chemsample-infraredspectroscopy-tlc-methods


 * Methods**

1. Prepare a developing chamber by obtaining two glass chambers with detachable lids. Put in filter paper that is as high as the chamber and covers three of the four walls, leaving one long side exposed. Add 5 mL of one of two eluents assigned (hexane and methanol). Cover and let sit for five minutes.

2. Obtain one TLC plate. Mark a thin line one cm from bottom and 0.5 cm from top of the TLC plate. Mark two faint hatchmarks to be spotting locations. On both hatchmarks spot once with stock solution filled micorpipet and allow to dry. Then, on only one hatchmark spot again with stock solution. Allow to dry.

3. Put TLC plate in developing chamber. Allow eluent to soak into TLC plate until the 0.5 cm mark at the top is reached. Immediately remove from chamber and allow to dry under fume hood. Observe under UV light and circle spots that appear. Repeat process with other eluent. Compare class results and determine which eluent is the most effective for developing the TLC plate. Also determine if single or double spotting is more effective for developing the TLC plate.

4. Using the most appropriate eluent, prepare chamber with this solution. Prepare one TLC plate with the stock solution and known solution and one with stock solution and assigned unknown solution. Develop as before. Using class results of known solutions, determine the order of substances in the stock solution and the identity of assigned unknown solution. Calculate Rf values for all spots on TLC plate.

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