色谱的介绍及历史(英文)Chromatography课件.ppt

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1、ChromatographyHistoryMikhailTswett,Russian,1872-1919BotanistIn1906TswettusedtochromatographytoseparateplantpigmentsHecalledthenewtechniquechromatographybecausetheresultoftheanalysiswas'writtenincolor'alongthelengthoftheadsorbentcolumnChromameans“color”andgrapheinmeansto“write”ImportanceC

2、hromatographyhasapplicationineverybranchofthephysicalandbiologicalsciences12Nobelprizeswereawardedbetween1937and1972aloneforworkinwhichchromatographyplayedavitalroleChromatographyisaphysicalmethodofseparationinwhichthecomponentstobeseparatedaredistributedbetweentwophasesoneofwhichisstati

3、onary(stationaryphase)whiletheother(themobilephase)movesthroughitinadefinitedirection.Thechromatographicprocessoccursduetodifferencesinthedistributionconstantoftheindividualsamplecomponents.ChromatographyIsatechniqueusedtoseparateandidentifythecomponentsofamixture.Worksbyallowingthemolec

4、ulespresentinthemixturetodistributethemselvesbetweenastationaryandamobilemedium.Moleculesthatspendmostoftheirtimeinthemobilephasearecarriedalongfaster.Classificationofchromatographyaccordingtomobilephase:1-Liquidchromatography:mobilephaseisaliquid.(LLC,LSC).2-Gaschromatography:mobilephas

5、eisagas.(GSC,GLC).Classificationaccordingtothepackingofthestationaryphase:1-Thinlayerchromatography(TLC):thestationaryphaseisathinlayersupportedonglass,plasticoraluminiumplates.2-Paperchromatography(PC):thestationaryphaseisathinfilmofliquidsupportedonaninertsupport.3-Columnchromatography

6、(CC):stationaryphaseispackedinaglasscolumn.Classificationaccordingtotheforceofseparation:1-Adsorptionchromatography.2-Partitionchromatography.3-Ionexchangechromatography.4-Gelfiltrationchromatography.5-Affinitychromatography.Thinlayerchromatography(TLC)isamethodforidentifyingsubstancesan

7、dtestingthepurityofcompounds.TLCisausefultechniquebecauseitisrelativelyquickandrequiressmallquantitiesofmaterial.SeparationsinTLCinvolvedistributingamixtureoftwoormoresubstancesbetweenastationaryphaseandamobilephase.Thestationaryphase:isathinlayerofadsorbent(usuallysilica