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PRESENTED BY THUSHARA C1ST YEAR MPHARMDEPT. OF PHARMACY PRACTICECOMPARISION OF THIN LAYER CHROMATOGRAPHY AND PAPER CHROMATOGRAPHY :

PAPER CHROMATOGRAPHYTLCPRINCIPLEPrinciple of separation is partitionPrinciple of separation is adsorptionStationary phaseWhatman filter papers of different grades like No.1, No.2, No.3, No.4, No.20, No.40, No.42 etc are usedSilica gel coated on a plateSilica gel H ( Silica gel with out binder )Silica gel G ( Silica gel + CaSO4 Silica GF (Silica gel + binder + fluorescent indicator)Alumina, Cellulose powder, Kieselguhr G

Mobile phasePure solvents, buffer solutions or mixture of solventsExamples- Hydrophilic mobile phase Isopropanol: ammonia:water Methanol : water N-butanol : glacial acetic acid : water Hydrophobic mobile phases dimethyl ether: cyclohexane kerosene : isopropanolpyridine, pet. ether, carbon tetrachloride, acetone, water, glycerol, ethanol, benzene

Development techniquesAscending , descending, circular or radialOne dimensional development, Two dimensional development,Horizontal development,Multiple development

Visualising agentsNon specific methods ( Physical methods) E.g. iodine chamber method, UV chamber for fluorescent compounds at 254 or at 365nm.Specific methods (Chemical methods) or Spraying method - examples, Ferric chloride,Ninhydrin in acetoneDragendroffs reagents3,5 dinitro benzoic acid , Phenolic comp. & tannins,Amino acids,AlkaloidsCardiac glycosides

Non specific methodsIodine chamber methodSulphuric acid spray reagent Same as PC

Quantitative estimationDirect technique:Comparison of visible spotsPhoto densitometryRadiotracer Method2. Indirect method 3. Rf value4. Rx valueDirect technique2. Indirect method 3. Rf value4. Rx valueApplicationSeparation of mixtures of drugs,Separation of carbohydrates, vitamins, antibiotics, proteins, etc.Identification of drugsIdentification of impuritiesAnalysis of metabolites of drugs in blood , urine .Purity of sampleExamination of reactionIdentification of compoundsBiochemical analysisIn pharmaceutical industrySeparation of multicomponent pharmaceutical formulationsIn food and cosmetic industry

COMPARISION OF THIN LAYER CHROMATOGRAPHY AND PAPER CHROMATOGRAPHY :

THIN LAYER CHROMATOGRAPHY PAPER CHROMATOGRAPHY The principle of separation is adsorption.The principle of separation is partition More amount of substance is required. Less amount of substance is required.Less time consuming i.e. 1545 minutes More time consuming i.e. 23 hours TLC plates can be heated in an oven for a long time Paper cannot be heated in an oven for a long time.Separation is more sharp Separation is less sharp.Thin layer have physical strength. Ascending techniques are preferred for this type Due to lack of physical strength in paper, descending techniques are used.In TLC, chromatoplates are prepared by coating thin layers of silica gel or alumina on glass plates.Here paper is generally used whatman filter paper. Silica gel or alumina cannot be used because they cannot be made into sheets. in TLC, corrosive reagents may be coated on glass plates. Here, corrosive reagents destroy the paper. Sensitivity of detection of the fraction on plate is high. The spots are less diffused Less sensitivity of detection. Spots easily diffused TLC can be evaluated under UV.Paper chromatography cannot be evaluated under UV.

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