TLC or thin layer chromatography is most often used in the lab as a means of analysis or trying to learn something about a mixture of compounds that we might have. It's used readily because it's quick and easy and pretty cheap, but we can use this same concept as a way of actually purifying a mixture of compounds. We could even do it using thin layer chromatography. There is a method called preparative thin layer chromatography or prep TLC. We would have a much larger TLC plate. This is not an exact example of it because it would be a lot thicker of a silica gel, a layer of silica gel, and we would use a pipette to introduce a line of our mixture, place this into a very large developing chamber and wait quite a while for it to develop. And once it's developed, we will end up having a strip, a line of each of our band of each of our components. And then we can literally scrape that band off, scrape the silica off of the glass backing, put it into a beaker, and then use a saw to wash the compound off of the silica gel. So we would actually be able to separate the components of our mixture and actually collect those little spots that we saw in the TLC. We can also use something called column chromatography to separate a larger scale mixture of components. Here is an example of a column and what we would do is we would take the silica gel and pour that into the column and make a length of the silica gel. We would use that and get it wet with a solvent, the eluint we're going to be using, the same we would use for our TLC plate. Then we would use a pipette to introduce our sample to the top of the silica gel. And when we fill this reservoir with solvent, we're going to have the solvent this time passed down through the silica gel. But in the same manner, exact same manner as the TLC between the stationary phase and the mobile phase or compounds will partition, our mixture will separate and with column chromatography now, we're going to collect various fractions with test tubes. And so in the end, ultimately you'll have the mixture of your components separated out over all the test tubes that you've collected. A lot of times this is called flash column chromatography because we will place some compressed air or compressed nitrogen up here and force the solvent through at a much more rapid pace. And that would be a way of very quickly separating mixtures of compounds.