JPS62168331A - Mass spectrograph - Google Patents

Abstract

PURPOSE:To simplify the putting in and out works of a collision chamber and shorten the time of evacuation, by installing a slit and the collision chamber side by side on a same base plate, and making the base plate slide in a direction vertical to the orbit of ions from the outside of a vacuum receptacle. CONSTITUTION:A collision chamber (C) is installed on a base plate (P) beside a slit (S). The collision chamber is one box, and its front and rear walls in an ion transmission direction are provided with openings (a) through which ions are able to be transmitted, so that a gas for activating the cillision can be introduced. Then, either the slit (S) or the collision chamber (C) can be located on the orbit (Ob) of ions, by sliding the base plate (P). Thus, they can be switched simply and quickly, and the vacuum of a mass spectrograph is not broken, so that the time of evacuation can be shortened.

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention is a method of mass spectrometry.
CMass analyzed Ion Kin
e [effect E n e r g y Spec
The present invention relates to an apparatus for measuring t'W).

Conventional technology Conventional mass spectrometry involves ionizing a sample and measuring the mass spectra of those ions. Additionally, there are metastable ions that spontaneously cleave into new ions and neutral molecules. Furthermore, when an appropriate molecule collides with the ion, the ion is activated by the impact and causes the above-mentioned cleavage reaction. Therefore, useful analytical information can be obtained by investigating what kind of ion (C daughter ion) is produced by cleavage from the specified original ion (parent ion). The method used for such investigations is the MIKES measurement method, which selects ions with a specific mass using mass spectrometry and measures the kinetic energy spectrum of daughter ions generated by the cleavage of the selected ions. . After the ion cleavage reaction, the velocity of the parent ion and the velocity of the daughter ion are the same, so the mass of the parent ion is MO1, the energy of motion is EO
% The mass of the daughter ion is M, and the kinetic energy Eo is determined by the acceleration voltage of the ion and is known, so the spectrum of the kinetic energy E represents the mass spectrum of the daughter ion.

MIKES measurements use a magnetic field-leading double-focusing mass spectrometer, but as mentioned above, MIKES measurements involve two methods: measuring the spectrum of daughter ions generated by spontaneous cleavage of a parent ion in a metastable state, and two methods using collisional activation. In some cases, the parent ion is forcibly cleaved and the spectrum of the daughter ion is measured. To perform the latter measurement, a collision chamber with an opening through which ions pass back and forth on the ion trajectory between the mass spectrometer and the energy analyzer is provided, and He is placed in this chamber.
A suitable gas such as ions is introduced to collide with the ions passing through the same chamber.

C. Problems to be Solved by the Invention As mentioned above, it is necessary to provide a collision chamber within the apparatus for MIKES measurement using collision activation. For this reason, conventionally, when attempting to perform either MIKES measurement with a single mass spectrometer, the collision chamber must be moved in and out of the mass spectrometer every time both MIKES measurements are switched, and the mass spectrometer Since the analyzer is a device that requires high vacuum, the work of moving it in and out of the collision chamber was very troublesome, and it was extremely inefficient as it took time to evacuate the vacuum.

The present invention attempts to solve the above-mentioned problems regarding switching between the two types of MIKES measurements.

2. Means for solving the problem: A slit to be installed on the ion trajectory between the mass spectrometry section and the energy analysis section and a collision chamber are installed side by side on the same substrate, and the above substrate is connected to the ion beam from outside the vacuum container. Made it slide in a direction perpendicular to the orbit.

E. The working slit and the collision chamber are mounted on the same substrate, and the substrate can be slid in the direction perpendicular to the ion trajectory from outside the vacuum chamber, so either the slit or the collision chamber can be positioned on the ion trajectory as desired. Therefore, for MIKES measurements in normal mass spectrometry and spontaneous dissociation of metastable ions, the slit should be located on the ion trajectory, and for tKES measurements by collisional activation, the collision chamber should be located on the ion trajectory. This switching operation can be performed by simply sliding the substrate from outside the vacuum container, so it is extremely simple and efficient without the need to break the vacuum of the quality I analyzer. FIG. 2 is a plan view of an example. This embodiment is a BE@EB type double convergence mass spectrometer in which both the mass spectrometry section and the energy analysis section are composed of a magnetic field and an electric field.

■ is the ion source, B1 is the magnetic field of the mass spectrometer, El is the electric field of the mass spectrometer, B2 is the electric field of the energy analyzer, B2 is the magnetic field of the energy analyzer, 3D is the ion detector, P
is a substrate that is slid from outside the vacuum vessel V, and its sliding direction is perpendicular to the ion trajectory ob. A slit S is provided in the substrate P, and the position of this slit on the ion trajectory is the convergence point of the ion flux leaving the mass spectrometer composed of Bl and El.

A collision chamber C is attached to the substrate P beside the slit S. The collision chamber is a single box, and openings a through which ions can pass are provided in the front and rear walls in the ion passing direction, so that gas for collision activation can be introduced. By sliding the substrate P, either the slit S or the collision chamber C can be positioned on the ion trajectory ob.

G. Effect According to the present invention, the two types of MIKES measurements can be switched simply by sliding the substrate P, so switching can be done easily and quickly, and there is no need to break the vacuum of the analyzer. A series of analyzes including conventional mass spectrometry can now be performed efficiently under stable and identical conditions.

[Brief explanation of drawings]

The drawing is a plan view of one embodiment of the present invention.

Claims (1)

[Claims] It consists of a mass spectrometry section and an energy analysis section, and a substrate is provided on the ion trajectory between the mass spectrometry section and the energy analysis section, so that it can be slid from outside the vacuum container. A mass spectrometer is provided with a collision chamber for ionization, and by sliding the substrate, either the slit or the collision chamber can be arbitrarily selected and positioned on the ion trajectory.