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Descending Paper Chromatography.pdf

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Drkalaivani2

Descending chromatography is a technique where the mobile phase moves downwards due to gravitational force. It works on the principles of adsorption and partition chromatography. To perform it, an adsorption filter paper, mobile phase solvent, glass chamber, and capillary for spotting are used. The analyte mixture is spotted on the filter paper and the mobile phase moves downwards, separating the analyte components and forming spots on the paper. Descending chromatography can be used to study fermentation, check purity of pharmaceuticals, detect adulterants, and determine drugs in humans and animals.

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z DESCENDING PAPER CHROMATOGRAPHY By; P.Rajeshwari I, M.Sc Biotechnology
z DEFINITION: ▪ Descending chromatography is a techniquein which the mobile phase movesto the downside. ▪ Paper chromatography and thin-layer chromatography is the technique in which Descending chromatography is used. ▪ Ascending chromatography is one of the chromatography technique used in which mobile phase run in upward direction opposite to the descending chromatography
z PRINCIPLE: ▪ In descending chromatography, the mobile phase runs to the downside because of the gravitational force. ▪ It works on the principle of adsorption chromatography and the partition chromatography. ▪ The term descending is given because the separation or the development of the chromatogram is taking place towards down.
z DIAGRAM:
z PROCEDURE: ▪ To perform the Descending chromatographyAdsorption filter paper/TLC plate, solvent as mobile phase, glass chamber with lid or beaker with lead, fine capillary for spotting is required. ▪ Descending chromatography set up is opposite to the ascending chromatography. The mobile phase tank is set at the top of the assembly. It is a quite complex setup than the Ascending chromatography.
z ▪ The mobile phase tank is placed at the top side of the assembly as shown in the diagram. The chamber needs to be saturated before the separation takes place. ▪ The spotting procedure in descending chromatography is the same as the Ascending chromatography. Syringe or glass capillary spotting of the mixture of the analyte is a place on the stationary phase at the marked place. ▪ After the spotting of the analyte, adsorption paper or the thin layer plate is attached at the top side in the chamber.
z ▪ The mobile phase gradually moves from the upper side to the downside. Along with the mobile phase spot of the analyte also moves with the mobile phase and its componentswill separate out ▪ The spot with a mixture of analyte travel through the mobile phase and separation of the analyte is observed on the paper in the form of the spot after drying. ▪ Reagent in case visual inspection of the spot is not possible (To visualize the spot).
z APPLICATION OF PAPER CHROMATOGRAPHY: ▪ To study the process of fermentation and ripening. ▪ To check the purity of pharmaceuticals. ▪ To inspect cosmetics. ▪ To detect the adulterants. ▪ To detect the contaminants in drinks and foods. ▪ To examine the reaction mixturesin biochemical laboratories. ▪ To determinedopes and drugs in humansand animals.

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Descending Paper Chromatography.pdf

  • 2. z DEFINITION: ▪ Descending chromatography is a techniquein which the mobile phase movesto the downside. ▪ Paper chromatography and thin-layer chromatography is the technique in which Descending chromatography is used. ▪ Ascending chromatography is one of the chromatography technique used in which mobile phase run in upward direction opposite to the descending chromatography
  • 3. z PRINCIPLE: ▪ In descending chromatography, the mobile phase runs to the downside because of the gravitational force. ▪ It works on the principle of adsorption chromatography and the partition chromatography. ▪ The term descending is given because the separation or the development of the chromatogram is taking place towards down.
  • 5. z PROCEDURE: ▪ To perform the Descending chromatographyAdsorption filter paper/TLC plate, solvent as mobile phase, glass chamber with lid or beaker with lead, fine capillary for spotting is required. ▪ Descending chromatography set up is opposite to the ascending chromatography. The mobile phase tank is set at the top of the assembly. It is a quite complex setup than the Ascending chromatography.
  • 6. z ▪ The mobile phase tank is placed at the top side of the assembly as shown in the diagram. The chamber needs to be saturated before the separation takes place. ▪ The spotting procedure in descending chromatography is the same as the Ascending chromatography. Syringe or glass capillary spotting of the mixture of the analyte is a place on the stationary phase at the marked place. ▪ After the spotting of the analyte, adsorption paper or the thin layer plate is attached at the top side in the chamber.
  • 7. z ▪ The mobile phase gradually moves from the upper side to the downside. Along with the mobile phase spot of the analyte also moves with the mobile phase and its componentswill separate out ▪ The spot with a mixture of analyte travel through the mobile phase and separation of the analyte is observed on the paper in the form of the spot after drying. ▪ Reagent in case visual inspection of the spot is not possible (To visualize the spot).
  • 8. z APPLICATION OF PAPER CHROMATOGRAPHY: ▪ To study the process of fermentation and ripening. ▪ To check the purity of pharmaceuticals. ▪ To inspect cosmetics. ▪ To detect the adulterants. ▪ To detect the contaminants in drinks and foods. ▪ To examine the reaction mixturesin biochemical laboratories. ▪ To determinedopes and drugs in humansand animals.