Ion trap mass analyzing apparatus
AssigneeHitachi High-Technologies Corporation
InventorsKiyomi Yoshinari, Yoshiaki Kato, Tadao Mimura, Masaru Tomioka
Life of this patent
Estimating the term…
Abstract
An ion-trap mass analyzing apparatus having means for generating ion-capture electric fields asymmetrical with respect to a reference plane containing a central point of a ring electrode and perpendicular to a central axis of the ring electrode in the inside of an ion trap to resonantly amplify ions rapidly to emit the ions from the ion trap in a short time to thereby permit high-sensitive high-accurate mass analysis stably regardless of the structural stability of ions as a subject of analysis.
Claims23
An ion-trap mass analyzing apparatus comprising:
- an annular ring electrode;
- two end cap electrodes disposed opposite to each other so as to sandwich said ring electrode;
- a radio-frequency voltage power supply for generating a radio-frequency voltage applied between said ring electrode and said end cap electrodes to generate an RF electric field in an inter-electrode space formed between said ring electrode and said end cap electrodes;
- an ion source for generating ions;
- means for capturing the generated ions in said inter-electrode space in which said RF electric field is generated;
- and
- means for detecting ions having a specific mass-to-charge ratio among all the ions captured in said inter-electrode space by emitting said ions having said specific mass-to-charge ratio from said inter-electrode space while separating mass successively in accordance with the mass-to-charge ratio in order to resonantly excite said ions having said specific mass-to-charge ratio in said inter-electrode space;
- wherein said ion-trap mass analyzing apparatus further comprises means for making the RF electric field distribution asymmetrical with respect to a reference plane when a plane containing a center point of said ring electrode and perpendicular to a rotational symmetry axis of said ring electrode is used as said reference plane, the RF electric field distribution being generated in said inter-electrode space to capture ions.
An ion-trap mass analyzing apparatus comprising:
- an annular ring electrode;
- two end cap electrodes disposed opposite to each other so as to sandwich said ring electrode;
- a radio-frequency voltage power supply for generating a radio-frequency voltage applied between said ring electrode and said end cap electrodes to generate an RF electric field in an inter-electrode space formed between said ring electrode and said end cap electrodes;
- an ion source for generating ions;
- means for trapping the generated ions in said inter-electrode space in which said RF electric field is generated;
- and
- means for detecting ions having a specific mass-to-charge ratio among all the ions trapping in said inter-electrode space by emitting said ions having said specific mass-to-charge ratio from said inter-electrode space while separating mass successively in accordance with the mass-to-charge ratio in order to resonantly excite said ions having said specific mass-to-charge ratio in said inter-electrode space;
- wherein said ion-trap mass analyzing apparatus further comprises means for making the RF electric field distribution asymmetrical with respect to a reference plane when a plane containing peaks of an inner convex surface of said ring electrode is used as said reference plane, the RF electric field distribution being generated in said inter-electrode space to capture ions.
An ion-trap mass analyzing apparatus wherein an RF electric field distribution generated in a space between electrodes is asymmetrical with respect to a predetermined reference plane.
Dependencies are inferred from the claim text.