Thin Layer Chromatography

1. Thin Layer Chromatography This animation is about thin layer chromatography and how it can be used to separate components from a mixture. - Dhrubajyoti Samanta

2. Master Layout 1 2 3 4 5

3. Definitions and animation directions: 1 • The silica gel is a white solid which does not move during the course of the animation. • The solvent, and the dots representing the components/ compounds move upwards during the course of the reaction. • The polarity levels determine the heights to which the components/compounds rises. • The solvent front rises to a constant height in each of the cases (say 4 inches). • The distance moved by the component/compound dots depend on the polarity of the solvent. The distance moved by the components is given by the table in the slides following each situation. 2 3 4 5

4. Thin Layer Chromatography (TLC) - Dhrubajyoti Samanta Please move the slider to choose the polarity of the components/compounds and the polarity of the solvent. Then press the start button to initiate the process of chromatography.

5. Step 1: 1 Thin Layer Chromatography is a technique by which components of a mixture may be separated based on differences in their polarity using an adsorbing agent (eg. Silica) which is taken in the form of a thin layer. The separation of the components depends on several factors, namely: the differences in polarity of the components and the polarity of the solvent depending on the type of adsorbing agent used. Taking silica as the adsorbing agent, a larger difference in polarity of the components causes an increase in the separation of the components and a greater polarity of the solvent leads to a decrease in the separation after a certain point. A characteristic of a component is given by the RF Value which is given by the equation : Another use of thin layer chromatography is to compare two substances. This is often used to determine the extent to which a reaction has taken place. 2 3 4 5

6. Step 2: 1 2 3 4 5

7. Step 3 – option compare: 1 2 3 4 5

8. Step 4 – option compare: 1 2 3 4 5

9. Step 5 – option compare: 1 2 3 4 5

10. Step 6 – option compare: 1 2 3 4 5

11. Input Directions

12. Step 7 – option compare: 1 2 3 4 5

13. Output Directions The distances moved by the compounds follow the following curves.

14. Step 8 – option compare: 1 2 3 4 5

15. Step 9 – option compare: 1 2 3 4 5

16. Input directions

17. Step 10 – option compare: 1 2 3 4 5

18. Output Directions The dots move to height according to the polarity as shown in the following graph.

19. Step 11 – option compare: 1 2 3 4 5

20. Step 3 – option separate: 1 2 3 4 5

21. Step 4 – option separate : 1 2 3 4 5

22. Step 5 – option separate : 1 2 3 4 5

23. Step 6 – option separate : 1 2 3 4 5

24. Input Directions

25. Step 7 – option separate : 1 2 3 4 5

26. Output Directions The distances moved by the components follow the following curves.

27. Step 8 – option separate : 1 2 3 4 5

28. Step 9 – option separate : 1 2 3 4 5

29. Input directions

30. Step 10 – option separate : 1 2 3 4 5

31. Output Directions The dots move to height according to the polarity as shown in the following graph.

32. Step 11 – option separate : 1 2 3 4 5

33. Links for further reading Books: Vogel’s Textbook of Practical Organic Chemistry, 5th Edition, A.I. Vogel, A.R. Tatchell, B.S. Furnis, A.J. Hannaford, P.W.G. Smith, Prentice Hall, 1996. Internet Reference: http://courses.chem.psu.edu/chem36/Experiments/PDF%27s_for_techniques/TLC.pdf