Okay so now we're going to look at rotary evaporation. So we've got this solvent and we've got our compound in the solvent. We need to get rid of the solvent. So we use a rotary evaporator such as one of these and we're going to place our sample in the flask. Flask goes on this end here and it will be clicked and essentially what we have is a distillation setup. So we have the flask here, we use a water bath to raise the temperature and then we have the vacuum over here. We have a condenser here to call the solvent that's coming off which will then be collected in this trap here. Over here at this point we have a tap which allows us to bleed air into the system. So in order to set it up first thing we're going to do is make sure we switch it on and here we can then set the temperature. Essentially for most organic solvents we're going to want 40 degrees would do very nicely and then we're going to turn on the cooling water. So it doesn't want to be too fast. Just running through the system. You do want to make sure that the receiver flask is empty. It should have been emptied by the last person but just check that because the last thing you want is to if your compound accidentally bumps and is pulled up over into this flask you don't want to be contaminated with anything anyone else has been using. So we're going to pour our compound into the flask and then we're going to carefully clip the flask in place. Be particularly careful with heavy solvent such as DCM because they are very dense and that can cause this to fall down. So we're going to make sure that this tap here is open and then follow the vacuum through round and we're going to turn on the vacuum. We can hear that now. So we can hear the vacuum hissing away and now we're going to start to rotate the flask and we're going to turn it until it's about 2 thirds, 1 o'clock position, keeping our hand underneath here just to make sure it will rotate gently against that and it's not going to fall in and then we start to close the tap. So we're turning that tap so it's closing and keeping eye on that solvent so we can see it's starting to evaporate. So this is dichloromythamus which has a very low boiling point anyway. So boiling point 45 so it doesn't take much and now you see we've got the tap closed. This rotating is bubbling away nicely and you can see on the glass this condensation is starting to fall from evaporation. Once that's going like that we then slowly use this to lower the flask just so bottom portion now is in the water bath. You don't need the whole flask in the water bath just that bit and we can see it's starting to evaporate. We can turn up the speed. The reason why we're rotating the flask is to ensure that it increases the surface area as the solvent's rotated and flung out by centrifugal force around the sides of the flask and it also means that as it's evaporating it also stops it from boiling and bumping and that's when essentially it jumps from this side over to here because the vacuum is built up and the solvent explosively evaporates very quickly. So we're going to leave that to evaporate nicely. It's there evaporating away. Okay so we've got to the end of our evaporation. You'll now see that everything's all the solvent has evaporated or it's gone. Slow that down, stop and then we're going to raise it up out of the bath. The next thing to do then is to open this tap. Let's help release the vacuum and we can go and switch the vacuum off. Once the vacuum's off we then are going to unclip, remove and then you'll want to give the flask a wipe with some blue rope and we're going to have to dry flask. One very important thing to remember is that if you are a preparedness sample it's to weigh the flask before you put anything into it and that means you can weigh the flask in afterwards and you can get the weight of the solids in your flask. Final thing to do then is switch off, switch off and then take your the receiver flask and screw, remove this and if there's any solvent in here, the result in this case because DCM is very low boiling and the house vacuum is very high, it's a very good vacuum but it's to make sure you do empty anything that you've collected in the receiver flask out of here. Take this back on, tighten the screw and there we go. You've got your compound.