sample at the temperature under consideration
4 Principle
EGA/MS and EGA/GCMS are used to characterize evolved gas impurities in samples of SWCNT. Evolved
gas compounds are identified by measuring the mass spectra of the gaseous component evolved from
the heated samples in a furnace or other suitable heating device, such as that used for programmed
temperature pyrolysis or thermogravimetric analysis. EGA/MS is used to determine the temperature
range over which the release of evolved gas components occurs. EGA/GCMS analysis is used to
identify each component separately by the use of a GC capillary column. Quantitative information can
additionally be obtained by the sample mass loss in thermogravimetric analysis (TGA) and the peak
area in EGA/MS.
NOTE Some details of the technique are described in References [2] to [6] in the Bibliography. EGA/
GCMS plays a complementary role to TGA, which is mainly devoted to quantifying the mass of the evolved gas
components.
5 Apparatus
Figure 1 shows a schematic diagram of EGA/MS which is composed of a furnace, a heating unit without
a GC capillary column and a MS unit. In the EGA/MS, evolved gas from the furnace is led to the MS unit
directly through a capillary tube without a separation process.
Figure 2 shows a schematic diagram of an EGA/GCMS which is composed of a furnace, a GC with a
capillary column and an MS unit. In the EGA/GCMS, all compounds evolved from the sample within the
furnace are captured by the cooling trap and are then introduced to the GC capillary column unit by
heating the trap. The compounds are separated by the column in the GC unit.
2 © ISO 2019 – All rights reserved

Key
1 furnace
2 heating unit
3 MS unit
4 temperature controller of furnace
Figure 1 — Schematic diagram of EGA/MS
Key
1 furnace
2 cooling trap
3 capillary column
4 GC unit
5 MS unit
6 temperature controller of furnace
Figure 2 — Schematic diagram of EGA/GCMS
6 Sample preparation
Sample preparation, such as dissolution or dispersion, is not required. For a qualitative analysis, the
sample shall be introduced into the EGA/MS or EGA/GCMS as it is. In order to avoid the vaporization of
any evolved gas that might be present, samples shall not be exposed to temperature above 30 °C before
analysis.
7 Measurement procedures for EGA/MS and EGA/GCMS
7.1 General
Load the SWCNT sample into the furnace and heat it up to identify the temperature range of gasification
using EGA/MS measurement, and use the EGA/GCMS to identify each component at the designated
temperature range.
7.2 Measurement procedure of EGA/MS
Weigh between 0,5 mg and 2 mg of the SWCNT sample, to the nearest 0,01 mg, using a calibrated mass
balance.
Load the weighed sample into the furnace, including the sample cup used when weighing.
Heat the sample at a constant rate until gas evolution stops. Measure the total ions from evolved gas
components. Determine the start temperature and the end-point of gasification using the EGA curve.
Compare the observed mass spectrum with the mass spectral database and determine each component
in the evolved gas species. For appropriate comparison of mass spectra, ionization energy and tuning
conditions used for the analysis shall match those in the spectral database.
Perform EGA/GCMS if the measured spectrum cannot be identified using the MS spectral database due
to the mixture of components (see 7.3).
Weigh the sample after EGA/MS measurement, to the nearest 0,01 mg.
NOTE The rate of heating depends on the calorific capacity of the sample. Generally, a range of 10 to 25 °C/
min is used for EGA/MS.
7.3 Measurement procedure of EGA/GCMS
Weigh between 0,5 mg and 2 mg of SWCNT from the same sample as that used in 7.2, to the nearest
0,01 mg.
Load the sample into the furnace.
Heat the sample at a constant rate to the lower temperature of either the end-point of the gasification or
upper limit of the instrument.
Compare the electron ionization (EI) mass spectrum for each of the GC peaks with the mass spectral
database and determine each component of the evolved gas species. For appropriate comparison of
mass spectra, ionization energy and tuning conditions used for the analysis shall match those in the
spectral database (typically 70 electron volts).
The mass analyser shall be calibrated manually or via the instrument’s tuning algorithm by using a
calibration reference material.
The rate of heating depends on the sample. Generally, a range of 45 to 65 °C/min is used for EGA/GCMS
to shorten the analytical time. The temperature of the trap should be less than abou
...