Why is mass spectrometry useful?

By ionizing a gaseous sample, separating it with a magnetic field, and detecting the signal with a vacuum-compatible particle counter such as a Faraday cup, mass spectrometry analyzes the mass-to-charge ratios of molecules. The signal is then converted to a current proportional to the molecular abundance, and the spectrum is plotted as abundance vs. mass-to-charge ratio.

It is generally useful in conjunction with infrared spectroscopy or gas chromatography for the full characterization of compounds; it is fast, reliable, and accurate (especially Ion Cyclotron Resonance). It is useful because by analyzing the fragmentation patterns of molecules, we can determine what they are by their fragmentation, even if they are constitutional isomers.

Mass spectrometry is useful because it can accurately determine the mass of molecules, identify unknown compounds, analyze the composition of complex mixtures, detect trace amounts of substances, and provide structural information about molecules. Additionally, it is widely used in various fields such as chemistry, biochemistry, pharmaceuticals, environmental science, and forensics.