The beakers were marked with the identity of the solvents. The filter papers inside the beakers were wet using the respective solvents then covered with aluminum foil. Three small TTL plates were obtained, carefully held on the edges to avoid contamination from fingers, and placed under a UP lamp to verify that there are no impurity spots on them. At approximate mm above the edge of the bottom of the TTL plates, a line was drawn across each one with an “X” in the middle of the line in each one indicating an origin.
The plates were visually checked to ensure that the silica gel was not disturbed. A single spot of the known mixture was placed on the origins using a capillary tube. The known mixture contains: Phenyl, Phenomenon, and Bondholder. The solvent was set aside to evaporate then placed under the UP amp once again to see if a dark spot is present in each plate. The plates were then placed in each of the beakers prepared earlier; one plate in the hexane eluting chamber, another plate in the methyl chloride eluting chamber and the last plate in the methanol eluting chamber.
The beakers were closed loosely with aluminum foil and the plates were left inside until the solvent traveled % of the way upward. The plates were removed and immediately a line was drawn across the plate where the solvent stopped (solvent front). The plates were set aside to dry and then visualized under short-wave lamp to locate and circle the pots. An acceptable eluting solvent is one that gives 3 distinct spots, therefore, methyl chloride was chosen. Determination of the Identity of an Unknown A large silica gel TTL plate was obtained and checked for contamination.
A light line was drawn across the plate approximately mm above the bottom edge with four “X” marks along the line. A spot of phenyl solution was placed on the first T, a spot of Phenomenon solution was placed on the second T, a spot of Bondholder solution was placed on the third “X” spot and a spot of the unknown was placed on the last The letter of the unknown was recorded in the lab taboos as. The spots were visualized under a UP lamp to ensure enough solution was present at each “X” mark. The plate was then eluted in a mall beaker of methyl chloride prepared similar as the above eluting chambers.