Disposable electrospray ion source suitable for portable mass spectrometer

Abstract

The utility model discloses a direct insertion type disposable electrospray ion source, belongs to the technical field of electrospray ion sources, and particularly relates to a disposable electrospray ion source suitable for a portable mass spectrometer, which comprises a sample introduction glass capillary tube, a copper tube electrode, a liquid storage filter element, a spray capillary tube, an upper section outer tube and a lower section outer tube, the mass spectrometer is simple in structure and low in cost, can stably and reliably increase voltage for a solution, can realize rapid sample loading, can rapidly form an electrospray ion flow with enough duration and an enough stable mass spectrum signal, not only greatly reduces the working pressure of a rear-end mass analyzer vacuum system, but also improves the anti-pollution capability of equipment, and is suitable for large-scale popularization and application. And meanwhile, a sample introduction system with a complex structure and high price does not need to be configured, so that the risk of cross contamination of a positive sample to a negative sample is fundamentally avoided.

Description

Technical Field

[0001] The utility model discloses a disposable electrospray ion source suitable for a portable mass spectrometer, belongs to the technical field, and particularly relates to a disposable electrospray ion source suitable for a portable mass spectrometer. Background Art

[0002] The mass spectrometer is a common precision physical and chemical analysis instrument. Its overall working principle includes three parts: ionization, separation, and detection. The corresponding components are the "ion source," "mass analyzer," "detector," and control workstation. The so-called "ionization" refers to the ionization of organic molecules or inorganic atoms in a sample or its extract to form ions through an ion source based on various principles. At the same time, the formed ions are vaporized into gaseous ions so that they can be captured and analyzed by the "mass analyzer." The mass analyzer uses technical means such as electric or magnetic fields to separate and identify different target ions in time or space according to their "mass-to-nuclear ratio (m / z)." The detector is responsible for converting the ion signals generated by the mass analyzer into electronic signals that can be recognized by software. Finally, the control workstation uses software to record the above electronic signals, perform specific data processing, and output them as information that can be understood and used by humans, such as mass spectra.

[0003] The ion source is one of the most critical components of a mass spectrometer, providing a stable and sufficient supply of target ions for the mass analyzer. Because the ion source comes into direct contact with the sample or sample extract, its principle, structure, and cost directly impact the overall performance, application scenarios, ease of use, and detection cost of the mass spectrometer.

[0004] Most common electrospray ionization sources currently on the market use a continuous flow injection mode, where liquid samples are introduced into the ion source via a liquid chromatograph or an infusion pump, generating a stable and continuous ion signal. However, liquid chromatographs rely on complex, sophisticated, and expensive injection systems. Infusion pumps consume large amounts of sample or its extract, making sample replacement complex and prone to cross-contamination. The continuous use of large amounts of solvent to aid sample delivery also significantly impacts the ion source's resistance to contamination and maintenance. Utility Model Content

[0005] The purpose of the utility model is to provide a disposable electrospray ion source suitable for a portable mass spectrometer to solve the above-mentioned problems.

[0006] Technical solution: A disposable electrospray ion source suitable for a portable mass spectrometer, comprising: a sample injection glass capillary, a copper tube electrode, a liquid storage filter element, a spray capillary, an upper outer tube, and a lower outer tube;

[0007] In a further embodiment, the sample solution is absorbed by the glass capillary and then injected into the upper end of the disposable ion source, the other end of the upper outer tube is sleeved on one end of the copper tube electrode, the liquid storage filter is located in the copper tube electrode, the other end of the lower outer tube is sleeved on the other end of the copper tube electrode, and the spray capillary is fixedly sleeved on the other end of the lower outer tube.

[0008] In a further embodiment, a sealing rubber plug is provided in the copper tube electrode, and the sealing rubber plug is located at the lower side of the liquid storage filter element to prevent internal liquid leakage.

[0009] In a further embodiment, a positioning rubber plug is provided at the other end of the lower outer tube, and the positioning rubber plug is fixedly connected to the spray capillary to position the end of the spray capillary.

[0010] In a further embodiment, the end of the spray capillary is accurately aligned with the ion transmission aperture of a portable mass spectrometer.

[0011] In a further embodiment, the other end of the spray capillary contacts the solution adsorbed in the liquid storage filter element, and ionizes the compounds in the sample under the action of the spray voltage to form a capillary liquid flow.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] (1) Significantly reduce solvent usage

[0014] Compared with the mainstream electrospray ion source with continuous liquid flow injection on the market, the disposable electrospray ion source only performs spray ionization within a few seconds to tens of seconds of injection detection and data collection. Therefore, the amount of solvent and sample extract entering the ion source is greatly reduced, which not only greatly reduces the working pressure of the vacuum system of the back-end mass analyzer, but also improves the equipment's anti-pollution ability.

[0015] (2) Avoid cross contamination

[0016] The disposable electrospray ion source of this utility model is a disposable experimental consumable. The ion source itself is the sample injector, eliminating the need for a complex and expensive injection system. This fundamentally avoids the risk of cross-contamination of negative samples by positive samples.

[0017] The utility model is a plug-in disposable electrospray ion source with a simple structure and low cost. The ion source includes a sample glass capillary, a copper tube electrode, a liquid storage filter, a spray capillary, an outer tube and other structures. Through extensive selection and experimental testing, the best liquid storage filter material is found to achieve stable and reliable high voltage for the solution. It can achieve rapid sample loading, quickly form an electrospray ion flow of sufficient duration and a sufficiently stable mass spectrometry signal; the disposable electrospray ion source of the utility model is a disposable experimental consumable. The ion source itself is an injector, and there is no need to configure a complex and expensive injection system, which fundamentally avoids the risk of cross contamination of negative samples by positive samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the disposable ion source of the present utility model.

[0019] Figure 2 It is a schematic diagram of the docking of the spray capillary end of the disposable ion source of the utility model and the ion transmission hole of the portable mass spectrometer.

[0020] Figure 3 The utility model uses a disposable electrospray ion source to inject a sample diluent, injects the sample into a portable mass spectrometer, and then reads a primary mass spectrum and a secondary mass spectrum.

[0021] Reference numerals: sampling glass capillary 1, copper tube electrode 3, liquid storage filter element 4, spray capillary 6, upper outer tube 2, lower outer tube 7, sealing rubber plug 5, positioning rubber plug 8. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] A disposable electrospray ion source suitable for a portable mass spectrometer is a plug-in disposable electrospray ion source, comprising: an inlet glass capillary 1, a copper tube electrode 3, a liquid storage filter element 4, a spray capillary 6, an upper outer tube 2, and a lower outer tube 7.

[0026] Example 1:

[0027] like Figure 1 As shown, the sampling glass capillary 1 absorbs the sample solution and then injects it into the upper end of the disposable ion source. The other end of the upper outer tube 2 is sleeved on one end of the copper tube electrode 3. The liquid storage filter element 4 is located in the copper tube electrode 3. The other end of the lower outer tube 7 is sleeved on the other end of the copper tube electrode 3. The spray capillary 6 is fixedly sleeved on the other end of the lower outer tube 7.

[0028] In one embodiment, Figure 1 As shown, a sealing rubber plug 5 is provided inside the copper tube electrode 3 , and the sealing rubber plug 5 is located at the lower side of the liquid storage filter element 4 to prevent internal liquid leakage.

[0029] In one embodiment, Figure 1 As shown, the other end of the lower outer tube 7 is provided with a positioning plug 8

[0030] The positioning rubber plug 8 is fixedly connected to the spray capillary 6 to position the end of the spray capillary 6.

[0031] In one embodiment, Figure 2 As shown, the end of the spray capillary 6 is accurately aligned with the ion transmission hole of the portable mass spectrometer.

[0032] In one embodiment, Figure 1 As shown, a plurality of capillary liquid holes are provided in the other end of the spray capillary 6 so that the solution can ionize the compounds in the sample under the action of the spray voltage to form a capillary liquid flow.

[0033] Example 2:

[0034] like Figure 1 As shown, the sample injection glass capillary 1 is used to draw and inject the sample solution into the ion source. It has a length of 80 mm, an outer diameter of 1.3 mm, and an inner diameter of 0.9 mm. It is made of glass.

[0035] The upper outer tube 2 is used to accommodate the injection glass capillary 1. It has a length of 30 mm, an outer diameter of 3.0 mm, and an inner diameter of 1.5 mm. It is made of polypropylene plastic.

[0036] The copper tube electrode 3 is used to accommodate the liquid storage filter 4 and connect the solution to the spray voltage. It is 12mm long, 3.0mm inner diameter, and 3.5mm outer diameter. It is made of copper.

[0037] The liquid storage filter element 4 is used to absorb the accumulated solution and cooperate with the spray capillary 6 to form a capillary phenomenon. It is 3mm long and 3.0mm in diameter. It is made of porous polyethylene.

[0038] The sealing rubber plug 5 is used to seal the lower end of the copper tube electrode 3 to prevent leakage of the internal liquid. It is 2mm long, 3.0mm outer diameter, and 1.0mm inner diameter. It is made of transparent silicone.

[0039] The spray capillary 6 is used to form a capillary flow at its end, ionizing the compounds in the sample under the action of the spray voltage. It is 40 mm long, 1.0 mm outer diameter, and 0.1 mm inner diameter. It is made of quartz glass.

[0040] The lower outer tube 7 is used to accommodate and protect the spray capillary 6. It has a length of 30 mm, an outer diameter of 3.0 mm, and an inner diameter of 1.5 mm. It is made of polypropylene plastic.

[0041] Positioning plug 8

[0042] , used to position the end of the spray capillary 6 to prevent it from being eccentric. Length 2mm, inner diameter 1mm, outer diameter 1.5mm.

[0043] Example 3:

[0044] Working principle: Figure 1 As shown in the figure, use the injection glass capillary 1 to dip about 20 to 30 μL of sample solution to form a liquid column with a height of 20 to 50 mm, and insert it into the upper outer tube 2 to the bottom. Part of the sample solution infiltrates the liquid storage filter 4 downward and fully contacts the inner wall of the copper tube electrode 3. If necessary, gently shake the disposable electrospray ion source. Due to the presence of the sealing plug 5, the sample solution is forced to enter the upper section of the spray capillary 6 through the liquid storage filter 4, and will not leak into the lower outer tube 7. At the same time, obvious droplets are formed at the end of the spray capillary 6. At this time, the sample solution forms a continuous liquid column in the disposable electrospray ion source. Insert the spray capillary 6 downward into the ion source fixture of the portable mass spectrometer. Due to the positioning plug 8 of the spray capillary 6

[0045] The existence of the spray capillary 6 can actively and accurately align the end of the ion transmission hole of the portable mass spectrometer, and the spray flow generated by the former is perpendicular to the ion flow introduction direction of the latter (as shown in the attached Figure 2 ).

[0046] The ionization voltage acts on the sample liquid through the copper tube electrode 3, ionizing the target compound in the sample solution. The ionization product forms electrospray ions when it is sprayed out from the end of the spray capillary 6, and then enters the mass spectrometer for analysis and testing.

[0047] Example 4:

[0048] Application example: Take a health-care capsule that claims to have the effect of lowering blood pressure, and weigh 2g of the content. Add 2mL of 50% (volume ratio) methanol aqueous solution, cover and shake by hand or vortex to mix, let it stand for 1 minute or centrifuge at 2000 rpm, and after clarification, take the supernatant and dilute it 10 times with 50% (volume ratio) methanol aqueous solution for later use. According to the operation method described in "Example 3", take the sample dilution and inject it into the disposable electrospray ion source, inject it into the portable mass spectrometer, and read the primary mass spectrum and secondary mass spectrum (as shown in the attached figure). Figure 3 As can be seen, a clear parent ion of reserpine (609 m / z) and a series of characteristic daughter ions of reserpine (195 m / z, 397 m / z, and 448 m / z) were obtained. This proves that the health capsules claiming to have blood pressure-lowering effects actually contain the illegal chemical "reserpine."

[0049] Example 5:

[0050] Mass spectrometers can be classified in many ways. The utility model is applicable to a portable mass spectrometer adapted for an electrospray ion source.

[0051] The "disposable electrospray ion source" described in the present invention is generally suitable for small, portable mass spectrometers, but this does not mean that the present invention is not applicable to other medium and large mass spectrometers.

[0052] Furthermore, although existing portable mass spectrometers also use disposable electrospray ionization sources, most of them are paper-based. After the sample is dripped onto the filter paper, it needs to be blown dry and replaced with a common solvent, which is a complex operation and not conducive to quantitative analysis.

[0053] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A disposable electrospray ion source suitable for a portable mass spectrometer, characterized in that: It is a plug-in disposable electrospray ion source, which includes: a sample injection glass capillary, a copper tube electrode, a liquid storage filter element, a spray capillary, an upper outer tube, and a lower outer tube; The sample solution is absorbed by the injection glass capillary and then injected into the upper end of the disposable ion source. The other end of the upper outer tube is sleeved on one end of the copper tube electrode. The liquid storage filter is located in the copper tube electrode. The other end of the lower outer tube is sleeved on the other end of the copper tube electrode. The spray capillary is fixedly sleeved on the other end of the lower outer tube.

2. A disposable electrospray ion source suitable for a portable mass spectrometer according to claim 1, characterized in that: A sealing rubber plug is provided in the copper tube electrode, and the sealing rubber plug is located at the lower side of the liquid storage filter element to prevent internal liquid from leaking.

3. A disposable electrospray ion source suitable for a portable mass spectrometer according to claim 1, characterized in that: The other end port of the lower section outer tube is provided with a positioning rubber plug, and the positioning rubber plug is fixedly connected to the spray capillary to position the end of the spray capillary.

4. A disposable electrospray ion source suitable for a portable mass spectrometer according to claim 1, characterized in that: The end of the spray capillary is accurately aligned with the ion transmission hole of the portable mass spectrometer.

5. The disposable electrospray ion source suitable for a portable mass spectrometer according to claim 1, characterized in that: The other end of the spray capillary contacts the solution adsorbed in the liquid storage filter element, and ionizes the compounds in the sample under the action of the spray voltage to form a capillary liquid flow.

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