The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 05, 2007
Filed:
Apr. 02, 2003
Frank Londry, Peterborough, CA;
Bruce A. Collings, Bradford, CA;
William R. Stott, King, CA;
MDS Inc., Concord, ON, CA;
Abstract
In the field of mass spectrometry, a method and apparatus for fragmenting ions with a relatively high degree of resolution and efficiency. The technique includes trapping the ions in a linear ion trap, in which the background or neutral gas pressure is preferably on the order of 10-5 Torr. The trapped ions are resonantly excited for a relatively extended period of time, e.g., exceeding 50 ms, at relatively low excitation levels, e.g., less than 1 Volt (0-pk). The technique allows selective dissociation of ions with a high discrimination. High fragmentation efficiency may be achieved by superimposing a higher order multipole field onto the quadrupolar RF field used to trap the ions. The multipole field, preferably an octopole field, dampens the radial oscillatory motion of resonantly excited ions at the periphery of the trap. This reduces the probability that ions will eject radially from the trap thus increasing the probability of collision induced dissociation.