The size of the current is proportional to the number of ions contacting the detector. When the positive ions hit the detector, they accept electrons, causing a current to flow. Not all ions will hit the detector, but the magnetic field strength can be altered to ensure that all the ion streams passing through the magnetic field can be detected. The mass spectrum is run under a vacuum to prevent the presence of anything other than the ions being tested. Ions with a larger charge are also deflected more. Lighter ions are deflected more, whilst heavier ions are deflected less. The positively charged ions are deflected as they pass through this field, with the magnitude of the deflection dependent on the mass/charge ratio of the ion. Once the sample has been ionised, it is accelerated through an electric field before being passed through a magnetic field generated by an electromagnet.

Most of the ions generated have a single positive charge, though some can have more. In some cases, the positive ions generated can fragment further, producing a mixture of smaller positive ions and neutral molecule fragments.

The beam of electrons the electron gun generates knock electrons out of molecules of the sample, creating positive ions. A small amount of sample is injected into the mass spectrometer, then it is ionised using an electron gun. First, we need to generate ions from our sample.

Mass spectrometry allows us to measure the masses of atoms and molecules, and also obtain information about their chemical structure.Д«efore we talk about interpreting spectra, letвЂ™s discuss how they are generated in the first place. So far, weвЂ™ve looked at how chemists can determine the presence of particular bonds present in molecules with infrared spectroscopy, and how they can gain information about the structure of molecules using hydrogen and carbon nuclear magnetic resonance. For the fourth in the analytical chemistry series, we turn to mass spectrometry.

Spec method map reading