Lab report on tlc analisys of

tlc errors

Since there was originally 75 mg of meta-nitroaniline present in the sample and only 0. Consequences would be inaccurate Rf values due to the uneven advance of sample origin spots.

thin layer chromatography conclusion

Experiment 2 consisted of two TLCs, containing the same compounds Aspirin, Acetaminophen, Ibuprofen and Caffeine but had different solvents. With pencil, two lines were drawn on each of the seven plates.

Thin layer chromatography lab report abstract

Do not use excessive forces when writing on a TLC plate as this will remove the stationary phase. The final analgestic TLC plates were invisible to the naked eye, therefore having to be viewed under a UV light. Once this first band was fully collected, a new Erlenmeyer flask was placed under the column for collection. The samples were dissolved in ethanol for spotting onto the plate. Sequence involved in TLC. Cut the plate to the correct size and using a pencil never ever use a pen , gently draw a straight line across the plate approximately 1 cm from the bottom. The first and middle fractions collected were azobenzene. These plates functioned as the stationary phase.

The Rf value of the unknown 0. The column was tilted and the slurry was added to the column.

Uses of thin layer chromatography

A cap is kept in place at all times, except when adding or removing a plate. The TLC plate was coated in a silica gel which acted as the stationary phase, which is the material that does not move. Most organic compounds will be temporarily stained brown. The two mobile phases to be used to separate the components were prepared. It is easy to see which are the two active ingredients in the unknown commercial pain relief medicine by comparison of the spots with the standard reference materials running on either side caffeine and acetominophen. If the start line should touch the solvent directly, the TLC experiment is ruined since some or all of the sample will be dissolved into the solvent pool. If the spot is not visible, more sample needs to be applied to the plate. Experiment 2 proved that a less polar solvent will bring higher Rf values than those of a more polar solvent.

When the mobile phase was strictly petroleum ether, the spot did not move at all on the TLC plate. Solvent 5 was just 5 mL of ethyl acetate. Although there were two dyes in the unknown, their Rf values were so close that the spots on the TLC plate overlapped, appearing to be only one spot.

Thin layer chromatography pdf

The second and first fractions were combined into one Erlenmeyer flask. To develop a plate with permanganate, spray or dip the plate and heat it with a heat-gun. Each of the seven beakers was covered in order to prevent evaporation while the solvents soaked up the plates. When the remainder of the orange band below the white band was collected, the eluent needed to be changed to the solvent containing just ethyl acetate. Therefore, the length of separation is limited compared to other chromatographic techniques. Geiss, Friedrich. If overlapping occurs, it would prove difficult to resolve the different components. Column chromatography is a method to physically separate all of the components also usually non-volatile of a mixture. This was also because the original dye spots on the plate were to large, causing the dye to smear slightly so they were more difficult to identify after developing. The capillary was not held to the plate, but rather just tapped, so the dot of the solution to be tested on the plate did not have a diameter of more than 3 mm. A column containing a fritted disk and a stop cock was assembled with two clamps to stand vertically in a fume hood.
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(DOC) Lab report 2 Thin Layer Chromatography