Thin Layer Chromatography Lab Report

Adsorption chromatography occurs when “one substance form[s] some sort of bonds to the surface of another one”, creating intermolecular forces between the two substances (Chemguide). For thin layer chromatography, the components of the mixture are adsorbed onto the stationary phase that covers the plate (Chemguide). The more polar a substance is, the more strongly adsorbed it is (Chemguide) and the strong intermolecular forces then result in a slower rate of migration with respect to the moving phase. As the solvent touches the TLC plate, the solute (mixture) is allowed to move up the TLC plate

Other information that can be obtained from a TLC analysis is the progress of a chemical reaction, which can be done by taking samples from the reaction mixture at various intervals and spotting them on TLC plates and taking down the Rf factor. Also TLC analysis can be used to determine the optimum conditions required to obtain a high yield of the desired product with little to no side products. Yield can be ascertained via TLC analysis in that the reactant and product intensity on the TLC plate will have varying degrees of intensity. At the end of the reaction, the product should have the most intensity, while the reactant has the least intensity. At the beginning of the reaction, it would be the other way around. With this, you can determine the percent yield of the

First, obtain a SpectroVis Plus device and connect with its corresponding LabQuest2 device. You need to calibrate by turning on the machine, allow the inner lamp to start heating up, and prepping a blank in the process. Obtain a dry cuvette, fill it with distilled water, and place into the SpectroVis plus device. Before doing so, be sure to wipe the outside of the cuvette with a Kimwipe to clean off any fingerprints that might be present. Fingerprints will skew with the calibration. Once the device notifies you that calibration is complete, click okay and prep for the next part of the lab.

Add RO water to the 25 ml volumetric flask up to the mark. Put stopper on the flask and shake it properly.

The solvent mixture we decided to use for our TLC was a 3:1 ratio of ethanol to ethyl acetate. Originally when testing plates, we found that ethanol was the solvent that created the most clear and vibrant image, while ethyl acetate made an image, in a much smaller amount of time, but this image was very light and unclear. At first we decided to use only ethanol for the final TLC, but after waiting 20 minutes and having the plate being nowhere near finishing, we decided to add some ethyl acetate to speed up the process. When testing, we added ethyl acetate 1 mL at a time until we found a combination of speed and clarity we were happy with. This is how we settled on the mixture of 75% ethanol and 25% ethyl acetate.

4.Measure 35mL of warm water and add them into each of the 4 test tubes at about roughly the same time. It is essential that the water is warm. Do not seal the test tube.

Repeat steps 3-4: Fill 1 tube with 50% NaCl. Weigh each of the tubes/cells. Record on the chart. 3. Label a 500mL beaker with 50% NaCl and fill it with 400mL of the 50% NaCl solution.

You should time this by 30 seconds to a minute and a half. After you put the substrate in you need to look at the displacement and find the difference, when the reaction stops. You should do the same thing with all the substrates you test throughout the lab. Make a data table of the information you have collected. This is the procedure we did and that one should do if one were to do the exact experiment.

In this experiment, the objective was to use thin layer chromatography to identify the major active ingredients in commercial analgesic preparations. TLC is a method to separate compounds and to see how many compounds are present in the mixture. The separation into components is also dependent on the solvent used. When TLC is performed, the Rf values are determined for the sample and they are compared to the Rf values of the standards. Similar Rf values help identify the standards that might be present in the sample.

1 ml of water should be added to the first test tube and make a note. In the second test tube, 1 ml of methyl alcohol should be added. In the third test tube, 1 ml of hexane must be added. Lastly, the fourth test tube will be a control.

Submerge the graduated cylinder in the plastic tub so that it is completely filled with water. Hold the open end of the graduated cylinder and move it vertically upside-down where the open end of the graduated cylinder is still submerged in the plastic tub. Clamp the graduated cylinder the ring stand of the lab table to keep it in place. perforate a hole in the top of the rubber cork for the solution container. Cut a straw the length of about four inches. place the straw inside of the rubber cork hole. Set up your timer for two minutes.

1. What was the main aim of the practical? (5-marks) The aim of this practical is to isolate lipid extracts of amniotic liquid through thin layer chromatography (TLC). This method is based on the separation of substances that form an analytical mixture because of the different affinity on the two phases (mobile and stationary).

The type of solvent used will determine the extent of separation of each component. The concept that like constituents are attracted to each other and are miscible plays an essential role in determining the migration distances of various components of the mixture. Each component has the option of entering either the mobile or stationary phase and the polarity of the solvent will influence its pathway. For example, a more polar solvent will compete with the polar components for positions on the polar adsorbent and also transport its counterpart along the plate until it finally becomes adsorbed. As a result, the polar components of the mixture will remain in the mobile phase for a longer period

Following that, a blotting sandwich is made by adding blotting buffer to the container and inserting the plastic cassette. Lay a wet fiber pad on the black side of the cassette. On top of that lay a wet blotting paper on the fiber pad and then roll a pen lightly across to get the air bubbles out. Place the gel on top of the previous layer and then lay a wet nitrocellulose membrane on the gel. Another wet blotting paper and fiber pad are placed on top of the gel. Once this is complete, close the cassette and set up the Mini Trans-Blot module. Fill with blotting buffer up to the top and then blot for 2.5 hours at 20V.

4. Spot the solution on a TLC plate and check with UV light to see