1、Designation: D8087 18Standard Test Method forColor of Maleic Anhydride in the Molten State and AfterHeating (Platinum-Cobalt Scale) Using TristimulusColorimetry1This standard is issued under the fixed designation D8087; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case 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 covers an instrumental method for theCIE (Commission
3、 International de lEclairage) tristimulusmeasurement of the color of maleic anhydride melt before andafter prolonged heating under specified conditions of time andtemperature. The measurement is converted to color values inthe platinum-cobalt system.1.2 This test method covers the range 0 to100 Pt-C
4、o color.1.3 In determining the conformance of the test results usingthis method to applicable specification, results shall be roundedin accordance with the rounding off methods of Practice E29.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included
5、 in thisstandard.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 limitat
6、ions prior to use.For specific hazard statements, see Sections 7, 10.3, and 10.6.1.6 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
7、 and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1209 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)D1686 Test Method for Color of Solid Aromatic Hy
8、drocar-bons and Related Materials in the Molten State (Platinum-Cobalt Scale)D3438 Practice for Sampling and Handling Naphthalene,Maleic Anhydride, and Phthalic AnhydrideD5386 Test Method for Color of Liquids Using TristimulusColorimetryD6809 Guide for Quality Control and Quality AssuranceProcedures
9、 for Aromatic Hydrocarbons and Related Ma-terialsD8005 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and Tra
10、nsmission Propertiesof MaterialsE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE313 Practice for Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color CoordinatesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Tes
11、t Method2.2 Other Document:3OSHA regulations, 29 CFR paragraphs 1910.1000 and1910.12003. Summary of Test Method3.1 A specimen is melted at 60C.3.2 Color is measured by tristimulus values of light trans-mitted by a freshly melted specimen as percent of lighttransmitted by distilled water. Convert the
12、 measured tristimu-lus values by appropriate equations to the platinum-cobaltscale.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-bility of Subcommittee D16.02 on Oxygenated Aromatics.Current editio
13、n approved Feb. 1, 2018. Published June 2018. DOI: 10.1520/D8087-182For referenced ASTM standards, visit the 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 we
14、bsite.3Available from U.S. Government Printing Office, Superintendent ofDocuments, 732 N. Capitol St., NW, Washington, DC 20401-0001, http:/www.access.gpo.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard
15、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 Barriers to Trade (TBT) Committee.13.3 After
16、heating for2hat140C, the color of the specimenis again measured by tristimulus values. Then convert themeasured tristimulus values by appropriate equations to theplatinum-cobalt scale.4. Significance and Use4.1 The color of maleic anhydride can be an indication ofthe purity of these materials. A hig
17、h color after heatingnormally indicates contamination or decomposition.4.2 This standard is suitable for process quality control anddetermining if the product meets specifications.5. Apparatus5.1 Instrument, with the following provision:5.1.1 Instrument Sensor, shall provide a beam for illuminat-ing
18、 the sample cell in transmission. The instrument shall becapable of converting light measured in total transmissionthrough the sample cell to CIE X Y Z tristimulus color valuesfor the measurement conditions of CIE illuminant C and theCIE 1931 2 degree standard observer as described in GuideE179 and
19、Practice E308.5.1.2 The CIE X Y Z tristimulus color values shall beconvertible to the instrumental yellowness index (YI) definedby Practice E308 and Practice E313. A correlation betweenmeasured yellowness index (YI) (Practice E313) values and thePt-Co standard solutions shall be used to yield an equ
20、ivalentinstrumental Pt-Co rating for liquid hydrocarbon samples.5.1.3 Sample Cells, shall have clear, colorless, parallelentrance and exit windows. The internal distance between thefaces shall be user selectable from 20 to 50 mm. Whenmeasuring samples using cells of the same path length, a pathlengt
21、h tolerance of 63 % or less is appropriate. Matched cellsare preferred but not required. Sample cells shall be hightemperature resistant.5.1.4 Heated Bath or Ovenelectric dry block or ovencapable of maintaining 60C (61C) and 140C (61C) anddeep enough to completely maintain molten specimen in cell.6.
22、 Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are avai
23、lable.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterReferences to water shall be under-stood to mean colorless distilled water, conforming to Type IVof
24、Specification D1193.6.3 Cobalt Chloride, (CoCl26H2O).6.4 Hydrochloric Acid (sp gr. 1.19)Concentrated hydro-chloric acid (HCl).6.5 Potassium Chloroplatinate, (K2PtCl6).6.6 Platimum-Cobalt Stock SolutionDissolve 1.245 g ofpotassium chloroplatinate (K2PtCl6) and 1.00 g of cobaltchloride (CoCl26H2O) in
25、water. Carefully add 100 mL ofhydrochloric acid (HCl sp gr 1.19) and dilute to 1 L withdistilled water. The absorbance of the 500 platinum-cobaltstock solution in a cell having a 10-mm light path with distilledwater in a matched cell as the reference solution must fallwithin the limits given in Tabl
26、e 1.6.7 Platinum-Cobalt StandardsFrom the stock solutionprepare color standards in accordance with Table 2 by dilutingthe required volumes to 100 mL with water in volumetricflasks. When properly sealed and stored these standards arestable for at least one year. 500 Platinum-Cobalt standards mayalso
27、be purchased.7. Hazards7.1 Consult current OSHA regulations, suppliers SafetyData Sheet, and local regulations for all materials used in thistest method.7.2 WarningWhen handling molten solids in open tubes,adequate ventilation must be provided and proper protectionshould be used to prevent thermal b
28、urns.8. Sampling and Handling8.1 Sample in accordance with Practice D3438.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for Laboratory
29、Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Absorbance Tolerance Limits for No. 500 Platinum-Cobalt Stock SolutionWavelength Absorbance430 0.110 to 0.120455 0.130 to 0.145480 0.10
30、5 to 0.120510 0.055 to 0.065TABLE 2 Platinum-Cobalt Color StandardsColor StandardNumberStock Solution,mLColor StandardNumberStock Solution,mL1 0.20 25 5.002 0.40 30 6.003 0.60 35 7.004 0.80 40 8.005 1.00 45 9.006 1.20 50 10.007 1.40 55 11.008 1.60 60 12.009 1.80 65 13.0010 2.00 70 14.0011 2.20 75 15
31、.0012 2.40 80 16.0013 2.60 85 17.0014 2.80 90 18.0015 3.00 95 19.0020 4.00 100 20.00D8087 1829. Calibration9.1 Setup the instrument for operation by following theinstrument manufacturers instructions. This should includesetting operating parameters such as the path length of thesample cells to be us
32、ed.9.2 Standardize the instrument using a cell of the selectedpath length containing water as the sample.9.3 Measure another sample of water in a cell of the selectedpath length to verify that the instrument produces a Pt-Coreading of 0.9.4 Measure several Pt-Co color standards from Table 2 thatspan
33、 the expected color range of the samples in a cell of theselected path length to verify the instrument produces thecorrect Pt-Co readings.10. Procedure10.1 Melt about 150 g of maleic anhydride and simultane-ously preheat a sample cell in an oven maintained at 60C.10.2 As soon as the sample is comple
34、tely liquid, mix bystirring with a clean dry glass rod, then quickly pour into thepreheated sample cell. Then quickly put sample cell into theinstrument.10.3 Use caution and wear appropriate safety equipmentwhen handling hot samples and equipment.10.4 Take three (3) instrumental readings without sam
35、plereplacement, with the average taken as being a representativePt-Co measurement of the sample. Exercise care to avoidsample contamination.10.5 Place the filled sample cell in heated bath or ovenwhich has been regulated at 140 6 1C. Allow the cell toremain in the block for 2 h (which includes 90 mi
36、n at the testtemperature). Protect cells adequately from contaminationduring the test period.10.6 Use caution and wear appropriate safety equipmentwhen handling hot samples.10.7 Remove the cell, place in the instrument.10.8 Take three (3) instrumental readings without samplereplacement, with the ave
37、rage taken as being a representativePt-Co measurement of the sample. Exercise care to avoidsample contamination.11. Report11.1 Report the following information:11.1.1 Report the instrumental Pt-Co measurement to near-est whole unit.11.1.2 The platinum cobalt color of the sample should bereported alo
38、ng with the specified test temperatures 60C and140C.12. Precision and Bias512.1 The precision of this test method is based on anintralaboratory study of Test Method D8087 conducted in2017. One laboratory tested one Maleic Anhydride sample forColor in the Molten State and After Heating Using Tristimu
39、lusColorimetry. Every test result represents an individual deter-mination. The laboratory reported 20 replicate results for eachanalysis/material combination in order to estimate the repeat-ability limits of the standard. Practice E691 was followed forthe design and analysis of the repeatability dat
40、a; the details aregiven in Research Report RR:D16-1065.12.1.1 Repeatability Limit (r)Two test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the “r” value for that material; “r” is theinterval representing the critical difference between two testresul
41、ts for the same material, obtained by the same operatorusing the same equipment on the same day in the samelaboratory.12.1.1.1 Repeatability limits are listed in Table 3 and Table4.12.1.2 Reproducibility has not been determined and will bedetermined within five years.12.2 BiasSince there is no accep
42、table reference material,bias has not been determined.13. Quality Guidelines13.1 Laboratories shall have a quality control system inplace.13.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality
43、control practices.13.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.13.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test r
44、esults.13.1.4 When there are no QA/QC protocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D16-
45、1065. ContactASTM CustomerService at serviceastm.org.TABLE 3 Repeatability Limits(Maleic Anhydride in the Molten State at 60C)Tristimulus ColorimetryAverageXRepeatabilityStandardDeviationSrRepeatabilityLimitrNumber (Platimun-Cobalt Scale)9 0.6 2TABLE 4 Repeatability Limits(Maleic Anhydride after Hea
46、ting at 140C)Tristimulus ColorimetryAverageXRepeatabilityStandardDeviationSrRepeatabilityLimitrNumber (Platinum-Cobalt Scale)17 1.2 3D8087 18314. Keywords14.1 instrumental color measurement; maleic anhydride;platinum-cobalt; Pt-Co; tristimulusASTM International takes no position respecting the valid
47、ity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subje
48、ct to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquart
49、ers. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-95
