ABSTRACT
Tracing its origins back to the beginning of the 20th century, mass spectrometry (MS) holds a special place among analytical techniques. Mass spectrometry measures an intrinsic property of a molecule-the molecular mass-with very high sensitivity,
mass resolution, and mass accuracy. Therefore, mass spectrometry is used in an amazingly wide range of scientific and analytical applications. For large analyte species, such as intact proteins and strands of nucleic acids, molecular weights can be measured with an accuracy of 0.01%—that is, to within 4 Daltons (Da) or atomic mass units (amu) for a sample of 40,000 Da. This is usually sufficient to allow minor mass changes to be detected (e.g.
