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ASTM F2605-2008e1 用体积排阻色谱与多角度光散射检测法(SEC-MALS)测定海藻酸钠的摩尔质量的标准试验方法体

作者:标准资料网 时间:2024-05-15 04:10:27  浏览:9228   来源:标准资料网
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【英文标准名称】:StandardTestMethodforDeterminingtheMolarMassofSodiumAlginatebySizeExclusionChromatographywithMulti-angleLightScatteringDetection(SEC-MALS)
【原文标准名称】:用体积排阻色谱与多角度光散射检测法(SEC-MALS)测定海藻酸钠的摩尔质量的标准试验方法体
【标准号】:ASTMF2605-2008e1
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:F04.42
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:Alginates;Sizeexclusionchromatographywithmulti-anglelightscatteringdetection(SEC-MALS);Tissueengineeredmedicalproducts(TEMPs)
【摘要】:Thecompositionandsequentialstructureofalginate,aswellasthemolarmassandmolarmassdistribution,determinesthefunctionalityofalginateinanapplication.Forinstance,thegellingpropertiesofanalginatearehighlydependentuponthecompositionandmolarmassofthepolymer.Lightscatteringisoneofveryfewmethodsavailableforthedeterminationofabsolutemolarmassandstructure,anditisapplicableoverthebroadestrangeofmolarmassesofanymethod.Combininglightscatteringdetectionwithsizeexclusionchromatography(SEC),whichsortsmoleculesaccordingtosize,givestheabilitytoanalyzepolydispersesamples,aswellasobtaininginformationonbranchingandmolecularconformation.Thismeansthatboththenumber-averageandmass-averagevaluesformolarmassandsizemaybeobtainedformostsamples.Furthermore,onehastheabilitytocalculatethedistributionsofthemolarmassesandsizes.Multi-anglelaserlightscattering(MALS)isatechniquewheremeasurementsaremadesimultaneouslyoverarangeofdifferentangles.MALSdetectioncanbeusedtoobtaininformationonmolecularsize,sincethisparameterisdeterminedbytheangularvariationofthescatteredlight.Molarmassmayinprinciplebedeterminedbydetectingscatteredlightatasinglelowangle(LALLS).However,advantageswithMALSascomparedtoLALLSare:(1)lessnoiseatlargerangles,(2)theprecisionofmeasurementsaregreatlyimprovedbydetectingatseveralangles,and(3)theabilitytodetectangularvariationallowsdeterminationofsize,branching,aggregation,andmolecularconformation.Sizeexclusionchromatographyusescolumns,whicharetypicallypackedwithpolymerparticlescontaininganetworkofuniformporesintowhichsoluteandsolventmoleculescandiffuse.Whileinthepores,moleculesareeffectivelytrappedandremovedfromtheflowofthemobilephase.Theaverageresidencetimeintheporesdependsuponthesizeofthesolutemolecules.Moleculesthatarelargerthantheaverageporesizeofthepackingareexcludedandexperiencevirtuallynoretention;theseareelutedfirst,inthevoidvolumeofthecolumn.Molecules,whichmaypenetratetheporeswillhavealargervolumeavailablefordiffusion,theywillsufferretentiondependingontheirmolecularsize,withthesmallermoleculeselutinglast.Forpolyelectrolytes,dialysisagainsttheelutionbufferhasbeensuggested,inordertoeliminateDonnan-typeartifactsinthemolarmassdeterminationbylightscattering(1,2).However,inthepresentmethod,thesizeexclusionchromatographystepprecedingthelightscatterdetectionisanefficientsubstituteforadialysisstep.ThesampleisseparatedonSECcolumnswithlargeexcessofelutionbufferfor30to40min,anditisthereforeinfullequilibriumwiththeelutionbufferwhenitreachestheMALSdetector.1.1Thistestmethodcoversthedeterminationofthemolarmassofsodiumalginateintendedforuseinbiomedicalandpharmaceuticalapplicationsaswellasintissueengineeredmedicalproducts(TEMPs)bysizeexclusionchromatographywithmulti-anglelaserlightscatteringdetection(SEC-MALS).AguideforthecharacterizationofalginatehasbeenpublishedasGuideF2064.1.2AlginateusedinTEMPsshouldbewellcharacterized,includingthemolarmassandpolydispersity(molarmassdistribution)inordertoensureuniformityandcorrectfunctionalityinthefinalproduct.Thistestmethodwillassistendusersinchoosingthecorrectalginatefortheirparticularapplication.AlginatemayhaveutilityasascaffoldormatrixmaterialforTEMPs,incellandtissueencapsulationapplications,andindrugdeliveryformulations.1.3Thevalue......
【中国标准分类号】:C10
【国际标准分类号】:11_120_10
【页数】:6P.;A4
【正文语种】:英语


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【英文标准名称】:Tungstenhalogenlamps(non-vehicle)
【原文标准名称】:卤钨灯泡
【标准号】:JISC7527-1994
【标准状态】:作废
【国别】:日本
【发布日期】:1994-01-01
【实施或试行日期】:1994-01-01
【发布单位】:日本工业标准调查会(JISC)
【起草单位】:Electricity
【标准类型】:()
【标准水平】:()
【中文主题词】:灯;卤钨灯;电灯;钨丝灯;白炽灯
【英文主题词】:lamps;electriclamps;incandescentlamps;tungsten-halogenlamps;tungstenlamps
【摘要】:
【中国标准分类号】:K71
【国际标准分类号】:29_140_20
【页数】:34P;A4
【正文语种】:日语


【英文标准名称】:SteelBars,Carbon,ColdFinished,Quality
【原文标准名称】:冷加工碳素钢棒材.质量
【标准号】:ASTMA108-1993
【标准状态】:作废
【国别】:美国
【发布日期】:1993
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:ASTM
【标准类型】:()
【标准水平】:()
【中文主题词】:冷加工;碳;碳素钢;钢;棒材
【英文主题词】:carbonsteels;bars(materials);steels;carbon;cold-working
【摘要】:
【中国标准分类号】:H44
【国际标准分类号】:77_140_70
【页数】:4P;A4
【正文语种】:英语



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