On 20 November 2019, 13 of our Year 13 Chemistry students attended an excellent visit to Bath University Chemistry Department. Earlier in the year we had synthesised samples of aspirin. We knew that we had white crystals and melting point analysis proved that they were pure and matched the published melting point of aspirin – but could we prove that the white crystals were actually aspirin? Is it possible to see the molecular structure of our crystals?
Obviously, molecules are far too small to see and so we were fortunate to be able to take our samples to Bath University to use their spectroscopic instruments to analyse our samples. Infra-red (IR) spectroscopy enabled us to identify the functional groups present by measuring the characteristic frequencies of the vibrations of the different bonds within the molecule. Mass spectrometry (MS) was used to measure the precise molecular mass of the molecules in our sample and finally Nuclear Magnetic Resonance (NMR) spectroscopy was used to build up a picture of how the atoms in the molecule were joined together. Utilising the information gained from all three techniques proved that we had managed to produce the desired molecule. Our students certainly have the potential to be the pharmacists of the future!
Once we had analysed our samples and seen the impressive kit at work, we moved to an undergraduate lab to complete some problem-solving questions using our reinforced understanding of spectroscopy. Our confidence grew as we applied our knowledge to these demanding questions and identified the molecules producing each set of spectra. Our grateful thanks to the staff at Bath University who gave up their time to enhance our understanding of spectroscopic techniques studied at both IB and A level. It was particularly good to see the equipment in real life.