Tandem mass spectrometry various scans

The various scan modes of the mass spectrometer provide powerful methods of analysis and unique capabilities for information gathering [54,55], For example, the full scan mode is used to survey the ions that are generated in the source to confirm or identify structure based on molecular weight assignment. The resulting full scan mass spectrum, therefore, contains an ion(s) that is indicative of molecular weight. Two dimensions of mass analysis or tandem mass spectrometry (MS/MS) provide powerful capabilities for qualitative and quantitative analysis. For example,... 

This section is concerned with just one aspect of the relatively new development that has been termed in various ways such as mass separation/mass spectrometry or mass spectrometry/mass spectrometry (both offering the same acronyms MS/MS), two-dimensional mass spectrometry, tandem mass spectrometry, etc.. The acronym MS/MS is the most appropriate and is certainly the most widely used. The definitions and the nomenclature relevant to these techniques will be introduced as they will arise in our mathematical development of the scan laws. 

Magnetic analyzers are often used in various combinations with electrostatic sectors. Sector instruments are characterized by good ion transmission. Depending on the order of these analyzers, very high resolution and wide mass ranges can be achieved. Sector instruments suffer from a relatively low scan rate, which makes their application in GC-MS and LC-MS studies somewhat limited. At the same time, some types of tandem mass spectrometry experiments with mass-selected ions can be performed only on this type of equipment. 

Various mass spectrometers such as a single quadrupole, triple quadrupole, and quadrupole ITMSs are used for the detection of explosives. However, the ITMS has several advantages for homeland security applications. For example, the quadrupole ion trap has high sensitivity with a full scan mode and has tandem mass spectrometry (MS/MS) capabilities. Furthermore, the quadrupole ion trap is robust, and complicated calibrations are not necessary with this instrument format. 

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