Mass Spectrometry

The Mass Spectrometry unit comprises:

Mass spectrometry is an analytical technique based on the chemistry of ions in the gaseous state. As in many other analytical techniques, the basic purpose of a mass spectrometer is to convert the sample into measurable products that indicate the structure of the original molecule. In this case, the products formed are gaseous ions whose masses and relative abundances constitute the mass spectrum. As can be deduced from the brief description above, the technique would, in principle, have the disadvantage of being destructive, although given the high sensitivity of the detectors used, a 1 mg sample is usually sufficient to provide the molecular mass of a compound, also providing structural and quantitative information.

The adaptation of mass spectrometry with a chromatographic technique (especially gas chromatography) dates back to the 1970s. This adaptation revolutionized the analysis of complex mixtures of organic compounds because it combines the high resolving power of gas chromatography with the high sensitivity of the adapted mass spectrometer. The development of capillary columns in the 1980s further increased the resolving power of gas chromatography and as a result gas chromatography-mass spectrometry (GC-MS) has become the most powerful method for the identification and quantification of relatively nonpolar organic molecules.

Starting in the 1980s and to a greater extent in the 1990s, EM has played an increasingly important role in the biological sciences, as two new ionization methods have been developed: Electrospray (ESI) and matrix assisted laser desorption/ionization (MALDI). They allow the measurement of the molecular masses of proteins, oligosaccharides and DNA.