Thin Layer Chromatography

TLC is used because it is “sensitive, fast, simple and inexpensive analytical technique”2 (Mohrig 151). The unknown solid (unknown #3 in this case) used in the experiment was obtained and added to a 2.5ml of Ethanol/dichloromethane in a test tube. This was the solvent used in the experiment because Dichloromethane volatility and ability to dissolve a wide range of organic compounds makes it a useful solvent for many chemical processes. The solid was already in powder form therefore we did not have to crush it but it the unknown was in a tablet form, one would need to reduce it to a powdery-like form in order to perform this Thin-Layer Chromatography experiment. The powder solution was thoroughly mixed with a glass rod in the test tube containing
The developing chamber is a critical technique of TLC for it becomes the principal reference to recording the Rf values of the solutions. 5ml of Ethyl Acetate Acid was poured inside a 250ml beaker. As stated in the introduction, CH3COOCH2CH3 was the developing solvent in our chamber for this solution. The beaker was then covered with a piece a foil and places under a hood. This was done so that the chamber would be ready as soon as the TLC plate prepared, as well as for security reason because of the level of toxicity of dichloromethane and it’s “possibility that prolonged inhalation […] may cause cancer.”1 (Lehman 145). For this reason, gloves and safety goggles were worn at all times. A TLC plate was obtained and with a pencil, 4 spots were made gently on its surface to serve as reference point to place the solutions. The points were respectively 1 cm from each other with the first and last point being at least 1.5 cm from their corresponding sides and all points were 1.5 cm from the bottom, to give time to the developing solvent to expand through all the points at the same rate once the TLC plate put in the developing chamber. Using capillary micropipettes, the solution were spotted to the