CN115274398A - Composite ion source and radio frequency power supply circuit thereof - Google Patents

Abstract

The invention relates to a composite ion source and a radio frequency power supply circuit thereof, wherein a torch tube and a torch tube coil of the composite ion source are positioned in a low vacuum region, the torch tube coil is wound on the torch tube, a vacuum slide valve, a photoionization device, a quadrupole deflection device and a focusing lens group are positioned in a high vacuum region, the photoionization device is arranged on the quadrupole deflection device, a vacuum interface and a sample injection capillary tube are connected with the low vacuum region and the high vacuum region through the vacuum slide valve, the torch tube is opposite to the vacuum interface, ions enter the quadrupole deflection region in the quadrupole deflection device through the vacuum interface or the sample injection capillary tube, and the ions discharged from the quadrupole deflection region enter the focusing lens group. According to the invention, through the design of an ion source structure and an electric control system in the mass spectrum, the combination of an inductively coupled plasma ionization source and a photoionization source is realized, so that the instrument can detect volatile organic compounds and heavy metal elements, the multi-substance detection application of the instrument is ensured, and the detection of water quality is more convenient and faster.

Description

A composite ion source and its radio frequency power supply circuit

technical field

The invention relates to the technical field of ionization, in particular to a composite ion source and a radio frequency power supply circuit thereof.

Background technique

A mass spectrometer is a scientific instrument for analyzing the composition of chemical substances. Its working method is to ionize the molecules of the analyte by certain means, and then sieve and measure the ions through the ion optical system. A mass spectrometer usually consists of a sampling system, an ion source, a mass analyzer, a detector, a vacuum system, and an electronic control system.

The ion source is a key component in the mass spectrometer, and its function is to ionize the gaseous sample molecules introduced by the sampling system into ions. The ionization of sample molecules is the first step in mass spectrometry analysis. The performance of the ion source has a major impact on many indicators of the instrument. Whether it can effectively ionize the sample molecules will directly affect important indicators such as the type of detectable substances and the detection limit. There are many types of ion sources, and different types of ion sources can analyze different substances. For example, inductively coupled plasma ionization (ICP) sources mainly analyze inorganic substances, electron bombardment ionization (EI) sources and photoionization ( The PI) source is mainly used for the analysis of volatile organic compounds (VOCs), and the electrospray ionization (ESI) source and atmospheric pressure chemical ionization (APCI) source are mainly used for the analysis of macromolecular organic compounds.

In recent years, with the development of industry, the water pollution of rivers and lakes has been serious, and water resources are closely related to people's survival, life, and production in the natural environment. Water quality monitoring can provide scientific information for water environment management, pollution source control, and environmental planning. It plays an important role in preventing and controlling water pollution. The current detection methods can only detect one type of substance in water. For example, some instruments can detect volatile organic compounds in water, and some instruments can detect heavy metal elements in water, but these instruments cannot meet all water quality parameters. detection.

Contents of the invention

In order to achieve the above-mentioned purpose and other advantages according to the present invention, the first object of the present invention is to provide a kind of composite ion source, comprising: torch tube, torch tube coil, vacuum interface, sampling capillary, vacuum slide valve, photoionization device, Quadrupole deflection device, focusing lens group, the torch and the torch coil are located in the low vacuum area, the torch coil is wound on the torch, the vacuum slide valve, the photoionization device, the torch The quadrupole deflection device and the focusing lens group are located in the high vacuum area, the photoionization device is installed on the quadrupole deflection device, the vacuum interface and the sampling capillary are connected to the low vacuum port through the vacuum slide valve. Vacuum area and high vacuum area, the torch is opposite to the vacuum interface, ions enter the quadrupole deflection area in the quadrupole deflection device through the vacuum interface or the sampling capillary, and are deflected from the quadrupole The ions discharged from the area enter the focusing lens group.

Further, the quadrupole deflection device includes a quadrupole deflection electrode, a quadrupole deflection entrance electrode, an ion repelling electrode, a neutral particle discharge electrode, and an ion extraction electrode; the quadrupole deflection entrance electrode, the ion repulsion electrode , the neutral particle discharge electrode, the ion extraction electrode are installed around the quadrupole deflection electrode, the quadrupole deflection inlet electrode is opposite to the neutral particle discharge electrode, and the ion repulsion electrode is connected to the The ion extraction electrode is opposite to the ion extraction electrode, the quadrupole deflection entrance electrode is opposite to the vacuum interface, and the ion extraction electrode is opposite to the focusing lens group.

Further, the photoionization device includes a discharge tube, a discharge tube coil, a discharge tube mounting plate, and an insulating column; the discharge tube mounting plate is installed on the quadrupole deflection electrode through the insulating column, and the discharge tube is installed On the discharge tube mounting plate, the discharge tube coil is wound on the discharge tube.

Further, the discharge tube is provided with a light window for releasing photons into the quadrupole deflection area at one end close to the quadrupole deflection device; the discharge tube is made of quartz glass; the discharge tube is filled with argon gas or krypton gas.

Further, the insulating post is made of nylon or ceramic material.

Further, the vacuum interface is a vacuum interface cone.

Further, the torch is made of quartz glass; the torch is filled with argon.

Further, the sampling capillary is made of quartz glass.

The second object of the present invention is to provide a radio frequency power supply circuit for a composite ion source, including: a high-power radio frequency power supply, a power detection circuit, a resonance matching control circuit, a tuning element, and a reflected power detection circuit, and the power detection circuit is connected to the The high-power radio frequency power supply is connected to the resonance matching control circuit, the power detection circuit and the resonance matching control circuit are connected to the tuning element, and the tuning element is connected to the torch coil and the discharge tube coil of the composite ion source, The torch coil and the discharge tube coil are connected to the reflected power detection circuit, and the reflected power detection circuit is connected to the resonance matching control circuit;

The radio frequency signal output by the high-power radio frequency power supply is coupled to the tuning element through the power detection circuit;

The tuning element outputs signals to the torch coil and the discharge tube coil;

The reflected power detection circuit detects the radio frequency signal reflected by the torch coil and the discharge tube coil, and inputs it to the resonance matching control circuit to generate a set of phase error signal and amplitude error signal;

The resonance matching control circuit generates a control signal to drive the tuning element according to the magnitude of the phase error signal and the amplitude error signal so that the load coil obtains the maximum power output.

Further, the tuning element includes two motors, the two motors drive the rotating handle, and the rotating handle is respectively connected to the movable piece of the adjustable capacitor to control the capacitance of the capacitor;

The resonant matching control circuit generates a control signal to drive two motors according to the magnitude of the phase error signal and the amplitude error signal, and adjusts the position of the moving piece of the adjustable capacitor, so that the loop parameters of the capacitor and the load coil inductance reach a resonance state, and the load coil for maximum power output.

Compared with prior art, the beneficial effect of the present invention is:

The invention provides a composite ion source and its radio frequency power supply circuit. Through the design of the ion source structure and the electric control system in the mass spectrometer, the combination of the inductively coupled plasma ionization source and the photoionization source is realized, so that the instrument can detect volatile organic Compounds can also detect heavy metal elements, which ensures the multi-substance detection application of the instrument and makes the detection of water quality more convenient and quicker.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, the preferred embodiments of the present invention and accompanying drawings are described in detail below. The specific embodiment of the present invention is given in detail by the following examples and accompanying drawings.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the composite ion source schematic diagram of embodiment 1;

FIG. 2 is a schematic structural diagram of a quadrupole deflection device in Embodiment 1;

Fig. 3 is a partial structural diagram of the quadrupole deflection device in Embodiment 1;

FIG. 4 is a schematic diagram of the radio frequency power supply circuit of the composite ion source in Embodiment 2. FIG.

In the figure: 1. torch; 2. torch coil; 3. vacuum interface cone; 4. sampling capillary; 5. vacuum slide valve; 6. quadrupole deflection device; 61. quadrupole deflection electrode; 62. quadrupole Deflection entrance electrode; 63. Ion repulsion electrode; 64. Neutral particle discharge electrode; 65. Ion extraction electrode; 7. Focusing lens group; 8. High vacuum area; 9. Photoionization device; 91. Discharge tube; 92. Discharge tube coil; 93, discharge tube mounting plate; 94, insulating column.

Detailed ways

Below, the present invention will be further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of not conflicting, the various embodiments described below or the technical features can be combined arbitrarily to form new embodiments. .

Example 1

A composite ion source, as shown in Figure 1, comprising: torch tube 1, torch tube 1 coil 2, vacuum interface, sampling capillary tube 4, vacuum slide valve 5, photoionization device 9, quadrupole deflection device 6, focusing lens Group 7, torch tube 1, coil 2 of torch tube 1 are located in a low vacuum area such as atmospheric pressure, coil 2 of torch tube 1 is wound on torch tube 1, vacuum slide valve 5, photoionization device 9, quadrupole deflection device 6, focusing lens group 7 is located in the high vacuum area 8, the photoionization device 9 is installed on the quadrupole deflection device 6, the vacuum interface and the sampling capillary 4 are connected to the low vacuum area and the high vacuum area 8 through the vacuum slide valve 5, and the torch 1 is opposite to the vacuum interface , the ions enter the quadrupole deflection area in the quadrupole deflection device 6 through the vacuum interface or the sampling capillary 4 , and the ions discharged from the quadrupole deflection area enter the focusing lens group 7 . In this embodiment, the vacuum interface adopts the vacuum interface cone 3 .

As shown in Fig. 2 and Fig. 3, the quadrupole deflection device 6 includes a quadrupole deflection electrode 61, a quadrupole deflection entrance electrode 62, an ion repulsion electrode 63, a neutral particle discharge electrode 64, and an ion extraction electrode 65; Electrode 62, ion repulsion electrode 63, neutral particle discharge electrode 64, ion extraction electrode 65 are installed around quadrupole deflection electrode 61, quadrupole deflection entrance electrode 62 is opposite to neutral particle discharge electrode 64, ion repulsion electrode 63 Opposite to the ion extraction electrode 65 , the quadrupole deflection entrance electrode 62 is opposite to the vacuum interface, and the ion extraction electrode 65 is opposite to the focusing lens group 7 .

As shown in Figure 2, the photoionization device 9 includes a discharge tube 91, a discharge tube 91 coil 92, a discharge tube 91 mounting plate 93, and an insulating post 94; the discharge tube 91 mounting plate 93 is installed on the quadrupole deflection electrode 61 through the insulating post 94 , the discharge tube 91 is installed on the discharge tube 91 mounting plate 93 , and the coil 92 of the discharge tube 91 is wound on the discharge tube 91 . In this embodiment, the insulating post 94 is made of nylon material or ceramic material. The discharge tube 91 is made of quartz glass; the discharge tube 91 is filled with argon gas or krypton gas, and different gases will produce photons with different energies under the action of radio frequency voltage. ₂ The light window is used to release photons into the quadrupole deflection area, that is, the VOCs ionization area.

For the ionization detection of heavy metal samples, the heavy metal samples are atomized and introduced into the torch tube 1. The torch tube 1 is made of quartz glass, and argon gas is passed into the torch tube 1 as auxiliary gas and cooling gas. Apply high-power radio frequency, under the action of high-power radio frequency, the argon gas becomes high-temperature plasma and interacts with the heavy metal sample to ionize the heavy metal sample. At this time, the vacuum slide valve 5 on the side of the vacuum interface cone 3 is opened, and the heavy metal ions pass through the vacuum interface. The cone 3 enters the high vacuum region 8, and is introduced into the quadrupole deflection region by the quadrupole deflection entrance electrode 62, and the ions are deflected under the action of the quadrupole deflection electrode 61, and are discharged from the quadrupole deflection region from the ion extraction electrode 65, while the neutral particles The neutral particles are discharged from the neutral particle discharge electrode 64 without being affected by the electric field. The ions extracted from the ion extraction electrode 65 are then focused and shaped by the focusing lens group 7, and finally enter the mass analyzer of the mass spectrometer for analysis and detection.

For ionization detection of volatile organic compounds (VOCs) samples, headspace sampling is first performed on the detection sample, and VOCs enters the sampling capillary 4, which is made of quartz glass. At this time, the sampling capillary 4- The vacuum slide valve 5 on the side is opened, and the VOCs sample enters the quadrupole deflection area, that is, the VOCs ionization area. At this time, a radio frequency voltage is applied to the coil 92 of the discharge tube 91. Under the action of the radio frequency voltage, the gas in the discharge tube 91 releases photons, and the photons enter the VOCs ionization region and collide with the VOCs molecules, so that the VOCs molecules are ionized into ions. The VOCs ions enter the focusing lens group 7 under the action of the ion repeller electrode 63 and the ion extraction electrode 65 for focusing and shaping, and the VOCs ions finally enter the mass analyzer of the mass spectrometer for analysis and detection.

Example 2

A radio frequency power supply circuit of a compound ion source, as shown in Figure 4, includes: a high-power radio frequency power supply, a power detection circuit, a resonance matching control circuit, a tuning element, a reflected power detection circuit, a power detection circuit and a high-power radio frequency power supply, and a resonance The matching control circuit is connected, the power detection circuit, the resonance matching control circuit are connected with the tuning element, the tuning element is connected with the torch tube 1 coil 2 and the discharge tube 91 coil 92 of the compound ion source, the torch tube 1 coil 2, the discharge tube 91 coil 92 and the The reflected power detection circuit is connected, and the reflected power detection circuit is connected with the resonant matching control circuit;

The tuning element includes two motors, the two motors drive the rotating handles, and the rotating handles are respectively connected to the movable plates of the adjustable capacitors to realize the capacitance control of the capacitors, thereby realizing impedance matching.

The RF signal output by the high-power RF power supply is coupled to the tuning element through the power detection circuit, and finally output to the coil 2 of the torch tube 1 or the coil 92 of the discharge tube 91 through the tuning element. Due to the different inductance values of the coil 2 of the torch 1 and the coil 92 of the discharge tube 91, the load impedance is different, and the load and the radio frequency signal source may not match for different loads, so that the power obtained on the load is not the maximum. and produce a signal that is reflected back to the RF source. The output radio frequency signal is detected by the reflected power detection circuit, the reflected radio frequency signal is detected by the reflected power detection circuit, and input to the resonance matching control board to generate a set of phase error and amplitude error signals, and the resonance matching control circuit is based on the two error signals. The size generates a control signal to drive two motors, adjust the position of the two tuning elements, that is, adjust the capacitance of the two capacitors, so that the loop parameters of the two capacitors and the load coil inductance reach a resonance state, so that the load coil can obtain the maximum power output . Wherein, the two load coils, that is, the coil 2 of the torch tube 1 and the coil 92 of the discharge tube 91 do not work at the same time. When one coil is working, the other coil is disconnected and not connected to the loop.

The invention realizes the combination of the inductively coupled plasma ionization source and the photoionization source through the design of the ion source structure and the electronic control system in the mass spectrometer, so that the instrument can detect both volatile organic compounds and heavy metal elements, ensuring the versatility of the instrument. The application of substance detection makes the detection of water quality more convenient and faster.

It should also be noted that the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes Other elements not expressly listed, or elements inherent in the process, method, commodity, or apparatus are also included. Without further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

Each embodiment in this specification is described in a progressive manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments.

The foregoing are merely examples of the present specification, and are not intended to limit one or more examples of the present specification. For those skilled in the art, various modifications and changes may be made to one or more embodiments of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included within the scope of claims of one or more embodiments of this specification. One or more embodiments of this description One or more embodiments of this description One or more embodiments of this description One or more embodiments of this description.

Claims (10)

1. A composite ion source, comprising: torch, torch coil, vacuum interface, advance kind capillary, vacuum slide valve, photoionization device, quadrupole deflection device, focusing lens group, the torch coil is located low vacuum region, the torch coil is around on the torch, the vacuum slide valve the photoionization device the quadrupole deflection device the focusing lens group is located high vacuum region, the photoionization device is installed on the quadrupole deflection device, the vacuum interface advance kind capillary all passes through the vacuum slide valve is connected low vacuum region and high vacuum region, the torch with the vacuum interface is relative, the ion warp the vacuum interface or advance kind capillary entering quadrupole deflection region in the quadrupole deflection device, follow the regional exhaust ion of quadrupole deflection gets into the focusing lens group.

2. The composite ion source of claim 1, wherein: the quadrupole deflection device comprises a quadrupole deflection electrode, a quadrupole deflection inlet electrode, an ion repulsion electrode, a neutral particle discharge electrode and an ion extraction electrode; the ion repulsion electrode is arranged on the periphery of the focusing lens group, and the ion repulsion electrode is arranged on the vacuum interface.

3. The source of claim 2, wherein: the photoionization device comprises a discharge tube, a discharge tube coil, a discharge tube mounting plate and an insulating column; the discharge tube mounting plate is mounted on the quadrupole deflection electrode through the insulating column, the discharge tube is mounted on the discharge tube mounting plate, and the discharge tube is wound on the discharge tube.

4. A source of complex ions according to claim 3, wherein: one end of the discharge tube close to the quadrupole deflection device is provided with an optical window which releases photons into a quadrupole deflection area; the discharge tube is made of quartz glass; argon or krypton gas is filled in the discharge tube.

5. A source of complex ions according to claim 3, wherein: the insulating column is made of a nylon material or a ceramic material.

6. A source of complex ions according to claim 1, wherein: the vacuum interface is a vacuum interface cone.

7. The composite ion source of claim 1, wherein: the torch tube is made of quartz glass; argon is introduced into the torch tube.

8. The composite ion source of claim 1, wherein: the sample injection capillary is made of quartz glass.

9. An rf power supply circuit for a composite ion source, comprising: the composite ion source comprises a high-power radio-frequency power supply, a power detection circuit, a resonance matching control circuit, a tuning element and a reflected power detection circuit, wherein the power detection circuit is connected with the high-power radio-frequency power supply and the resonance matching control circuit;

the radio frequency signal output by the high-power radio frequency power supply is coupled to the tuning element through the power detection circuit;

the tuning element outputs a signal to the torch coil, the discharge tube coil;

the reflected power detection circuit detects radio frequency signals reflected by the torch coil and the discharge tube coil and inputs the radio frequency signals to the resonance matching control circuit to generate a group of phase error signals and amplitude error signals;

and the resonance matching control circuit generates a control signal according to the phase error signal and the amplitude error signal to drive the tuning element so that the load coil obtains the maximum power output.

10. The rf power supply circuit of claim 9, wherein: the tuning element comprises two motors, the two motors drive a rotating handle, and the rotating handle is respectively connected with a moving plate of the adjustable capacitor to control the capacitance value of the capacitor;

the resonance matching control circuit generates control signals according to the phase error signals and the amplitude error signals to drive the two motors, and adjusts the position of the movable plate of the adjustable capacitor, so that the loop parameters of the capacitor and the inductance of the load coil reach a resonance state, and the load coil obtains the maximum power output.

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