1、Designation: E346 081Standard Test Methods forAnalysis of Methanol1This standard is issued under the fixed designation E346; 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 indicat
2、es 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 U.S. Department of Defense.1NOTESection 2.1 Referenced Documents was editorially corrected in June 2014.1. Scope*1.1
3、These test methods cover chemical and physical tests formeasuring the quality of 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
4、 28 to 30Water 31 to 33Water Miscibility 34 to 36Ethanol 37 to 47Acetone 48 to 55Trimethylamine 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 in
5、formation concerning toxicity, first aid proce-dures and safety precautions for the 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
6、safety and health practices and determine the applica-bility of regulatory limitations 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:2D891 Test Methods for Specific Gravity,Apparent, of LiquidIndustrial
7、ChemicalsD1078 Test Method for Distillation Range of Volatile Or-ganic LiquidsD1193 Specification for Reagent WaterD1209 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)D1363 Test Method for Permanganate Time of Acetone andMethanolD1613 Test Method for Acidity in Volatile Solvents andC
8、hemical Intermediates Used in Paint, Varnish, Lacquer,and Related ProductsD1722 Test Method for Water Miscibility of Water-SolubleSolventsE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)3E203 Test Method for W
9、ater Using Volumetric Karl FischerTitrationE300 Practice for Sampling Industrial ChemicalsE1140 Practice for Testing Nitrogen/Phosphorus ThermionicIonization Detectors for Use In Gas Chromatography3. Significance and Use3.1 These test methods are suitable for manufacturing con-trol and for determini
10、ng compliance with specification limitsfor the properties designated by the test methods. For those testmethods that use the procedure given in other ASTM methods,1These test methods are under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and are the direct res
11、ponsibility ofSubcommittee D16.16 on Industrial and Specialty Product Standards.Current edition approved Dec. 15, 2008. Published January 2009. Originallyapproved in 1968 as E346 68 T. Last previous edition approved in 2003 asE346 99 (2003)1. DOI: 10.1520/E0346-08E01.2For referenced ASTM standards,
12、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.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summar
13、y of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.or
14、g) for the latest information1those test methods should be consulted for additional informa-tion on the significance, use, and possible interferences.4. Purity of Reagents4.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reage
15、nts shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening thea
16、ccuracy of the determination.4.2 Unless otherwise indicated, references to water shall beunderstood to mean Type II or III reagent water conforming toSpecification D1193. It is essential that the reagent water befree of ammonia when used in the method for acetone.5. Hazards5.1 Methanol is toxic both
17、 as a liquid and 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
18、 to 36.5 volume % 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 t
19、est. The sample submittedshould be sufficient to make all tests without reuse of anyfraction. For details of sampling methanol, refer to PracticeE300.ACIDITY7. Procedure7.1 Determine the acidity of the methanol as acetic acidusing the titration method as described in Test Method D1613.8. Report8.1 F
20、or concentrations 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 for
21、judging the acceptability 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
22、 absolute percentage value in the table.9.1.2 Laboratory Precision (Within-Lab Between-Days)The standard deviation of results (each the average ofduplicates), obtained by the same analyst on different days, hasbeen estimated to be the absolute percentage value in Table 1at the indicated degrees of f
23、reedom. The 95 % limit for thedifference between two such averages is the absolute percent-age value in the 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 theabs
24、olute percentage 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 appr
25、oximately0.0010 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 E180 was used in developing theseprecision estimates.9.2 BiasThe bias of this test method has not been deter-mined
26、due to the unavailability 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 car
27、bonizables content in therange from 0 to 70 on the platinum-cobalt scale (see TestMethod D1209).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 impurities4Re
28、agent 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 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaa
29、nd National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Acidity Precision Values, % Acetic AcidLevel,%mass (m/m)Repeatability Laboratory Precision Within-Lab, Between-Days ReproducibilityStandardDeviationDegrees ofFreedom95 % LimitStandardDeviationDegrees ofFreedom95
30、% LimitStandardDeviationDegrees ofFreedom95 % Limit0.0010 0.000067 18 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 0.002E346 0812in the methanol is estimated by comparison of the test mixturewith platinum-cobalt color standards.12. Significance and Us
31、e12.1 Because this test is designed to measure low concen-trations of impurities that carbonize or darken in the presenceof 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 boro
32、silicate glass.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 contaminat
33、ion.13.5 Electric 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 D1209.15. Hazards15.1 Concentrated sulfuric acid is corrosive; contact withthe body is to be avoided at
34、all times. Use 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 allglas
35、sware in a dichromate-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-coba
36、lt colorstandard 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
37、30 s.(WarningDo 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 u
38、pon a white 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 g
39、o,no-go test.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 o
40、f results (see 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
41、results (each the average ofduplicates), obtained by the same analyst on different days, hasbeen estimated to be the value in Table 2 at the indicateddegrees of freedom. The 95 % limit for the difference betweentwo such averages is the value in the table.18.1.3 Reproducibility (Multilaboratory)The s
42、tandard de-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 precisi
43、on estimates 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 E180 was used in developing these precisionestimates.18.2 BiasThe bias of this
44、test method has not beendetermined due to the unavailability of suitable referencematerials.COLOR19. Procedure19.1 Determine the color of the methanol as described inTest Method D1209.TABLE 2 Carbonizables Precision Values, Pt-Co UnitsPt-Co LevelLaboratory Precision Within-Lab, Between-Days Reproduc
45、ibilityStandard DeviationDegrees ofFreedom95 % Limit Standard DeviationDegrees ofFreedom95 % Limit5113326 515 1 13 3 3 6 1060 1 13 3 5 6 15E346 081320. Report20.1 Estimate and report the color of the methanol to thenearest 1 Pt-Co unit.21. Precision and Bias21.1 PrecisionThe following criteria shoul
46、d be used forjudging the acceptability of results (see Note 4):21.1.1 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
47、 Between-Days)The standard deviation of results (each the average ofduplicates), obtained by the same analyst on different days, hasbeen estimated to be the value in Table 3 at the indicateddegrees of freedom. The 95 % limit for the difference betweentwo such averages is the value in the table.21.1.
48、3 Reproducibility (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 is
49、the value 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 E180 was used indeveloping 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 methan
