| 摘要 |
A mass spectrometer and method of mass spectrometry are disclosed, wherein an Electron Collision Dissociation (ECD), Electron Transfer Dissociation (ETD), Surface Induced Dissociation (SID), or other type of fragmentation/reaction device is repeatedly switched between a high fragmentation mode and a low fragmentation mode. Parent or precursor ions from a first sample are passed through the device and parent/precursor ion mass spectra and daughter/fragment/adduct/product ion mass spectra are obtained. Precursor or parent ions from a second sample are then passed through the device and a second set of precursor/parent ion mass spectra and product/adduct/fragment/daughter ion mass spectra are obtained. The mass spectra are then compared and if either certain parent ions or certain fragmentation ions in the two samples are expressed differently then further analysis is performed to seek to identify the ions which are expressed differently in the two different samples. |
