1、Designation: E2402 11 (Reapproved 2017)Standard Test Method forMass Loss and Residue Measurement Validation ofThermogravimetric Analyzers1This standard is issued under the fixed designation E2402; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides procedures for validatingmass loss and residue measurements by the
3、rmogravimetricanalyzers (TGA) and analytical methods based upon themeasurement of mass loss or residue content. Performanceparameters determined include mass loss and residue repeat-ability (precision), detection limit, quantitation limit, linearity,and bias.1.2 Validation of apparatus performance a
4、nd analyticalmethods is requested or required for quality initiatives or whereresults may be used for legal purposes.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 There is no ISO standard equivalent to this test method
5、.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to us
6、e.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers
7、to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE473 Terminology Relating to Thermal Analysis and Rhe-ologyE1142 Terminology Relating to Thermophysical PropertiesE1582 Test Method for Temperature Calibration
8、 of Thermo-gravimetric AnalyzersE1970 Practice for Statistical Treatment of ThermoanalyticalDataE2040 Test Method for Mass Scale Calibration of Thermo-gravimetric AnalyzersE2161 Terminology Relating to Performance Validation inThermal Analysis and Rheology2.2 Other Standard:U.S. FDA Q2B Validation o
9、f Analytical Procedures:Methodology, 62 FR 27464, May 19, 199733. Terminology3.1 Technical terms used in this standard are defined inPractice E177 and in Terminologies E473, E1142, and E2161.3.2 Definitions of Terms Specific to This Standard:3.2.1 highly volatile mattermaterials (such as moisture,pl
10、asticizer, residual solvent, etc.) that boil at temperaturesbelow 200C.3.2.2 medium volatile mattermaterials (such as oil andpolymer degradation products) that boil in the temperaturerange between 200 and 400C.3.2.3 residuematerial remaining (such as metalcomponents, filler content or inert reinforc
11、ing materials) aftermore volatile components are vaporized.3.2.4 mass loss plateaua region of a thermogravimetriccurve with a relatively constant mass (that is, accompanied bya minima in the first derivative of mass with respect to time).4. Summary of Test Method4.1 Mass is the primary dependent par
12、ameter and tempera-ture is the primary independent parameter measured by TGA.4.2 Mass loss and residue measurements are validated bytheir direct measurement using thermogravimetric apparatus1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct resp
13、onsibility of Subcommittee E37.10 onFundamental, Statistical and Mechanical Properties.Current edition approved Dec. 15, 2017. Published December 2017. Originallyapproved in 2005. Last previous edition approved in 2011 as E2402 11. DOI:10.1520/E2402-11R17.2For referenced ASTM standards, visit the AS
14、TM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Food and Drug Administration (FDA), 10903 NewHampshire Ave., Silver Spring, MD 20993
15、-0002, http:/www.fda.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles fo
16、r theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1over a specified temperature range using reference materials ofknown volatiles content as an analyte.4.3 Alternatively, validation of a TGA meth
17、od based uponmass loss and residue measurements may be performed usinga specific test specimen as the analyte.4.4 The mass loss of three or more specimens (nominallyrepresenting the maximum, midpoint, and minimum of therange of this test method) is measured at least in triplicate. Afourth blank spec
18、imen, containing no analyte, is also measuredat least in triplicate.NOTE 1Repeatability is determined by performing a sufficient numberof determinations to calculate statistically valid estimates of the standarddeviation or relative standard deviation of the measurements.4.4.1 Mass loss and residue
19、linearity and bias are deter-mined from the best-fit straight-line correlation of the resultsfrom measurements of the three or more specimens.4.4.2 Mass loss and residue detection limit and quantitationlimit are determined from the standard deviation of the blankspecimen measurements.4.4.3 Mass loss
20、 and residue repeatability are determinedfrom the repeatability measurements of the three or moreanalyte-containing specimens.5. Significance and Use5.1 This test method may be used to validate the perfor-mance of a specific TGA apparatus.5.2 This test method may be used to validate the perfor-mance
21、 of a specific method based upon a TGA mass loss orresidue measurement.5.3 This test method may be used to determine the repeat-ability of a specific apparatus, operator or laboratory.5.4 This test method may be used for specification andregulatory compliance purposes.6. Interferences6.1 This test m
22、ethod depends upon distinctive thermalstability ranges of the measured components as a principle ofthe test. For this reason, impurities or other materials that haveno well-defined thermally stable range, or the thermal stabilityof which are the same as other components, may createinterferences.7. A
23、pparatus7.1 Thermogravimetric Analyzer (TGA)The essential in-strumentation required to provide minimum thermogravimetrycapability for this test method includes:7.1.1 A thermobalance composed of:7.1.1.1 A furnace to provide uniform controlled heating of aspecimen to a constant temperature of 400C and
24、 at a constantrate between 5 and 25C/min.7.1.1.2 A temperature sensor to provide an indication of thespecimen/furnace temperature to 60.1C.7.1.1.3 A continuous recording balance with a minimumcapacity of 100 mg and a sensitivity of 610 g to measure thespecimen mass.7.1.1.4 A means of maintaining the
25、 specimen/containerunder a controlled atmosphere using an inert gas of 99.9+ %purity at a purge rate of 50 to 100 6 5 mL/min.NOTE 2Excessive purge rates should be avoided as they mayintroduce interferences due to turbulence effects and temperature gradi-ents.7.1.2 A temperature controller capable of
26、 executing a spe-cific temperature program by operating the furnace betweenselected temperature limits at a rate of temperature change of5 to 25C/min to within 6 0.5C/min.7.1.3 A data collection device, to provide a means ofacquiring, storing, and displaying measured or calculatedsignals, or both. T
27、he minimum output signals required forthermogravimetry are mass, temperature, and time.7.1.4 Containers (pans, crucibles, etc.) that are inert to thespecimen and that will remain gravimetrically stable up to450C.7.2 Graduated micropipettes with a capacity of 20 to 40 Lmeasurable to within 61 L.8. Re
28、agents and Materials8.1 Mass Loss Reference Materials, preferably certified formass loss covering a range of 2, 50, and 98 % mass loss overthe temperature range of 25 to 200C.NOTE 3Materials with other mass loss values may be used but shallbe reported.8.2 Nitrogen (or other inert purge gas) of 99.9+
29、 % purity.9. Hazards9.1 During the course of these experiments, organic vaporsare evolved from the specimen and will exhaust from theinstrument.Aventilation system shall be used to ensure that theoperator is not exposed to these vapors.9.2 Review the Material Safety Data Sheets (MSDS) for thecompone
30、nts of the mass loss reference materials for additionalsafety information.10. Calibration and Standardization10.1 After turning the power on, allow the instrument toequilibrate for at least one hour prior to any measurement.10.2 Perform any cleaning and calibration procedures de-scribed by the manuf
31、acturer in the apparatus operatorsmanual.10.3 If not previously established, perform temperature andmass calibrations according to Test Methods E1582 and E2040,respectively, using the same purge gas, purge flow rate andheating rate (here 10C/min) to be used for validation experi-ments.11. Procedure
32、for Determining Mass Loss and ResidueMeasurement Repeatability, Detection Limit,Quantitation Limit, Linearity and Bias11.1 This process involves characterizing, in triplicate,specimens with no mass loss and at least three or more testspecimens taken to represent the low, medium and highextremes of t
33、he range over which performance is to bevalidated.E2402 11 (2017)2NOTE 4The details of this procedure are written using mass lossreference materials as an analyte, and with a generic set of experimentalconditions. For validation of a specific mass loss method, specimens of theanalyte should be prepa
34、red to represent the range of the intended testmethod, and steps 11.2 to 11.20 replaced with the specific mass lossprocedure (that is, sample size, heating rate, purge gas, purge flow rate,etc.).11.2 Prepare at least 150 mg quantities of each of thereference specimens covering the mass loss range of
35、 the test.Nominal mass values might be 2, 50, and 98 mass loss %.NOTE 5Most thermoanalytical methods cover 1.5 to 2 decades ofrange. 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.
36、11.4 Using a micropipette, load 20 to 40 L 6 1Loflargest mass loss specimen (for example, the 98 mass loss %reference material) onto the sample container. Close theapparatus in preparation for conducting the experiment. Weighand record the test specimen mass as Mo(1). Purge the samplechamber with dr
37、y nitrogen (or other inert gas) at a flow rate of50 to 100 mL/min 6 10 % throughout the experiment.NOTE 6Other specimen volumes may be used but shall be reported.11.5 Heat the test specimen at 10C/min from 25 to 400Cand record the thermal curve.NOTE 7Other heating rates may be used but shall be repo
38、rted. Higherrates, however, may reduce the resolution between high volatility andmedium volatility component leading to poorer detection and quantitationlimits.11.6 Cool the test specimen to 25C. The thermal curveneed not be recorded.11.7 Select a point on the mass loss thermal curve from 11.5before
39、 and another on the mass loss plateau immediately afterthe first mass loss. These temperature points are identified at T1and T2, respectively. Record the masses at these two points asM1(1) and M2(1) (see Fig. 1).NOTE 8The valley of the first derivative curve may be useful inidentifying T2the point o
40、f maximum resolution between the lower (highvolatility) and higher temperature (medium volatility) mass loss regions.NOTE 9It is common to select T1to be ambient temperature and M1(1)to be Mo(1)11.8 Determine the mass loss between M1(1) and M2(1) asmass loss Mmax(1) according to Eq 2.11.9 Repeat ste
41、ps 11.3 through 11.8 for the medium massloss test specimen from step 11.2. Use the same measurementlimits (T1and T2) determined in step 11.7. Record this massloss Mmid(1).11.10 Repeat steps 11.3 through 11.8 for the low mass losstest specimen from step 11.2 Use the same measurement limits(T1and T2)
42、determined in step 11.7. Record the mass lossMmin(1).11.11 Repeat steps 11.3 through 11.8 for an empty containerin which no test specimen is used. This is the blank determi-nation. Use the same measurement limits (T1and T2) deter-mined in step 11.7 (Fig. 2). Record the mass remaining (Mr(1)in mg.NOT
43、E 10Observe and record the sign of the value for Mr. It may bepositive (apparent weight gain) or negative (apparent mass loss).11.12 Repeat steps 11.3 through 11.8 two more times for thelarge mass loss specimen. Record these values as mass lossesMmax(2) and Mmax(3).11.13 Repeat steps 11.3 through 11
44、.8 two more times for themedium mass loss specimen. Record these values as masslosses Mmid(2) and Mmid(3).FIG. 1 Determination of Mass Loss for Medium Mass Loss MaterialE2402 11 (2017)311.14 Repeat steps 11.3 through 11.8 two more times for thelow mass loss specimen. Record these values as mass loss
45、esMmin(2) and Mmin(3).11.15 Repeat steps 11.3 through 11.7 two more times for theblank (no test specimen) case. Record these values as residueMr(2) and Mr(3).11.16 Calculate the means (Mrand M), and standarddeviations (s) for the mass losses, respectively, from thereplicate determinations made on ea
46、ch of the three blank andmass loss specimens (see Practice E1970). Record these valuesas Mr, Mmax, Mmid, Mmin, sr, smax, smid, and smin.11.17 Using the standard deviation for the mass loss of theblank (sr) from 11.16, determine and report the mass loss andresidue detection limit (DL) and quantitatio
47、n limit (QL) usingEq 3 and Eq 4, respectively.11.18 Calculate the pooled relative standard deviation forthe mass loss from the smax, smid, and sminobtained in 11.16(see Practice E1970). Report this value as the mass lossrepeatability value (r) in mass %.11.19 Using the known mass loss values from st
48、ep 11.2 asthe independent (X) values and the mean values for mass lossfrom step 11.16 as the dependent (Y) values, determine theleast squares best-fit values for the slope (m) and intercept (b)(see Practice E1970).11.20 Calculate the linearity (L) from the values in 11.19using Eq 5.11.21 Report the
49、measurement bias as M, in mg. Themeasurement bias may be expressed as mass % for comparisonpurposes to the other validation parameters using Eq 6.12. Calculation12.1 When performing these calculations, retain all avail-able decimal places in the measured values and in intermediatecalculated values. The final result should be rounded to threesignificant figures.12.2 Residue is calculated by Eq 1.R 5 M23100%/Mo(1)where:R = residue, mass %,M2= mass at the higher temperature, mg, andMo= mass at the beginning of the experim
