Simultaneous Collision Induced Dissociation of the Charge Reduced Parent Ion during Electron Capture Dissociation

摘要

A method of performing collision induced dissociation (CID) on the charge-reduced parent ion as it is formed during electron capture dissociation (ECD), called ECD+CID, is described. In ECD+CID, the charge-reduced parent ion is selectively activated using resonant excitation and collisions with the helium bath gas inside a linear quadrupole ion trap ECD device (ECDLIT). It has been observed that ECD+CID can improve the sequence coverage for melittin over performing ECD alone (i.e., from 76 % to 88 %). Perhaps just as important, ECD+CID can be used to reduce the extent of multiple electron capture events observed when performing ECD in the ECDLIT. Consequently, the abundance of mass-to-charge ratios corresponding to ECD product ions that contain neutralized protons is decreased, simplifying the interpretation of the product ion spectrum.