Atmospheric pressure photoionization rapid desolventizing device and method

Abstract

The invention relates to an atmospheric pressure photo ionization rapid desolventizing device and method, and the device comprises a sampling valve which is installed on a sampling pipe of a high-pressure reactor and can be opened and closed according to a preset frequency; the atomizing unit is mounted on the sampling pipe at the downstream of the sampling valve and is used for atomizing a sample solvent; an inlet of the laval spray pipe is connected with an outlet of the sampling pipe, and an outlet of the laval spray pipe is led to a normal-pressure photo ionization area, so that a solvent is subjected to flash evaporation removal, and a product flows to the photo ionization area to realize ionization; wherein the Laval nozzle is provided with a temperature control system which is used for controlling the temperature of the Laval nozzle. According to the method, the solvent can be quickly removed, the integrity of thermal instability components is ensured, and the analysis accuracy is improved.

Description

Technical Field

[0001] The present invention belongs to the field of mass spectrometry instruments and analysis methods. Specifically, it relates to an atmospheric pressure photoionization rapid desolvation device and method, which is applicable to the real-time analysis of high-pressure reaction systems, especially for the efficient detection of thermally unstable components in dynamic complex reaction systems. Background Art

[0002] Atmospheric Pressure Photoionization (APPI), as a soft ionization technique, has important applications in the analysis of complex organic molecules. However, traditional sample introduction methods rely on liquid injection needles or nebulizers. When directly coupled to high-pressure reactors, the following problems exist: (1) The atomization efficiency is limited, and it is difficult for high-pressure liquids to evaporate uniformly, affecting the detection of target molecules; (2) The solvent removal is incomplete, resulting in an enhanced matrix effect and reduced quantitative accuracy; (3) Thermally unstable components are prone to decomposition during sampling and desolvation, affecting the analysis results. Therefore, developing an efficient desolvation device and method to improve the stability of target molecules and detection sensitivity is of great significance for the real-time analysis of high-pressure reaction systems. Summary of the Invention

[0003] The object of the present invention is to provide an atmospheric pressure photoionization rapid desolvation device and method to solve the above problems. For this purpose, the technical solution adopted by the present invention is as follows:

[0004] According to one aspect of the present invention, there is provided an atmospheric pressure photoionization rapid desolvation device, which may include:

[0005] A sampling valve, which is installed on the sampling pipe of the high-pressure reactor and can be switched on and off at a preset frequency;

[0006] An atomization unit, which is installed on the sampling pipe downstream of the sampling valve and is used for atomizing the sample solvent; and

[0007] A Laval nozzle, the inlet of which is connected to the outlet of the sampling pipe, and the outlet leads to the atmospheric pressure photoionization region, so that the solvent flashes off and the product flow flows to the photoionization region to achieve ionization; wherein, the Laval nozzle is provided with a temperature control system for controlling the temperature of the Laval nozzle.

[0008] In one embodiment, the preset frequency is 0.1 - 10 Hz.

[0009] In one embodiment, the atomization unit includes a high-pressure inert gas injection device and an ultrasonic nebulizer. The high-pressure inert gas injection device is disposed on the sampling pipe downstream of the sampling valve for preliminarily atomizing the sample solvent, and the ultrasonic nebulizer is disposed on the sampling pipe downstream of the high-pressure inert gas injection device for further atomizing the sample solvent.

[0010] In one embodiment, the high-pressure inert gas injection device uses Mpa nitrogen, and the ultrasonic nebulizer is an ultrasonic nebulizer at the MHz level.

[0011] In one embodiment, the temperature adjustment range of the temperature control system is 80 to 200 °C.

[0012] According to another aspect of the present invention, there is also provided an atmospheric pressure photoionization rapid desolvation method, which may include:

[0013] Providing the atmospheric pressure photoionization rapid desolvation device as described above;

[0014] Releasing the liquid phase sample in the high-pressure reactor through the sampling valve at a preset frequency;

[0015] Atomizing the sample solvent through the atomization unit;

[0016] The atomized sample solvent is accelerated and further vaporized in the Laval nozzle, and rapidly expands in the atmospheric pressure photoionization region after leaving the Laval nozzle, realizing solvent flash evaporation removal and the product flow direction to the photoionization region; wherein, the temperature of the Laval nozzle is adjusted by the temperature control system to ensure the stability of the target molecules.

[0017] In one embodiment, the preset frequency is 0.1 to 10 Hz.

[0018] In one embodiment, the atomization unit includes a high-pressure inert gas injection device and an ultrasonic nebulizer. The high-pressure inert gas injection device is disposed on the sampling pipe downstream of the sampling valve for preliminarily atomizing the sample solvent, and the ultrasonic nebulizer is disposed on the sampling pipe downstream of the high-pressure inert gas injection device for further atomizing the sample solvent.

[0019] In one embodiment, the high-pressure inert gas injection device uses Mpa nitrogen, and the ultrasonic nebulizer is an ultrasonic nebulizer at the MHz level.

[0020] In one embodiment, the temperature adjustment range of the temperature control system is 80 to 200 °C.

[0021] The present invention adopts the above technical solutions, and the beneficial effects are as follows:

[0022] (1) Based on pulse sampling + MHz ultrasonic atomization, the solvent removal efficiency is improved;

[0023] (2) A Laval nozzle is used to strengthen the solvent removal process and reduce matrix effects;

[0024] (3) The temperature control parameters are optimized to ensure the integrity of thermally unstable components, and it is applicable to real-time on-line analysis of reaction systems such as high-pressure catalysis, aromatic hydrocarbon conversion, and biomass pyrolysis. Description of the Drawings

[0025] Figure 1 It is a schematic structural diagram of an atmospheric pressure photoionization rapid desolvation device according to an embodiment of the present invention;

[0026] Figure 2 It is a flowchart of an atmospheric pressure photoionization rapid desolvation method according to an embodiment of the present invention. Detailed Embodiments

[0027] The following will describe the preferred embodiments of the present invention in detail with reference to the drawings to more clearly understand the purpose, features, and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not limitations on the scope of the present invention, but only illustrate the essential spirit of the technical solution of the present invention.

[0028] In the following description, certain specific details are set forth for purposes of explaining various disclosed embodiments to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other instances, well-known devices, structures, and techniques associated with the present application may not be shown or described in detail so as not to unnecessarily obscure the description of the embodiments.

[0029] Unless the context requires otherwise, throughout the specification and claims, the words "comprising" and its variations, such as "including" and "having", should be understood in an open, inclusive sense, i.e., construed to mean "including, but not limited to".

[0030] References to "one embodiment" or "an embodiment" throughout the specification mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of "in one embodiment" or "in an embodiment" throughout the specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.

[0031] As used in this specification and the appended claims, the singular forms "a" and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally used in its inclusive sense of "and / or" unless the context clearly dictates otherwise.

[0032] In the following description, in order to clearly show the structure and working mode of the present invention, many directional terms will be used for description. However, words such as "front", "rear", "left", "right", "outer", "inner", "outward", "inward", "up", and "down" should be understood as convenient terms and should not be understood as limiting terms.

[0033] In addition, terms such as "horizontal", "vertical", "hanging" do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0034] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0035] As Figure 1 shown, an atmospheric pressure photoionization rapid desolvation device of the present invention may include a sampling valve 1, an atomization unit 2, and a Laval nozzle 3. Among them, the sampling valve 1 is installed on the sampling pipe 101 of the high-pressure reactor 100 and can be switched on and off at a preset frequency (for example, 0.1 - 10 Hz) to achieve pulsed sampling. The sampling volume each time is 1 - 5 microliters. The pressure in the high-pressure reactor 100 is between 1 and 10 MPa. The sampling valve 1 can be a solenoid valve or a pneumatic valve that can be quickly switched. The atomization unit 2 is installed on the sampling pipe downstream of the sampling valve 1 and is used to atomize the sample solvent to reduce the droplet size of the solvent to the sub-micron level. The inlet of the Laval nozzle 3 is connected to the outlet of the sampling pipe 101, and the outlet leads to the atmospheric pressure photoionization region 200. When the solvent gas leaves the Laval nozzle 3, the pressure drops suddenly to atmospheric pressure, causing the solvent to expand and flash off. Finally, the product stream flows to the photoionization region 200 to achieve ionization, and then the target molecule can be detected and analyzed by a mass spectrometer (not shown); among them, the Laval nozzle 3 is provided with a temperature control system for controlling the temperature of the Laval nozzle 3 to ensure the stability of the target molecule and improve the analysis accuracy.

[0036] The present invention is based on pulsed sampling + MHz ultrasonic atomization, which greatly reduces the solvent droplet size, improves the solvent removal efficiency, and uses a Laval nozzle to strengthen the desolvation process and reduce the matrix effect, and is applicable to the real-time on-line analysis of reaction systems such as high-pressure catalysis, aromatic hydrocarbon conversion, and biomass pyrolysis.

[0037] In this embodiment, the atomization unit 2 includes a high-pressure inert gas injection device 21 and an ultrasonic nebulizer 22. Among them, the high-pressure inert gas injection device 21 is arranged on the sampling pipe 101 downstream of the sampling valve and is used to preliminarily atomize the sample solvent; the ultrasonic nebulizer 22 is arranged on the sampling pipe 101 downstream of the high-pressure inert gas injection device 21 and is used to further atomize the sample solvent. Specifically, the transducer of the ultrasonic nebulizer 22 acts on the sample solvent in the sampling pipe 101, and the sample solvent is atomized through high-frequency vibration. By combining the use of the high-pressure inert gas injection device 21 and the ultrasonic nebulizer 22, the present invention can greatly reduce the droplet size, for example, reduce it to the sub-micron level, and significantly improve the evaporation rate and removal efficiency of the solvent.

[0038] Preferably, the high-pressure inert gas injection device 21 uses Mpa nitrogen, which has low cost and high safety. Preferably, the ultrasonic nebulizer 22 is an ultrasonic nebulizer of MHz level, and the droplet size is reduced through high-frequency vibration. The ultrasonic nebulizer 22 is commercially available, and its structure is well-known and will not be elaborated here.

[0039] In a specific embodiment, the temperature adjustment range of the temperature control system of the Laval nozzle 3 is 80 - 200 °C. The temperature of the Laval nozzle 3 can be controlled at an appropriate temperature according to the characteristics of the target molecule to ensure the temperature property of the target molecule. Preferably, the heat transfer medium of the temperature control system is oil. The Laval nozzle 3 includes a converging section and a diverging section, which strengthens the gas-liquid mass transfer during the fluid acceleration process and promotes the vaporization of the solvent. The structure of the Laval nozzle 3 is well-known and will not be elaborated here.

[0040] As Figure 2 shown, the present invention provides an atmospheric pressure photoionization rapid desolvation method, which may include:

[0041] S1: Provide the atmospheric pressure photoionization rapid desolvation device as described above;

[0042] S2: Release the liquid-phase sample in the high-pressure reactor through the sampling valve at a preset frequency (for example, 0.1 Hz - 10 Hz), and the sampling volume each time is 1 - 5 microliters;

[0043] S3: Atomize the sample solvent through the atomization unit to reduce the droplet size to the sub-micron level to improve the evaporation rate and removal efficiency of the solvent;

[0044] S4: The atomized sample solvent is accelerated and further vaporized in the Laval nozzle, and rapidly expands in the atmospheric pressure photoionization region 200 after leaving the Laval nozzle to achieve solvent flash evaporation removal. Among them, the temperature of the Laval nozzle is adjusted by the temperature control system to ensure the stability of target molecules. The final product flows to the photoionization region to achieve ionization, and then the target molecules can be detected and analyzed by a mass spectrometer.

[0045] The present invention is based on pulsed sampling + MHz ultrasonic atomization, which greatly reduces the solvent droplet size, improves the solvent removal efficiency, and uses a Laval nozzle to strengthen the desolvation process and reduce the matrix effect, and is applicable to real-time online analysis of reaction systems such as high-pressure catalysis, aromatic hydrocarbon conversion, and biomass pyrolysis.

[0046] The preferred embodiments of the present invention have been described in detail above, but it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention. These equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. An atmospheric pressure photoionization rapid desolvation device, characterized in that, Comprising: A sampling valve, which is installed on the sampling pipe of the high-pressure reactor and can be switched on and off at a preset frequency; An atomization unit, which is installed on the sampling pipe downstream of the sampling valve and is used for atomizing the sample solvent; And A Laval nozzle, the inlet of the Laval nozzle is connected to the outlet of the sampling pipe, and the outlet leads to the atmospheric pressure photoionization region, so that the solvent is flash-evaporated and removed and the product stream flows to the photoionization region to achieve ionization; wherein, the Laval nozzle is provided with a temperature control system for controlling the temperature of the Laval nozzle.

2. The atmospheric pressure photoionization rapid desolvation device according to claim 1, wherein The preset frequency is 0.1 - 10 Hz.

3. The atmospheric pressure photoionization rapid desolvation device according to claim 1, wherein The atomization unit includes a high-pressure inert gas injection device and an ultrasonic atomizer. The high-pressure inert gas injection device is arranged on the sampling pipe downstream of the sampling valve and is used for preliminarily atomizing the sample solvent. The ultrasonic atomizer is arranged on the sampling pipe downstream of the high-pressure inert gas injection device and is used for further atomizing the sample solvent.

4. The atmospheric pressure photoionization rapid desolvation device according to claim 3, characterized in that, The high-pressure inert gas injection device uses Mpa nitrogen, and the ultrasonic atomizer is an ultrasonic atomizer of MHz level.

5. The atmospheric pressure photoionization rapid desolvation device according to claim 1, wherein The temperature adjustment range of the temperature control system is 80 - 200 °C.

6. An atmospheric pressure photoionization rapid desolvation method, characterized in that, Comprising: Providing the atmospheric pressure photoionization rapid desolvation device as described in claim 1; Releasing the liquid-phase sample in the high-pressure reactor through the sampling valve at a preset frequency; Atomizing the sample solvent through the atomization unit; The atomized sample solvent is accelerated and further vaporized in the Laval nozzle, and rapidly expands in the atmospheric pressure photoionization region after leaving the Laval nozzle, realizing solvent flash-evaporation and removal and the product stream flowing to the photoionization region; wherein, the temperature of the Laval nozzle is adjusted through the temperature control system to ensure the stability of the target molecules.

7. The atmospheric pressure photoionization rapid desolvation method according to claim 6, characterized in that, The preset frequency is 0.1 - 10 Hz.

8. The atmospheric pressure photoionization rapid desolvation method according to claim 6, wherein The atomization unit includes a high-pressure inert gas injection device and an ultrasonic atomizer. The high-pressure inert gas injection device is arranged on the sampling pipe downstream of the sampling valve and is used for preliminarily atomizing the sample solvent. The ultrasonic atomizer is arranged on the sampling pipe downstream of the high-pressure inert gas injection device and is used for further atomizing the sample solvent.

9. The atmospheric pressure photoionization rapid desolvation method according to claim 8, characterized in that, The high-pressure inert gas injection device uses Mpa nitrogen, and the ultrasonic atomizer is an ultrasonic atomizer of MHz level.

10. The atmospheric pressure photoionization rapid desolvation method according to claim 6, wherein The temperature adjustment range of the temperature control system is 80 - 200 °C.

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