Compound Discoverer GC EI/MS Tutorial - Compound Discoverer GC EI/MS Tutorial - Compound Discoverer Software - Compound Discoverer Software - Thermo Scientific™ Compound Discoverer™ is a small molecule identification application for GC Orbitrap and high-resolution LC/MS/MS data. This tutorial guides you through the process of setting up a study and an analysis for a set of Xcalibur RAW files acquired with a GC/Orbitrap™ mass spectrometer (MS) in the electron impact ionization (EI) mode, submitting the analysis to the job queue, reviewing the results of the analysis, and generating a report.