Ion exchange chromatography

IEC

1. ION EXCHANGE
CHROMATOGRAPHY
By
D.MAHENDRA
Orbicular Complex Injectables
Analytical Research
Empid :-111228
Designation :-Research Associate
Presentation Date :-28-10-2017

2. CONTENTS
INTRODUCTION OFIEC
PRINCIPLE OFSEPARATION
ION EXCHANGE RESINS(CLASSIFICATION
OFRESINS)
PRACTICALREQUIREMENTS
FACTORS AFFECTING IONEXCHANGE
SEPARATION
APPLICATIONS

3. ION EXCHANGECHROMATOGRAPHY
DEFINITION:
Ionexchangechromatographyisa
processbywhichamixtureofsimilar
chargedionscanbeseparatedbyusingan
ionexchangeresinwhichexchangesions
accordingtotheirrelativeaffinities.

4. INTRODUCTION
Ion exchange chromatography is a typeof
adsorptionchromatography.
There is a REVERSIBLE EXCHANGE OF
SIMILAR CHARGEDIONS.
Mostly similar charged ions like cationsand
anions can be conveniently separated by this
technique.
Many drugs and pharmaceutical agentsare
weakly or strongly acidic or basic innature.
Hence a mixture of similar chargedsubstances
can also be separated into purecomponents.

6. PRINCIPLEOFSEPERATION
This is by reversible exchange of ions between the ions
present in the solution andthose present in the ion
exchangeresin.
CATIONEXCHANGE:
The separation of cations using cation exchangeresin.
The cations to be separated are present in solution and
exchanges for similar ions present in cation exchange
resin, a solid matrix. the exchange can be represented
by the followingequation:
X
+
+R
−
K
+
X+R
−
+K
+
(solution)
(solution)

7. The cations retained by the solid matrix of ion
exchange resin can be eluted by using buffers of
different strength and hence separation of cationscan
beeffected.
ANIONEXCHANGE:
Separation of anion using anion exchange resin can
be carried out. The anions to be separated are present
in solution and exchanges for similar ions present in
anion exchange resin, a solid matrix the exchangecan
be represented by the followingequation:
(solid)
X
-
+R
+
Cl
-
X-R
+
+Cl
-
(anion
exchange)
(solution)

8. The anions retained by the solid matrix of ion
exchange resin can be eluted by using buffers of
different strength and hence separation of anionscan
beeffected.

9. CLASSIFICATIONOF
ION EXCHANGE RESINS:
There are 6types,
1.Source of theresin
2.Chemicalnature
3.Functionalgroup
4.Structuraltype
5.Physicalproperties
6.Chemicalstructure
Ion exchange resin should have followingrequirements
»It must be chemicallystable.
»It should be insoluble in commonsolvents.
»It should have a sufficient degree of crosslinking.
»The swollen resin must be denser thanwater.
»It must contain sufficient no. of ion exchange
groups.

10. Divided in totwo,
1.Natural
cation –Zeolytes, Clay,etc
Anion –Dolomite
2.Synthetic
In organic and Organicresins
1

11. 2.Synthetic
In organic and Organicresins
Organic resins are polymeric resinmatrix.
The resin composed of–
Polystyrene (sitesforexchangeablefunctional
groups)
Divinyl benzene(Cross linking agent)-offersstability.
2
2.According to chemicalnature:
4 types:
1.Strong cation exchangeresin
2.weak cation exchangeresin
3.Strong anion exchangeresin
4.weak anion exchangeresin

12. Strongly acidic cation exchanger ---sulphonicacid
groups attached to styrene and di vinyl benzenecopolymer.
Weakly acidic cation exchanger---carboxylic acidgroups
attached to acrylic and divinyl benzeneco-polymer
Strongly basic anion exchanger-----quaternary
ammonium groups attached to styrene and divinylbenzene
co-polymer N+
Weakly basic anion exchanger-----poly alkyl amine
groups attached to styrene and divinyl benzeneco-polymer
FUNCTIONAL GROUPS PRESENT IN DIFFERENTION
EXCHANGERESINS:
Strong cation exchange resin-SO
3H
Weak cation exchange resin-COOH,OH,SH,PO
3H
2
Strong anion exchange resin-N+R
3,NR
2
Weak anion exchange resin-NHR,NH
2

13. STRUCTURAL TYPE OF IONEXCHANGE
RESINS
sins:
It contains 4 types. Theyare,
1.Pellicular type with ion exchangefilm
2.Porous resin coated with exchangerbeads.
3.Macro reticular resinbead.
4.Surface sulfonated and bondedelectro
statically with anionexchanger
a) Pellicular type with ion exchangere
»30 -40µ with 1-2µ filmthickness
»Very low exchangecapacity
» their ion exchange efficiency is 0.01-0.1 meq/g
of ion exchangeresin.

14. b) Porous resin coatedwithexchangerbeads
» Size 5 -10µ
»they are totally Porous & highlyefficient.
» their exchange capacities are from 0.5-2
meq/g of ion exchangeresin
c) Macroreticular resinbead
» Not highly efficient & very lowexchange
capacities.

15. d) Surface sulfonated and boned electrostatically withanion
exchanger:
» The particles are sulfonated and they arebonded
electrostatically with anion exchangerresin.
» They are less efficient and have low exchangecapacity.
» their exchange capacity is 0.02meq/g ofexchange
resin.

16. PRACTICALREQUIREMENTS:
1.Column material anddimension
2.Type of ion exchange resin & the selection dependon
followingproperties
a.) type of ions
b.) nature ofions
c.) efficiency ofresin
d.) Particlesize
e.) Structuraltype
3.Packing ofcolumn
4.Mobile phase –acids, alkali, andbuffers.
5.Development ofchromatogram
6.Analysis of theelute
7.Regeneration of ion exchangeresin

17. 1.Column material anddimensions:
Columns used in the laboratories are made upof
glass. In industries are made up of either high
quality stainless steel or polymers which are
resistant to strong acids andalkalis.
Thecolumndimensionsarealsoimportantanda
length:diameterratioof20:1to100:1forhigher
efficiencycanbeused.
2.Type of ion exchangeresin:
Typeofionscations (or)anions
natureofionsStrong (or)weak
Efficiency oftheresinIt is measured byion
exchangecapacity

18. Ionexchangecapacity:
Itisthetotalionexchangecapacityintermsof
theexchangablefunctionalgroupsexpressedasmilli
equivalentspergramoftheionexchangeresin.
Particle size oftheresin Porous,Pellicular
Amount of the cross linkingagent
Which decides swelling of theresin
3. PACKING OF THECOLUMN:
Wet packing method is used.
Resin + Mobile phase –packing in thecolumn
uniformly.
m.Eq / g =1000 /eq.wt

19. 4. MOBILEPHASE:
Organic solvents are less useful and they are not usedat
all.
Only strengths of acids, alkalies and buffers are usedas
elutingsolvents.
E.g. 0.1N HCL, 1N NaOH, Phosphate buffer,Acetate
buffer, Borate buffer, phthalate buffer,etc
5. DEVELOPMENT OF THECHROMATOGRAM
ANDELUTION
After introduction of the sample, development of the
chromatogram is done by using different mobile phases.
As, mentioned earlier, organic solvents are less usefuland
only acids, alkalis and buffers of different pH areused.

20. There are two elutiontechnique:
1.Isocraticelution
2.Gradientelution
Isocraticelution:
Same solvent composition is used. i.e., same
solvent of acid or alkali orbuffer.
Gradientelution:
In gradient elution technique, initially less acidicor
basic character is used followed by increasing the
acidity or basicity of the mobilephase.
this elution technique is usually used forcomplex
mixtures. The different fractions of the eluent is
collected volume wise or time wise andanalysed.

23. ANALYTES OF THEELUTE:
several methods of analysis can be used which
depends up on the nature & the quantity of thesample.
1.Spectrophotometricmethod
2.Polarographicmethod
3.Conductometricmethod
4.Amperometricmethod
5.Flame photometricmethod
6.Radio chemicalmethods
Geiger muller counter
ionization chambermethod.
after analyzing similar fraction are mixed in order
to get pure ions or compound of eachtype.

24. REGENERATION OF THE IONEXCHANGE
RESIN:
o
o
oRegeneration makes the used ion exchange resin to beas
efficient as a virginresin.
oRegeneration refers to the replacement of the
exchangable cations or anions present in theoriginal
resin.
Hence regeneration of the cation exchange resin isdone
by the charging the column with strong acid like HCl
acid.
Regeneration of anion exchange resin is done byusing
strong alkali like sodium hydroxide or potassium
hydroxide.

25. INSTRUMENTATION

26. FACTORS AFFECTING IONEXCHANGE
SEPARATIONS:
1.Nature and properties of ion exchangeresins.
2.Nature of exchangingions.
1. Nature and properties of ion exchangeresins:
Cross linking and swelling is important factor
which depends on the proportion of cross linkingagent
is andpolystrene.
when more cross linking agent is present, theyare
more rigid, but swellsless.
When swelling is less, separation of different sizes
is difficult as they cannot pass through the pores
present and it becomes selective to ions of different
sizes.

27. 2.Nature of exchangingions:
a.Valency ofions
b.Size ofions
c.Polarizability
d.Concentration ofsolution
e.Con. & charge ofions

28. CONCENTRATION AND CHARGE OFIONS:
If resin has higher +ve charge and solution haslower
+ve charge, exchange is favoured athigher
concentration.
If the resin has lower +ve charge and solutionhas
high +ve charge, then exchange is favoured at low
concentration.

29. APPLICATIONS:
Conversionfromonesalttoothere.g.wecan
preparetetrapropylammoniumhydroxidefroma
tetrapropylsaltofsomeotheranion.
Household(laundrydetergentsandwaterfilters)to
produce softwater
Ion exchange is used to prepare de-ionizedwater
Separate and purifymetals
Dealkalization
Analysis and purification ofimmunoglobulin's
Separation of inorganicions