Element detection device and method based on mass spectrometry technology

Abstract

The present invention provides an element detection device and method based on mass spectrometry technology, wherein the element detection device based on mass spectrometry technology comprises a mass analysis unit and a detector; and further comprises: an ion source adopts a magnetron electron cyclotron resonance ion source, ions emitted from the ion source sequentially enter a first ion lens group, a second ion lens group and a mass analysis unit; ions passing through the first ion lens group are focused; and the kinetic energy of ions passing through the second ion lens group matches the mass analysis unit. The present invention has the advantages of simple structure, high sensitivity, etc.

Description

Technical Field

[0001] The present invention relates to mass spectrometry analysis, and in particular to an element detection device and method based on mass spectrometry technology. Background Art

[0002] At present, ICP-MS technology is a common analytical technology. The specific method is: using a unique interface technology to combine the high-temperature ionization characteristics of ICP with the advantages of sensitive and fast scanning of quadrupole mass spectrometer, forming a new element and isotope analysis technology. ICP-MS can measure almost all samples and realize the simultaneous determination of multiple elements in one acquisition, thus establishing the leading position of ICP-MS in trace metal detection technology.

[0003] In recent years, industries such as life sciences, alloys, and semiconductors have become hot topics, and the demand for the sensitivity and detection limit of mass spectrometry detection instruments has also increased. The original ICP-MS mass spectrometry equipment is facing challenges. For example, in the semiconductor industry, the concentrations of K, Ca, and Fe in high-purity substances need to be as low as ppt, but due to the interference of argon compounds, these elements are difficult to measure by ICP-MS; in the field of life sciences, complex matrix samples are often encountered, and cone deposition often occurs, resulting in signal drift; in alloy detection, such as high-purity manganese dioxide, Cu alloys, etc., as long as the sample enters, the sensitivity is almost gone, and trace metal impurities cannot be detected at all. In order to solve the above problems, the following methods are usually used:

[0004] 1. Cold plasma mode is used for the detection of K, Ca and Fe to reduce the interference of Ar-based ions. The technical problems brought about by this are:

[0005] The cold mode has its limitations. It cannot avoid the interference of water cluster ions on elements, and the temperature is difficult to control, tuning is difficult, and the reproducibility is poor.

[0006] 2. Using the interference correction equation, but the technical problems that come with it are:

[0007] Without solving the problem at its root, the deposition at the cone mouth still exists and the maintenance frequency is high. The difference in substrates can easily lead to the failure of the interference correction equation, and the application solution developers need to make continuous corrections.

[0008] 3. Reduce the injection volume and dilute the sample online, but the technical problems that follow are:

[0009] There is basically no significant optimization; sometimes, in order to maintain sensitivity, the sample is diluted thousands of times, resulting in the inability to detect elements at several ppb levels. Summary of the invention

[0010] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides an element detection device based on mass spectrometry technology.

[0011] The objective of the present invention is achieved through the following technical solutions:

[0012] The element detection device based on mass spectrometry technology comprises a mass analysis unit and a detector; the element detection device based on mass spectrometry technology further comprises:

[0013] An ion source, wherein the ion source adopts a magnetron electron cyclotron resonance ion source, and ions emitted from the ion source sequentially enter a first ion lens group, a second ion lens group and a mass analysis unit;

[0014] a first ion lens group, through which ions passing through the first ion lens group are focused;

[0015] A second ion lens group, wherein the kinetic energy of ions passing through the second ion lens group is matched with the mass analysis unit.

[0016] The present invention also provides an element detection method based on mass spectrometry technology, and the object of the invention is achieved through the following technical solutions:

[0017] The element detection method based on mass spectrometry technology comprises the following steps:

[0018] (A1) The analyte is ionized in a magnetron electron cyclotron resonance ion source;

[0019] (A2) The ions are focused and their kinetic energy is reduced in sequence, and the kinetic energy of the ions matches that of the mass analysis unit;

[0020] (A3) The detector receives the ions emitted from the mass analysis unit, thereby obtaining the content of the elements in the object to be analyzed.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention solves the difficulty of combining the magnetron electron cyclotron resonance ion source with the mass spectrometry technology, so that the two can be combined together as a whole, achieving many technical advantages, such as;

[0023] 1. High sensitivity, achieving ppt-level trace element detection;

[0024] Taking advantage of the characteristics of the magnetron electron cyclotron resonance ion source, the high current intensity and good beam quality greatly improve the sensitivity and optimize the detection limit. It can also accurately quantify trace elements without complicated mass spectrometry calibration calculations.

[0025] 2. Simple structure, stable operation and long service life;

[0026] Taking advantage of the characteristics of the magnetron electron cyclotron resonance ion source, the entire detection device has a simple structure, stable operation and long service life;

[0027] For complex matrices, there is no need to worry about signal drift caused by non-mass spectrometry interference, and the ion optical system does not require maintenance;

[0028] 3. It solves the bottleneck problem of low-resolution mass spectrometry in life sciences, alloys, semiconductors and other industries, while retaining the advantages of fast scanning of low-resolution mass spectrometers;

[0029] 4. High resolution;

[0030] The mass analysis unit of the present invention can achieve second-order time focusing for wider ion initial position dispersion, and the mass resolution is significantly improved;

[0031] 5. The use of double pulse repulsion technology can reduce the technical requirements for high voltage pulses; the patent of this invention adopts a double repulsion method of positive pulse push (repulsion electrode) and negative pulse pull (traction electrode), which can reduce the demand for high voltage by half, so the rising edge is steeper and the pulse waveform can be improved;

[0032] Adding the first grid and the second grid of equal potential in the middle of the double pulse repulsion can reduce the electric field penetration effect of the acceleration region on the ion modulation region;

[0033] The first grid and the second grid are directly grounded, without adding extra voltage, and the adjustment is easy;

[0034] A wider modulation area can be achieved to improve ion flux and sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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:

[0036] Figure 1 is a schematic structural diagram of an element detection device based on mass spectrometry technology according to an embodiment of the present invention;

[0037] Figure 2 is a schematic structural diagram of a mass analysis unit according to an embodiment of the present invention;

[0038] Figure 3 is based on Figure 2 The second-order time focusing effect diagram of the mass analysis unit;

[0039] Figure 4 is a schematic structural diagram of a mass analysis unit according to an embodiment of the present invention;

[0040] Figure 5 is based on Figure 4 A diagram of the second-order time focusing effect of the mass analysis unit. DETAILED DESCRIPTION

[0041] Figure 1-5 The following description describes the optional embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to explain 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 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 embodiments, but is only limited by the claims and their equivalents.

[0042] Embodiment 1:

[0043] Figure 1 A schematic diagram of the structure of the element detection device based on mass spectrometry according to an embodiment of the present invention is given. Figure 1 As shown, the element detection device based on mass spectrometry technology includes:

[0044] The mass analysis unit 81 and the detector 91 are prior art in the art;

[0045] An ion source 61, wherein the ion source 61 adopts a magnetron electron cyclotron resonance ion source, and ions emitted from the ion source 61 sequentially enter a first ion lens group 71, a second ion lens group 72 and a mass analysis unit 81;

[0046] A first ion lens group 71, through which ions passing through the first ion lens group 71 are focused;

[0047] The second ion lens group 72 , the kinetic energy of ions passing through the second ion lens group 72 is matched with the mass analysis unit 81 .

[0048] In order to reduce the kinetic energy of the emitted ions so as to facilitate matching with the mass analysis unit 81, the second ion lens group 72 further includes a plurality of ion lenses, and the voltages applied to the plurality of ion lenses in sequence are alternatingly positive and negative, so that the kinetic energy of the ions passing through the second ion lens group 72 is reduced by two orders of magnitude.

[0049] In order to remove neutral particles in the ion flow, the element detection device further includes:

[0050] The third ion lens group, ions pass through the second ion lens group and the third ion lens group in sequence, and the ions passing through the third ion lens group are deflected.

[0051] In order to screen the ions, the mass analysis unit further comprises a first-stage multipole mass analyzer, a collision reaction cell and a second-stage multipole mass analyzer which are arranged in sequence.

[0052] like Figure 2 As shown, the quality analysis unit of the embodiment of the present invention includes:

[0053] A repeller 11, a field-free flight zone 30 and a detector 51, wherein the field-free flight zone 30 includes a first incident grid 31;

[0054] A traction electrode 12, wherein a first ion acceleration region is formed between the traction electrode 12 and the first incident grid 31;

[0055] a first grid 21 and a second grid 22, wherein the potential difference between the first grid 21 and the second grid 22 is zero; a second ion acceleration region is formed between the repeller 11 and the first grid 21, and between the second grid 22 and the pull electrode 12; ions sequentially pass through the first grid 21, the second grid 22, the first incident grid 31 and the field-free flight region 30, and are received by the detector 51;

[0056] There are multiple electrodes between the pulling electrode 12 and the first incident grid 31 for allowing ions to pass through, and the multiple electrodes are divided in voltage by using a voltage dividing resistor.

[0057] In order to reduce the requirement on power supply, further, the first grid 21 and the second grid 22 are grounded.

[0058] In order to reduce the requirement for high voltage of power supply, further, the element detection device based on mass spectrometry technology also includes:

[0059] A power supply, wherein the power supply applies a positive pulse voltage to the repeller 11 and a negative pulse voltage to the pull electrode 12; or, the power supply applies a negative pulse voltage to the repeller 11 and a positive pulse voltage to the pull electrode 12.

[0060] The element detection method based on mass spectrometry technology of the embodiment of the present invention comprises the following steps:

[0061] (A1) The analyte is ionized in a magnetron electron cyclotron resonance ion source, and the kinetic energy of the ions is in the kiloelectron volt range, which is not compatible with existing mass analysis units;

[0062] (A2) The ions are focused and their kinetic energy is reduced in sequence, and the kinetic energy of the ions matches that of the mass analysis unit (the kinetic energy of the ions must be on the order of ten electron volts);

[0063] (A3) The detector receives the ions emitted from the mass analysis unit, thereby obtaining the content of the elements in the object to be analyzed.

[0064] Embodiment 2:

[0065] An application example of the element detection device based on mass spectrometry technology according to Example 1 of the present invention.

[0066] In this application example, the first ion lens group includes three single lenses, which apply high voltage-negative low voltage-positive voltage respectively, so as to focus the ionized single-charged ions and efficiently transmit them into the subsequent system; the second ion lens group is composed of multiple ion lenses, and the voltages applied to the multiple ion lenses in sequence are alternatingly positive and negative, and the kinetic energy of ions passing through the second ion lens group is reduced by two orders of magnitude to tens of electron volts; the third ion lens group adopts a right-angle deflection lens to effectively remove neutral particles.

[0067] like Figure 2 As shown, in the mass analysis unit, the first grid 21 and the second grid 22 are grounded to ensure that the first grid 21 and the second grid 22 have the same electric potential; there are multiple electrodes between the traction electrode 12 and the first incident grid 31 to allow ions to pass through, and the multiple electrodes are divided by a voltage divider resistor to make the electric field strength in the first ion acceleration zone uniform; the power supply applies a positive pulse voltage to the repeller 11 and a negative pulse voltage to the traction electrode 12.

[0068] In order to achieve second-order focusing, the second ion acceleration region and the field-free reflection region satisfy:

[0069]

[0070]

[0071] E1 and E3 are the electric field strengths of the second ion acceleration region and the first ion acceleration region, respectively. G d1, d2, and d3 are respectively the distance between the incident ion and the first grid 21, the distance between the first grid 21 and the second grid 22, the distance between the second grid 22 and the traction electrode 12, and the distance between the traction electrode 12 and the first incident grid 31; L is the length of the ion flying in the field-free region between the first incident grid 31 and the detector 51.

[0072] Taking the ion with mass-to-charge ratio of 100amu as an example, the second-order time focusing effect is shown in the attached figure. Figure 3 , the specific parameters and resolution are shown in the following table:

[0073]

[0074]

[0075] The element detection method based on mass spectrometry technology of the embodiment of the present invention, that is, the working method of the element detection device using the present embodiment, comprises the following steps:

[0076] (A1) The analyte is ionized in a magnetron electron cyclotron resonance ion source, and the kinetic energy of the ions is in the kiloelectron volt range, which is not compatible with existing mass analysis units;

[0077] (A2) The ions are focused and their kinetic energy is reduced in sequence, and the kinetic energy of the ions matches that of the mass analysis unit (the kinetic energy of the ions must be on the order of ten electron volts);

[0078] (A3) The detector receives the ions emitted from the mass analysis unit, thereby obtaining the content of the elements in the object to be analyzed.

[0079] Embodiment 3:

[0080] The application example of the element detection device based on mass spectrometry technology according to Example 1 of the present invention is different from Example 2 in that:

[0081] like Figure 4 As shown, in the mass analysis unit, the first grid 21 and the second grid 22 are grounded to ensure that the first grid 21 and the second grid 22 have the same electric potential; there are multiple electrodes between the pull electrode 12 and the first incident grid 31 that allow ions to pass through, and the multiple electrodes are divided by a voltage divider resistor to make the electric field strength of the first ion acceleration zone uniform; the power supply applies a positive pulse voltage to the repeller 11 and a negative pulse voltage to the pull electrode 12;

[0082] The reflection area includes a first reflection field and a second reflection field, the first reflection field includes a second incident grid 32 and a reflection electrode 41, and the second reflection field includes the reflection electrode 41 and a reflection plate 42; ions emitted from the field-free flight area 30 are reflected by the reflection area and then received by the detector 51;

[0083] In the first ion acceleration region and the first reflection field and the second reflection field, multiple electrodes that allow ions to pass through are arranged, and the multiple electrodes are divided by voltage-dividing resistors to make the electric field strength in the first ion acceleration region, the first reflection field and the second reflection field uniform;

[0084] In order to achieve second-order focusing, the second ion acceleration region and the first reflection field and the second reflection field satisfy:

[0085]

[0086]

[0087] E1, E3, E4, and E5 are the electric field intensities of the second ion acceleration region, the first ion acceleration region, the first reflection field, and the second reflection field, respectively. G , d2, d3, d4, d5 are respectively the distance between the incident ion and the first grid 21, the distance between the first grid 21 and the second grid 22, the distance between the second grid 22 and the traction electrode 12, the distance between the traction electrode 12 and the first incident grid 31, the distance between the second incident grid 32 and the reflection electrode 41, and the distance between the reflection electrode 41 and the reflection plate 42; L It is the length that the ions fly in the field-free region between the first incident grid 31 and the detector 51.

[0088] Taking the ion with mass-to-charge ratio of 100amu as an example, the second-order time focusing effect is shown in the attached figure. Figure 5 , the specific parameters and resolution are shown in the following table:

[0089] parameter Existing Design This patented design d1(mm) 50 50 z0(mm) 25 25 dG(mm) 0 5 d2(mm) 10 10 d3(mm) 102 102 L=l1+l2(mm) 1680 1680 d4(mm) 58 58 E1(V / mm) 20 20 E3(V / mm) 30 30 E4(V / mm) -46.6212 -53.0416 E5(V / mm) -19.9160 -21.7276 Δz(mm) 4 4 m / z 100 100 Tof(μs) 29.779 28.8359 Resolution 95986 1271962

[0090] Embodiment 4:

[0091] The application example of the element detection device based on mass spectrometry technology according to Example 1 of the present invention is different from Example 2 in that:

[0092] The mass analysis unit comprises a first-stage multipole mass analyzer, a collision reaction cell and a second-stage multipole mass analyzer which are arranged in sequence.

Claims

1. An element detection device based on mass spectrometry technology, comprising a mass analysis unit and a detector; characterized in that: The element detection device based on mass spectrometry technology also includes: An ion source, wherein the ion source adopts a magnetron electron cyclotron resonance ion source, and ions emitted from the ion source sequentially enter a first ion lens group, a second ion lens group and a mass analysis unit; a first ion lens group, through which ions passing through the first ion lens group are focused; a second ion lens group, wherein the kinetic energy of ions passing through the second ion lens group is matched with the mass analysis unit; The mass analysis unit comprises a repeller, a field-free flight zone and a detector, wherein the field-free flight zone comprises a first incident grid; the mass analysis unit further comprises: A pull electrode, wherein a first ion acceleration region is formed between the pull electrode and the first incident grid; a first grid and a second grid, wherein the potential difference between the first grid and the second grid is zero; a second ion acceleration region is formed between the repeller and the first grid, and between the second grid and the pull electrode; ions sequentially pass through the first grid, the second grid, the first incident grid and the field-free flight region, and are received by the detector; The second ion acceleration region and the field-free reflection region satisfy: ； ； E1 and E3 are the electric field strengths of the second ion acceleration region and the first ion acceleration region, respectively. G d1, d2, and d3 are respectively the distance between the incident ion and the first grid, the distance between the first grid and the second grid, the distance between the second grid and the traction electrode, and the distance between the traction electrode and the first incident grid; L is the length of the ion flying between the first incident grid and the detector.

2. The element detection device based on mass spectrometry technology according to claim 1, characterized in that: The second ion lens group includes a plurality of ion lenses, and the voltages applied to the plurality of ion lenses in sequence are alternatingly positive and negative, so that the kinetic energy of ions passing through the second ion lens group decreases by two orders of magnitude.

3. The element detection device based on mass spectrometry technology according to claim 1, characterized in that: The element detection device also includes: The third ion lens group, ions pass through the second ion lens group and the third ion lens group in sequence, and the ions passing through the third ion lens group are deflected.

4. The element detection device based on mass spectrometry technology according to claim 1, characterized in that: The mass analysis unit comprises a first-stage multipole mass analyzer, a collision reaction cell and a second-stage multipole mass analyzer which are arranged in sequence.

5. The element detection device based on mass spectrometry technology according to claim 1, characterized in that: The quality analysis unit also includes: The reflection zone includes a first reflection field and a second reflection field, the first reflection field includes a second incident grid and a reflection electrode, and the second reflection field includes the reflection electrode and a reflection plate; ions emitted from the field-free flight zone are reflected by the reflection zone and then received by the detector.

6. The element detection device based on mass spectrometry technology according to claim 5, characterized in that: The second ion acceleration region and the first reflection field and the second reflection field satisfy: ； ； E1, E3, E4, and E5 are the electric field intensities of the second ion acceleration region, the first ion acceleration region, the first reflection field, and the second reflection field, respectively. G d2, d3, d4, and d5 are respectively the distance between the incident ion and the first grid, the distance between the first grid and the second grid, the distance between the second grid and the traction electrode, the distance between the traction electrode and the first incident grid, the distance between the second incident grid and the reflection electrode, and the distance between the reflection electrode and the reflection plate; L is the length of the ion flying between the first incident grid and the detector.

7. The element detection method based on mass spectrometry technology of the element detection device according to claim 1, wherein the element detection method based on mass spectrometry technology comprises the following steps: (A1) The analyte is ionized in a magnetron electron cyclotron resonance ion source; (A2) The ions are focused and their kinetic energy is reduced in sequence, and the kinetic energy of the ions matches that of the mass analysis unit; (A3) The detector receives the ions emitted from the mass analysis unit to obtain the content of the elements in the analyte.

8. The element detection method based on mass spectrometry according to claim 7, characterized in that: In step (A2), the kinetic energy of the ions is reduced by two orders of magnitude.

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