IV. ANALYTICAL TECHNIQUES

3. Thin Layer Chromatography (TLC)

1. Name the three steps to a thin-layer chromatography analysis?
2. What is the development process for thin-layer chromatography? How is chromatography affected?
3. Describe three methods of visualization for thin-layer chromatography.
4. Explain why the standard of a suspected drug substance should be spotted alongside the unknown sample during a thin-layer chromatography analysis.
5. In your opinion, is it necessary to measure the Rf of an analyte if you run an authenticated standard alongside?
6. What is normal phase TLC?
7. What is reverse phase TLC?
8. What is the "Rf" value and what role does it play in TLC?
9. What does Rf correct for?
10. What makes for a good solvent system in TLC?
11. What is "visualization"? Why is it necessary in TLC?
12. List the visualization spray reagent used in marihuana analysis.
13. List the visualization spray reagent used in psilocin analysis.
14. List some problem issues that occur with TLC that are not encountered with other analysis techniques.
15. List some drugs that are especially applicable to analysis by TLC.
16. SWGDRUG recommendations include having reviewable data. How could reviewable data be captured for TLC analysis?
17. Describe what a multi-developmental TLC is. What drug(s) benefit from such an analysis?
18. What is preparative TLC? Why is it used?
19. How is a control used in TLC?
20. What is chromatographic polarity?
21. What is a dielectric constant of a solvent and how does it relate to polarity?
22. What is partitioning?
23. What is the difference between reverse phase and normal phase?
24. How does a preparatory plate differ from a standard TLC plate?
25. What types of silica are involved in TLC?
26. Why do we add base to most TLC systems?
27. What is the difference between Plaster of Paris and Gypsum?
28. What happens when you have more that 40% water in a silica gel TLC system?
29. What is gel filtration chromatography?
30. What is molecular weight exclusion chromatography?
31. Name five TLC stationary phases.
32. What is liquid adsorption chromatography?
33. What are two advantages of a pre-absorbent zone on TLC plates?
34. What is kieselguhr?
35. What is the advantage of a single-solvent mobile phase?
36. What is solvent demixing?
37. What is liquid-liquid TLC?