Tandem Mass Spectrometry
Tandem mass spectrometry explains various steps of mass selection or analysis, usually separated by some form of fragmentation. In a tandem mass spectrometer, ions are formed in the ion source and separated by mass-to-charge ratio in the first stage of mass spectrometry (MS1). Ions of a particular mass-to-charge ratio (precursor ions) are selected and fragment ions (product ions) are created by collision-induced dissociation, ion-molecule reaction, photo dissociation, or other process. The resulting ions are then separated and detected in a second stage of mass spectrometry (MS2). There are different methods for fragmenting molecules for tandem MS, including electron capture dissociation (ECD), collision-induced dissociation (CID), blackbody infrared irradiative dissociation (BIRD) and infrared multi photon dissociation (IRMPD).