1、Designation: E2403 06 (Reapproved 2018)Standard Test Method forSulfated Ash of Organic Materials by Thermogravimetry1This standard is issued under the fixed designation E2403; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 describes the determination of sulfatedash content (sometimes called residue-on-ignition) of org
3、anicmaterials by thermogravimetry. This test method convertscommon metals found in organic materials (such as sodium,potassium, lithium, calcium, magnesium, zinc, and tin) intotheir sulfate salts permitting estimation of their total content assulfates or oxides. The range of this test method is from
4、 0.1 to100 % metal content.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 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
5、 standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decis
6、ion on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D874 Test Method for Sulfated Ash from Lubricating Oilsand AdditivesD914 Test Meth
7、ods for EthylcelluloseD3516 Test Methods for Ashing CelluloseE473 Terminology Relating to Thermal Analysis and Rhe-ologyE1131 Test Method for Compositional Analysis by Thermo-gravimetryE1142 Terminology Relating to Thermophysical PropertiesE1582 Test Method for Temperature Calibration of Thermo-grav
8、imetric AnalyzersE2040 Test Method for Mass Scale Calibration of Thermo-gravimetric Analyzers2.2 Other Standards:The United States Pharmacopeia XXII and The NationalFormulary XVII, United States PharmacopeialConvention, Rockville, MD, 1990, Section 281, p. 15273. Terminology3.1 DefinitionsTechnical
9、terms used in this standard aredefined in Terminologies E473 and E1142.3.1.1 sulfated ash, nthe residue remaining after a speci-men has been oxidized, and the residue subsequently treatedwith sulfuric acid and heated to constant weight.3.1.2 residue-on-ignition, ROI, na commonly used aliasfor sulfat
10、ed ash.3.1.3 volatiles, nfor the purpose of this test, those mate-rials evolving as gas at temperatures below 160C in an airatmosphere.4. Summary of Test Method4.1 A test specimen is ignited and burned in an air atmo-sphere at temperatures up to 600C until only ash remains.After cooling, the residue
11、 is treated with sulfuric acid andheated to 800C to constant weight. The residue remaining isidentified as sulfated ash.4.2 This test method is similar to Test Method D874 forlubricating oils and additives, Test Methods D914 for ethylcellulose, Test Methods D3516 cellulose, and that of TheUnited Sta
12、tes Pharmacopeia XXII and makes use of thermo-gravimetric apparatus to perform the determination.5. Significance and Use5.1 The sulfated ash may be used to indicate the level ofknown metal-containing additives or impurities in an organicmaterial. When phosphorus is absent, barium, calcium,magnesium,
13、 sodium and potassium are converted to theirsulfates. Tin and zinc are converted to their oxides.5.2 This test method may be used for research anddevelopment, specification acceptance, and quality assurancepurposes.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasuremen
14、ts and is the direct responsibility of Subcommittee E37.01 on Calo-rimetry and Mass Loss.Current edition approved April 1, 2018. Published May 2018. Originallyapproved in 2004. Last previous edition approved in 2012 as E2403 06 (2012).DOI: 10.1520/E2403-06R18.2For referenced ASTM standards, visit th
15、e ASTM 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. U
16、nited StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barri
17、ers to Trade (TBT) Committee.16. Interferences6.1 If phosphorus is present with metals, it partially orwholly remains in the sulfated ash as metal phosphates.6.2 Sulfur and chlorides do not interfere.7. Apparatus7.1 Thermogravimetric Analyzer (TGA)The essential in-strumentation required to provide t
18、he minimum thermogravi-metric analytical 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 aspecimen to a constant temperature of 850C and at a constantrate of 5 to 60C/min7.1.1.2 A temperature sensor to provide an i
19、ndication of thespecimen or furnace temperature to 61C.7.1.1.3 A continuously recording balance to measure thespecimen mass with a minimum capacity of 50 mg and asensitivity of 60.01 mg.7.1.1.4 A means of maintaining the specimen or containerunder atmospheric control of air at a purge flow rate of 5
20、0 to100 mL/min 6 5 mL/min.7.1.2 A temperature controller capable of executing a spe-cific temperature program by operating the furnace betweenselected temperature limit at a rate of 5 to 60C/min and to anisothermal temperature of up to 850C which is maintainedconstant to 610C for a minimum of 70 min
21、utes.7.1.3 A recording device, capable of recording and display-ing any fraction of the specimen mass signal (TGA curve)including signal noise.7.1.4 Containers (pans, crucibles, etc.) that are inert to thespecimen and to concentrated sulfuric acid and that will remaingravimetrically stable up to 850
22、C. Platinum is a commonmaterial of construction for this purpose.7.2 Graduated micropipette with capacity of 4050 L8. Reagents and Materials8.1 Sulfuric acid, concentrated (98 %), with a relativedensity of 1.84. (WarningPoison. Corrosive. Strong Oxi-dizer.)8.2 AirZero grade or better purity9. Hazard
23、s9.1 Sulfuric acid may be corrosive to some thermogravimet-ric apparatus. A regular visual inspection of the apparatus willdetermine if any corrosion is taking place.9.2 The exhausted purge gas from the apparatus will containsulfuric acid fumes. This purge gas shall be treated byexhausting to a acid
24、 hood or by bubbling through a solution ofsodium bicarbonate to absorb the acidic fumes.10. Preparation of Apparatus10.1 After turning the power on, allow the instrument toequilibrate for at least one hour prior to any measurements.10.2 Perform any cleaning and calibration procedures de-scribed by t
25、he manufacturer in the apparatus OperatorsManual.11. Calibration and Standardization11.1 Perform temperature calibration of the thermogravi-metric analyzer according to Test Method E1582 using refer-ence materials suitable for the temperature range of thismethod, namely 25 to 800C.11.2 Perform mass
26、calibration of the thermogravimetricanalyzer according to Test Method E2040.12. Procedure12.1 Transfer 30 to 40 mg of the sample into a tared, clean,and dry sample container. Assemble the thermogravimetricanalyzer for operation. Record the initial weight of the testspecimen as Woto within 60.01 mgNO
27、TE 1The sample container may be preconditioned by heating in anair atmosphere to 800C.NOTE 2Smaller quantities of test specimen will reduce the quantifi-cation capability of this method.12.2 Heat the specimen from ambient to 600C at 10C/minunder an air purge gas with a flow rate of 50 to 100 6 5mL/m
28、in and record the thermal curve.12.3 Cool the heated sample and thermogravimetric appa-ratus to 20 to 25C.12.4 If desired, record the weight at 150C (Wv) as the massafter apparent loss of volatiles. Record the weight at 600C asthe mass of the residue (Wr).NOTE 3Mass loss due to apparent loss of vola
29、tiles at 150C andresidue at 600C are not required for the sulfated ash determination butmay be recorded for additional sample characterization (see Test MethodE1131).NOTE 4The temperature at which the mass loss due to volatiles isdetermined may range from 100 to 160C depending upon the material.Othe
30、r values may be used but shall be reported.12.5 Using a micropipette, add 30 40 L of 98 % gradesulfuric acid to the sample residue (in the container). Reas-semble the instrument for operation.12.6 Heat the specimen from ambient to 800C at 50C/minand hold isothermally at 800 6 25C for 60 6 1 minutes
31、underan air purge at 50 to 100 6 5 mL/min.12.7 Cool the heated specimen and thermogravimetric ap-paratus to 20 to 25C.12.8 Record the residue mass Ws.12.9 Calculate percent Sulfated Ash (S) using Eq 1.12.10 In the absence of interferences and if the specificmetal in the test specimen is known, then
32、its mass percent (M)may be calculated by multiplying the sulfated ash value by thefactors presented in Table 1 using Eq 2.TABLE 1 Sulfated Ash FactorsMetal Sulfated Ash FactorSodium (Na) Na2SO40.3237Potassium (K) K2SO40.4487Lithium (Li) Li2SO40.1263Calcium (Ca) CaSO40.2944Magnesium (Mg) MgSO40.2019Z
33、inc (Zn) ZnO 0.8034Tin (Sn) SnO 0.8812E2403 06 (2018)212.11 If desired, calculate the Percent Volatiles (V) andPercent Residue (R) using equations 3 and 4, respectively.13. Calculation13.1 Sulfated Ash (S) may be determined using the follow-ing equation:S 5 Ws3100 %/Wo(1)where:S = Sulfated ash, mass
34、 %,Ws= Mass of sulfated ash from Section 12.8, mg,Wo= Original mass of the test specimen from Section 12.1,mg.13.2 If the specific metal in the test specimen is known andif this is the only metal ion present, then its mass percent (M)may be calculated by multiplying the sulfated ash value by thefact
35、ors presented in Table 1 using Eq 2.M metal! 5 Factor 3 S (2)where:M = Percent of the identified metal, mass %.14. Report14.1 Report the sulfated ash (S) to three significant figures.14.2 Report to three significant figures the percent metal(M) when desired and the metal is known.14.3 Provide a copy
36、 of the original thermal curve.14.4 The specific dated version of this test method used.15. Precision and Bias15.1 An interlaboratory study was conducted in 2005 inwhich lithium cyclohexanebutyrate and calcium oxalate mono-hydrate were tested. Eight laboratories participated in the testusing seven i
37、nstrument models from two manufacturers. AResearch Report is available from ASTM Headquarters.315.2 Precision:15.2.1 Within laboratory variability may be described usingthe repeatability value (r) obtained by multiplying the repeat-ability standard deviation by 2.8. The repeatability valueestimates
38、the 95 % confidence limit. That is, two results fromthe same laboratory should be considered suspect (at the 95 %confidence level) if they differ by more than the repeatabilityvalue.15.2.1.1 The within laboratory repeatability standard devia-tion for lithium in lithium cyclohexanebutyrate was 0.057
39、%(RSD of 1.5 %) with 20 degrees of experimental freedom.15.2.1.2 The within laboratory repeatability standard devia-tion for calcium in calcium oxalate monohydrate was 0.24 %(RSD of 0.92 %) with 20 degrees of experimental freedom.15.2.2 Between laboratory variability may be describedusing the reprod
40、ucibility value (R) obtained by multiplying thereproducibility standard deviation by 2.8. The reproducibilityvalues estimates the 95 % confidence limit. That is, two resultsobtained from different laboratories, operators or apparatusshould be considered suspect (at the 95 % confidence level) ifthey
41、differ by more than the reproducibility value.15.2.2.1 The between laboratory reproducibility standarddeviation for lithium in lithium cyclohexanebutyrate was 0.10% (RSD = 2.5 %) with 20 degrees of experimental freedom.15.2.2.2 The between laboratory reproducibility standarddeviation for calcium in
42、calcium oxalate monohydrate was0.32 % (RSD = 1.2 %) with 20 degrees of experimentalfreedom.15.3 Bias:15.3.1 Bias is the difference between the mean value ob-tained and an accepted reference value for the same material.15.3.1.1 The lithium cyclohexanebutyrate used in this studywas supplied (by Sigma-
43、Aldrich, St. Louis, MO) with aCertificate of Analysis indicate an ICP assay of 3.9 % lithium.The sample is 3.94 % lithium by formula weight.15.3.1.2 The mean value for lithium in lithium cyclo-hexanebutyrate characterized by this method was found to be3.93 %, indicating no detectable bias in this me
44、thod.16. Keywords16.1 ash; residue on ignition; sulfated ash; thermogravimet-ric analysis; thermogravimetryASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised th
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