7. ThinLayer Chromatography Chemistry （7所示。）.pdf

7. Thin-Layer Chromatography You will need to bring your package of TLC plates on this day. Not all plates will be used in this experiment; some will be needed in lab the following week. Be sure to include all the analgesics and solvents used in this experiment in your Chemical Data Tables. Don’t forget to include the Chromatographic Behavior Comparison section in this PreLab. An example can be found in section 3.2. PreLab exercise: Using a greatly magnified diagram of a TLC plate, locate or define each of the following terms: PreLab Exercise 1. Origin 2. Stationary Phase 3. Mobile Phase 4. Solvent Front 5. Component “spot” 6. R value f 7. Development 8. Visualization of spots 9. What is meant by differential partitioning between stationary and mobile phase? 10. What is the recommended procedure for cleaning a TLC spotting capillary? Introduction Chromatography is the separation of two or more compounds or ions by the distribution Definition of between two phases, one which is moving and the other which is stationary. These two phases Chromatography can be solid-liquid, liquid-liquid or gas-liquid. Although there are many different variations of chromatography, the principles are essentially the same. If you took Chem 15 at University Park, you may remember using paper chromatography to separate inks and food dyes. The cellulose paper was the stationary or solid phase and the 1-propanol/water mixture was the mobile or liquid phase. This chapter explores a very similar microscale technique for separating organic molecules, thin-layer chromatography. Thin-layer chromatography or TLC, is a solid-liquid form of chromatography wher