1、Designation:D479494(Reapproved 2017)Standard Test Method forDetermination of Ethoxyl or Hydroxyethoxyl Substitution inCellulose Ether Products by Gas Chromatography1This standard is issued under the fixed designation D4794;the number immediately following the designation indicates the year oforigina
2、l adoption 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 is applicable to the determination ofethoxyl or hydroxye
3、thoxyl substitution in cellulose ether prod-ucts by a Zeisel gas chromatographic technique.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,associa
4、ted 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 limitations prior to use.For specific hazard statements,see Section 5 and Note 3.1.4 This international standard wa
5、s developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Summary of T
6、est Method2.1 When a cellulose ether containing ethyl or hydroxyethylsubstitutes is allowed to react with hydriodic acid,one mole ofiodoethane is liberated for each mole of ethoxyl or hydroxy-ethoxyl ether substituted on the cellulose chain.The iodoeth-ane is extracted in situ with o-xylene and quan
7、titated by gaschromatography using an internal standard technique.It isrecommended to run duplicate samples.3.Apparatus3.1 Gas Chromatograph with thermal conductivity detectorand heated injection port.3.2 Electronic Integrator.3.3 Columnstainless steel,1829 mm in length,3.2 mm inoutside diameter,pac
8、ked with the reagent in 4.6,coiled to fitthe chromatograph used;or equivalent column and packing asappropriate.3.4 Syringe,10 L.3.5 Reaction Vials,Caps,and Heating Block.23.6 Syringe,100 L.3.7 Cover,stainless steel,fabricated to cover the heatingblock.4.Reagents and Materials4.1 Purity of ReagentsRe
9、agent 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 available.3Other grades may beused,provided it is fir
10、st ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.4.2 Iodoethane,99%minimum.4.3 O-xylene.4.4 Toluene.4.5 Hydriodic Acid,57%(sp gr 1.69 to 1.70).4.6 Column Packing,10%methyl silicone stationary phaseUSP code G1 coated on
11、 inert diatomite solid support USPcode S1A,100/120 mesh.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved Dec
12、.1,2017.Published December 2017.Originallyapproved in 1988.Last previous edition approved in 2009 as D4794 94(2009).DOI:10.1520/D4794-94R17.2The sole source of supply of a heating block,Silli-Therm Heating Module,Reacti-Block 21,Reacti-Vials,and Minnert valve tops,known to the committee atthis time
13、is the Pierce Chemical Company P.O.Box 117,Rockford,IL 611059976.If you are aware of alternative suppliers,please provide this information to ASTMInternational Headquarters.Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.3Reag
14、ent 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 Pharmacopeiaand National F
15、ormulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established
16、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.1 5.Hazards5.1 Safety precautions must be taken for handling of hydri-odic acid.5.2 During the reaction,the glass vials are under pressure.Exercise precaution in handling the hot vials.6.Apparatus Preparation and Conditioning6.1 Column(Note 1)Columns are packed with reagentunder vacuum and mechanical vibration usin
