And finally, after adding more solvent, rinsing until it is just above the silica level, and then adding more, the actual elution can begin. This is done by spotting a TLC plate on a line penciled in 1cm from the bottom of the plate.
It moved through the column slower than the fluorine because Column chromatography of fluorene and fluorenone was much more polar.
The retention factor was then calculated. This all in all, confirms the experiment was a success. The solvent system was changed to a mixture of hexane and acetone If I had done the procedure in a better way, the separation between the two compounds would have been purer and my retention factors would have changed.
Techniques in Organic Chemistry. Solvent is allowed to run up the plate. Once the separated out flurenone was completely collected from the column chromatography, the process is completed. The plate showed that fluorene moved up the plate at a higher level than 9-fluorenone.
Following this, 4 elutions were collected in test tubes as hexane was continuously being added to the column.
The TLC plate was removed as soon as the solvent traveled up the plate until it was 1cm from the top.
This makes sense because the mixture being tested has a nonpolar molecule, flourene, and a polar molecule, fluorenone so naturally the solvent would have to have both qualities as it did.
Spots are shown under this light because the compounds that cause it absorb the light at the spectrum and therefore show up as dark spots on the TLC plates. Finally, the spots from text tube 5 and 6 showed solely a spot at 1.
Overall, my TLC plate could have shown better results had the length of my silica gel been higher than 4cm. Because 9-fluorenone was held tighter in the silica gel beads in the column, it did not go down the column as fast as fluorene did. Finally, a TLC chromatography was perfomed to compare the spotting from the elutions collected to the spotting of pure fluorene and fluorenone.
The final part of the experiment is one more TLC chromatography test with each of the test tubes collected to confirm the separation and the presense of both fluorene and fluorenone in the initial mixture. To load the column, about.
The retention factors were calculated to find the distances the samples of the compounds being tested moved up the plate relative to the distances moved by the solvent front.
Fluorene was visible only under UV light because it is a colorless compound, unlike 9-fluorenone which is yellow.
For this difference, the oxygen that sticks out from 9-fluorenone was able to hydrogen bond to the silica gel beads which allowed it to be held tighter in the column than fluorene.
The next solvent tested, ethyl acetate, showed only one spot on the TLC plate with an Rf of.
Because fluorene moves faster through the column than the fluorenone, it makes sense that it will show up in the earlier test tubes because it is eluted first. When put under the light, there was no spotting from test tube 1, but the solution from test tubes 2 and 3 showed a spot at 3cm with an Rf of.
This step is crucial because this solvent will be used throughout the rest of the experiment and if the solvent does not work well, then the data collected later will be inaccurate at best. In the first part of the experiment, a proper solvent was experimentally found.A spot from each of the test tubes are added to a TLC plate as well as a spot of pure fluorene and fluorenone.
The solvent used in the column chromatography that was earlier determined, 10% ethyl acetate and hexanes, was also used as. Chromatographic Separation of Fluorene and Fluorenone Abstract: A mixture of Fluorene (1) and Fluorenone (2) was separated by column chromatography.
Chemical Equation: Fluorene (1) Fluorenone (2) Mp C mp 83 C MW MW Introduction: Column chromatography was invented by Tswett in so that his study of the. COLUMN CHROMATOGRAPHY will be used to SEPARATE FLUORENE from an OXIATION PRODUCT 9-FLUORENONE One of htese compounds is WHITE AND THE OTHER IS YELLOIWW the progress of hte chromatography may be followed by evaporation of the solvent at periodic intervals as well as by observing teh slower.
Robby-Sean Cayetano Chem. L- Thursday am 10/07/12 Chromatographic Separation of Fluorene and Fluorenone Abstract: Liquid (column) chromatography was used in this experiment to separate fluorene and fluorenone from a mixture%(5). Column chromatography is an extremely important technique in organic chemistry.
It is a versatile method used to separate and purify organic compounds. And can be used to purify both solids and liquids. Chromatographic Separation of Fluorene and Fluorenone Abstract: A mixture of Fluorene (1) and Fluorenone (2) was separated by column chromatography.Download