 My name is Giles and I'm a mass spectrometrist. So what that means is I use mass spectrometres, which are these gadgets here to determine the molecular weight of molecules. So the reason why this has been sort of wearing away and making all this noise is because it's got a very high vacuum system. So inside here we have a couple of turbo molecular pumps which are spinning around at 60,000 revs a minute and then underneath there's another pump underneath which is like a big Dyson vacuum cleaner which sort of sucks away all of the air which comes down from these turbo molecular pumps and then it just exhausts out of the back. So there's lots of power supplies in there, high voltage power supplies, high vacuum, some hot temperatures, high voltages. So the talk today is basically what does mass spectrometry have to do with me or have to do with you guys because you probably haven't seen a mass spectrometer. Well, you probably have seen them but you might not have noticed them. So there's a lot of mass spectrometry that goes on behind the scenes so they do have a big part to play in your daily lives. So if I just move the... So what I'm going to do, I'm going to give you, this is just a quick overview, so I'm going to tell you what a mass spectrum is, so that's the output from a mass spectrometer. It's going to be a bit of a chemistry lesson to start with just to sort of get you up to speed with all the terminology. So I'm going to start quite basic with what an atom is, an element and isotopes. And I'm going to talk to you, well describe what the periodic table is. This is a very important table we have. What molecules are, what ionisation is. If it's going to go on. Hang on a minute, I'm just waiting for this to advance. All right, here's some ionisation. So ionisation usually involves high voltage of some kind, some description. What is a mass spectrometer? So I'll give you a brief description of what this gadget here is. There it is. And I'm going to give you a brief history of mass spectrometry. So we're all originated from. It wasn't with Roy Castle and Cheryl Baker, but I will go through some mass spectrometry world records, which you may find interesting, and some mass spectrometry applications which affect you guys. And then we'll have a practical session. So moving swiftly on. So first of all, what is a mass spectrum? This is a very simple mass spectrum I found of some gases inside a mass spectrometer. So what we have is intensity. So it's a graph plot versus mass. Now these are some, well four of the most common elements in biological organisms. So carbon has a mass of 12. Hydrogen has a mass of one. 16, nitrogen 14. So we can see on the spectrum, it's detected some hydrogen, H2. So there's a peak at two. There's also some hydrogen on its own. There's a peak at 12 for the carbon. There's some H2O, there's some carbon monoxide and nitrogen. They have the same mass and there's also some carbon dioxide. So if we look at the masses, so we've got the different masses here. So water, because it's one oxygen and two hydrogens, it's 16 plus two ones, which makes 18. Nitrogen is two 14s, which makes 28. And then the carbon dioxide, it's a 12 plus two 16s, which adds up to 44. Now the problem with this mass spectrum here is we have carbon monoxide and nitrogen which have the same mass. So they're actually called isobaric. And with this particular mass spectrometer which analysed this air, it hasn't got high enough resolution to resolve these two peaks. There is a slight mass difference, but we won't get into that at the moment. So are there any chemists among you? Does anyone know what an atom is? OK, right. OK, that's good sort of. So here's an atom. So this is... I don't think atoms really look like this, but this is a common sort of model of an atom, if you like. We've got a nucleus in the middle with electrons which whizz around the outside or really form a cloud. So in the middle, in the nucleus, we've got protons and neutrons. So the protons have a positive charge and a massive one. A positive charge of one as well. Neutrons have no charge and also a massive one. And then whizzing around the outside are electrons which have a negative charge of one. This is equal but opposite to the charge on the proton, but their mass is almost 2,000 times less than that of a proton. So the number of protons in your atom defines what the atom is. So if we move on to... Oh, also the mass of a proton is equal to 1.67 times 10 to the minus 24 grams. So in order to weigh a proton, which is essentially the mass of a hydrogen, because a hydrogen is just one proton and one electron, you need a device that can measure to that level of accuracy. So that's the full 1.67 times 10 to the minus 24. So then we move on to elements. So we have hydrogen, which is one proton. So that's an atomic number of one. Carbon has six protons, six neutrons. Nitrogen has seven and oxygen has eight. We'll see that in more detail when we move on to the periodic table. But the other thing, when we start looking at molecules, we need to know how these atoms join together. So hydrogen forms one bond. So it has one hand that it can hang on to other atoms. Carbon forms four bonds. Nitrogen forms three bonds usually. Oxygen forms two bonds. So that's where with our water we have H2O. So the oxygen has two hands and it holds on to two hydrogens. So this symbol dA here is the symbol Dalton, which is named after John Dalton, who was one of the pioneers in developing atomic theory. And he was born in Manchester. And like I said before, these four elements are the most common elements in living organisms. So they're very important. Right, I'm going to have to mention isotopes. So I'm going to use carbon as an example here. You may have heard of carbon dating. I'm going to run through that in some more detail later. But essentially all the carbon in our universe, well, all the carbon on our planet, let's say, is most of the vast majority is carbon 12. So about 99% is carbon 12. 1% is carbon 13. And then there's a background level in parts per trillion of carbon 14, which is actually radioactive and that's formed in the atmosphere. So we had Frederick Soddy and Soddy and Francis Aston. Now they both won Nobel Prizes for chemistry for their work on isotopes. And then we had James Chadwick, who was awarded a Nobel Prize in Physics for the discovery of neutrons. So the main issue here, I should have mentioned this before, if you look at all of these atoms of carbon or these isotopes, they're all carbon because they've all got six protons, but they've got a different number of neutrons. So chemically they're identical because they've got six protons and six electrons, but they have a different number of neutrons. They weigh a different amount, but they're chemically identical. So now we move on to the periodic table. Now this is quite an amazing table. It was a discovery. Now it's basically Dimitri Mendelev published his version of the periodic table in 1869 and all he did, he arranged, this is before he had a mass spectrometer or anything, but he basically grouped the elements in groups of similar properties and increasing mass. And if you look here, the atomic number, it goes across one, two, three, four, five, six, seven, eight, nine. So as the atomic number increases, you increase the number of protons in your atom. So the periodic table that Mendelev put together had lots of holes in it because many of these elements hadn't actually been discovered yet. When all the elements were discovered, they filled all the gaps in the periodic table. And this was even done long before we had mass spectrometry and it was quite amazing that everything fitted together and then the mass spectrometer was invented and all the masses lined up and it was pretty amazing. So the chemical elements are ordered by the atomic number. The number underneath, this is the atomic weight. So sometimes you have different numbers of neutrons, so that's why the weight is not equal to the atomic number. Incidentally, anything larger than lead is radioactive. All of these elements fall apart and all of these ones along the bottom here are man-made. So these are made by just bombarding atoms with neutron beams, hoping that something is going to stick and you're going to create a new element and there's a nuclear fusion reaction to create a new element. So this is a picture of Mendelev. So, yeah, a very clever man. Big beard. The other thing I was going to say about the aliens, now I think there are aliens out there but I believe the aliens have the same periodic table. It's just a logical way of organising all of the elements. So if you're in this universe, you're going to have the same elements and they're going to be ordered in that way so we can communicate with them in terms of our chemistry. But only 4.9% of the matter that we can detect in this universe is ordinary matter. Now, the rest of it is dark matter and dark energy and we don't really know much about that at all. So this is where our elements came from. So this is a periodic table here. So the hydrogen and helium, they came from the big bang. Various other elements came from cosmic rays, large stars, small stars and that's what we know from the chemistry. This is a pie chart of the matter in our universe. So with our mass spectrometer, we can only detect the ordinary matter. I don't think this stuff's going to work in our mass spectrometer but it's only 4.9%. The reason we know that is because the spaceship went out or the satellite, the Planck space observatory has a picture of it and it went out and it monitored the cosmic microwave background and from that we determined the average density of the ordinary and the dark matter within the universe. It also gave us an accurate age of the universe of 13.7 billion years, plus or minus 200 million years. So a molecule, here's some molecules. So do you know what the first one is? That's water. Second one, methane. Third one, alcohol. So in order to determine the mass, well we can just basically add them up. So if I give you the masses here, the waterway is 18, the methane way is 16 and the alcohol, if we add up all the carbon, hydrogen, oxygen comes to 46. So if we put these in a mass spectrometer we should be able to determine the mass of those molecules. Now all molecules and atoms are neutral. They have no overall charge. Everything around us is pretty much neutral unless it's got electricity flowing through it or it's an iron. So an iron is basically a molecule or an atom that has an overall positive or negative charge. So there's many different means of ionisation. I'm only going to talk about electrospray ionisation because that's what we're using on this mass spectrometer here. And what that does, that protonates a molecule. So it sticks a proton onto a molecule. So this is our molecule here. We add a proton. So hydrogen is just one proton and one electron. If we take an electron away, H plus is actually a proton. Give it some ionisation and then we go to make a protonated molecule. So this is our M plus H. So it'll be the mass of the molecule plus one. Now the main take-home message about the ions is if you have an ion you can move it around with a magnetic field or an electrostatic field. So it's all about the Fleming's left and right hand rule. If you remember those from your physics lessons. But basically the mass spectrometer, there are a series of voltages. It can move ions and fly the ions through the instrument. So the mass spectrometer is not working with light or anything. It's actually flying the ions through the system and then they fly through and hit the detector at the end. So what is a mass spectrometer? Here's a nice simple explanation. So first of all you have to create ions. So there's three main components. So you create ions in the ion source. So on this instrument it's on the front. This bit I can pull that off from the second show it to you. We then have a mass analyser which separates out the ions according to their mass and then we need some kind of means of detection at the end. So the mass spectrometer also must operate under high vacuum. So in this system we've got the two turbo molecular pumps spinning at 60,000 revs a minute. So these are like jet engines and then we have a mechanical pump underneath which sucks everything out. So these actually work on a sort of probability if some air molecules hit the blade so just get knocked to the bottom of the pump and then the pump at the bottom here sucks them away. So here's a cross-section of our mass spectrometer the same as this one. So we've got the electric spray ion source to the front. The mass analysers. Detector at the end. The vacuum system with the scroll pump underneath. Ion source. The ions move through. We've actually got two mass analysers in this one. We've got a mass analyser and a collision cell. Another mass analyser and at the end we have the detector which basically sees the ions. Now the detector doesn't know what it's seeing it just detects something as hitting it. So the detector needs to be synced with the mass analyser so when it's plotting its graph it needs to know what mass it is looking at. So I'm just going to give you a very brief history of mass spectrometry. So it started with this guy, JJ. So John Joseph Thompson determined the mass of the electron first with a cathode ray tube. So we had a cathode ray tube with an electron gun shooting it down an evacuated tube and he had a couple of plates here because the electron is a charged particle he could move, deflect the electron beam up and down and depending on what voltage he put on here he deflects it by a certain amount and depending on that and some clever maths he could actually determine the mass of an electron which is pretty small. He was instrumental in developing the first mass spectrometer so this is shooting negative particles from a cathode he must have just reversed the polarities and started shooting positive particles so if this was full of neon gas he's going to be ionising his neon the neon positive, because these were electrons the positive neon's going to be flying down and the first instrument he made was a mass spectrograph so if you imagine the end of this bulb here this is covered in a phosphor paint so when an ion or an electron hits it you get a scintillation and it will light up so like an old TV screen so you can put a photographic plate in there and the ions were deflected with a magnet for this mass spectrometer and so different ions with different masses were deflected so he's got some neon here some carbon dioxide and some carbon monoxide this is a replica of Thompson's and Aston's third mass spectrometer they weren't happy with this mass spectrograph because it's a bit hard to interpret so what they did, rather than using this as the output they focused the ion beam through a couple of slits and then they had a detector so as they changed the magnet power they're letting the lightweight mass ions go through first and the medium mass ions and the heavy ions so as it's scanning across from low mass to high mass as something hits the detector on their chart record it can plot a peak so this is actually a mass spectrum of some carbon monoxide the first mass spectrum which looks pretty good compared to when they were doing it JJ won a Nobel Prize in 1906 he did lots of work on gases and was the grandfather of mass spectrometry so now we'll just look at some applications so we had the Olympics recently so there's lots of drugs of... well they're not really drugs of performance enhancing drugs so in the 2012 Olympics King's College London there was a whole room full of these mass spectrometers that tested all the athletes so this was one of the main products waters because I used to work for the company that made this they had nearly all the mass spectrometers in there were water's ones it's not only for humans also in horses the chemical industry they use mass spectrometers so if you're making something that you've made use a mass spectrometer or tell you what you've made to a certain extent food security so a lot of... we're lucky in this country our food gets screened food that's imported and exported and then I suppose the largest... well the pharmaceutical industry drugs, it's a heavily regulated environment there's also clinical applications screening for natural products, you name it the main thing about the mass spectrometer is it's very fast so it's got high speed high selectivity and high sensitivity so I think it's one of the most I think it is the most sensitive analytical instrument we've got and by selectivity I mean you can distinguish between different masses so neonatal screening anyone who's born from the mid let me think late 90s onwards would have been screened with a mass spectrometer in this country and we can screen for many different diseases which are basically expressed by the lack of certain metabolites so this if you're missing this enzyme medium chain acyl coenzymae dehydrogenase deficiency so if you're missing this enzyme you can't metabolite the fats and basically if it doesn't get picked up soon your child could die so we're very lucky in this country all of our children are screened in America they're all screens if you pay your medical insurance a lot of countries in the world are not screened so this is all the neonatal screening centres in the country and they all use water's mass spectrometers as well so food security it's a nice image I got from the museum of carrots websites I'm sure their carrots are all fine but basically we need to screen our food for pesticides there's lots of pesticides which are not good for us mass spectrometer very fast high selectivity can screen for hundreds of pesticides in less than 10 minutes it can detect up to well hundreds of a milligram a thousand for a milligram in a kilogram of carrots so if you just imagine that much pesticide in a kilogram of carrots they're extremely sensitive instruments and this is just showing essentially a chromatogram with a series of pesticides which have been detected so if you do detect some pesticides your carrots won't go to market you won't be able to sell them you won't be able to export them so not every carrot gets tested but batches of carrots will be tested security screening anyone seen one of these before in the airport every time you go through the airport after you put your bags in the x-ray they'll be one of these at the end of the x-ray now this is a simple ion mobility mass spectrometer and if you're unlucky enough to be pulled to one side they'll get one of these dusters they'll dust you, they'll dust your bag and they'll shove it in here the sample gets thermally desorbed and this is the inside of the mass spectrometer so you've got some drift gas which is blowing through this tube here the sample gets sucked in here this one is actually ionizing it with some radioactive nickel the ions fly down this drift tube and depending on the mass of the ions they have a different drift time and the drift time is proportional to the mass so the system has a library inside it and if the drift time corresponds to an explosive or a narcotic it will ring in a light and then you'll get taken to one side then they'll get a better sample and put you through a decent mass spectrometer and you might, well I don't know you might go to prison I guess right so I'll just go through some other applications carbon dating this is a large accelerator mass spectrometer these are usually state like government institutions government facilities because it's quite large so we use this to determine the age of organic material so carbon 14 is generated in the atmosphere so we have nitrogen in the atmosphere with seven protons and seven neutrons some cosmic rays and it goes to carbon 14 so it changes the number of protons so this is a nuclear reaction it's going from one element to another there's a bit of alchemy going on but it has the same mass because protons and neutrons weigh the same so both weigh 14 the carbon 14 is radioactive and as it's produced it will go decay back to nitrogen so this is the isotopic ratios of our carbon 12 carbon 13 and carbon 14 there's only parts per trillion levels so it's very sensitive, well not a lot of it around basically the ions are accelerated through the mass spectrometer and it separates them into carbon 12, 13 and 14 it measures the isotopic ratio so what happens is the way it works the carbon 14 it gets exchanged with the carbon in the atmosphere which is carbon dioxide the carbon dioxide is absorbed by grass in a process called photosynthesis so now the carbon 14 is locked in the grass the grass gets eaten by an animal, a cow well this could make a tree if you like and then the cow dies poor cow someone finds a bone they dig up the bone and then they measure how much carbon 14 is in it and if they measure the amount of carbon 14 is basically going to tell you how much of it is left because once the cow is dead it can't exchange any carbon from the atmosphere anymore so the carbon 14 only comes from the atmosphere so any carbon 14 that's in the bone is going to basically disappear and if you can measure the amount of carbon 14 you can determine the age because the half life of the carbon 14 is 5,730 years so that means half the amount of carbon 14 is going to disappear every 5,730 years so this method of dating is good up to about 60,000 years so we'll go through a few mass spectrometry world records do you know what the time is? 10 minutes ok so these are all in the mass spectrometry Guinness book of records unfortunately we haven't got any mass spectrometers in the world record book yet so we've got the longest running mass spectrometer this is one that was at the University of Manchester we've got Grenville Turner who was born in Toddmaddon now he aged all of the lunar samples brought back from the Apollo missions and this mass spectrometer well he built it in Sheffield and it moved to Manchester I've seen it up and running unfortunately it's not running at the moment but it was running for about 50 years which is I think a world record I've asked people around the world about this and I think it is the longest running mass spectrometer best travelled mass spectrometers so this is the Rosetta space mission so there was two mass spectrometers on this there was the Ptolemy and Cossack and they travelled more than 1,000 million kilometres and they were actually on the Philae landa so then they travelled on to the comet and they measured the amino acids and the elemental composition on the comet largest iron excuse me largest iron measured this is a bit biology but biologists do use mass spectrometers this is a viral virus 17,900 kilodaltons well it's lightest it's a handheld device 1.8 kilograms with a battery it's pretty good only consumes 5 watts of power and that includes the vacuum system and everything this was done in 2008 I think this is still the world record and this is detecting a this is a precursor for sarin gas so again this is used for what the Americans call homeland security there's a picture here I'll just go back to that picture this is Stephen Hawkins I'm sure he's not a member of the Illuminati but mass spectrometers do get used for some dodgy applications as well so the biggest mass spectrometer this one this is used in the Manhattan project so they actually used the mass spectrometer to separate out the isotopes of uranium to purify the uranium because there was a a shortage of copper in the war they used 13,000 tons of silver for their electromagnets and this actually so the ions of uranium were flying around this mass spectrometer and collected on a metal plate and they actually collected 64 kilograms of pure uranium 235 and the uranium 235 the atomic ratio is less than a percent there's a small amount the amount of uranium 238 the one through that is probably tons longer relationship between man and mass spectrometer this is my friend Jacob John so he had a mass spectrometer in 1980 and he's been running it ever since this mass spectrometer here is going to go to Jacob John they've got quite a few mass spectrometers this is in Pakistan Karachi and now we'll get on to our system here the Zevo usually this has another instrument with it called a chromatograph and what that does it separates out a mixture so we have our sampling solution I'm just in the interest of time I'm just going to run through this so the ionisation source this is a needle which ends there and this is another needle here so we have nitrogen gas nebulising the solution out of here this is all at high voltage about 5000 volts or 3500 this is a talochone this is here this is where the ionisation occurs so this sample is nebulised out we have hot nitrogen gas coming around the outside and the ions go into the orifice of the mass spectrometer and then they can be manipulated by the electronics inside so John Fenn got a Nobel Prize for this it's a huge breakthrough this is a quadrupole mass analyser this is how this instrument separates out the ions so what we have is radio frequency and direct currents applied to four molybdenum rods the ions travel through the rods and when a low voltage is applied we have a stable trajectory for the low mass ions and when a high voltage is applied we have a stable trajectory for the high mass ions so again there was another Nobel Prize for this by Wolfgang Paul so this is the RF which is ramping up and down as the mass spectrometer scans from low mass to high mass so this is a mass spectrum here so at a low voltage we have a stable trajectory for the low mass ions for a medium voltage we have a stable trajectory for the medium mass ions and for a high voltage we have a stable trajectory for the high mass ions so the mass spectrometer scans from low mass to high mass all the time in a sawtooth fashion but it can scan up to 10,000 these are called mass units it can scan up to 10,000 mass units in a second so it can do this exceedingly fast and this little space here is just the interscandalade just for the electronics to reset so this is our mass spectrometer here we have two quadruples and a collision cell in the middle and then at the end we have our detector so we'll just get onto our practical session I've got some paracetamol and some diazipow okay so what I'll do I'll just get this going quickly so I'll just switch it on so at the moment what I've got going through this is just I'll put some more solution in there this is just a these are the masses at the bottom actually perhaps if I just get rid of this is the vacuum here at the top here this is the for the electrospray capillary and this so here so this is our mass spectrum actually let's just go straight for the paracetamol I'll just put some of that in it so if you look at the paracetamol molecule there you'll see that there's eight carbons nine hydrogens and nitrogen and oxygen so all of these carbon corners here are carbons you can add up the carbons the hydrogens and this is a benzene ring so we've actually got hydrogen here on each of these corners so that all adds up and what we're going to do we're going to protonate it and stick a proton on there and after we've done that we should see 151 plus 1 which is 152 is our where's our mass 152 that doesn't want to come through does it let's give it a bit of encouragement so I'm just turning the heat up now let's give it a bit more gas actually no this is the wrong one paracetamol's in here isn't it sorry that was a different chemical I'm using this syringe pump here just because it's got inbuilt fluidics on the front so it can suck its own samples in but it just takes a while what's happening to my paracetamol sample there's something coming through now there we go my there's some paracetamol a little bit there what we can do though if we just get it on a spectrum how long have I got just another couple of minutes okay let's just have a look on this so if I just put this mass here is the mass in the middle of the screen so if I set it to about mass 80 80 is going to go in the middle and I increase the span to 140 we should be able to see there is our paracetamol at the end there I'm going to try a stronger sample let's try this one I think this is a lot more concentrated this is the diaziperm I was a bit scared of putting too much in there because this is such a sensitive system I shouldn't have any I should have prepared some samples at university so what's the mass of the diaziperm that's 285 right here we go there's our diaziperm now the diaziperm we've got four peaks there I'll just explain why we've got four peaks if you look at the the molecule here we've got a chlorine atom and chlorine has two isotopes one of them is chlorine 37 and one of them is chlorine 35 and so what we have this peak here is the M plus H with the chlorine 35 and this is the M plus H with the chlorine 37 now these other little peaks here are due to the carbon isotope now do you remember we're telling you about carbon you've got carbon 12 and 99% carbon 12 and 1% is carbon 13 so if you just had a molecule with one carbon like methane you're going to have two peaks for the methane you're going to have one peak at 99% and another peak at 1% so one peak is for the carbon 12 the other is for the carbon 13 now if you look at this molecule here we've got about 16 carbons and if they all make up 1% so this basically we're going to have about 16% of these ions are going to be carbon 13 so this is the carbon 13 peak for chlorine 35 and this is the carbon 13 peak for the chlorine 37 and what we could try and do is just fragment it so now we have this we've got the peaks here they're looking quite nice but let's show you what this does this is the capillary voltage if we turn this down this is the ionisation this is the high voltage on the ionisation so if we kill the high voltage we stop the ionisation we've also got this is the mass resolution here now with the quadrupole it's using radio frequency and direct current and the ratio of the radio frequency to the direct current is about 10 to 1 so we can change the ratio and if we do that we can make the peaks fatter or thinner so this is our mass resolution our mass resolving power but you don't get something for nothing so if we increase the resolution we get less sensitivity we've also the ions have to move through the system so this is we have to give them some ion energy so everything is going from a high potential energy to a low potential energy so at the moment we've got an ion energy of about 0.3 we try and make them go backwards they're not going to go backwards and if we push them through the quadrupole too much we get chicken head peaks so basically the ions are going through the quadrupole too fast and they're not they haven't got enough cycles of RF to be properly resolved so you have to keep the ions are travelling through here at about 300 meters per second something like that so they're travelling through quite quickly we could just have a quick go at fragmenting this so what we'll do we'll set it up for a door to scan so if this is our parent here mass 285 so this is the mass of our parent 285 so we've got two quadrupole and a collision cell so if we do a door to scan the first quadrupole will only let through the parent so it's only mass 285 and then we can scan the daughters