Mass spectrometry device and method based on multiple ionization techniques

Abstract

The present invention provides a mass spectrometer and method based on multiple ionization technologies, wherein the mass spectrometer comprises a soft ionization unit, an injection cone and a power supply; a hard ionization unit comprises 2N electrodes, and is arranged between the soft ionization unit and the injection cone; electrodes uniformly distributed on the circumference surround a cylindrical structure, the 2i-th electrode is connected to the positive electrode of the power supply, and the (2i-1)-th electrode is connected to the negative electrode of the power supply, i=1,2…N, N is a positive integer greater than 1; the distance between the output end of the hard ionization unit and the injection cone is #imgabs0#, R is the maximum distance between the electrodes in the hard ionization unit, Q is the gas flow rate, V is the discharge voltage, A is the coefficient, and t is the time. The present invention has the advantages of simple structure and the like.

Description

Technical Field

[0001] The present invention relates to mass spectrometry technology, and in particular to a mass spectrometry device and method based on multiple ionization technologies. Background Art

[0002] Mass spectrometry is a powerful technical method for material analysis. It has developed rapidly in recent years and has become an indispensable research tool in many fields such as proteomics and tissue imaging. At present, ESI, HESI, APCI and other ionization devices are widely used in gas ionization. The shortcomings of this ionization method are:

[0003] 1. The soft ionization method has problems such as incomplete ionization and low ionization efficiency, which leads to weak signal intensity and large signal RSD.

[0004] 2. An additional heating system is required, which consumes huge power and is complex to operate and manufacture. Summary of the invention

[0005] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides a mass spectrometer based on multiple ionization technologies.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A mass spectrometer based on multiple ionization technologies, the mass spectrometer comprising a soft ionization unit, an injection cone and a power supply; and further comprising:

[0008] A hard ionization unit, wherein the hard ionization unit comprises 2N electrodes and is arranged between the soft ionization unit and the injection cone; the electrodes evenly distributed on the circumference surround a cylindrical structure, the 2i-th electrode is connected to the positive electrode of the power supply, and the (2i-1)-th electrode is connected to the negative electrode of the power supply, i=1,2…N, N is a positive integer greater than 1;

[0009] The distance between the output end of the hard ionization unit and the injection cone , R is the maximum distance between electrodes in the hard ionization unit, Q is the gas flow rate, V is the discharge voltage, A is the coefficient, and t is the time.

[0010] Another object of the present invention is to provide a mass spectrometry analysis method, which is achieved by the following technical solutions:

[0011] According to the mass spectrometry analysis method of the mass spectrometry device based on multiple ionization technologies of the present invention, the mass spectrometry analysis method comprises the following steps:

[0012] (S1) The sample gas flow enters the soft ionization unit for the first stage of ionization, after which the sample enters the hard ionization unit;

[0013] (S2) the electrodes of the hard ionization unit are discharged, and the generated ions enter the injection cone;

[0014] During the discharge, the sample is heated, accelerating the ionization efficiency.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. High ionization efficiency;

[0017] Adding hard ionization on the basis of soft ionization improves the ionization efficiency;

[0018] 2. High signal-to-noise ratio;

[0019] In the hard ionization unit, high voltage is used, and the heat generated increases the temperature of the sample, which is beneficial to ionization and improves the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings:

[0021] Figure 1 is a schematic structural diagram of a mass spectrometer based on multiple ionization technologies according to an embodiment of the present invention;

[0022] Figure 2 is a schematic structural diagram of a hard ionization unit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Figure 1-Figure 2 The following description describes optional specific embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to teach the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or replacements derived from these specific embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional specific embodiments, but is only limited by the claims and their equivalents.

[0024] Embodiment 1:

[0025] The mass spectrometer based on multiple ionization techniques of embodiment 1 of the present invention is as follows: Figure 1 As shown, the mass spectrometer based on multiple ionization techniques includes:

[0026] Soft ionization unit 11, injection cone 31 and power supply;

[0027] Hard ionization unit 21, such as Figure 2As shown, the hard ionization unit 21 includes 2N electrodes 22, and is arranged between the soft ionization unit 11 and the injection cone 31; the electrodes 22 evenly distributed on the circumference surround a cylindrical structure, the 2i-th electrode 22 is connected to the positive electrode of the power supply, and the (2i-1)-th electrode 22 is connected to the negative electrode of the power supply, i=1,2...N, N is a positive integer greater than 1;

[0028] The distance between the output end of the hard ionization unit 21 and the injection cone 31 is , R is the maximum distance between the electrodes 22 in the hard ionization unit 21, Q is the gas flow rate, V is the discharge voltage, A is the coefficient, and t is the time.

[0029] In order to improve the ionization efficiency, the mass spectrometer further comprises:

[0030] The sheath 41 , the soft ionization unit 11 and the hard ionization unit 21 are arranged in the sheath 41 , and the injection cone 31 is arranged downstream of the outlet end of the sheath 41 .

[0031] In order to achieve soft ionization, further, the soft ionization unit 11 includes:

[0032] The capillary 12 and the discharge needle 13 are open at both ends of the capillary 12, and the diameter of the output end is smaller than the diameter of the input end. The discharge needle 13 extends into the capillary.

[0033] The mass spectrometry analysis method of the embodiment of the present invention, that is, the working method of the mass spectrometry device based on multiple ionization technologies of the present embodiment, comprises the following steps:

[0034] (S1) The sample gas flow enters the soft ionization unit 11 and undergoes the first stage ionization, after which the sample enters the hard ionization unit 21;

[0035] (S2) the electrode 22 of the hard ionization unit 21 discharges, and the generated ions enter the injection cone 31;

[0036] During discharge, due to the use of high voltage, the heat generated increases the temperature of the sample, which is beneficial to ionization and improves the signal-to-noise ratio.

[0037] Embodiment 2:

[0038] An application example of a mass spectrometry device and method based on multiple ionization techniques according to embodiment 1 of the present invention.

[0039] In this application example, Figure 1 The soft ionization unit 11 includes a capillary 12 and a discharge needle 13. The output end of the capillary 12 is tapered, and the diameter of the outlet is smaller than the diameter of the input end. The discharge needle 13 is inserted into the capillary 12.

[0040] In the hard ionization unit 21, Figure 2 As shown, 8 rod-shaped electrodes 22 are used, which are evenly distributed on the circumference. The 2i-th electrode 22 is connected to the positive pole of the power supply, and the (2i-1)-th electrode 22 is connected to the negative pole of the power supply, i=1,2,3,4.

[0041] The soft ionization unit 11 and the hard ionization unit 21 are both arranged in a cylindrical sheath 41 , and the injection cone 31 is arranged downstream of the outlet of the sheath 41 .

[0042] The power supply provides 5.5KV DC high voltage to the discharge needle 13 and 1KV AC high voltage to the electrode 22 .

[0043] R is the distance between the electrode sheets. The parameters that affect R include the electrode sheet material, high voltage, and sheath gas composition. Nitrogen is generally used as the sheath gas. According to the Thomson second coefficient γ, different materials have different γ values. According to the Thomson second coefficient γ and Baschen's law, and according to its breakdown voltage expression, 0.6 cm is selected in this embodiment.

[0044] At the same time, Q is selected as 0.5L / min in this embodiment; A is a coefficient, which is selected as 3 in this embodiment; D is limited to ensure that the sample is in strong ionization before entering the cone mouth. While the sample is fully and strongly ionized, it is also guaranteed to be fully heated. If D is too small, the ionization range becomes smaller and the heating time becomes shorter. If D is too large, the ionization range will not be increased, and there will be a cooling time after heating, resulting in insufficient heating. According to the formula: The distance between the output end of the hard ionization unit 21 and the injection cone 31 , R is the maximum distance between the electrodes 22 in the hard ionization unit 21, Q is the gas flow rate, V is the discharge voltage, A is the coefficient, t is the time, and D=2.62cm is obtained, thereby achieving efficient ionization.

[0045] The mass spectrometry analysis method of the embodiment of the present invention, that is, the working method of the mass spectrometry device based on multiple ionization technologies of the present embodiment, comprises the following steps:

[0046] (S1) The sample gas flow enters the sheath 41, then passes through the capillary 12 and the soft ionization unit 11, undergoes the first stage ionization, and then the sample enters the hard ionization unit 21;

[0047] (S2) the electrode 22 of the hard ionization unit 21 discharges, and the generated ions enter the injection cone 31;

[0048] During the discharge, the sample is heated, which increases the ionization effect.

[0049] Embodiment 3:

[0050] The application example of the mass spectrometry device and method based on multiple ionization technologies according to Example 1 of the present invention is different from Example 2 in that:

[0051] 1. The electrode 22 is in the shape of a long strip.

Claims

1. A mass spectrometer based on multiple ionization techniques, the mass spectrometer comprising a soft ionization unit, an injection cone and a power supply; characterized in that: The mass spectrometer based on multiple ionization techniques also includes: A hard ionization unit, wherein the hard ionization unit comprises 2N electrodes and is arranged between the soft ionization unit and the injection cone; the electrodes evenly distributed on the circumference surround a cylindrical structure, the 2i-th electrode is connected to the positive electrode of the power supply, and the (2i-1)-th electrode is connected to the negative electrode of the power supply, i=1,2…N, N is a positive integer greater than 1; The distance between the output end of the hard ionization unit and the injection cone , R is the maximum distance between electrodes in the hard ionization unit, the unit is cm, Q is the gas flow rate, the unit is L / min, V is the discharge voltage, the unit is KV, A is the coefficient, A=3, and t is the time.

2. The mass spectrometer based on multiple ionization techniques according to claim 1, characterized in that: The mass spectrometer also includes: The soft ionization unit and the hard ionization unit are arranged in the sheath, and the injection cone is arranged downstream of the outlet end of the sheath.

3. The mass spectrometer based on multiple ionization techniques according to claim 1, characterized in that: The soft ionization unit comprises: A capillary tube and a discharge needle, wherein both ends of the capillary tube are open, the diameter of the output end is smaller than the diameter of the input end, and the discharge needle extends into the capillary tube.

4. The mass spectrometer based on multiple ionization techniques according to claim 1, characterized in that: The electrode is in sheet shape.

5. The mass spectrometry analysis method of a mass spectrometry device based on multiple ionization techniques according to any one of claims 1 to 4, the mass spectrometry analysis method comprising the following steps: (S1) The sample gas flow enters the soft ionization unit for the first stage of ionization, after which the sample enters the hard ionization unit; (S2) the electrodes of the hard ionization unit are discharged, and the generated ions enter the injection cone; During the discharge, the sample is heated, accelerating the ionization efficiency.

6. The mass spectrometry method according to claim 5, characterized in that: The power supply applies a DC high voltage to the soft ionization unit and applies an AC high voltage to the hard ionization unit.

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