ASTM E2402-19

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of the standard as published by ASTM is to be considered the official document.
Designation: E2402 − 11 (Reapproved 2017) E2402 − 19
Standard Test Method for
Mass Loss Loss, Residue, and ResidueTemperature
Measurement Validation of Thermogravimetric Analyzers
This standard is issued under the fixed designation E2402; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This test method provides procedures for validating mass loss loss, residue, and residuetemperature measurements by
thermogravimetric analyzers (TGA)(TGAs) and analytical methods based upon the measurement of mass loss or residue content.
content or temperature. Performance parameters determined include mass loss loss, residue, and residuetemperature repeatability
(precision), detection limit, quantitation limit, linearity, and bias.
1.2 Validation of apparatus performance and analytical methods is requested or required for quality initiatives or where results
may be used for legal purposes.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 There is no ISO standard equivalent to this test method.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E473 Terminology Relating to Thermal Analysis and Rheology
E1142 Terminology Relating to Thermophysical Properties
E1582 Test Method for Temperature Calibration of Thermogravimetric Analyzers
E1970 Practice for Statistical Treatment of Thermoanalytical Data
E2040 Test Method for Mass Scale Calibration of Thermogravimetric Analyzers
E2161 Terminology Relating to Performance Validation in Thermal Analysis and Rheology
2.2 Other Standard:
U.S. FDA Q2B Validation of Analytical Procedures: Methodology, 62 FR 27464, May 19, 1997
3. Terminology
3.1 Technical terms used in this standard are defined in Practice E177 and in Terminologies E473, E1142, and E2161. including
analyte, bow, calibration, Celsius, certification, certified reference material, Curie temperature, derivative, detection limit,
extrapolated onset value, linearity, magnetic transformation, onset point, plateau, precision, quantification limit, reference
material, repeatability, slope, standard deviation, thermogravimetry, thermogravimetric analysis, temperature, and validation.
3.2 Definitions of Terms Specific to This Standard:
This test method is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.10 on Fundamental,
Statistical and Mechanical Properties.
Current edition approved Dec. 15, 2017Sept. 1, 2019. Published December 2017September 2019. Originally approved in 2005. Last previous edition approved in 20112017
as E2402 – 11.E2402 – 11 (2017). DOI: 10.1520/E2402-11R17.10.1520/E2402-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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3.2.1 highly volatile matter—matter, n—materials (such as moisture, plasticizer, residual solvent, etc.) that boil at temperatures
below 200°C.200 °C.
3.2.2 mass loss plateau, n—a region of a thermogravimetric curve with a relatively constant mass (that is, accompanied by a
minima in the first derivative of mass with respect to time).
3.2.3 medium volatile matter—matter, n—materials (such as oil and polymer degradation products) that boil in the temperature
range between 200 °C and 400°C.400 °C.
3.2.4 residue—residue, n—material remaining (such as metal components, filler content or inert reinforcing materials) after
more volatile components are vaporized.
3.2.4 mass loss plateau—a region of a thermogravimetric curve with a relatively constant mass (that is, accompanied by a
minima in the first derivative of mass with respect to time).
4. Summary of Test Method
4.1 Mass is the primary dependent parameter and temperature is the primary independent parameter measured by
TGA.thermogravimetric analysis.
4.2 Mass loss and residue measurements are validated by their direct measurement using thermogravimetric apparatus over a
specified temperature range using reference materials of known volatiles content as an analyte.
4.3 Alternatively, validation of a TGAthermogravimetic method based upon mass loss and residue measurements may be
performed using a specific test specimen as the analyte.
4.4 The mass loss of three or more specimens (nominally representing the maximum, midpoint, and minimum of the range of
this test method) is measured at least in triplicate. A fourth blank specimen, containing no analyte, is also measured at least in
triplicate.
NOTE 1—Repeatability is determined by performing a sufficient number of determinations to calculate statistically valid estimates of the standard
deviation or relative standard deviation of the measurements.
4.4.1 Mass loss and residue linearity and bias are determined from the best-fit straight-line linear regressions (best-fit straight
line) correlation of the results from measurements of the three or more specimens.
4.4.2 Mass loss and residue detection limit and quantitation limit limit, quantitation limit, and repeatability are determined from
the standard deviation of the blank specimen measurements.
4.4.3 Mass loss and residue repeatability are determined from the repeatability measurements of the three or more
analyte-containing specimens.
4.5 Temperature measurement is validated using three or more temperature calibration materials (nominally representing the
minimum, midpoint, and maximum of the range of the test method) that are measured at least in triplicate.
4.5.1 Temperature linearity, bias, detection limit, quantitation limit, and repeatability are determined from the standard deviation
of these measurements.
5. Significance and Use
5.1 This test method may be used to validate the performance of a specific TGA apparatus.thermogravimetric analyzer.
5.2 This test method may be used to validate the performance of a specific method based upon a TGAthermogravimetry mass
loss or residue measurement.
5.3 This test method may be used to determine the repeatability of a specific apparatus, operator, or laboratory.
5.4 This test method may be used for specification and regulatory compliance purposes.
6. Interferences
6.1 This test method depends upon distinctive thermal stability ranges of the measured components as a principle of the test.
For this reason, impurities or other materials that have no well-defined thermally stable range, or the thermal stability of which
are the same as other components, may create interferences.
7. Apparatus
7.1 Thermogravimetric Analyzer (TGA)—The essential instrumentation required to provide minimum thermogravimetry
capability for this test method includes:
7.1.1 A thermobalance composed of:
7.1.1.1 A furnace to provide uniform controlled heating of a specimen to a constant temperature of 400°C at least 400 °C and
at a constant rate between 5 °C/min and 25°C/min.25 °C/min.
7.1.1.2 A temperature sensor to provide an indication of the specimen/furnace temperature readable to 60.1°C.60.1 °C.
7.1.1.3 A continuous recording balance (thermobalance) with a minimum capacity of 100 mg and a sensitivity of 610 μg to
measure the specimen mass.
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7.1.1.4 A means of maintaining the specimen/container under a controlled atmosphere using an inert gas of 99.9+ % purity at
a purge rate of 50 mL/min to 100 mL/min 6 5 mL/min.
NOTE 2—Excessive purge rates should be avoided as they may introduce interferences due to turbulence effects and temperature gradients.
7.1.2 A temperature controller capable of executing a specific temperature program by operating the furnace between selected
temperature limits at a rate of temperature change of 5 °C/min to 25°C/min 25 °C/min to within 6 0.5°C/min.0.5 °C/min.
7.1.3 A data collection device, to provide a means of acquiring, storing, and displaying measured or calculated signals, or both.
The minimum output signals required for thermogravimetry are mass, temperature, and time.
7.1.4 Containers (pans, crucibles, etc.) that are inert to the specimen and that will remain gravimetrically stable up to 450°C.450
°C.
7.2 Graduated micropipettes with a capacity of 20 μL to 40 μL measurable to within 61 μL.
8. Reagents and Materials
8.1 Mass Loss Reference Materials, preferably certified for mass loss covering a range of 2, 50, and 98 % mass loss nominally
2 %, 50 %, and 98 mass loss % over the temperature range of 25 °C to 200°C.200 °C.
NOTE 3—Materials with other mass loss values may be used but shall be reported.
8.2 Temperature Calibration Materials, preferably certified for transition temperature, representing the minimum, midpoint and
maximum of the applicable temperature range of the thermogravimetric analyzer (see Test Method E1582).
8.3 Nitrogen (or other inert purge gas) of 99.9+ % purity.
9. Hazards
9.1 During the course of these experiments, organic vapors are evolved from the specimen and will exhaust from the instrument.
A ventilation system shall be used to ensure that the operator is not exposed to these vapors.
9.2 Review the Material Safety Data Sheets (MSDS)(SDS) for the components of the mass loss reference materials and the
temperature reference materials for additional safety information.
10. Calibration and Standardization
10.1 After turning the power on, allow the instrument to equilibrate for at least one hour prior to any measurement.
10.2 Perform any cleaning and calibration procedures described by the manufacturer in the apparatus operator’s manual.
10.3 If not previously established, perform temperature and mass calibrations according to Test Methods E1582 and E2040,
respectively, using the same purge gas, purge flow rate, and heating rate (here 10°C/min) 10 °C/min) to be used for validation
experiments.
11. Procedure for Determining Mass Loss and Residue Measurement Repeatability, Detection Limit, Quantitation
Limit, Linearity, and Bias
11.1 This process involves characterizing, in triplicate, specimens with no mass loss and at least three or more test specimens
taken to represent the low, medium, and high extremes of the range over which performance is to be validated.
NOTE 4—The details of this procedure are written using mass loss reference materials as an analyte, and with a generic set of experimental conditions.
For validation of a specific mass loss method, specimens of the analyte should be prepared to represent the range of the intended test method, and steps
11.2 to 11.20 replaced with the specific mass loss procedure (that is, sample size, heating rate, purge gas, purge flow rate, etc.).
11.2 Prepare at least 150 mg 150-mg quantities of each of the reference specimens covering the mass loss range of the test.
Nominal mass values might be 2, 50, 2 %, 50 %, and 98 mass loss %.loss %.
NOTE 5—Most thermoanalytical methods cover 1.5 to 2 decades of range. The mass values selected should approximate the anticipated range. Other
masses losses and mass ranges may be used but shall be reported.
11.3 Tare the empty sample pan.
11.4 Using a micropipette, load 20 μL to 40 μL 6 1 μL of the largest mass loss specimen (for example, the 98 mass loss % loss
% reference material) onto the sample container. Close the apparatus in preparation for conducting the experiment. Weigh and
record the test specimen mass as M (1). Purge the sample chamber with dry nitrogen (or other inert gas) at a flow rate of 50 mL/min
o
to 100 mL/min 6 10 % throughout the experiment.
NOTE 6—Other specimen volumes may be used but shall be reported.
11.5 Heat the test specimen at 10°C/min 10 °C/min from 25 °C to 400°C 400 °C and record the thermal curve.
NOTE 7—Other heating rates may be used but shall be reported. Higher rates, however, may reduce the resolution between high volatility and medium
volatility component leading to poorer detection and quantitation limits.
11.6 Cool the test specimen to 25°C. 25 °C. The thermal curve need not be recorded.
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11.7 Select a point on the mass loss thermal curve from 11.5 before and another on the mass loss plateau immediately after the
first mass loss. These temperature points are identified at T and T , respectively. Record the masses at these two points as M (1)
1 2 1
and M (1) (see Fig. 1).
NOTE
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