Electrospray ion source and mass spectrometer

Abstract

An electrospray ion source and a mass spectrometer comprising: an electrode configured to apply a high voltage to induce a solution in a sample vial to be charged across the air; the sample bottle is used for bearing a sample solution to be detected, and the electrode is arranged on the outer side or at the bottom of the sample bottle, so that the electrode can induce the solution in the sample bottle to generate electrospray through high voltage; the capillary tube is inserted into the sample bottle and is used for sucking the solution in the sample bottle to a spray emission tip of the capillary tube, and electric spray is generated through the emission tip of the capillary tube. The electrode is used for mass spectrum detection, the electrode can be prevented from being in contact with a solution, interference caused in the analysis process is reduced, the sample analysis accuracy is improved, and the sample consumption is low. The electrospray ionization can be applied to laboratory mass spectrometry and portable on-site mass spectrometry, and convenient and rapid analysis of samples is realized.

Description

Technical Field

[0001] The invention relates to chemical analysis technology, in particular to an electrospray ion source and a mass spectrometer. Background Art

[0002] Mass spectrometry is a powerful analytical technique that is widely used in many fields such as chemistry, biology, medicine, and environmental science, and can achieve fast and accurate chemical analysis. The ion source is a crucial component of the mass spectrometry system. Its main function is to convert molecules in the sample into charged ions, which can then be manipulated and detected in the mass spectrometer. Among various ion sources, the electrospray ion source (ESI) has the widest application range due to its high stability and sensitivity, and the most mature technology. The electrospray ion source in the prior art generally has the problem of residual contamination caused by the contact between the high-voltage power supply and the sample solution, which affects the accuracy of sample analysis, as well as the disadvantages of large sample consumption, cumbersome injection operation and long analysis time, which also increases the restrictions on the analysis samples and limits the application scope of mass spectrometry. In addition, although non-contact electrodes can be used to avoid contact, there are multiple challenges such as uneven electric field distribution, insufficient intensity, poor space utilization and susceptibility to interference, which restrict the efficiency and sensitivity of electrospray.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] The main purpose of the present invention is to solve the problems existing in the above-mentioned background technology and to provide an electrospray ion source and a mass spectrometer.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An electrospray ion source, comprising:

[0007] An electrode configured to apply a high voltage to induce charging of a solution in the sample bottle through air;

[0008] A sample bottle, used for carrying a sample solution to be tested, wherein the electrode is arranged on the outside or bottom of the sample bottle so that the electrode can induce the solution in the sample bottle to generate electrospray through a high voltage;

[0009] A capillary is inserted into the sample vial and used to draw the solution in the sample vial to the spray emission tip of the capillary, and electrospray is generated through the emission tip of the capillary.

[0010] Further, the electrode is a ring-shaped electrode placed on the outside of the bottle wall of the sample bottle and / or a thin-sheet electrode placed on the bottom of the sample bottle.

[0011] Furthermore, it also includes a supporting shell, the sample bottle is placed in a groove of the supporting shell, and the electrode is placed in the supporting shell.

[0012] Furthermore, the annular structure electrode is placed in the supporting shell in an embedded or buried form.

[0013] Furthermore, a partition is provided in the side wall of the groove of the supporting shell, and the annular structure electrode is embedded in the partition, preferably in a spiral annular structure, and extends in the height direction of the sample bottle and surrounds the sample bottle.

[0014] Furthermore, a fixing structure is provided on the supporting shell for fixing on a moving platform or a fixing device so as to indirectly fix the position of the capillary.

[0015] Furthermore, the minimum distance between the annular structure electrode and the outer side of the bottle wall of the sample bottle is no more than 2 cm.

[0016] Furthermore, the area of ​​the thin-sheet electrode is not less than the bottom area of ​​the sample bottle and the minimum distance between the thin-sheet electrode and the bottom of the sample bottle is not greater than 2 cm.

[0017] Furthermore, the outer diameter of the capillary is not greater than 1.5 mm, the inner diameter is not greater than 800 μm, and the inner diameter of the spray emission tip of the capillary is not greater than 150 μm.

[0018] A mass spectrometer is provided with the electrospray ion source.

[0019] In some embodiments, a simple electrospray ion source includes an electrode, a sample bottle carrying a solution, a capillary, and a supporting shell. The capillary is inserted into a sample bottle containing a solution, and the bottom absorbs the solution to the emission tip or the tip absorbs a trace amount of solution and then inserts the sample bottle. The liquid column in the capillary is connected to the solution in the sample bottle. An electrode is arranged on the outside or bottom of the sample bottle. The height of the longitudinally encircled lower section of the electrode is not higher than the liquid level of the solution in the sample bottle. A high voltage is applied to the electrode. The electrode can be placed in the supporting shell. The electrode induces the solution in the sample bottle to be charged in the air, and the solution at the tip of the capillary connected to the solution begins to spray. The sample bottle can be embedded in the supporting shell to serve as its bracket to fix the position.

[0020] The capillary needs to be filled with a liquid column, which may be a continuous liquid column or a liquid column containing bubbles or an air column, and the tip may be filled with a solution.

[0021] The capillary can be made of different materials such as quartz, glass, etc. At the same time, the inner wall of the capillary can be modified or filled according to the test requirements of the sample to achieve online enrichment or impurity removal of the sample.

[0022] There is no limitation on the depth, angle and position of the capillary tube inserted into the sample bottle solution.

[0023] The sample bottle can be a columnar hollow liquid-carrying groove of various shapes, and the inner wall of the bottle can be modified or filled with fillers according to the test requirements of the sample to perform online enrichment or impurity removal of the sample.

[0024] The electrodes can be placed in various shapes of annular structures on the outside of the sample bottle wall; or placed in a sheet of any shape at the bottom; or both methods can be used.

[0025] The electrodes can be made of conductive materials such as metal, graphite, etc. Without considering the cost, materials with good conductivity are preferred, such as precious metals such as gold, platinum, silver, etc.

[0026] The longitudinally encircling lower end of the annular structure electrode is not lower than the liquid level of the solution in the sample bottle.

[0027] The inner wall of the capillary can be modified or filled according to the test requirements of the sample to achieve online enrichment or impurity removal of the sample.

[0028] The supporting shell can be made of various insulating materials, and the processing methods include but are not limited to 3D printing, mechanical cutting, etc.

[0029] Different usage methods can be selected according to different testing requirements of the sample to be tested. For samples that require continuous online analysis, the root of the capillary can be inserted into a sample bottle containing a sample solution, and the sample solution can be sucked until the emission tip; for samples that require a single test, the tip of the capillary can be inserted into the sample solution to take a sample, and then inserted into a sample bottle containing a conductive solution (the root of the capillary is below the liquid surface), and the conductive liquid enters part of the capillary to form a liquid column and does not contact the sample solution. The liquid column of the solution in the capillary is connected to the solution in the sample bottle, and the outer side (or bottom) of the sample bottle is covered with an electrode, and the lower cross-section of the electrode is placed below the liquid level of the solution in the bottle. A high voltage is applied to the electrode, and the electrode can be placed in a supporting shell. The electrode induces the liquid in the sample bottle to be charged through the air, and then the tip sample solution is charged and sprayed.

[0030] The conductive solution can be any conductive liquid such as common organic solvents and water.

[0031] The present invention has the following beneficial effects:

[0032] The present invention proposes an electrospray ion source, wherein an electrode is arranged on the outside or the bottom of a sample bottle, and the sample bottle is spaced apart to induce the solution to be charged, so that the solution at the tip of the capillary connected to the solution is sprayed. The present invention is used for mass spectrometry detection, which can prevent the electrode from contacting with the solution, reduce the interference caused during the analysis process, improve the accuracy of sample analysis, and reduce the sample consumption.

[0033] The design of the electrospray ion source provided by the present invention prevents the electrode from directly contacting the sample to be tested, thereby avoiding the residual influence caused by the sample switching process. It can be achieved by only cooperating with the capillary and the electrode. Compared with other electrospray ion sources, it can reduce the interference caused by the analysis process, and has a simple structure and low cost, and does not require a syringe pump and complex piping equipment.

[0034] During the working process, the capillary force of the capillary tube is used to automatically absorb the sample, and the sample consumption is small. The capillary tube can also filter large solid particles such as soil and tea leaves to achieve online pretreatment, thereby accurately identifying the analyte in the solution.

[0035] The electrospray ion source of the present invention makes up for the shortcomings of conventional electrospray, can be applied to laboratory mass spectrometry and portable on-site mass spectrometry, realizes convenient and rapid analysis of samples, and is not only suitable for traditional laboratory tests, but also can be used for on-site applications.

[0036] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the structure of a simple electrospray ion source in the first embodiment of the present invention

[0038] Figure 2 A schematic diagram of the structure of a simple electrospray ion source in the second embodiment of the present invention

[0039] Figure 3 A schematic diagram of the structure of a simple electrospray ion source in the third embodiment of the present invention

[0040] The numbers in the figure are:

[0041] 1. Sample solution, 2. Capillary, 3. Sample bottle, 4. Air column, 5. Conductive solution, 6. Electrode, 7. Support shell, 8. Sub-atmospheric pressure closed cavity, 9. Mass spectrometer inlet. DETAILED DESCRIPTION

[0042] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0043] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0044] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0046] See also Figures 1 to 3 The embodiment of the present invention provides an electrospray ion source, comprising: an electrode 6, which is configured to apply a high voltage to induce the solution in the sample bottle 3 to be charged in the air; a sample bottle 3, the sample bottle 3 is used to carry the sample solution 1 to be tested, and the electrode 6 is arranged on the outside or bottom of the sample bottle 3, so that the electrode 6 can induce the solution in the sample bottle 3 to generate electrospray through the high voltage; a capillary 2, the capillary 2 is inserted into the sample bottle 3 and used to draw the solution in the sample bottle 3 to the spray emission tip of the capillary 2, and generate electrospray through the emission tip of the capillary 2. The inner liquid column of the capillary 2 is connected to the solution in the sample bottle 3, and the electrode 6 on the outside or bottom of the sample bottle 3 can induce the solution at the tip of the capillary 2 to generate electrospray through the high voltage, so as to facilitate mass spectrometry analysis.

[0047] See also Figure 1 to Figure 2 In a preferred embodiment, the electrode 6 is a ring-shaped electrode placed outside the bottle wall of the sample bottle 3. In another embodiment, the electrode can also be a thin sheet electrode (not shown) placed at the bottom of the sample bottle 3. In addition, the above two electrodes can also be provided at the same time.

[0048] See also Figures 1 to 3 In a preferred embodiment, the electrospray ion source further comprises a supporting shell 7, the sample bottle 3 is placed in a groove of the supporting shell 7, and the annular electrode 6 is placed in the supporting shell 7. Preferably, the annular electrode 6 is placed in the supporting shell 7 in an embedded or buried form. Figure 1 to Figure 2As shown, preferably, a partition is provided in the side wall of the groove of the support shell 7, and the spiral annular structure electrode 6 is embedded in the partition, extending in the height direction of the sample bottle 3 and surrounding the sample bottle 3. By providing a support shell and cleverly placing the electrode in the support shell in the form of embedding or embedding, preferably providing a partition embedded electrode on the side wall of the groove, this special non-contact electrode design based on the integrated structure of the support shell optimizes space utilization and enhances the stability of the device. By more effectively utilizing the space, the layout of the electrode is made more compact, the volume of the overall device is reduced, and it is conducive to isolating external interference. At the same time, through the spiral annular structure electrode design in the support shell, the extension and surrounding in the height direction of the sample bottle effectively enhance the strength and consistency of the electric field applied to the solution in the sample bottle 3. This special configuration enhances the electric field strength and optimizes the electric field distribution, so that the efficiency of the solution to generate charged particles is improved and it is easier to form a stable charged spray, thereby helping to improve the efficiency and quality of electrospray, making the experimental results more consistent and reliable, and thus improving the sensitivity and accuracy of mass spectrometry. Therefore, the above preferred embodiments improve the accuracy of measurement, thereby enhancing the performance and reliability of the entire electrospray ion source.

[0049] In a preferred embodiment, a fixing structure (not shown) is provided on the support shell 7, which is used to be fixed on the mobile platform or the fixing device to indirectly fix the position of the capillary 2. Specifically, the support shell 7 can be provided with a fixing hole, and can be fixed on the three-dimensional mobile platform or other fixing device by clamping, magnetic attraction, threading, snap connection, etc., to adjust the positional relationship between the capillary 6 and the mass spectrometer injection port 9 of the mass spectrometer.

[0050] In a preferred embodiment, the minimum distance between the annular structure electrode and the outer side of the bottle wall of the sample bottle 3 is no more than 2 cm. The area of ​​the thin sheet electrode is no less than the bottom area of ​​the sample bottle 3 and the minimum distance between the thin sheet electrode and the bottom of the sample bottle 3 is no more than 2 cm. The outer diameter of the capillary 2 is no more than 1.5 mm, the inner diameter is no more than 800 μm, and the inner diameter of the spray emission tip of the capillary 2 is no more than 150 μm.

[0051] See also Figures 1 to 3 An embodiment of the present invention also provides a mass spectrometer having an electrospray ion source according to any of the aforementioned embodiments.

[0052] In some embodiments, the electrospray ion source proposed in the present invention includes an electrode, a sample bottle containing a sample solution, and a capillary. The capillary is inserted into the sample bottle containing the solution so that it absorbs the solution to the emission tip. The liquid column in the capillary is connected with the solution in the sample bottle. The outer side of the sample bottle is covered with a ring-shaped electrode. The inner diameter of the electrode is not less than the outer diameter of the sample bottle, and the lower cross-section of the electrode must be placed below the liquid level of the solution in the bottle. A high voltage is applied to the electrode, and the ring-shaped electrode separates the sample bottle to induce the solution to be charged, and the solution at the tip of the capillary connected to the solution begins to spray.

[0053] The present invention is used for mass spectrometry detection, which can prevent the electrode from contacting with the solution, reduce the interference caused in the analysis process, improve the accuracy of sample analysis, and reduce the sample consumption. At the same time, the capillary can filter large solid particles containing soil, tea leaves, etc., to achieve online pretreatment, thereby accurately identifying the analyte in the solution.

[0054] The following further describes application examples of the present invention.

[0055] like Figure 1 As shown, the first embodiment of the present invention provides a simple electrospray ion source for continuous online mass spectrometry detection, including a sample solution 1 to be tested, a capillary 2, a sample bottle 3, an annular metal spiral electrode (electrode 6) and a supporting shell 7, wherein the sample bottle carries the sample solution 1 to be tested and is placed in a groove of the supporting shell 7, the electrode 6 is placed in the supporting shell 7, and the root of the capillary 2 is inserted below the liquid surface of the solution to be tested to absorb the sample to the tip of the capillary.

[0056] The sample bottle 3 may be equipped with a rubber stopper or a perforated bottle cap to fix the position of the capillary tube 2 inserted therein.

[0057] When the sample volume is small, a liner tube can be placed in the sample bottle to raise the liquid level in the sample bottle.

[0058] The electrodes 6 can be placed in the supporting shell in an embedded or buried form, and then connected with wires for applying high voltage.

[0059] The support shell 7 has fixing holes on its outside, and can be fixed on a three-dimensional mobile platform or other fixing devices by clamping, magnetism, threading, snap-fitting, etc., to adjust the positional relationship between the capillary 6 and the inlet of the mass spectrometer.

[0060] The specific usage of this embodiment is as follows:

[0061] Insert the root of the capillary 2 into the sample bottle 3 containing the sample solution 1, and draw the sample solution to the tip;

[0062] The sample bottle after the above operation is placed in the groove of the supporting shell 7 where the annular spiral metal electrode 5 is placed;

[0063] The annular spiral metal electrode 6 is connected to a wire and a high voltage direct current is applied, which generates an electrospray at the tip of the capillary, completing the ionization process of the sample, and the subsequent mass spectrometry detection can be carried out.

[0064] like Figure 2 As shown, the second embodiment of the present invention provides a simple electrospray ion source for single trace mass spectrometry detection, including a sample solution 1 to be tested, a capillary 2, a sample bottle 3, an air column 4, a conductive solution 5, a ring-shaped metal spiral electrode (electrode 6) and a supporting shell 7, wherein the sample bottle 3 carries the conductive solution 5 and is placed in the supporting shell 7, and the electrode 6 is placed in the supporting shell 7. The tip of the capillary 2 absorbs the solution to be tested and then inserts it into the liquid surface of the conductive solution. At this time, the conductive solution automatically climbs along the inner wall of the capillary and forms a section of air column 4;

[0065] The sample bottle 3 may be equipped with a rubber stopper or a perforated bottle cap to fix the position of the capillary tube 2 inserted therein.

[0066] The electrodes 6 can be placed in the supporting shell in an embedded or buried form, and then connected with wires for applying high voltage.

[0067] The support shell 7 has fixing holes on its outside, and can be fixed on a three-dimensional mobile platform or other fixing devices by clamping, magnetism, threading, snap-fitting, etc., to adjust the positional relationship between the capillary 6 and the inlet of the mass spectrometer.

[0068] The specific usage of this embodiment is as follows:

[0069] The tip of the capillary 2 is used to absorb the solution to be tested, and then the root of the other end is inserted into the sample bottle 3 containing the conductive solution. At this time, the conductive solution automatically climbs up in the capillary 2 by capillary force and forms an air column 4;

[0070] The sample bottle 3 after the above operation is placed in the groove of the supporting shell 7 on which the annular spiral metal electrode 5 is placed;

[0071] The annular spiral metal electrode 6 is connected to a wire and a high voltage direct current is applied, which generates an electrospray at the tip of the capillary, completing the ionization process of the sample, and the subsequent mass spectrometry detection can be carried out.

[0072] like Figure 2 As shown, the third embodiment of the present invention provides a simple electrospray ion source for continuous online mass spectrometry detection, including a sample solution 1 to be tested, a capillary 2, a sample bottle 3, an annular metal spiral electrode (electrode 6), a support shell 7, a sub-atmospheric pressure closed cavity 8, and a mass spectrometer injection port 9. The sample bottle carrying the sample solution 1 to be tested is placed in the groove of the support shell 7, the electrode 6 is placed in the support shell 7, and the root of the capillary 2 is inserted below the liquid surface of the solution to be tested to absorb the sample to the tip of the capillary.

[0073] The sample bottle 3 may be equipped with a rubber stopper or a perforated bottle cap to fix the position of the capillary tube 2 inserted therein.

[0074] When the sample volume is small, a liner tube can be placed in the sample bottle to increase the liquid level in the sample bottle.

[0075] The electrodes 6 can be placed in the supporting shell in an embedded or buried form, and then connected with wires for applying high voltage.

[0076] The inner diameter of the capillary 2 is not less than 30 μm and not more than 200 μm.

[0077] The pressure in the sub-atmospheric closed cavity is no more than 90 kPa.

[0078] The support shell 7 has a fixing hole on its outer side, which can be fixed on the three-dimensional mobile platform or other fixing device by clamping, magnetism, threading, snap connection, etc. to fix the position of the capillary 2.

[0079] The specific usage of this embodiment is as follows:

[0080] Insert the root of the capillary 2 into the sample bottle 3 containing the sample solution 1, and use the pressure difference between the cavity and the atmospheric pressure to draw the sample solution to the tip;

[0081] The sample bottle after the above operation is placed in the groove of the supporting shell 7 where the annular spiral metal electrode 5 is placed;

[0082] The annular spiral metal electrode 6 is connected to a wire and a high voltage direct current is applied, which generates an electrospray at the tip of the capillary, completing the ionization process of the sample, and the subsequent mass spectrometry detection can be carried out.

[0083] Through the above different injection methods, continuous or single testing can be achieved to meet different application requirements. Using this ion source for mass spectrometry detection can not only eliminate the cross contamination caused by the contact between the electrode and the sample to be tested, thereby accurately identifying the chemical composition of the sample to be tested, but also significantly reduce the sample consumption and the dead volume in the detection process, thereby expanding the application scope of mass spectrometry analysis.

[0084] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. An electrospray ion source, characterized in that include: An electrode configured to apply a high voltage to induce charging of a solution in the sample bottle through air; A sample bottle, used for carrying a sample solution to be tested, wherein the electrode is arranged on the outside or bottom of the sample bottle so that the electrode can induce the solution in the sample bottle to generate electrospray through a high voltage; A capillary is inserted into the sample vial and used to draw the solution in the sample vial to the spray emission tip of the capillary, and electrospray is generated through the emission tip of the capillary.

2. The electrospray ion source according to claim 1, characterized in that The electrode is a ring-shaped electrode placed on the outside of the bottle wall of the sample bottle and / or a sheet electrode placed on the bottom of the sample bottle.

3. The electrospray ion source according to claim 1 or 2, characterized in that It also includes a supporting shell, the sample bottle is placed in a groove of the supporting shell, and the electrode is placed in the supporting shell.

4. The electrospray ion source according to claim 3, characterized in that The annular structure electrode is placed in the supporting shell in an embedded or buried form.

5. The electrospray ion source according to claim 4, characterized in that A partition is provided in the side wall of the groove of the supporting shell, and the annular structure electrode is embedded in the partition, preferably in a spiral annular structure, and extends in the height direction of the sample bottle and surrounds the sample bottle.

6. The electrospray ion source according to any one of claims 3 to 5, characterized in that The supporting shell is provided with a fixing structure for fixing on a moving platform or a fixing device so as to indirectly fix the position of the capillary.

7. The electrospray ion source according to claim 2, characterized in that The minimum distance between the annular structure electrode and the outer side of the bottle wall of the sample bottle is no more than 2 cm.

8. The electrospray ion source according to claim 2, characterized in that The area of ​​the thin-sheet electrode is not less than the bottom area of ​​the sample bottle and the minimum distance between the thin-sheet electrode and the bottom of the sample bottle is not greater than 2 cm.

9. The electrospray ion source according to any one of claims 1 to 8, characterized in that The outer diameter of the capillary is not greater than 1.5 mm, the inner diameter is not greater than 800 μm, and the inner diameter of the spray emission tip of the capillary is not greater than 150 μm.

10. A mass spectrometer, characterized in that: A method comprising: providing an electrospray ion source according to any one of claims 1 to 9.

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