1、Designation: E1868 10 (Reapproved 2015)Standard Test Methods forLoss-On-Drying by Thermogravimetry1This standard is issued under the fixed designation E1868; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. 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 These test methods describe a procedure for determiningthe amount of volatile matter of any kind that is driven off froma test spec
3、imen under a specific set of temperature and timeconditions. These test methods determine only the mass ofmaterial lost, not its identity.1.2 These test methods are applicable to a wide variety ofsolid or liquid materials, mixtures, or blends where the majorcomponent is stable at the test temperatur
4、e.NOTE 1These test methods can be applied to the analysis of volatileorganic compounds (VOC) content in metalworking fluids and directcontact lubricants subject to South CoastAir Quality Management District(SCAQMD) Rule 1144.1.3 The applicable temperature range for these test methodsare generally be
5、tween ambient temperature and 1000C.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 There is no ISO method equivalent to this test standard.1.6 This standard does not purport to address all of thesafety concerns, if any,
6、 associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D6 Test Method for Loss on Heating of Oil and Asphal
7、ticCompoundsD1475 Test Method For Density of Liquid Coatings, Inks,and Related ProductsD1509 Test Methods for Carbon BlackHeating LossD2216 Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Rock by MassD2288 Test Method for Weight Loss of Plasticizers onHeating (Withdr
8、awn 2010)3D2595 Test Method for Evaporation Loss of LubricatingGreases Over Wide-Temperature RangeD2832 Guide for Determining Volatile and Nonvolatile Con-tent of Paint and Related CoatingsD3175 Test Method for Volatile Matter in the AnalysisSample of Coal and CokeD4017 Test Method for Water in Pain
9、ts and Paint Materialsby Karl Fischer MethodD4893 Test Method for Determination of Pitch VolatilityE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE359 Test Methods for Analysis of Soda Ash (SodiumCarbonate)E473 Terminology Relating to Thermal Analysis and Rhe-ologyE691 Prac
10、tice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE897 Test Method for Volatile Matter in theAnalysis Sampleof Refuse-Derived Fuel (Withdrawn 2011)3E1142 Terminology Relating to Thermophysical PropertiesE1582 Practice for Calibration of Temperature Scale forTherm
11、ogravimetryE1860 Test Method for Elapsed Time Calibration of Ther-mal AnalyzersE2040 Test Method for Mass Scale Calibration of Thermo-gravimetric Analyzers2.2 SCAQMD Documents:4Rule 1144 Metalworking Fluids and Direct-Contact Lubri-cants3. Terminology3.1 Definitions:3.1.1 Specific technical terms us
12、ed in this test method aredefined in Terminology E473 and Terminology E1142, includ-ing thermogravimetry, thermogravimetric analyzer,repeatability, and reproducibility.1These test methods are under the jurisdiction of ASTM Committee E37 onThermal Measurements and is the direct responsibility of Subc
13、ommittee E37.01 onCalorimetry and Mass Loss.Current edition approved May 1, 2015. Published May 2015. Originallyapproved in 1997. Last previous edition approved in 2010 as E1868 10. DOI:10.1520/E1868-10R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
14、service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from South Coast Air Quality Management District (SCAQMD),21
15、865 Copley Drive, Diamond Bar, CA, 91765, http:/aqmd.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 A specimen of known mass is heated at a constanttemperature while its mass is continuously measured
16、as afunction of time. At the end of a pre-determined time interval,or when the loss reaches a pre-determined rate, the mass loss ofthe specimen is recorded as a percent of the original mass. Thisvalue is identified as the loss-on-drying (LOD) value. TheLOD value is a function of both temperature and
17、 time.Therefore these values must be identified and reported. Atypical LOD value is reported as LOD = XX % (60 min at120C). The volatile content, V (g/L), or VOC content, VOC(g/L), may be calculated.NOTE 2For SCAQMD Rule 1144 purposes, at the end of a pre-determined time interval and specified tempe
18、rature, the mass loss of thespecimen is recorded as a percent of the original mass. Additionally, thedensity and water content of the sample are determined. These values arethen used to calculate the VOC content.5. Significance and Use5.1 These test methods are used to estimate the amount ofvolatile
19、 materials present in a material.5.2 These test methods are useful for design purposes,service evaluation, regulatory statutes, manufacturing control,quality control, specification acceptance, development, andresearch.5.3 The results obtained by these test methods may beequivalent to those obtained
20、by other test methods and may beknown by other terms in their respective fields. Other tests andterms encountered include loss-on-heating (see Footnote5andTest Methods D6, D2288, and E359); heating loss (see TestMethod D1509); evaporative loss (see Test Method D2595);volatile organic carbon, moistur
21、e, or water (see Test MethodsD2216 and D3175); volatility (see Test Method D4893); highlyvolatile matter (see Test Method E897); and volatile content(see Guide D2832).6. Interferences6.1 Because the specimen size is usually small, care must betaken to ensure that each specimen is representative of t
22、hesample as a whole.6.2 This test procedure measures total mass loss underspecific experimental conditions. If more than one volatilecomponent is present, the results will reflect the total of allthose volatile components present.6.3 If the test temperature is set too high, the resultantweight loss
23、may include some decomposition of the matrixmaterial.6.4 When calculating VOC content for SCAQMDRule 1144 purposes, it may be necessary to measure andcorrect for water content. Refer to Test Method D4017 todetermine the water content of the specimen.7. Apparatus7.1 Thermogravimetric Analyzer, capabl
24、e of continuouslyrecording specimen mass and temperature as a function of timeconsisting of:7.1.1 Electrobalance, with a minimum specimen capacity of100 mg capable of continuously recording 10 g or smallermass changes. Performance may be verified in accordance withTest Method E2040.7.1.2 Specimen Ho
25、lders, that are inert to the specimen andof suitable structural shape and integrity to contain the 10 mgtest specimen used in these test methods. Specimen holders,composed of platinum, aluminum, or quartz may be used, butother holders may be considered.NOTE 3For SCAQMD Rule 1144 purposes, specimen h
26、olders must beshallow and composed of platinum.7.1.3 Furnace, whose temperature can be controlled from25 to 1000C, capable of a heating rate, at a minimum, of5C/min and of maintaining a set temperature isothermallywithin that range to 62C.7.1.4 Temperature Sensor to provide an indication of thespeci
27、men or furnace temperature, or both, to 60.1C.NOTE 4The temperature sensor shall be placed as close as practical tothe test specimen without disturbing weight measurements or as specifiedby the manufacturer. In addition, it must be located in exactly the sameposition during analytical determinations
28、 as used during calibration.7.1.5 Specimen Atmosphere Control System, capable ofsupplying inert dry gas (usually purified grade nitrogen) withan operator selectable flow rate of 50 to 100 mL min to within65 mL min.NOTE 5For SCAQMD Rule 1144 purposes, use purified grade nitro-gen for both the sample
29、purge flow and balance protection flow.7.1.6 Measurement System, to continuously record speci-men temperature to within 60.1C over the range from 25 to1000C.7.1.7 Timer, capable of continuously recording elapsed timeup to 20 h to within 6 0.1 min or 61 %, whichever is greater.Performance may be veri
30、fied in accordance with Test MethodE1860.7.1.8 Controller, capable of executing a temperature pro-gram by operating the furnace from 25 to 1000C at aminimum rate of 5C/min to within 60.1C/min and ofmaintaining a set temperature isothermally within the range of62C.7.1.9 Data Collection Device, provid
31、e a means of acquiring,storing, and displaying measured or calculated signals, or both.The minimum output signals required for thermogravimetricanalysis (TGA) are mass, temperature, and time.7.1.10 While not required, it is convenient to have a dataanalysis device that will continuously perform and
32、display thefollowing calculation:7.1.10.1 Specimen mass as a percent of the initial mass.7.1.10.2 Specimen mass rate of change (in mass % min)capable of detecting 0.01 % min.7.1.11 While not required, it is convenient to have anexperiment control device capable of terminating the experi-ment under t
33、he following conditions:5Formulary Vol XVII is available from U.S. Pharmacopeia (USP), 12601Twinbrook Pkwy., Rockville, MD 20852-1790, http:/www.usp.org.E1868 10 (2015)27.1.11.1 When an operator selected period of time at anisothermal temperature condition has elapsed, and7.1.11.2 When an operator s
34、elected rate of mass loss isachieved.7.2 Gas Exhaust System capable of removing from thelaboratory the potentially noxious purge gas effluent of thesystem above.7.3 Inert GasPurified grade nitrogen.7.4 Micropipettes or Syringes, for liquids, capable of dis-pensing up to 15 6 1 L.8. Hazards8.1 Toxic
35、or corrosive effluent, or both, may be releasedwhen heating some materials and could be harmful to person-nel and to apparatus.9. Sampling9.1 Samples are usually analyzed on “as received” basis.Should some thermal or mechanical treatment (such as grind-ing or sieving) be applied to the sample prior
36、to analysis, itshall be indicated in the report. Grinding may release volatilesdue to the heating generated by grinding process.9.2 Since small test specimens are used, they must behomogeneous and representative of the sample. The mixing orstirring of samples prior to analysis is recommended wheneve
37、rpossible.9.3 If experiments are to be initiated at room temperature,equilibrate samples in their sealed containers to room tempera-ture prior to testing.NOTE 6For SCAQMD Rule 1144 purposes, samples containing solidparticles should be filtered prior to analysis.10. Calibration10.1 Calibrate the temp
38、erature signal from the apparatusaccording to Practice E1582 using a heating rate of 1C/minand a transition temperature close to the isothermal testtemperature used in this procedure.10.2 Calibrate the mass signal from the apparatus accordingto Test Method E2040.NOTE 7Regular analysis of performance
39、 standards (materials ofknown mass loss characteristics) where available,6serves as a check oninstrument status, operator efficiency, etc., and provides for a comparisonof results from different laboratories. Verify mass measurement confor-mity to better than 1 %. Verify time measurement conformity
40、to betterthan 1 %.10.3 Calibrate the time signal from the apparatus accordingto Test Method E1860.NOTE 8For SCAQMD Rule 1144 purposes, calibrate the mass signalevery week, the temperature signal every three months, and the time signalevery six months.11. ProcedureNOTE 9For SCAQMD Rule 1144 purposes,
41、 additional proceeduresmay be required by the agency.11.1 Obtain a suitable baseline correction.11.2 Set the furnace and flow parameters.NOTE 10For SCAQMD Rule 1144 purposes, the total flow must be50 mL min, divided (balance protection flow:sample purge flow) either10:40 mL/min or 20:30 mL/min.11.3
42、Cool the specimen test area of the apparatus to ambienttemperature. For the purpose of this test, ambient temperatureis 35C or lower.NOTE 11Cooling of the specimen test area to 25C following anexperiment is time consuming on some apparatus. To improveproductivity, it is possible with some test sampl
43、es to initiate the experi-ment at a somewhat higher temperature. This must be done with cautionsince volatility is a function of temperature. For highly volatile materials,appreciable portions of the test specimen mass may be lost in experimentalset up, if initiated at too high of a temperature.NOTE
44、 12For SCAQMD Rule 1144 purposes, initial temperature is25 6 2C.11.4 With the apparatus closed in the normal operatingposition, tare the balance so that the empty sample panindicates zero mass.11.5 Open the apparatus to expose the specimen holder.11.6 Carefully place 10 6 1 mg of the test specimen o
45、n thespecimen holder. Other specimen sizes may be used but mustbe indicated in the report.NOTE 13Care should be taken to ensure that the sample is free of airbubbles.NOTE 14For SCAQMD Rule 1144 purposes, specimen size is10 6 1 L, autosamplers are not to be used and the specimen must bedistributed ev
46、enly over the bottom of the specimen holder.11.7 Close the apparatus and record the initial mass as mi.Ifthe apparatus has provisions for direct recording of masspercent, adjust it to read 100 %.NOTE 15Should the test specimen have appreciable volatility atambient temperature, it may lose a signific
47、ant amount of mass as it isplaced into the test position. In such cases, care should be taken to perform11.6 and 11.7 as quickly as is practical.11.8 Heat the test specimen at 5C/min to the isothermal testtemperature, while recording specimen mass (or mass percent),temperature and elapsed time. Othe
48、r heating rates may be used,but must be indicated in the report.NOTE 16Selection of the optimum operating parameters of isothermaltest temperature and test time (tt) is dependent on the class of materialsbeing tested. The technique of response surface methodology (RSM) maybe useful in predicting opt
49、imum operating parameters.7,8Some commonexperimental conditions are presented in Tables 1 and 2.NOTE 17For SCAQMD Rule 1144 purposes, heating rate is 25C/minand isothermal test temperature is 81C.11.9 Once the isothermal test temperature is reached, it isheld there for the remainder of the experiment. The time fromstart to the isothermal portion of the experiment is taken as ti.11.10 After 5 min at the isothermal test temperature, thespecimen temperature may be recorded.6Performance Standards for low (2 %), medium (50 %), and high (99
