Method For Collisional Activation/Dissociation in Ion Trap Mass Spectrometry

Reference Number(s)
     Laboratory:  178
     DOE reference no.(s): 108,653

Abstract

There are several areas of study in which the fragmentation of polyatomic ions in mass spectrometry can lead to valuable qualitative and quantitative information about the parent ions. Examples include the ability to sequence a protein or peptide based on its fragmentation products and the ability to remove isobaric polyatomic interferences in elemental analyses. Many commercial instruments are available to effect the dissociation of polyatomic ions from a variety of ion sources, and linear and three-dimensional quadrupoles are the most common of these instruments.  The invention tailors the excitation events in number, amplitude, scan rate and phase to allow the resonance excitation frequencies to be spaced far enough apart to minimize constructive and destructive interferences.

Application(s) of the Technology

This discovery provides additional tools and resources which can lead to valuable qualitative and quantitative information about the parent ions. Examples include the ability to sequence a protein or peptide based on its fragmentation products and the ability to remove isobaric polyatomic interferences in elemental analyses. Many commercial instruments are available to effect the dissociation of polyatomic ions from a variety of ion sources, and linear and three-dimensional quadrupoles are the most common of these instruments.

Main Advantages of Invention

The DCID process allows higher applied voltages to be used, thus allowing higher instantaneous energies, yet lower average kinetic energies, to be accessed relative to continuous excitation. DCID allows more efficient conversion of ion kinetic energy to ion internal energy. Dissociation of the most tenacious bonds results, as average ion kinetic energy is reduced. A prior knowledge of an ion’s m/z value is not necessary to guarantee on-resonance excitation. Another benefit of DCID is that product ions are resonantly ejected and detected more rapidly than conventional CID, minimizing secondary reactions.

Status/Availability

Available both Exclusively and Non Exclusively

Patents & Applications

Posting Date:  Monday, Feb 6 2006

Contact

Ashok Choudhury
Oak Ridge National Laboratory
P.O. Box 2008
Building /4500N, Room 137
Mailstop 6196
Oak Ridge, TN 37831
(865) 574-0393
choudhurya@ornl.gov