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1. GEL PERMEATION
CHROMATOGRAPHY
Presented by :
Engr. Zafar Ahmad
Engr. Mudassir Jalal Shah
Engr. M. Amir Hamza
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2. CONTENTS
• Chromatography
• definition
• Gel Permeation Chromatography (GPC)
• GPC Separation Mechanism.
• Theory
• Main Components Of GPC Apparatus
• Solvent Containers
• Pump
• Oven
• Samples
• Injector
• Column
• Detector
• Applications & Uses
• Advantages of GPC over Old Technique.
• Refrences
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3. Chromatography is a Greek
word chroma “colour” and
graphein “to write”.
chromatography is a family of
analytical chemistry techniques
for the separation of mixtures.
It was the Russian botanist
“Mikhail Tsvet” who invented the
first chromatography technique in
1901.
CHROMATOGRAPHY
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4. • Gel permeation chromatography is a type of high performance liquid
chromatography (LC).
• Separates molecules on the basis of their size, hence ‘size exclusion’.
• Determine the molecular weight distributions of polymers.
• GPC/SEC uses columns packed with very small, round, porous particles
to separate molecules contained in the solvent that is passed through
them.
• The first GPC/SEC columns were packed with materials referred to as
gels, hence ‘gel permeation’
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GELPERMEATION CHROMATOGRAPHY
(GPC)

5. Figure : Principle of gel chromatography: A) mixture applied to the top of
the column; B) partial separation; C) complete separation; D)excluded
substance emerges from the column.
GPCSEPERATIONMECHANISM
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Mobile
Phase
Stationary
Phase

7. 7

8. • Total volume of column packed with a solid matrix
that has been swelled by water or other solvent is
given by
Vt = Vg + VM + VS
Vt = total bed volume
Vg = volume occupied by solidmatrix.
VM = void volume of mobile phase i.e. unbound
solvent in interstices between the solvent loaded
porous particles.
VS = volume of solvent held in pores
THEORY8

9. Time taken for Solution
molecules to diffuse into
pore is less as compared to
time spent by molecule near
pore.
Separation process is
independent of
diffusion.
Assumed conditions:
 Under these conditions:
 Ve= Vo+Kd.Vl
 Where,
 Ve = vol. of effluent flowing through column between point ofsample
injection & sample emergence from column.
 Kd = distribution coefficient.
 FOR LARGE MOLECULES : Kd = 0 , Vo=Ve
 FOR MOLECULES THAT CAN PENETRATE ALL THE PORES:
 Kd = 1 , Ve = Vo+Vl
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MainComponentsofGPC10

11. 1. Solvent and Solvent Containers
• The solvent must be able to dissolve the sample,
sometimes a polymer insoluble at room temperature
will dissolve at higher temperature.
• The solvent must not induce any other interactions
between the sample and the stationary phase, so that
the separation is solely on the basis of sample size.
• The solvent container should be made of clear
glass, or amber glass for solvents affected by
sunlight, with a stopper to exclude dust and limit
evaporation.
SolventContainer
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12. 2. PUMP
The pump takes the solvent and delivers it to the rest of the
system at a constant, accurate and reproducible flow rate.
The pump has to be able to run the same flow rate regardless of
viscosity, so that results can be compared from one analysis to
another
The pressure delivered by the pump also needs to be
smooth so that there are no pulses in the flow.
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13. 3. OVEN
• GPC is usually carried out at room temperature, but some
instruments have heated and thermostatically controlled ovens in
which the columns and detectors are placed.
• Higher temperatures, up to 220 °C, are necessary for some
solvents that have much higher viscosities, such as
trichlorobenzene or chloronaphthalene .
• Operating the instrument at high temperatures reduces viscosity
and hence column back pressure, with a corresponding increase
in efficiency.
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14. 4. SAMPLE
• Toprepare a sample for analysis it is first dissolved in an
appropriate solvent, such as tetrahydrofuran (THF) for
organic GPC.
• Since the separation obtained depends on the size of the sample
molecules, it is important that they are allowed to swell and then
fully dissolve in the solvent before being put through the
chromatograph .
• Where possible, the eluent used to prepare the samples should
be the same as the solvent running through the system
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15. 5. INJECTION&INJECTORS
• Injectors introduce the polymer sample into the flowing
solvent stream.
• It is important that the injector does not disturb the flow of the
mobile phase
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16. 6. Different TypesOfColumn
Packing
Columnpacking
Semirigid
Crosslinked
macromolecular
polymers.
Rigid
Controlledpore-
sizeglassesor
silica
• Separation of the sample takes place inside the column, a hollow
tube tightly packed with extremely small porous beads, typically
polymer or silica.
• The columns vary in length from 50 mm to 300 mm, and internal
diameters of 4.6 to 25 mm, depending on their intended use.
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17. A. Semi Rigid Polymers
These materials swell slightly
Limited to a max. pressure of 300 psi.
Bead diameters are usually 5 micrometer
Styrene divinylbenzene polymers are used for compounds
of molecular weight ranging from 100-500 million
Sulphonated polystyrene beads are compatible with
aqueous systems , non sulphonated with non aqueous
systems.
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18. B. Rigid Porous Glasses or Silica
Cover wide range of pore diameter
Chemically resistant
Used with aqueous and polar organic solvents.
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19. 7. DETECTORS
So, it has to be very
sensitive since the changes
they measure in the mobile
phase are very small.
Detectors may
respond to a change in
the mobile phase due
to the presence of the
sample
So, it has much greater
sensitivity but often only
work with specific
samples
Detectors may
respond to a
property of the
sample alone
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20. DETECTORS
Measure
concentration alone
>Differential refractive
index (DRI) detector *
> UV detector
>Evaporative light
scattering (ELS) detector.
whose response is
proportional to
concentration and other
properties of the
polymer molecules.
Static light scattering
detectors or viscometers.
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•These detectors work by assessing the
difference in refractive index between
the mobile phase and the pure solvent
•Since the refractive index of polymers is
usually constant above molecular weights
of about 1,000 g/mol, the detector
response is directly proportional to the
sample concentration.
WIDELYUSEDDETECTORS
•Use the fact that a beam of light will be
scattered when it strikes a polymer
molecule
•Low Angle Laser Light Scattering
(LALLS),
•Multi-angle Laser Light Scattering
(MALLS)
• Right Angle Laser Light Scattering
(RALLS).
•The advantage of these detectors is that they
give a response directly proportional to the
molecular weight of the polymer molecules,
and can provide size information
Static Light Scattering Detectors:Differential Refractometer
(Universal detector) :
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22. APPLICATIONS
Gum Arabic : Gum arabic is a polysaccharide widely used in the food
industry as a viscosity modifier or gelling agent. The physical properties and
processibility of these water soluble polymers are related to their molecular
weight distributions, which can be determined by GPC.
Modifying PVC (Poly Vinyl Chloride) : Unplasticized PVC has a high melt
viscosity leading to some difficulties in processing. In order to overcome
these problems, additives are used as impact modifiers to ensure more
uniform flow and hence improve surface finish.
The properties of the final material are dependent on the molecular
weight distribution of the PVC and the type and level of the added
plasticizers.
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23. USES OF
CHROMATOGRAPHY
It is used in
crime scene
investigations
In hospitals it
can be used to
detect alcohol
levels in a
patient's blood
stream
It is used for
environmental agencies
to determine the level
of pollutants in water
supplies
It is used to purify
chemicals needed
to make a product
in a manufacturing
plant
It is used by
pharmacists to
determine the
amount of each
chemical found in
each product.
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24. • Short analysis time.
• Well defined separation.
• Narrow bands and good sensitivity.
• There is no sample loss.
• The small amount of mobile phase required.
• The flow rate can be set.
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AdvantagesofGPC OverOldTechniques

25. REFERENCES
• https://www.agilent.com/cs/library/primers/Public/5990-
6969EN%20GPC%20SEC%20Chrom%20Guide.pdf
• http://pubs.acs.org/doi/pdf/10.1021/ed083p1567.2
•https://link.springer.com/article/10.1007/BF00562169
•https://microbenotes.com/gel-permeation-chromatography/
•Demo Youtube Video
https://www.youtube.com/watch?v=9trws35gLNM
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