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:
Nov. 18, 2014
Filed:
Nov. 16, 2005
Sadao Takeuchi, Nagaokakyo, JP;
Hiroaki Waki, Kyoto, JP;
LI Ding, Manchester, GB;
Roger Giles, West Yorkshire, GB;
Sadao Takeuchi, Nagaokakyo, JP;
Hiroaki Waki, Kyoto, JP;
Li Ding, Manchester, GB;
Roger Giles, West Yorkshire, GB;
Shimadzu Corporation, Kyoto, JP;
Abstract
The present invention provides a mass spectrometer having an ion lens capable of transporting an ion having a large mass to charge ratio with a high level of ion-passing efficiency even under a low-vacuum atmosphere. In conventional atmospheric pressure ionization mass spectrometers or similar mass spectrometers, applying an excessively high voltage to the ion lens undesirably causes an electric discharge. Therefore, the passing efficiency for an ion having a large mass to charge ratio cannot be adequately improved, which leads to a poor detection sensitivity. To solve this problem, the mass spectrometer according to the present invention includes a voltage controllerthat controls a variable radiofrequency (RF) voltage generatorso that both the amplitude and the frequency of the RF voltage applied to the lens electrodes of an ion lensare changed according to the mass to charge ratio of an ion to be analyzed. This control enables the ion lensto focus an ion and transport it to the subsequent stage with a high level of passing efficiency even in the case of analyzing an ion having a large mass to charge ratio. Thus, the detection sensitivity is improved. The aforementioned control is conducted on the basis of the control data stored in a voltage control data storage. These data are obtained in advance by a measurement of a sample containing a substance having a known mass to charge ratio, in which the intensity of the signal of an ion detector is maintained while the analysis conditions are changed.