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Bacterial Identification by Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry

Types of Mass Spectrometry

Slide 4

February 2012

Mass spectrometry requires an ion source, mass analyzer, and detector. There are multiple possible ion sources. In the past, ionization required molecules in the gas phase, limiting analysis to volatile compounds or those that could be rendered volatile. Large nonvolatile polar molecules, such as proteins, were not easily analyzed and, therefore, mass spectrometry was not used for protein analysis. With the arrival in the late 1980s of matrix-assisted laser desorption ionization, mass spectrometry based on microbial proteomics became possible. Matrix-assisted laser desorption ionization is a soft ionization technique allowing molecules to remain relatively intact during ionization. Proteins can be measured as little protein fragmentation occurs. Following ionization, the ions are separated, enabling measurement of mass. Using the approach covered in today’s presentation, ions are separated by time of flight in a flight tube.

Types of Mass Spectrometry


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