Why is mass spectrometry used for elemental analysis?

Mass spectrometry is used for elemental analysis because it can accurately identify and quantify the elements in a sample.

Mass spectrometry is a powerful analytical tool that can provide detailed information about the elemental composition of a sample. It works by ionising the atoms or molecules in a sample and then separating them based on their mass-to-charge ratio. This allows for the identification and quantification of the elements present, making it an invaluable tool for elemental analysis.

The process begins by introducing the sample into the mass spectrometer, where it is vaporised and ionised. This is typically achieved through a process known as electron impact, where high-energy electrons are used to knock electrons off the atoms or molecules in the sample, creating positive ions. These ions are then accelerated through an electric field towards a detector.

The key to mass spectrometry's ability to identify elements lies in the fact that each element has a unique set of isotopes, each with a distinct mass. When the ions are accelerated, they are deflected by a magnetic field. The degree of deflection depends on the mass-to-charge ratio of the ions, with lighter ions being deflected more than heavier ones. By measuring the degree of deflection, the mass-to-charge ratio of the ions can be determined, allowing for the identification of the elements present.

In addition to identifying the elements in a sample, mass spectrometry can also quantify the amount of each element present. This is achieved by measuring the intensity of the signal produced by the ions as they hit the detector. The intensity of the signal is proportional to the number of ions, and therefore the amount of each element in the sample.

In conclusion, mass spectrometry is used for elemental analysis due to its ability to accurately identify and quantify the elements in a sample. Its high sensitivity and precision make it an invaluable tool in a wide range of fields, from environmental science to forensic analysis.