ATMOSPHERIC AND VACUUM PRESSURE MALDI ION SOURCE

摘要

A Matrix Assisted Laser Desorption Ionization (MALDI) Source (1) operated at atmospheric or vacuum pressure is interfaced to a multipole ion guide (8) or ion funnel with alternating current "AC or RF" waveforms applied. The multipole ion guides (8, 68) or ions funnels are configured to focus transport, trap and/or separate ions produced from a MALDI ion source (1) an d direct the MALDI produced ions to a mass analyzer (3) for MS or MS/MSn mass to charge analysis. The MALDI sample targets (4) can be positioned at the entrance of a multipole ion guide (8) or ion funnel with gas flow (14) and electric fields configured to direct ions efficiently into the ion guide (8) or ion funnel. Ions produced by MALDI (1) operated at atmospheric or intermediate vacuum pressures experience ion to neutral gas collisions as th ey are transported in the multipole ion guide (8) or ion funnel in the presence of RF electric fields. The gas collisions serve to damp the ion trajectories toward the ion centerline, improving ion transport efficiency into and throu gh vacuum. Ion mobility and mass to charge separation of ions can be performed in the multipole ion guide and ion funnel devices while transporting and focusi ng ions.