Question: Having recently studied gas chromatography and mass spectrometry in Chemistry, what would you be looking for in it to identify drugs as being illegal?

Emma Ashley answered on 14 Mar 2013:

Once the sample has been analysed on the analyser (it is vapourised by the gas chromatography analyser then different size and charged compounds are separated, the mass spectrometry part of the analyser allows you to separate compounds which are very similar), the analyser produces a graph where each peak relates to a different drug compound or metabolite. You know which peak is which because they are compared to a big library of peaks for known drug compounds. We can identify lots of different drugs, legal (eg. paracetamol, caffeine) and illegal.