Thermal desorption ionization reaction device and application

Abstract

The present application relates to atmospheric pressure ion manipulation technology, specifically, the present application discloses a thermal desorption ionization reaction device, specifically, a thermal desorption ionization reaction device, comprising a stainless steel metal desorption ionization cavity, the metal desorption ionization cavity is a hollow circular cylinder with an open upper end and a closed lower end, an insulating cover for sealing the open upper end is arranged on the open upper end, and a gas and ion outlet is arranged in the middle of the insulating cover; the counter electrode and the electrode with holes are connected to the high-voltage output end of the high-voltage power supply and the ground electrode (or negative electrode) respectively. The voltage applied to the counter electrode and the electrode with holes is alternating current or direct current, and the voltage amplitude is 2000V. The present application improves the consistency and stability of batch production of thermal desorption ionization modules based on integrated design, reduces power consumption and processing cost, and is beneficial to the industrialization of mass spectrometry or ion mobility spectrometry.

Description

Technical Field

[0001] This invention belongs to the field of analytical chemistry instruments, and specifically relates to a thermal desorption ionization reaction device. Background Technology

[0002] An ion trap mass spectrometer is an analytical instrument that uses an electromagnetic field to confine ions within a limited space. Ions are then allowed to escape individually or in batches from the ion trap by changing the electric field parameters, allowing for mass analysis. Working principle: An ion trap uses a radio frequency voltage applied to a ring electrode to cause ions to oscillate in three-dimensional space. By gradually increasing the radio frequency voltage, ions are forced into an unstable region and expelled through a small aperture, thus obtaining a mass spectrum. Structural composition: A typical ion trap consists of a ring electrode and two end cap electrodes, which can form a three-dimensional ion trap. A linear ion trap (LIT) is a type of ion trap where ions are focused along a line, increasing ion storage capacity and improving sensitivity. Advantages and features: High sensitivity: Ion traps can detect ions at very low abundance. Multistage mass spectrometry: It can perform MSn (multistage mass spectrometry) analysis, aiding in the structural identification of complex samples. Ease of operation: Compared to other types of mass spectrometers, ion trap mass spectrometers are simple to operate and maintain. Cost-effectiveness: Compared to other types of mass spectrometers, ion trap mass spectrometers offer a better cost-effectiveness ratio. Ion trap mass spectrometers are powerful and easy-to-operate analytical tools with significant applications in multiple fields.

[0003] Thermal desorption sampler is an essential component in multifunctional ion mobility spectrometry (IMS) rapid detection instruments. Its performance directly determines the injection efficiency and the overall performance of the IMS spectrometry. Existing IMS thermal desorption samplers use heating rods for temperature control, operating in a constant-temperature mode. Heating time varies depending on the heating rod power, currently ranging from 10-30 minutes. This method is relatively slow and consumes a significant amount of energy. Traditional heating rod temperature control offers the advantage of good temperature stability (CN201220715903), but its disadvantages include the inability to simultaneously achieve thermal desorption of low-boiling-point compounds at low temperatures and high-boiling-point compounds at high temperatures; it cannot simultaneously achieve thermal desorption of both low- and high-boiling-point targets. Infrared lamp heating offers the advantage of rapid heating (CN201210563261), but its disadvantage is that it is limited by lamp life and cannot operate for extended periods.

[0004] Current thermal desorption / ionization methods often employ a two-body structure of thermal desorption + ionization separation, and typically place the heating rod and temperature sensing element inside the heating block, resulting in large size and high power consumption (the heating block diameter is often 3-5 cm); moreover, a stepper motor and sampling plate are often required to achieve sample desorption and ionization. In contrast, ion trap mass spectrometry typically introduces samples in the microliter range, eliminating the need for bulky heating components. Summary of the Invention

[0005] The purpose of this invention is to provide a thermal desorption ionization reaction device. Utilizing an integrated design, the size and power consumption of the desorption ionization device will be significantly reduced, laying the foundation for the field application of miniature mass spectrometry.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A thermal desorption ionization reaction device includes a metal desorption ionization chamber, which is a hollow circular cylinder with an open upper end and a closed lower end. An insulating cover for sealing the upper opening end is provided at the upper opening end, and a gas and ion outlet is provided in the middle of the insulating cover.

[0008] An annular insulating sheet is provided on the inner bottom surface of the cylinder;

[0009] A groove is provided in the middle of the inner bottom surface of the cylinder, in the area surrounded by the annular insulating sheet, to serve as a thermal desorption zone;

[0010] A circular perforated metal cylinder with openings at both ends is provided on the upper part of the annular insulating sheet, serving as a perforated electrode. A gap or void is left between the perforated electrode and the inner wall of the metal desorption ionization chamber, forming a discharge electrode pair with the perforated electrode and the metal desorption ionization chamber wall. The metal desorption ionization chamber wall corresponding to the perforated electrode serves as the counter electrode. The area between the perforated electrode and the counter electrode is the reaction ion generation region, and the area in the middle of the perforated electrode is the ionization reaction region.

[0011] A liquid sample inlet and a liquid sample outlet are provided on the side wall of the metal desorption ionization chamber where the thermal desorption zone is located; an electric heating device and a temperature sensor are embedded in the side wall and / or bottom surface of the metal desorption ionization chamber where the thermal desorption zone is located.

[0012] A discharge gas inlet is provided on the side wall of the metal desorption ionization chamber, which serves as the counter electrode.

[0013] The thermal desorption zone is cylindrical or square in shape, with a volume of 5-100 μL.

[0014] Valves are installed at the liquid sample inlet and liquid sample outlet respectively;

[0015] The metal material of the metal desorption ionization chamber is one or more of stainless steel, aluminum, or copper.

[0016] The perforated electrode is a cylinder formed by a metal mesh or a metal cylinder with multiple through holes; the metal material is one or more of stainless steel, aluminum or copper.

[0017] The electric heating device is one or more of the following: electric heating wire, electric heating rod, electric heating strip, or electric heating block; the electric heating device is connected to an external power source via a wire and a temperature controller.

[0018] The temperature sensor is connected to the temperature controller via wires.

[0019] The counter electrode and the perforated electrode are connected to the high-voltage output terminal of the high-voltage power supply and the ground electrode (or negative electrode), respectively.

[0020] The voltage applied to the electrodes and the perforated electrodes is alternating current or direct current, with a voltage amplitude ranging from 50V to 5000V.

[0021] The analysis process is as follows:

[0022] Liquid sample is added to the thermal desorption zone through the liquid sample inlet. The thermal desorption zone is heated by an electric heating device to cause the solvent and low-boiling-point sample to evaporate. At this time, no voltage is applied to the counter electrode and the perforated electrode. If voltage is applied, discharge between them and ionization of the sample can be achieved. The ionized sample is led out from the gas and ion outlets to the detector for detection.

[0023] After the solvent and low-boiling-point sample have evaporated, the power applied to the electric heating device is increased to raise the temperature to a higher level, allowing the remaining sample to continue evaporating. At the same time, voltage is applied to the counter electrode and the perforated electrode to achieve discharge between them and ionization of the sample. The ionized sample is then led out through the gas and ion outlets to the detector for detection.

[0024] The detector is one or both of mass spectrometry and ion mobility spectrometry.

[0025] The advantages of this invention are:

[0026] 1. Based on integrated design, the consistency and stability of mass production of thermal desorption ionization modules are improved, while power consumption and processing costs are reduced, which is conducive to the industrialization of mass spectrometry or ion mobility spectrometry.

[0027] 2. The design of this invention is simple, easy to process, and easy to mass-produce. Attached Figure Description

[0028] Figure 1A thermal desorption ionization reaction apparatus, wherein in the figure: 1. metal desorption ionization chamber, 2. thermal desorption zone, 3. ionization reaction zone, 4. annular insulating sheet, 5. insulating cover, 6. gas and ion outlet, 7. counter electrode, 8. perforated electrode, 9. discharge gas inlet, 10. liquid sample inlet, 11. liquid sample outlet, 12. electric heating device, 13. temperature sensor, 14. reaction ion generation zone;

[0029] Figure 2 Typical spectrum of a regular e-liquid. Detailed Implementation

[0030] like Figure 1 As shown, a thermal desorption ionization reaction device includes a metal desorption ionization chamber made of stainless steel. The metal desorption ionization chamber is a hollow circular cylinder with an open upper end and a closed lower end. An insulating cover for sealing the upper opening end is provided at the upper opening end, and a gas and ion outlet is provided in the middle of the insulating cover.

[0031] An annular insulating sheet is provided on the inner bottom surface of the cylinder;

[0032] A groove is provided in the middle of the inner bottom surface of the cylinder, in the area surrounded by the annular insulating sheet, to serve as a thermal desorption zone;

[0033] A circular perforated metal cylinder with openings at both ends is provided on the upper part of the annular insulating sheet as a perforated electrode. A gap or void is left between the perforated electrode and the inner wall of the metal desorption ionization chamber. The perforated electrode and the wall of the metal desorption ionization chamber form a discharge electrode pair. The wall of the metal desorption ionization chamber corresponding to the perforated electrode serves as the counter electrode. The area between the perforated electrode and the counter electrode (7) is the reaction ion generation area, and the area in the middle of the perforated electrode is the ionization reaction area.

[0034] A liquid sample inlet and a liquid sample outlet are provided on the side wall of the metal desorption ionization chamber where the thermal desorption zone is located; an electric heating device and a temperature sensor are embedded in the side wall and / or bottom surface of the metal desorption ionization chamber where the thermal desorption zone is located.

[0035] A discharge gas inlet is provided on the side wall of the metal desorption ionization chamber, which serves as the counter electrode.

[0036] The thermal desorption zone is cylindrical or square in shape, with a volume of 50 μL.

[0037] Valves are installed at the liquid sample inlet and liquid sample outlet respectively;

[0038] The metal material of the metal desorption ionization chamber is stainless steel;

[0039] The perforated electrode is a cylinder formed by a metal mesh (or a metal cylinder with multiple through holes); the metal material is stainless steel.

[0040] The electric heating element is an electric heating rod; the electric heating element is connected to an external power source via a wire and a temperature controller.

[0041] The temperature sensor is connected to the temperature controller via wires.

[0042] The counter electrode and the perforated electrode are connected to the high-voltage output terminal of the high-voltage power supply and the ground electrode (or negative electrode), respectively.

[0043] The voltage applied to the electrode and the hole electrode is (alternating current or) direct current, with a voltage amplitude of 2000V.

[0044] The analysis process is as follows:

[0045] 1) Add a liquid sample to the thermal desorption zone 2 through the ordinary e-cigarette liquid sample inlet 10. The temperature of the thermal desorption zone 2 is controlled at 80°C by the electric heating rod 12 to make the solvent and low boiling point sample evaporate. If the low boiling point components are not to be analyzed, no voltage is applied to the counter electrode 7 and the perforated electrode 8. If the low boiling point components are to be analyzed, voltage is applied to achieve discharge between them and ionization of the sample (at this time, nitrogen gas needs to be introduced through the discharge gas inlet 9). The ionized sample is taken out through the gas and ion outlet 6 to the detector for detection.

[0046] 2) After the solvent and low-boiling-point sample have evaporated, increase the power applied to the electric heating rod 12 to raise the temperature to a higher 180°C, so that the remaining high-boiling-point sample can continue to evaporate and achieve desorption. At the same time, apply voltage to the counter electrode 7 and the perforated electrode 8 to achieve discharge between them and ionization of the sample (at this time, nitrogen gas needs to be introduced through the discharge gas inlet 9). The ionized sample is led out through the gas and ion outlet 6 to the detector for detection.

[0047] The detector is a mass spectrometer. For example... Figure 2 As shown, Figure 2 Typical spectrum of e-liquid containing common e-cigarette liquid.

Claims

1. A thermal desorption ionization reaction device, comprising a metal desorption ionization chamber (1), wherein the metal desorption ionization chamber (1) is a hollow circular cylinder with an open upper end and a closed lower end, and an insulating cover (5) for sealing the upper opening end is provided at the upper opening end, and a gas and ion outlet (6) is provided in the middle of the insulating cover (5). An annular insulating sheet (4) is provided on the inner bottom surface of the cylinder; A groove is provided in the middle of the inner bottom surface of the cylinder, in the area surrounded by the annular insulating sheet (4), as a thermal desorption zone (2); A circular perforated metal cylinder with openings at both ends is provided on the upper part of the annular insulating sheet (4) as a perforated electrode (8). A gap or void is left between the perforated electrode (8) and the inner wall of the metal desorption ionization chamber (1). The perforated electrode (8) and the wall of the metal desorption ionization chamber (1) form a discharge electrode pair. The wall of the metal desorption ionization chamber (1) corresponding to the perforated electrode (8) serves as the counter electrode (7). The area between the perforated electrode (8) and the counter electrode (7) is the reaction ion generation area (14), and the area in the middle of the perforated electrode (8) is the ionization reaction area (3). A liquid sample inlet (10) and a liquid sample outlet (11) are provided on the side wall of the metal desorption ionization chamber (1) where the thermal desorption zone (2) is located; an electric heating device (12) and a temperature sensor (13) are embedded in the side wall and / or bottom surface of the metal desorption ionization chamber (1) where the thermal desorption zone (2) is located; A discharge gas inlet (9) is provided on the side wall of the metal desorption ionization chamber (1) that serves as the counter electrode (7).

2. The apparatus according to claim 1, characterized in that: The thermal desorption zone (2) is cylindrical or square in shape, with a volume of 5-100 μL.

3. The apparatus according to claim 1, characterized in that: Valves are provided at the liquid sample inlet (10) and the liquid sample outlet (11); The metal material of the metal desorption ionization chamber (1) is one or more of stainless steel, aluminum or copper; The perforated electrode (8) is a cylinder surrounded by a metal mesh or a metal cylinder with multiple through holes; the metal material is one or more of stainless steel, aluminum or copper.

4. The apparatus according to claim 1, characterized in that: The electric heating device (12) is one or more of the following: electric heating wire, electric heating rod, electric heating strip, or electric heating block; the electric heating device (12) is connected to an external power source via a wire and a temperature controller. The temperature sensor (13) is connected to the temperature controller via a wire.

5. The apparatus according to claim 1, characterized in that: The counter electrode (7) and the perforated electrode (8) are connected to the high voltage output terminal of the high voltage power supply and the ground electrode (or negative electrode), respectively.

6. The apparatus according to claim 1, characterized in that: The voltage applied to the electrode (7) and the hole electrode (8) is alternating current or direct current, with a voltage amplitude of 50V to 5000V.

7. The application of the thermal desorption ionization reaction apparatus according to any one of claims 1-6, characterized in that: The analysis process is as follows: 1) A liquid sample is added to the thermal desorption zone (2) through the liquid sample inlet (10). The thermal desorption zone (2) is heated by the electric heating device (12) to make the solvent and low boiling point sample evaporate. At this time, no voltage is applied to the counter electrode (7) and the perforated electrode (8). If a voltage is applied, discharge between them and ionization of the sample can be achieved. The ionized sample is taken out by the gas and ion outlet (6) to the detector for detection. 2) After the solvent and low-boiling-point sample have evaporated, increase the power applied to the electric heating device (12) to raise the temperature to a higher level so that the remaining sample continues to evaporate. At the same time, apply voltage to the counter electrode (7) and the perforated electrode (8) to achieve discharge between them and ionization of the sample. The ionized sample is then taken out from the gas and ion outlet (6) to the detector for detection.

8. The application according to claim 7, characterized in that: The detector is one or both of mass spectrometry and ion mobility spectrometry.

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