Q1 Full Scan (Start – Stop) : Q1 always used as single MS analyzer. Used primarily for identification of precursor ions.
SIM - Selected Ion Monitoring: Used to optimize analyzer for specific ions. SIM used for quantitative analyses. Q1 SIM used to “optimize” precursor ion. Maximize signal in preparation for MS/MS.
Product Ion Scan: After identification, the precursor ion is sent into the collision cell and fragmented by CID. Q1 is fixed, Q3 sweeps a given mass range. Used for structural elucidation. First step to developing quantitative methods:
m3 + scanned or m1+ fixed.
Precursor Ion Scan: Q1 sweeps a given mass range, Q3 is fixed.
Used to determine the “origin” of particular product ion(s) created in the collision cell.
Frequently well used for drug metabolite identification (common product ion observed in the metabolites).
