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:
Dec. 22, 1992
Filed:
May. 10, 1991
Paul Kelley, San Jose, CA (US);
Teledyne CME, Mountain View, CA (US);
Abstract
A mass spectrometry method in which trapped ions are excited in non-consecutive mass order for detection. The ions can be ejected from the trap in non-consecutive mass order for detection at an external detector, or detected at an in-trap detector in non-consecutive mass order before they leave the trap. In one embodiment, a sequence of supplemental AC voltage signals, each having a frequency matching a resonant frequency of one of the ions to be detected, is applied to a trap to resonate trapped ions in non-consecutive mass order. In another embodiment, the amplitude of the fundamental RF trapping voltage is varied while a sequence of supplemental AC voltage signals is applied to a trap to resonate trapped ions (or cause them to become unstable) in non-consecutive mass order. Another embodiment enables detection of both high mass ions and low mass ions with improved high mass resolution, when the ions are stably trapped in a three-dimensional quadrupole trapped field. In the latter embodiment, the amplitude of the fundamental RF trapping voltage is controlled to increase the Mathieu q coordinate of a high mass ion, and the high mass ion is then excited for detection.