 In this video we will show you how to perform a TLC. For your TLC you will need pure starting material dissolved in solvent and your reaction mixture or a diluted reaction mixture. You will need a TLC plate, a jar to run the TLC in, a piece of filter paper that fits in the jar, a measurement cylinder to measure out your solvent that you're going to use for your TLC, capillaries, a pencil, it's useful to have a ruler, you will need some tweezers, a scissor to cut your TLC plate to size, and generally you will need a visualization agent that can be a stain in this case, and a cell light, it could also be that you can use a UV light or that your product is just visible by the naked eye. To perform your TLC you will need to cut the TLC plate to size. In this measurement we're going to take two spots, our starting material and our reaction mixture, and for each spot you will need roughly one centimeter between the edge and the spot and one centimeter between your spot and the next spot. So for two spots we will need three centimeters of TLC plate. You can use a ruler to measure or eye ball it, and make sure that you make a clean cut through your TLC plate in one go and that there is no damage to the edges of the TLC plate because that will ruin the separation when the water up in your solvent is flowing through your TLC plate. Now there's one more thing we need to do before we start adding our spots and that is cutting off the corners, so a slight cut in the corners and that will make sure that our solvent front will be nice and smooth over the whole TLC plate. This TLC plate already had a pencil line in the bottom. This line you can use as your starting line for the TLC, your solvent will run up from the bottom to the top and you have to make sure that it ends before it reaches the top and then draw another line and then you can use those two lines to determine the distance it traveled and the RF value of your compound. When cutting your TLC plate make sure you do this in the view mood and that you do it above a small box to collect the silica because now as you can see the silica is moving all around our view mood and that might cause some health issues, but for now this is okay. We have cut our TLC plate to size, we've cut off the edges and we have a nice straight line. Now we're going to add our starting material and our reaction mixture. Make a small line on the baseline and write down what you're going to place there, so starting material on the left and product or reaction mixture on the right and take a capillary and take our starting material and you just have to place one small dot that is more than enough and then you can close it, clean your capillary or take a new clean capillary which is often easier and place the reaction mixture on the other spot that you want to make. So this is the solid phase of our TLC, now we need the liquid phase of our TLC. For that you will use the TLC jar and you will place your solvent in the TLC jar. It's easy to use a 10 milliliter graduated cylinder because then you can easily determine 20% or 40% depending on what solvent you need to use or in this case 20% pentane and 80% ethyl acetate but every experiment will have a different ratio or you will have to determine your own ratio. Place the filter paper in your jar and pour in the solvent. The filter paper will pull the liquid up into the jar and then fill the whole jar with the vapors of the solvent making sure you get a nicer separation. Also make sure that the liquid level of your TLC jar is lower than the baseline you draw on your TLC plate. Place the TLC inside of the jar and it's useful when you're doing this to use tweezers because your fingers often don't fit into the jar. Carefully place it down leaning against the filter paper and close the jar. Now you will see that the solvent will run up and our different components will have different speeds in the solvent during this. Keep a close eye on your TLC and don't let it run over the top of your TLC plate. So we're almost at the end of our TLC plate. So we'll open the jar and remove the TLC plate from the jar using our tweezers and draw a line at where the solvent reached the top. So now we just have to wait until the solvent evaporates and after the solvent evaporates we can see one bright yellow spot in our starting material and a bright yellow spot in our product. As we can clearly see them by our naked eye we want to circle them with our pencil because it might be that over time the spots disappear and then you won't know anymore where they were. And now we circled both spots. Now we'll use different techniques to visualize what else is on the TLC plate. So one technique to visualize spots that are not visible in normal light we can use UV light. The TLC plate is covered with fluorescent coating that fluoresces green under 254 nanometers and other compounds that absorb UV light might show up as different colors. As is the case in our TLC where you see a blue spot halfway through the TLC plate. If we remove the TLC plate from underneath the UV light we won't be able to see this spot anymore so we have to make sure that we circle this spot with pencil before removing it from the UV light. As you can see here. So we tested our TLC plate for visible spots. We tested it for spots that are visible on the UV light but it might be that there are spots on your TLC plate that are not visible on the UV or visible by the naked eye. So what you can do is to stain the TLC plate using chemical stains and these chemicals will often react with compounds on your TLC plate. In this case we're going to use the TLC stain anazaldehyde and to use that you just open your stain jar and carefully dip in your TLC plate. When you removed your TLC plate from the stain you carefully remove the excess liquid that might be attached to your TLC plate. In general these stains require light heating or intense heating to visualize the spots that are on your TLC plate. So we can still sort of see the spots on the top but if we use a hot gun and heat it up you will see that the TLC starts changing color. Make sure that you circle any spot that you start visualizing while doing this and then continue heating until all the spots are visible and that you don't burn your TLC plate. And now we see that there is one more spot in the bottom of our product and we circle that spot as well. Keep in mind that when using this technique you need to be careful with your TLC plate because stains are often toxic and require to be handled with care. This is how you can analyze reactions using TLC.