ASTM E346-2008 317 Standard Test Method for Analysis of Methanol《甲醇分析的标准试验方法》.pdf

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1、Designation: E 346 08Standard Test Methods forAnalysis of Methanol1This standard is issued under the fixed designation E 346; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indica

2、tes the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 These test methods cover chemical and physical tests formeasuring the quality of

3、methanol and appear in the followingorder:SectionsPurity of Reagents 4Safety Precautions 5Sampling 6Acidity 7 to 9Carbonizables 10 to 18Color 19 to 21Distillation Range 22 to 24Permanganate Time 25 to 27Specific Gravity 28 to 30Water 31to33Water Miscibility 34 to 37Ethanol 37 to 47Acetone 48 to 55Tr

4、imethylamine 56 to 651.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 Review the current Material Safety Data Sheets (MSDS)for detailed information concerning toxicity, first aid proce-dures and safety precautions for the

5、 chemicals used in thisstandard.1.4 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 and health practices and determine the applica-bility of regulatory limitati

6、ons prior to use. Specific hazardsstatements are given in Sections 5 and 15 and in 16.1, 16.4, and52.2.2.2. Referenced Documents2.1 ASTM Standards:2D 891 Test Methods for Specific Gravity, Apparent, ofLiquid Industrial ChemicalsD 1078 Test Method for Distillation Range of VolatileOrganic LiquidsD 11

7、93 Specification for Reagent WaterF 1209 Guide for Ecological Considerations for the Use ofOil Spill Dispersants in Freshwater and Other InlandEnvironments, Ponds and SloughsD 1363 Test Method for Permanganate Time of Acetoneand MethanolD 1613 Test Method for Acidity in Volatile Solvents andChemical

8、 Intermediates Used in Paint, Varnish, Lacquer,and Related ProductsD 1722 Test Method for Water Miscibility of Water-SolubleSolventsE 180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 203 Test Method for Water Using Volumetric

9、Karl FischerTitrationE 300 Practice for Sampling Industrial ChemicalsE 1140 Practice for Testing Nitrogen/Phosphorus Thermi-onic Ionization Detectors for Use In Gas Chromatography3. Significance and Use3.1 These test methods are suitable for manufacturing con-trol and for determining compliance with

10、 specification limitsfor the properties designated by the test methods. For those testmethods that use the procedure given in other ASTM methods,those test methods should be consulted for additional informa-tion on the significance, use, and possible interferences.1These test methods are under the j

11、urisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and are the direct responsibility of Subcommit-tee E15.02 on Product Standards.Current edition approved Dec. 15, 2008. Published January 2009. Originallyapproved in 1968 as E 346 68 T. Last previous edition approved in 2003 asE 3

12、46 99(2003)1.2For 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 website.1*A Summary of Changes section appears at the en

13、d of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Purity of Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform

14、 to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the de

15、termination.4.2 Unless otherwise indicated, references to water shall beunderstood to mean Type II or III reagent water conforming toSpecification D 1193. It is essential that the reagent water befree of ammonia when used in the method for acetone.5. Hazards5.1 Methanol is toxic both as a liquid and

16、 as a vapor, and isdangerous if not properly handled. Avoid any skin contact.Clothing contaminated with methanol should be removedimmediately. Any body exposure to methanol requires imme-diate medical attention.5.2 Methanol is flammable and its vapor is explosive in therange from 6.0 to 36.5 volume

17、% in air. Any spills should beflushed away promptly with water.6. Sampling6.1 Sampling is not within the scope of these test methods.It should be understood, however, that reference to a “sample”means a representative portion of methanol contained in asingle container submitted for test. The sample

18、submittedshould be sufficient to make all tests without reuse of anyfraction. For details of sampling methanol, refer to PracticeE 300.ACIDITY7. Procedure7.1 Determine the acidity of the methanol as acetic acidusing the titration method as described in Test Method D 1613.8. Report8.1 For concentrati

19、ons of acetic acid at the 0.0010 % mass(m/m) level, report the results to the nearest 0.0001 % mass(m/m). For concentrations at the 0.010 % masss (m/m) level,report the results to the nearest 0.001 % mass (m/m).9. Precision and Bias9.1 PrecisionThe following criteria should be used forjudging the ac

20、ceptability of results (Note 1):9.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be theabsolute percentage value in Table 1 at the indicated degrees offreedom (df). The 95 % limit for the difference between twosuch runs is the absolute perc

21、entage value in the table.9.1.2 Laboratory Precision (Within-Lab Between-Days)The standard deviation of results (each the average of dupli-cates), obtained by the same analyst on different days, has beenestimated to be the absolute percentage value in Table 1 at theindicated degrees of freedom. The

22、95 % limit for the differencebetween two such averages is the absolute percentage value inthe table.9.1.3 Reproducibility (Multilaboratory)The standard de-viation of results (each the average of duplicates), obtained byanalysts in different laboratories, has been estimated to be theabsolute percenta

23、ge value in Table 1 at the indicated degrees offreedom. The 95 % limit for the difference between two suchaverages is the absolute percentage value in the table.NOTE 1The above precision estimates are based on an interlaboratorystudy performed on two samples of methanol containing approximately0.001

24、0 and 0.01 % mass (m/m) acetic acid. A total of nine laboratoriescooperated in the studies in which duplicate determinations were per-formed on each of two days. Practice E 180 was used in developing theseprecision estimates.9.2 BiasThe bias of this test method has not been deter-mined due to the un

25、availability of suitable reference materials.CARBONIZABLES10. Scope10.1 This test method describes a procedure for detectingthe presence of impurities in methanol that carbonize or darkenin the presence of concentrated sulfuric acid. The test methodis applicable to methanol having a carbonizables co

26、ntent in therange from 0 to 70 on the platinum-cobalt scale (see TestMethod D 1209).11. Summary of Test Method11.1 Methanol is mixed with a known volume of concen-trated sulfuric acid under controlled conditions. The colorformed by the action of the acid on the carbonizable impuritiesin the methanol

27、 is estimated by comparison of the test mixturewith platinum-cobalt color standards.12. Significance and Use12.1 Because this test is designed to measure low concen-trations of impurities that carbonize or darken in the presence3Reagent Chemicals, American Chemical Society Specifications , AmericanC

28、hemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), R

29、ockville,MD.TABLE 1 Acidity Precision Values, % Acetic AcidLevel,%mass (m/m)Repeatability Laboratory Precision Within-Lab, Between-Days ReproducibilityStandardDeviationDegrees ofFreedom95 % LimitStandardDeviationDegrees ofFreedom95 % LimitStandardDeviationDegrees ofFreedom95 % Limit0.0010 0.000067 1

30、8 0.0002 0.000065 18 0.0002 0.00024 8 0.000070.010 0.00034 18 0.001 0.000437 18 0.001 0.00061 8 0.002E346082of concentrated sulfuric acid, erroneously high results may beobtained if all glassware is not cleaned as described in theprocedure.13. Apparatus13.1 Erlenmeyer Flask, 125-mL borosilicate glas

31、s.13.2 Nessler Tubes, 50-mL high form, matched.13.3 Ring Stand.13.4 Buret, 25-mL, with TFE-fluorocarbon stopcock.NOTE 2A 25-mL automatic buret graduated in 0.1-mL incrementsprovides a safe convenient way of dispensing the sulfuric acid and protectsthe acid from dust and other contamination.13.5 Elec

32、tric Stirrer and Bar.14. Reagents14.1 Sulfuric AcidConcentrated sulfuric acid (sp gr 1.84).14.2 Platinum-Cobalt Stock Solution and Color Standards,made in accordance with Test Method D 1209.15. Hazards15.1 Concentrated sulfuric acid is corrosive; contact withthe body is to be avoided at all times. U

33、se proper protectiveequipment, including adequate eye protection. If the eyes areaffected or if a burn results, obtain immediate medical atten-tion.16. Procedure16.1 All glass apparatus used for this test must be kept freeof materials which produce color with sulfuric acid. Clean allglassware in a d

34、ichromate-sulfuric acid cleaning solutionfollowed by rinsings with tap water and reagent water. Drywith clean air or rinse with methanol that is known to give littleor no color with sulfuric acid. (WarningDo not use acetoneto dry apparatus.)16.2 Transfer 50 mL of the proper platinum-cobalt colorstan

35、dard into one of the matched 50-mL Nessler tubes.16.3 Pipet 30 mL of the sample into a 125-mL Erlenmeyerflask.16.4 Add, at a uniform rate, 25 mL of H2SO4to the samplewhile stirring constantly using an electric stirrer and stirringbar. The total time of the acid addition shall be 5 min 6 30 s.(Warnin

36、gDo not cool the mixture.)16.5 Allow the mixture to stand for 15 min 6 30 s at roomtemperature, pour the mixture from the flask into a 50-mLNessler tube and compare the color of the sample to the properplatinum-cobalt standard by looking down through the longi-tudinal axis of the tubes upon a white

37、or mirrored surface atsuch an angle that light is reflected through the column ofliquid. Hold the tubes at some convenient height 50 to 150 mmfrom the surface.17. Report17.1 According to the type of specification used, this testcan be made to give specific color readings or be simply a go,no-go test

38、.17.2 When specific color readings are required, report theplatinum-cobalt color to the nearest 5 units. Averages ofduplicate determinations should be reported to the nearest 2.5units.18. Precision and Bias18.1 PrecisionThe following criteria should be used forjudging the acceptability of results (s

39、ee Note 3):18.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be 1.7units at 21 df. The 95 % limit for the difference between twosuch runs is 5 units.18.1.2 Laboratory Precision (Within-Lab Between-Days)The standard deviation of results (eac

40、h the average of dupli-cates), obtained by the same analyst on different days, has beenestimated to be the value in Table 2 at the indicated degrees offreedom. The 95 % limit for the difference between two suchaverages is the value in the table.18.1.3 Reproducibility (Multilaboratory)The standard de

41、-viation of results (each the average of duplicates), obtained byanalysts in different laboratories, has been estimated to be thevalue shown in Table 2 at the indicated degrees of freedom.The 95 % limit for the difference between two such averages isthe value in the table.NOTE 3The precision estimat

42、es in Table 2 are based on an interlabo-ratory study performed on three samples at the color levels listed. Oneanalyst in each of seven laboratories performed duplicate measurementson each of two days. Practice E 180 was used in developing theseprecision estimates.18.2 BiasThe bias of this test meth

43、od has not beendetermined due to the unavailability of suitable referencematerials.COLOR19. Procedure19.1 Determine the color of the methanol as described inTest Method D 1209.20. Report20.1 Estimate and report the color of the methanol to thenearest 1 Pt-Co unit.21. Precision and Bias21.1 Precision

44、The following criteria should be used forjudging the acceptability of results (see Note 4):TABLE 2 Carbonizables Precision Values, Pt-Co UnitsPt-Co LevelLaboratory Precision Within-Lab, Between-Days ReproducibilityStandard DeviationDegrees ofFreedom95 % Limit Standard DeviationDegrees ofFreedom95 %

45、Limit5113326 515 1 13 3 3 6 1060 1 13 3 5 6 15E34608321.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be 0.7units at 36 df. The 95 % limit for the difference between twosuch runs is 2 units.21.1.2 Laboratory Precision (Within-Lab Between-D

46、ays)The standard deviation of results (each the average of dupli-cates), obtained by the same analyst on different days, has beenestimated to be the value in Table 3 at the indicated degrees offreedom. The 95 % limit for the difference between two suchaverages is the value in the table.21.1.3 Reprod

47、ucibility (Multilaboratory)The standard de-viation of results (each the average of duplicates), obtained byanalysts in different laboratories, has been estimated to be thevalue shown in Table 3 at the indicated degrees of freedom.The 95 % limit for the difference between two such averages isthe valu

48、e in the table.NOTE 4The above precision estimates are based on an interlaboratorystudy performed on two samples of methanol having Pt-Co color values of0 and 10 respectively. One analyst in each of eight laboratories performedduplicate measurements on each of two days. Practice E 180 was used indev

49、eloping these precision estimates.21.2 BiasThe bias of this test method has not beendetermined due to the unavailability of suitable referencematerials.DISTILLATION RANGE22. Procedure22.1 Determine the distillation range of the methanol asdescribed in Test Method D 1078. ASTM Solvents DistillationThermometer 39C (range 48 to 102C with 0.2 subdivisions)should be used.22.2 Use a K value of 0.033 for calculating the barometriccorrection to be applied to each corrected thermometer readingfor the following volumes of distillate: 1st drop, 5, 50, 95 mLand dry p