JPH049728Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention connects a first mass spectrometer (hereinafter referred to as MS1) and a second mass spectrometer (hereinafter referred to as MS2) in series, and The first mass spectrometer extracts and detects specific ions (precursor ions), and the collision gas generates dissociated ions (daughter ions) of the precursor ions in the collision chamber, and these daughter ions are sent to the second mass spectrometer. The present invention relates to a mass spectrometer capable of performing analysis, and particularly to a mass spectrometer capable of disposing a collision chamber and a detector in a narrow space at the connection between a first and second mass spectrometer.

[Conventional technology]

Generally, MS1 and MS2 are connected in series,
MS/MS that extracts a precursor ion with MS1, dissociates this precursor ion in a collision chamber and converts it into a daughter ion, and analyzes this daughter ion with MS2.
Mass spectrometry is being performed.

In such MS/MS mass spectrometry, the first step of measurement is to detect precursor ions that have passed through MS1. In that case, precursor ion detection can also be performed on the MS2 detector side, but in order to allow the precursor ion to pass through MS2, various complicated condition settings are required, so it is generally not possible to detect the precursor ion.
A unique MS1 detector is installed, and the collision chamber is also located near the MS1 detector.

Figure 3 shows, for example, the magnetic field B as MS1, and the magnetic field B as MS2.
This is a diagram showing the arrangement of the detector and collision chamber for MS1 in a so-called BE type MS/MS mass spectrometer that uses electric field E as an electric field. 1 is the collector slit of MS1;
2 is a convergence dynode, 3 is a detector, 4
is the collision chamber.

In the figure, the ion beam that has passed through the collector slit 1 of MS1 is attracted by the potential of the conversion dynode 2 and collides with it, and the resulting secondary electrons or secondary ions are detected by the detector 3, and the ion beam passes through the collector slit 1 of MS1. Analysis is performed. Also, on the MS2 side,
Mass spectrometry is performed by taking the energy spectrum of daughter ions produced when the ion beam collides with the collision gas in the collision chamber 4 without both the convergence dynode 2 and the detector 3 working. On the other hand, in the case of double convergence mass spectrometry, neither the detector 3 nor the collision chamber 4 is operated, and the magnetic field and electric field are used simultaneously to function as a single mass spectrometer, thereby performing high-resolution analysis.

[Problem that the invention attempts to solve]

By the way, as mentioned above, such a mass spectrometer also performs double-focus mass analysis using a magnetic field and an electric field at the same time, but because of this, there is a space restriction in the middle part between the deflection magnetic field and the electric field, which is particularly difficult for high-resolution analysis. In the case of a mass spectrometer equipped with a quadrupole electrostatic lens, there is a drawback that there is not enough space to accommodate a collision chamber and a detector at the same time.

This invention is intended to solve the above problems.
MS1 and MS2 even with space constraints
An object of the present invention is to provide a mass spectrometer in which a detector and a collision chamber can be easily placed between the two.

[Means for solving problems]

To this end, the mass spectrometer of the present invention is a mass spectrometer in which a first mass spectrometer and a second mass spectrometer are connected in series, and a collision chamber and a detector are provided at the connection part. The convergence dynode is hollow, and a collision gas is introduced into the interior to serve as a collision chamber, and the convergence dynode is movable in a direction intersecting the optical axis.

[Effect]

The mass spectrometer of the present invention is a mass spectrometer in which a first mass spectrometer and a second mass spectrometer are connected in series, and a collision chamber and a detector are provided at the connection part. By using the convergence dye node as a collision chamber and configuring the conversion dye node to be movable in a direction intersecting the optical axis, the collision chamber and detector can be easily arranged even if there are space constraints. ing.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a collision chamber and a detector according to the present invention, in which Figure A shows a case in which it functions as a detector, and Figure B shows a case in which it functions as a collision chamber. . In the figure, 10 is the collector slit on the MS1 side, 11 is the conversion dynode,
12 is a detector, 13 is a collision chamber, and 14 is a pore.

In the figure, an off-axis type detector is used as the detector of MS1, which is composed of a convergence dynode 11 and a detector 12, and is arranged on both sides of the ion beam trajectory. The convergence dynode 11 is hollow and has a collision chamber 13 with a structure capable of introducing collision gas, and has a pore 14 on its side surface for passage of ions. Furthermore, this dynode has a structure that allows it to move perpendicular to the ion trajectory, and can be set at two positions: as a convergence dynode as shown in Figure A, and as a collision chamber as shown in Figure B. Further, the conversion dynode 11 and the detector 12 are configured to be able to move in conjunction with each other.

In the case of the position shown in FIG. Analysis of MS1 is performed. Also, Figure B
At the position, the hole in the center of the convergence dynode 11 is on the optical axis, the ion beam is irradiated into the collision chamber 13, and the daughter ions generated by the collision with the collision gas are detected by the detector at the subsequent stage. Analysis of MS2 is performed. At this time, the detector 12 has been moved to a position off the optical axis.

In this way, the convergence dynode 11 is also used as a collision chamber, and by making the convergence dynode 11 and detector 12 movable perpendicular to the ion trajectory, the detector and collision chamber can be effectively used even in a limited space. Can be placed in MS1
and MS2 analysis can be performed selectively. Although the convergence dynode and the detector have been described as being configured to move together perpendicular to the ion trajectory, this is not always necessary, and depending on the surrounding circumstances, the direction of movement of the dynode and whether they should be moved together or not may be changed. , or whether to move them independently can be determined as appropriate.
Alternatively, the dynode may be fixed at the position and only the dynode may be moved.

FIG. 2 is a diagram showing an example of an MS/MS mass spectrometer using the convergence dynode and detector shown in FIG. 1. In the figure, the same numbers as in FIG. 1 indicate the same contents, 21 is the ion source, 22 is the source slit, 23 is the magnet, 24 is the slit, 2
5 is an electrode, 26 is a slit, 27 is a magnet, 28 is a detection slit, and 29 is an ion detector.

The illustrated mass spectrometer has a deflection magnetic field B ₁ , an electric field E,
It is a so-called BEB type consisting of a deflection magnetic field B ₂ , and B ₁
When MS1 and EB ₂ are MS2, B ₁ E is MS1 and B ₂
There are two types of combinations when is set as MS2,
It is necessary to place a collision chamber and a detector between B ₁ and E and E and B ₂ . Since a space problem occurs at each position, the conversion dynode 11 and the detector 12 are placed immediately after the slit 24 or immediately after the slit 26 as shown in the figure.

In addition to this, MS/MS mass spectrometers include:
When the electric field is E, the magnetic field is B, and the quadrupole mass filter is Q, BE, EBE, BEBE (EBEB), EBQ
There are combinations such as (BEQ) and QQQ, each with its own characteristics, and it goes without saying that the convergence dynode and detector according to the present invention can be applied to all of these combinations. In addition, in the case of BEBE (EBEB) type, usually B ₁ E ₁ and B ₂ E ₂
In many cases, an independent connection consisting of a collision chamber and a detector is placed in the middle of the connection, and in this case space issues are not a major limiting factor, but in this case too, it is possible to improve the ion passage rate through the connection. For MS1
Since the distance between (B ₁ E ₁ ) and MS2 (B ₂ E ₂ ) should be as small as possible, application of the present invention is extremely effective.

[Effects of the invention] As described above, according to the invention, by using the conversion dynode of the off-axis detector as a collision chamber, it is possible to perform all types of MS/MS.
In mass spectrometry, the collision chamber and detector can be easily arranged even in a narrow space. Also especially
When applied to BEBE (EBEB) type, MS1 and
It is possible to shorten the distance of MS2 and improve the passing rate.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of a collision chamber and a detector according to the present invention. FIG. 1A is a diagram showing the case where it functions as a detector, FIG. Figure 2 shows an example of an MS/MS mass spectrometer using the convergence dynode and detector shown in Figure 1, and Figure 3 shows a conventional MS/MS mass spectrometer.
FIG. 2 is a diagram showing the arrangement of a detector and a collision chamber of an MS/MS mass spectrometer. DESCRIPTION OF SYMBOLS 10... Collector slit, 11... Conversion dynode, 12... Detector, 13... Collision chamber, 14... Pore, 21... Ion source, 22...
...Source slit, 23... Magnet, 24... Slit, 25... Electrode, 26... Slit, 27...
...Magnet, 28...Detection slit, 29...Ion detector.

Claims (1)

[Scope of utility model registration request] In a mass spectrometer in which a first mass spectrometer and a second mass spectrometer are connected in series, and a collision chamber and a detector are provided at the connection part, the conversion dynode of the off-axis detector is made hollow, and the conversion dynode of the off-axis detector is made hollow. A mass spectrometer characterized in that a collision gas is introduced to serve as a collision chamber, and the conversion dynode is movable in a direction intersecting an optical axis.