CHE301 Final Term Notes

liquids,ordissolvedsubstances.

•  Chromatographycanbeusedtoidentifydrugs,poisonsandmanyother substances.
•  Separationisdeterminedbythemolecularsizeand/orcharge.

Q11. Stationaryphase:

•  Astationaryphase(absorbent)phasethematerialonwhichtheseparation takesplace.canbesolid,gel,orliquid. Alsocalledmatrix,resin,orbeads. Mobilephase:
•  Themobilephaseisthesolventtransportsthesampleanditisusuallyaliquid, butmayalsobeagas. Alsocalledelutingbuffer.
•  Thecompoundstobeseparatedareconsideredsolutes. ImportantNote: MobilePhase:NonPolar StationaryPhase:Polar

Q12.  Bymobilephase:

1. Liquidchromatography
2. Gaschromatography

MobilePhasesUsed:

•  Hexanes,ether,tetrachloromethane, Xylene, Toluene
•  Chloroform, DichloromethaneEthylAcetate
•  Water, Alcohol
•  Buffer
•  ByStationaryPhases:
•  SilicaGel, Alumina, Polyamide(inTLC)
•  Squalene,carbowaxM,Dimethylpolysiloxane(inGC)
•  C-8,C-18, Licosorb, Silicone(inHPLC

Q13. Themechanism thatcausesthestationaryphasetoretardthemovement of molecules:

1. Sievemechanism:

SeparationaccordingtosizeorMW.(molecularsieve=gelfiltration= size exclusion=gelpermeation).

2. Chargeinteraction:

Separationbasedonnetcharge.

3. Solubilitycharacteristics:

SeparationbasedonpolarityHydrophobicchromatography,reverse-phase chromatography, Adsorptionornormal-phase

4. BiologicalorSpecificinteraction:

Captureanymoleculethatexhibitsuchproperty affinitychromatography,dyechromatography Antibody-antigen:(Immunoprecipitationsandotherforms)

Q14.  PaperChromatography

•  Thinlayerchromatography
•  ColumnChromatography
•  HighPerformance

Q15. water:alcoholororganicsolvents

•  Usechromatographictank,beakercoveredwithpetridish,anyjarwithlid
•  Toanalyze:Ink,steroids,foodcolours,pigmentsanddrugs
•  AqualitativetechniquetocalculateandcompareRfvalues
•  Rfisratiobetweendistancetraveledbyindividualcomponentdividedbythe distancetravelbysolvent

Q16. Adsorbentsilicapastedonglassoraluminum plates

Usuallyorganicsolvents(pureormixedinvariableratios)

•  TLCplatesaremadeofglassoraluminum
•  Solventequilibratetheenvironment
•  Maybeplacedwithwallsothatitmaynotfallinthechamber Developingagents:
•  Ninhydrin(aminoacids)
•  Quantitativetechniquewhenscratchedandquantifiedtheanalyte

Q17. Silicagel,flashsilica,alumina

organicsolvents(startingfrom lesspolartohighpolarity) Stationaryphaseisheldinanarrow MobilePhasetubethroughwhichthemobilephaseisforcedunderpressureor under theeffectofgravity.

•  Choiceofstationaryphasedependsuponchemistryofanalytes.
•  SilicaGelused,isavailableinvariedmeshsizesstartingfrom 60to800Mesh.
•  Alumina(Al2O3)usedassolidsupport,availableinacidicbasicandneutral phases.

Q18. Inflashcolumnchromatographythesampleispumpedthroughthepackedglass column. Flashsilicahasquitesmallermeshsize.

Q19. Defineelectrophoresisanditstypesandtwodimensional electrophoresis.?

Define: