Title:
MASS SPECTROMETER
Document Type and Number:
WIPO Patent Application WO/2014/181396
Kind Code:
A1
Abstract:
In an SIM measurement, during the pause time for changing the voltage applied to a quadrupole mass filter and other ion transfer optics so as to switch the mass-to-charge ratio of the ions to be measured, the polarity of the direct current voltage applied to a quadrupole mass pre-filter is reversed temporarily. In addition, the duration of the voltage polarity reversal is altered according to the pause time so that the ion intensity rises sufficiently at the time point where the subsequent dwell time starts. On an insulating coat, such as from dirt attached to the surface of the quadrupole mass pre-filter, and on insulating support structures, electric charges are dispersed and charge buildup is eliminated when the polarity of the voltage applied to the quadrupole mass pre-filter is reversed. In addition, since no ion passes through, charging of the main quadrupole mass filter in the subsequent stage is also mitigated.
Inventors:
FUJITA SHINJIRO (JP)
Application Number:
PCT/JP2013/062914
Publication Date:
November 13, 2014
Filing Date:
May 08, 2013
Export Citation:
Assignee:
SHIMADZU CORP (JP)
International Classes:
H01J49/42
Foreign References:
| JP2004362982A | 2004-12-24 | |||
| JP2002117802A | 2002-04-19 | |||
| JPH087830A | 1996-01-12 |
Other References:
See also references of EP 2988317A4
Attorney, Agent or Firm:
Kyoto International Patent Law Office (JP)
Patent business corporation Kyoto international patent firm (JP)
Patent business corporation Kyoto international patent firm (JP)
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