Mass spectrometry

Mass spectrometry (also known as mass spectroscopy (deprecated)1 or in common speech “mass-spec”) is an analytical technique used to measure the mass-to-charge ratio of ions . It is most generally used to find the composition of a physical sample by generating a mass spectrum representing the masses of sample components. The technique has several applications, including:

• identifying unknown compounds by the mass of the compound molecules or their fragments
• determining the isotopic composition of elements in a compound
• determining the structure of a compound by observing its fragmentation
• quantifying the amount of a compound in a sample using carefully designed methods (mass spectrometry is not inherently quantitative)
• studying the fundamentals of gas phase ion chemistry (the chemistry of ions and neutrals in vacuum)
• determining other physical, chemical or even biological properties of compounds with a variety of other approaches

A mass spectrometer is a device that measures the mass-to-charge ratio of ions. This is achieved by ionizing the sample and separating ions of differing masses and recording their relative abundance by measuring intensities of ion flux. A typical mass spectrometer comprises three parts: an ion source , a mass analyzer, and a detector system.