How much caffeine in coffee?


[Applause] I used to drink a lot of coffee and my hand shook even more than they do now about 12 years ago maybe more now I went to China for a week and when I left I was really addicted to coffee and when I came back I was found myself addicted to green tea and since then I drank nearly entirely green tea and very rarely do I drink coffee and the result is that if I do have some coffee I feel hyper for the rest of the day and I really can’t sleep well it’s a molecule I know and I can just about recognize its structure together some carbons carbonless we’ve got nitrogen we’ve got oxygen and hydrogen scattering atoms everywhere if I just saw it as a random molecule I would probably recognize it because you usually see it on people’s coffee cups and things like that so there’s quite a good thing this is cupping if you’ve never had coffee before then you probably do get some stimulation from it there’s no doubt about that’s been proven it can help making a bit more alert and feel a bit bit more vital for a few minutes if you have too much of course a lethal dose of coffee is about 80 cups a day so do not approach that at all I have read the Tyrian I don’t know if this is correct that if you take coffee or and some other caffeinated drink at a regular time each day then your body starts making the antidote to the caffeine before you get to coffee time so if you have coffee at 10:30 in the morning round about 10 o’clock your body starts making this antidote so you’ve tend to feel really quite in need of the caffeine just to get you back to normal state so this is about six cups of coffee in here and we’re just going to cool that down but on the other hand if you’re suddenly given coffee at a time when you’re not expecting it then your body hasn’t got ready to receive this dose of caffeine and it has a much bigger effect than you expect and so it maybe not so much that people are addicted to coffee but they are counteracting the negative effects of what’s in their body caffeine is very soluble in hot water there’s much much less than 30 times less soluble in room-temperature water so we’re going to cool it down so it’s less soluble in water hydroxide solution drinking tea and coffee is very important in science in the UK and in many labs people meet together every day to drink tea and coffee and some of the best ideas can grow up over tea and coffee because when people are relaxed suddenly clever ideas come in their head an unexpected side effect of caffeine is its role in science not directly but in many labs many departments like this one at Nottingham the scientists meet together once or perhaps twice a day to drink coffee and quite often they have really good ideas the caffeine of relaxes them and when they’re not thinking really hard suddenly a good idea comes into their head in fact at the laboratory of molecular biology in Cambridge which has won I think 14 Nobel prizes there was a rule perhaps there still is that if people are discussing in the coffee room it’s not allowed to close in case they’re just about to get a good idea and if the coffee room closes it may be lost forever so you never know if you sit a long time drinking coffee you might win the Nobel Prize the water water’s more dense than ether estate so it sinks to the bottom they’re not miscible so we’re just draining off that bottom layer at the moment the water layer [Music] and as it goes down you’ve seen the top layer is actually fairly clear so the caffeine now hopefully is in that top layer flask there’s still some water in the philosophy so we’re going to use is a drying agent magnesium sulfate otherwise known as epsom salts it’s a student’s often asked me how do you know how much magnesium sulfate ready to dry and the answer is when it goes completely white and fluffy so it’s quite long water and they see its client using clump together so it’s put a bit more in says when you get that sort of snow storm effect just let that dry for a moment filter off so what we have here is our caffeine so the Reds here deny oxygen you’ve got carbon atoms represented by the black these smaller white ones are hydrogen and then the blue ones here which you’ve got for our nitrogen so it’s kind of the most common elements that make up so many aromatics or organic molecules I tried to find a mug with a caffeine molecule in here to go back to the parent table but what we had sent in by one of our viewers this gentleman here is clearly a fan of periodic videos and he’s there enjoying a video of Martin with his broom in hand but he also included in his email to us tattoo that he’s got as you can see there the molecule of caffeine so it’s clearly a much more devoted fan to the molecule than I am I just prefer drinking it or rather than inking it on myself okay so now our caffeine is in the flat state solution and we’re now going to remove these last eight from it so you put one of these on these are called Keck clips and dr. Keck sadly died last year but very handy clip that bears his name will go on for many many years to come but no need to car dice okay so this carebye approach to how to do it so here we’ve got some solid sake so we’re gonna use that condense the ether state so it doesn’t go down the drains or into the atmosphere okay so what we’re doing is we’re lowering the pressure in the system so that means that allowing the boiling point we’re lowering the boiling point of the organic solvent methyl acetate so in here we’ve got youthful acetate very low pressure in here currently around 90 milli bars and that’s all that this evaporating that’s coming up here and it’s condensing on this very cold card ice cold finger here and you can see it coming down and being collected in the flask below so what we want to do is to remove all of that solvent and just leave what was insulted I hope we’ll have some in there I don’t hear it very much because it was only six cups of coffee but there should be 20 or 30 milligrams maybe a little bit more for lucky so what do you think about someone I’ve done one in himself with a caffeine molecule it’s certainly a level of geekdom that I have not subscribed to but I commend him for his devotion to this particular molecule well Sam that’s about to change because we’ve been sent something which I’m giving to you as a gift this was sent to periodic videos mainly well this is absolutely incredible oh my gosh so where you’ve got rid of most of the ether acetate now just the last few dregs coming off and you can see that we’ve got a fairly light yellow page and some of the color has come through from the coffee so there we go here’s some caffeine now if we were really good chemist we’d recrystallized that gets a nice white crystals and what we’re going to do is just going to put this on a high vacuum system to get the very last traces of ethyl acetate this is absolutely gorgeous I’ve got a caffeine molecule on a chain it’s a necklace evidently but it’s so cool what is this oh no it’s made of I absolutely adore this it is it’s incredible and it’s so Daris it’s a dose caffeine but it’s so sweet it’s so cute and I love it but you just you just said people who have done themselves with care yeah I know I take it right now that I look like a complete idiot at all right there’s a difference between getting inked permanently and being able to take it on and off I’m gonna wear this because I I’m going to the Webby Awards and I’m gonna wear this I’m definitely gonna wear this on the night it’s going to be amazing I had planned on wearing something else but now I’m definitely going to take this to New York and I’m going to wear it for the Webby Awards because it’s just it’s absolutely immense I love it thank you to whoever made this it’s now it’s been on there for five minutes so we’ll take this off now okay wait Oh 100 milligrams so six cups of coffee has 100 milligrams of caffeine 17 also milligrams in a cup of that particular coffee so in its amorphous powder form [Music]

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