Thermo Scientific* LTQ XL high performance linear ion trap delivers more structural information than any other ion trap mass spectrometer. LTQ XL is the only mass spectrometer that offers multiple dissociation techniques, PQD, ETD and CID. Pulsed Q Collision Induced Dissociation (PQD*) is a proprietary technique that eliminates the low mass cut-off concern inherent with all ion traps. This results in extensive coverage for predicted and unpredicted metabolites, and the ability to perform peptide quantification using iTRAQ* labels. In addition, fast polarity switching for high-sensitivity analysis of unknowns, high resolution isolation (HRI), intelligent Data Dependent* acquisition, and optional high resolution accurate mass functionality are all tools to help the researcher gain confident structural identification routinely.