The Sciex QTrapTM 5500 is a highly sensitive triple quadrupole / linear ion trap mass spectrometer, equipped with a TurboVTM ion source for electrospray (ESI) or atmospheric pressure chemical ionization (APCI). The instrument handles ions in a range up to m/z 1’250 (50-1’000 in LIT) and can be operated in various scan modes for qualitative and quantitative applications. In combination with an HPLC system (Dionex UltiMate® 3000 RS series), it is ideally suited for LC-MS/MS analysis of trace amounts of low mass organic compounds in complex matrices, but can also be used for detection of multiply charged biopolymers in samples of biological origin.