Presentation on principle of paper chromatography and Rf Value

1. Presentation on
Paper Chromatography
Principle and R
fValue
Presented to:-
Dr. B.M.Gurupadayya,
Dept.of Pharmaceutical Chemistry,
JSSCP, Mysore.
Presented by:-
Tekuri Manoj Kumar,
1
st
M.Pharm(IP).

2. Overview:-
•Introduction.
•Definitionofpaperchromatography.
•Principleinvolvedinpaperchromatography.
•Typesofpaperchromatography.
•Advantagesofpaperchromatography.
•R
fvalue.
•FactorswhichaffectR
fvalue.
•References.

3. Introduction:-
•Allthecreditforthepresentstatusofpaper
chromatographygoestoMartinandhisco-
workersviz.Consden,GordenandSynge.
•MartinandSynge(1941)developedforty-
platecomplicatedapparatusforthe
separationofacetylatedaminoacids.
•Consden,GordenandMartin(1944)replaced
silicagelwithafilterpaperbyusingn-butanol
asamobilephase.
•Itwasoriginallyusedtoseparateorganic
mixtures,butitwasquicklyadoptedfor
separationofinorganicionsbyvarious

4. Definition:-
Paperchromatography isthe
techniqueinwhichtheseparationofan
unknownsubstanceismainlycarriedout
bytheflowofsolventsonthespecially
designedchromatographicpaper.
Inthiscasethesolventgoesupby
capillaryaction.
Theseparationiseffectedbydifferential
migrationofthesubstancedueto
differenceindistributioncoefficients.

5. Theoretical principle:-
largelyby partitioncoefficient
phenomenon.
•separationisaccomplishedbysuccessive
equilibrationsofsamplebetweentwophases;
oneofwhichmovesovertheother.
•Thestationaryphaseismadeupofthe
solventheldbythepaperandmobilephase
istheirrigatingeluent.
•Boththesephasesareincontactoveravery
largeinterfaceonfilterpaper.
•Thewaterabsorbedinamorphousregionsof
celluloseisdistinctfromthebulkofmobile

7. Types of paper chromatography:-
 Dependinguponthemigration
forcesthatareinvolvedin
separation,paperchromatographyis
classifiedintotwotypes.
Theyare:-
i.Paperpartitionchromatography.
ii.Paperadsorptionchromatography.

8. Paperpartitionchromatography:-
Instandardmethodofanalysiswherethe
paperisutilizedasasupportwithonesolvent
asmobilephaseandotherasastationary
phase.Themigrationofsubstancesisdueto
differencesinpartitioncoefficients.
Paperadsorptionchromatography:-
Insomecasesthepapertobeusedis
coatedorimpregnatedwithadsorbentslike
silicageloraluminia,isusedasanadsorbent
andthesolventisallowedtoflowoverthe
unknowncomponents.Thus,migrationof
substancesisduetothedifferencein
adsorptivepowersofsubstancestobe
separated.
However,thistechniqueisnotmuchused

9. Advantages over other methods:-
i.Theequipmentisverysimpleandis
easilyavailable.
ii.Ithashighefficiencyofseparation.
iii.Separationcanbeeffectedonmacro,
microandsemi-microscale.
iv.Closelyrelatedhomologues,isotopes,
isomersandverylabileandreactive
substancescanbeseparatedreadilyand
satisfactorily.

10. R
fVALUE:-
•Inpaperchromatographytheresultsare
representedbyR
fvaluewhichrepresent
themovementormigrationofsolute
relativetothesolventfront.Thisis
indicatingpositionofmigratedspotson
chromatogram.
•TheR
fvalueiscalculatedas:-

11. •R
fisafunctionofpartitioncoefficientsand
isa constantfora given
substance,providedtheconditionsof
chromatographicsystemarekept
constant.
•Forgreaterreliability,referencestandards
areusedinparallelrunsorasinternal
standards.
•Sometimesthesolventfrontrunsoffthe
paper.Thenthepositionofindividualspot
ismeasuredrelativetopositionof
standardsubstances.
R
fvalueisalwayslessthanunitybutR
x
canbegreaterthan1.

12. factors which affect R
fvalue are:-
•Thesolventsystemandits
composition.
•Temperature.
•Thequalityofthepaper.
•Distancethroughwhichthesolvent
runs.
•Thequalityandnatureofsolvents
used.
•Thedirectionofthefibresofthe

13. References:-
A text book of Pharmaceutical
analysis by Dr. A.V.Kasture.
Volume –II, page no-31.

14. ….Thank
You