WO2015085651A1

WO2015085651A1 - Quadrupole rod mass analysis device for bidirectional introduction and transmission of ions

Info

Publication number: WO2015085651A1
Application number: PCT/CN2014/000846
Authority: WO
Inventors: 聂宗秀; 侯剑; 熊彩侨; 张宁; 何清
Original assignee: 中国科学院化学研究所
Priority date: 2013-12-10
Filing date: 2014-09-16
Publication date: 2015-06-18
Also published as: CN103681208B; CN103681208A

Abstract

A quadrupole rod mass analysis device for bidirectional introduction and transmission of ions. The quadrupole rod mass analysis device comprises two ion deflection devices (2) and a quadrupole rod mass analyzer (3), wherein the ion deflection devices (2) are arranged at the two axial ends of the quadrupole rod mass analyzer (3), the ion deflection devices (2) are arranged in a plane which is axially perpendicular to the quadrupole rod mass analyzer (3); and ion source vacuum interfaces (1, 5) are arranged at the two ends of each ion deflection device. The quadrupole rod mass analysis device of a simple structure breaks through the limitation of the unidirectional transmission of an existing quadrupole rod, and provides a new idea for the design of mass spectrometers. The quadrupole rod mass analysis device facilitates the research of the interaction between ions in a condition of vacuum, and can conduct separation analysis on products of ionic reaction. By adding appropriate ion receiving components, this design can also realize the surface assembling and decoration of a single-molecular layer or a multi-molecular layer.

Description

Quadrupole mass spectrometer for ion bidirectional introduction and transmission

Technical field

The invention relates to a quadrupole mass analysis device for ion bidirectional introduction and transmission.

Background technique

The flight path of charged particles in the mass spectrometer is the basis of instrument design. After the sample molecules are ionized by the ion source, they enter the ion transport tube through the vacuum interface, are separated according to the mass-to-charge ratio in the mass analyzer, and finally reach the detector and are detected. Each of these steps requires precise control of the electromagnetic field.

The quadrupole mass analyzer, or quadrupole, is the most common ion transport and mass analysis device in mass spectrometers. The quadrupole is a sequential mass analyzer that allows mass-to-charge ratio analysis of the extracted ion beam. A typical quadrupole consists of four precision-machined electrode rods and an electrode analyzer consisting of two sets of high-voltage, high-frequency radio frequencies applied in the x and y directions. The analyzed ions enter the end of the quadrupole device axially. The high frequency RF voltage applied to the analyzer causes all ions to enter an oscillating path, providing auxiliary energy for the ions to move in the analyzer. This energy is selective. - Only ions that meet certain energy and momentum can be accelerated without unrestricted, resulting in a stable path safely exiting the other end through the quadrupole analyzer. Other ions are deflected excessively, collide with the poles, and are neutralized and lost on the poles.

In a typical mass spectrometer, the quadrupole used can only allow one-way flight of ions. Such ion transport design can effectively analyze ions in a certain mass-to-charge ratio range, and meet the needs of mass spectrometers for analyzing and detecting samples. However, with the ever-widening of mass spectrometer applications and the emergence of preparative mass spectrometry concepts, the design requirements of mass spectrometers are diversified, and unidirectional quadrupole transmission devices are no longer able to meet the needs of rapidly evolving application research. For example, the use of mass spectrometers to study the interactions between ions under gas phase conditions, the design using conventional unidirectional ion transport can greatly limit the types of reactive ions and types, because the ions produced by the same ionization source have mutual The effect of inhibition, the early mixing of molecules can also complicate the ionization process. Current mass spectrometer conditions can be used to explore single-ion reactions in quadrupoles, but it is not conducive to the study of gas-phase reactions between different kinds of ions. Therefore, designing quadrupoles for dual-channel ion introduction and transmission has a wide range of theoretical and practical significance. .

Summary of the invention

The object of the present invention is to provide a quadrupole mass spectrometer for ion bidirectional introduction and transmission. The invention can realize bidirectional transmission control and mass spectrometry of ions, and provides a platform for introducing multi-ion analysis and detection of opposite flight, and expands the mass spectrum. The function of the quadrupole mass analyzer.

The invention provides an ion bidirectional introduction and transmission quadrupole mass analyzing device, which comprises two ion deflecting devices and a quadrupole mass analyzer;

The ion deflecting device is disposed at two ends of the quadrupole mass in the axial direction; and the ion deflecting device is disposed in a plane perpendicular to an axial direction of the quadrupole mass analyzer;

An ion source vacuum interface is disposed at both ends of the ion deflecting device.

In the above-described quadrupole mass spectrometer, the ion deflecting device comprises four electrodes, four of the electrodes are arranged in a rectangular shape, and two electrodes arranged along a diagonal line are connected to the same DC power source, so that The voltage electrical properties of each pair of electrodes on each diagonal are controlled to be opposite.

In the quadrupole mass spectrometer described above, the electrodes may be disposed perpendicular to the axial direction of the quadrupole mass analyzer.

In the above quadrupole mass spectrometer, the ion source vacuum interface is a through hole provided in a cone to prevent a large amount of molecules that are not ionized from entering the mass analyzer, thereby reducing gas exchange between the inside and the outside of the device. At the same time, it is ensured that the ions can enter the vacuum environment; the material of the ion source vacuum interface may be a conductive material such as stainless steel or an insulator material coated with a conductive film on the surface. When using a vacuum ionization source, the interface can work directly without modification.

In the above quadrupole mass analyzing device, an ion lens is disposed between the ion source vacuum interface and the ion deflecting device to achieve ion focusing;

An ion lens is disposed between the ion deflecting device and the quadrupole mass to achieve ion focusing.

In the above quadrupole mass spectrometer, the electrode of the quadrupole mass analyzer is a hyperboloid electrode or a cylindrical electrode, and the RF frequency scan of the quadrupole mass analyzer is performed to analyze different ion mass-to-charge ratios. It can be either positive or reverse, and the ions in the quadrupole mass analyzer can selectively fly out from one end depending on the direction of the frequency sweep.

In the above quadrupole mass analyzing device, a detector is connected to an outlet end of the ion deflecting device;

The detector can be a photomultiplier tube, a microchannel plate or a Faraday cup.

In the above quadrupole mass spectrometer, the outlet end of the ion deflecting device can be connected to the ion receiving device;

The ion receiving device is disposed on the three-dimensional moving platform, and by moving the three-dimensional moving platform, the selected target ions can be dropped in different parts to obtain a two-dimensional distribution pattern of the selected ions.

In the quadrupole mass spectrometer of the present invention, the ion deflecting device acts as an ion transporting channel when it is not deflected, and can allow ions to fly freely without applying electricity, or can apply the same ion charging property on the four electrodes of the ion deflecting device. The low DC voltage achieves a certain degree of ion focusing.

The quadrupole mass analyzing device of the invention can perform mass screening and ion deflection in a low vacuum environment (10 ^-3 torr to 10 ^-5 torr), and the mechanical pump and the molecular pump provide the necessary vacuum degree.

The ionization source suitable for analysis and separation of the quadrupole mass spectrometer of the present invention may be an atmospheric ionization source, such as electrospray ionization, real-time direct analysis of a mass spectrometer ion source, or a non-atmospheric ion source, such as a chemical ionization source. Matrix-assisted laser desorption ionization source and the like.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view of a quadrupole mass spectrometer for ion bidirectional introduction and transmission of the present invention.

2 is a top plan view of a quadrupole mass spectrometer of the ion bidirectional introduction and transmission of the present invention.

The figures are as follows: 1,5 ion source vacuum interface, 2,4 ion deflection device, 3 quadrupole mass analyzer, 6,7 detector.

detailed description

As shown in FIG. 1 and FIG. 2, the quadrupole mass spectrometer for ion bidirectional introduction and transmission provided by the present invention comprises two ion deflecting devices 2 and 4 and a quadrupole mass analyzer 3. The ion deflecting devices 2 and 4 each include four electrodes (not shown), four electrodes are arranged in a rectangular shape, and two electrodes disposed along the diagonal line are respectively connected to the same DC power source, thereby being controllable in each strip. The voltage of each pair of electrodes on the diagonal is electrically opposite. And the ion deflecting devices 2 and 4 are disposed at both axial ends of the quadrupole massor 3, and are disposed in a plane perpendicular to the axial direction of the quadrupole massor 3, and the electrodes and the electrodes of the ion deflecting devices 2 and 4 The axial vertical setting of the stage mass analyzer 3. An ion

source vacuum interface

1 and 5 are respectively disposed at both ends of the ion deflecting devices 2 and 4, which are through holes provided in a cone to prevent a large amount of molecules that are not ionized from entering the mass analyzer, thereby reducing the device. Internal and external gas exchange, while ensuring that ions can enter the vacuum environment.

In the quadrupole mass spectrometer of the present invention, an ion lens can be disposed between the ion source vacuum interface and the ion deflection device and between the ion deflection device and the quadrupole mass analyzer to achieve ion focusing.

In the quadrupole mass spectrometer of the present invention, the electrode of the quadrupole mass analyzer 3 is a hyperboloid electrode or a cylindrical electrode. In order to analyze different ion mass-to-charge ratios, the radio frequency sweep of the quadrupole massor can be performed. It is either positive or reverse. Depending on the direction of the frequency sweep, the ions in the quadrupole massifier can selectively fly out from one end.

In the quadrupole mass spectrometer of the present invention, detectors 6 and 7 such as a photomultiplier tube, a microchannel plate or a Faraday cup may be connected to the outlet end of the

ion deflecting devices

2 and 5; or an ion receiving device may be connected and The ion receiving device is disposed on a three-dimensional moving platform, and by moving the three-dimensional moving platform, the selected target ions can be dropped in different parts to obtain a two-dimensional distribution pattern of the selected ions.

When using the quadrupole mass spectrometer of the present invention, a mechanical pump or a molecular pump is first used to provide a certain vacuum environment for the operation of the device. Then, the positive ionization caused by electrospray, matrix-assisted laser desorption ionization and other ionization techniques The sub-ion source vacuum interface 1 enters the device from the ionization source, and a small (0 to 30 V) DC voltage is applied to the four electrodes of the ion deflection device 2, and the positive ions are focused by the positive electric field. The focused positive ions enter the quadrupole mass analyzer 3, and the selected positive mass-to-charge ratio positive ions are analyzed by the quadrupole mass analyzer 3 to enter the ion deflecting device 4, and the upper left and lower right electrodes of the ion deflecting device 4 Add positive DC, add negative DC to the upper right and lower left electrodes. The ions are deflected at right angles under the action of the electric field force and are eventually detected or received by the detector 7. The voltage required for the entire device is adjusted accordingly based on the mass-to-charge ratio of the ions. If the introduced ion is negatively charged, the electrode voltage of the ion deflecting device 2 is correspondingly a negative voltage, and the positive and negative voltages of the voltage of the ion deflecting device 4 are exchanged with each other.

The above process can be reversed, that is, ions enter the quadrupole mass analyzer 3 from the ionization source vacuum interface 5 via the ion deflecting device 4, and are in the quadrupole mass analyzer 3 according to the mass-to-charge ratio. After separation, it is deflected by 90 degrees under the electric field of the ion deflecting device 2, that is, in the case of positive ions, the upper right and lower left electrodes of the ion deflecting device 2 are negatively charged with direct current, and the upper left and lower right electrodes are positively charged with direct current, in the case of negative ions. The voltages are reversed. The deflected ions eventually hit the detector 6.

When the ion reaction product is separated and analyzed using the ion bidirectional introduction and transmission quadrupole mass spectrometer of the present invention, the following steps can be performed:

When the ion reaction is performed in the quadrupole mass spectrometer, the initial ions enter through the ion source vacuum interface 1, and then enter the quadrupole mass analyzer 3 under the focusing action of the ion deflecting device 2; at this time, from the quadrupole The other end of the mass spectrometer, i.e., the ion source vacuum interface 5, introduces ligand ions; the ligand ions are focused by the ion deflecting device 4 into the quadrupole mass analyzer 3, and are separated from the quadrupole mass analyzer 3 The initial ionic interaction of a particular mass-to-charge ratio. The activated initial ions are axially thrown out of the quadrupole mass analyzer 3, at which time the DC voltage applied to the ion deflecting device 4 is switched to the deflection mode, and the reacted ions are deflected and landed on the detector 7, ie The detection of the product of the ion reaction can be carried out.

Industrial application

The invention provides a simple quadrupole mass analysis device, which breaks through the limitation of the existing quadrupole unidirectional transmission and provides a new idea for the design of the mass spectrometer. The quadrupole mass spectrometer of the invention facilitates the study of the interaction between gas phase ions under vacuum conditions and enables separation and analysis of the products of the ion reaction. This design also enables surface assembly and modification of monolayer or multi-molecular layers by the addition of appropriate ion receiving components.

Claims

A quadrupole mass analysis device for ion bidirectional introduction and transmission, characterized in that:

The quadrupole mass analyzer includes two ion deflection devices and a quadrupole mass analyzer;

The ion deflecting device is disposed at two ends of the axial direction of the quadrupole mass analyzer; and the ion deflecting device is disposed in a plane perpendicular to an axial direction of the quadrupole mass analyzer;

An ion source vacuum interface is disposed at both ends of the ion deflecting device.
The quadrupole mass spectrometer according to claim 1, wherein the ion deflecting device comprises four electrodes, four of the electrodes are arranged in a rectangular shape, and two of the electrodes are disposed along a diagonal line. Connected to the same DC power supply.
The quadrupole mass analyzing apparatus according to claim 2, wherein said electrode is disposed perpendicular to an axial direction of said quadrupole mass analyzer.
The quadrupole mass spectrometer according to any one of claims 1 to 3, wherein the ion source vacuum port is a through hole provided in a cone.
The quadrupole mass spectrometer according to any one of claims 1 to 4, wherein an ion lens is disposed between the ion source vacuum interface and the ion deflecting device;

An ion lens is disposed between the ion deflector and the quadrupole mass analyzer.
The quadrupole mass spectrometer according to any one of claims 1 to 5, characterized in that the electrode of the quadrupole massor is a hyperboloid electrode or a cylindrical electrode.
The quadrupole mass spectrometer according to any one of claims 1 to 6, wherein a detector is connected to an outlet end of the ion deflecting device;

The detector is a photomultiplier tube, a microchannel plate or a Faraday cup.
The quadrupole mass spectrometer according to any one of claims 1 to 6, wherein an ion receiving device is connected to an outlet end of the ion deflecting device;

The ion receiving device is disposed on a three-dimensional mobile platform.