Comparision of thin layer chromatography and paper chromatography

comparison of PC and TLC

1. PRESENTED BY THUSHARA C 1 ST YEAR MPHARM DEPT. OF PHARMACY PRACTICE COMPARISION OF THIN LAYER CHROMATOGRAPHY AND PAPER CHROMATOGRAPHY :

2. PAPER CHROMATOGRAPHY TLC PRINCIPLE Principle of separation is partition Principle of separation is adsorption Stationary phase Whatman filter papers of different grades like No.1, No.2, No.3, No.4, No.20, No.40, No.42 etc are used Silica gel coated on a plate Silica gel H ( Silica gel with ou t binder ) Silica gel G ( Silica gel + CaSO4 Silica GF (Silica gel + binder + fluorescent indicator) Alumina, Cellulose powder, Kieselguhr G Mobile phase Pure solvents, buffer solutions or mixture of solvents Examples- Hydrophilic mobile phase Isopropanol : ammonia:water Methanol : water N- butanol : glacial acetic acid : water Hydrophobic mobile phases dimethyl ether: cyclohexane kerosene : isopropanol pyridine, pet. ether, carbon tetrachloride, acetone, water, glycerol, ethanol, benzene

3. Development techniques Ascending , descending, circular or radial One dimensional development, Two dimensional development, Horizontal development, Multiple development Visualising agents Non 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 acetone Dragendroff’s reagents3,5 dinitro benzoic acid , Phenolic comp. & tannins,Amino acids,Alkaloids Cardiac glycosides Non specific methods Iodine chamber method Sulphuric acid spray reagent Same as PC

4. Quantitative estimation Direct technique: Comparison of visible spots Photo densitometry Radiotracer Method 2. Indirect method 3. Rf value 4. Rx value Direct technique 2. Indirect method 3. Rf value 4. Rx value Application Separation of mixtures of drugs, Separation of carbohydrates, vitamins, antibiotics, proteins, etc. Identification of drugs Identification of impurities Analysis of metabolites of drugs in blood , urine …. Purity of sample »Examination of reaction »Identification of compounds »Biochemical analysis »In pharmaceutical industry »Separation of multicomponent pharmaceutical formulations »In food and cosmetic industry

5. 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. 15—45 minutes More time consuming i.e. 2—3 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.

6. T h a n k y o u