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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

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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】:StandardSpecificationforStainlessSteelForgings
【原文标准名称】:不锈钢锻件标准规范
【标准号】:ASTMA473-2001
【标准状态】:现行
【国别】:
【发布日期】:2001
【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】:A01.17
【标准类型】:(Specification)
【标准水平】:()
【中文主题词】:钢;锻件
【英文主题词】:austeniticstainlesssteel;austenitic-ferriticduplexstainlesssteel;ferriticstainlesssteel;martensiticstainlesssteel;stainlesssteelforgings;NumberCode77.140.85(Ironandsteelforgings)
【摘要】:1.1Thisspecificationcoversaustenitic,austenitic-ferritic,ferritic,andmartensiticstainlesssteelforgingsforgeneraluse,andforlow-orhigh-temperatureservice.1.2Thevaluesstatedininch-poundunitsaretoberegardedasthestandard.
【中国标准分类号】:J32
【国际标准分类号】:77_140_85
【页数】:4P.;A4
【正文语种】:


基本信息
标准名称:压铸模零件 A型导套
英文名称:Die-cast die components--Guide bushings type A
中标分类: 机械 >> 工艺装备 >> 模具
ICS分类: 机械制造 >> 无屑加工设备 >> 模制设备和铸造设备
替代情况:被GB/T 4678.6-2003代替
发布日期:1984-09-27
实施日期:1985-08-01
首发日期:1900-01-01
作废日期:2004-03-01
出版日期:1900-01-01
页数:2页
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所属分类: 机械 工艺装备 模具 机械制造 无屑加工设备 模制设备和铸造设备