GEL PERMEATION CHROMATOGRAPHY by Mehak

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GEL PERMEATION CHROMATOGRAPH Y Presented By: MEHAK 14320022 M.Sc. Chemistry Large size molecule Intermedi ate size molecule Small size molecu le
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Transcript of GEL PERMEATION CHROMATOGRAPHY by Mehak

Flash Chromatography

GELPERMEATION CHROMATOGRAPHYPresented By:MEHAK14320022M.Sc. Chemistry

1NIT JALANDHAR

CONTENTSChromatography definition Uses of ChromatographyGel Permeation Chromatography (GPC)GPC Separation Mechanism. TheoryMain Components Of GPCSolvent Containers PumpOvenSamplesInjectorColumnDetector Applications Refrences

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Mehak 14320022 Nov 2'20153CHROMATOGRAPHY

Mehak 14320022 Nov 2'20154It is used by pharmacists to determine the amount of each chemical found in each product.

GEL PERMEATION CHROMATOGRAPHY (GPC)

Mehak 14320022 Nov 2'20155 Gel permeation chromatography is a type of high performance liquid chromatography (LC). GPC/SEC separates molecules on the basis of their size, hence size exclusion.

GPC/SEC is used to 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

GPC/SEC is used to determine the molecular weight distributions of polymers

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. GPC SEPERATION MECHANISMMehak 14320022 Nov 2'20156

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www.separations.us.tosohbioscience.com/ServiceSupport/TechSupport/ResourceCenter/PrinciplesofChromatography/SizeExclusion/

Mehak 14320022 Nov 2'20159 Thus ,

LARGE MOLECULESSMALL MOLECULESINTERMEDIATE MOLECULES

Total volume of column packed with a solid matrix that has been swelled by water or other solvent is given by

Vt = total bed volume Vg = volume occupied by solid matrix. 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

Vt = Vg + VM + VSMehak 14320022 Nov 2'201510

THEORY

Ve = Vo + Kd.Vl

Mehak 14320022 Nov 2'201511Under these conditions: Assumed conditions:Where,Ve = vol. of effluent flowing through column between point of sample 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

Mehak 14320022 Nov 2'201512 MAIN COMPONENTS OF GPC

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.Mehak 14320022 Nov 2'201513

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.Solvent Container

PUMPSMehak 14320022 Nov 2'201514

OVENSMehak 14320022 Nov 2'201515

SAMPLESMehak 14320022 Nov 2'201516

INJECTION AND INJECTORSMehak 14320022 Nov 2'201517

Different Types Of Column Packing18

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DETECTORSMehak 14320022 Nov 2'201521

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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. WIDELY USED DETECTORS 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) :

Mehak 14320022 Nov 2'201524APPLICATIONS

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.

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

http://www.separations.us.tosohbioscience.com/ServiceSupport/TechSupport/ResourceCenter/PrinciplesofChromatography/SizeExclusion/

Instrumental Methods of Analysis, Willard, Merritt, Dean and Settle, CBS Publisher and Distributors.,1986.

Principles of Instrumental Analysis, Skoog, Holder, Nieman, Fifth edition Thomson Books ,1998.Mehak 14320022 Nov 2'201525

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