Electrospray needle, ionization device and analysis method

Abstract

The application provides an electrospray needle, an ionization device and an analysis method, the electrospray needle is made of an organic polymer material, and the polymer material contains at least one of a hydroxyl group, a carboxyl group, a sulfonic acid group, an amino group and a halogen polar functional group. The electrospray ionization device comprises the electrospray needle, a three-way connector, an electrode, a sample tube, a gas tube and a sleeve; the three-way connector comprises a first interface, a second interface and a third interface, the electrode is connected to the first interface, the sample tube is connected to the second interface, and the tail end of the electrospray needle is connected to the third interface; sample solution in the electrospray needle forms an electrospray under the action of the electrode, the electrospray can be ionized to enter the inlet of a mass spectrometer; one end of the sleeve is provided with an end cover, the end cover is provided with a mounting hole coaxial with the sleeve, the electrospray needle is arranged in the mounting hole and the sleeve, and the inner diameter of the sleeve is greater than the maximum diameter of the electrospray needle; the end cover is provided with an air inlet, and the air inlet is connected to the gas tube.

Description

Technical Field

[0001] This invention belongs to the field of analytical technology, and particularly relates to an electrospray nozzle, an ionization device, and an analytical method. Background Technology

[0002] Electrospray ionization mass spectrometry is one of the most widely used mass spectrometry techniques because it can analyze a variety of types of compounds, making it possible to analyze biomolecules that are unstable and non-volatile in the hot state.

[0003] The electrospray ionization method uses a capillary tube as the electrospray nozzle. The sample solution enters the electrospray nozzle through the tubing and is subjected to a high voltage inside the nozzle. Under the action of the electric field, the sample solution forms a spray at the tip of the electrospray nozzle.

[0004] The spray consists of multiple small droplets. As the solvent in these droplets moves toward the inlet of the mass spectrometer, it evaporates continuously, causing the droplets to burst and eventually form ions that enter the mass spectrometer for detection.

[0005] Because metals are ductile, hard, easy to process, and have good electrical conductivity, stainless steel capillary tubes are currently used as electrospray needles in most mass spectrometers on the market. However, using metal capillary tubes as electrospray needles (hereinafter referred to as metal capillary needles) has the following disadvantages: Because the tip of the metal capillary nozzle is prone to discharge under high voltage, this discharge suppresses the signal and reduces the detection sensitivity of the mass spectrometer. Especially in negative ion mode, the discharge voltage and spray voltage are very close, resulting in severe suppression of the mass spectrometry signal. Its signal intensity is usually 1-2 orders of magnitude lower than that in positive ion mode. This makes the application of negative ion mode electrospray mass spectrometry far less common than that in positive ion mode.

[0006] Furthermore, electrochemical reactions unrelated to the analysis may occur in the sample solution within the metal capillary nozzle. These reactions can lead to various processes such as hydrolysis and polymerization of compounds in the sample solution, thus the spectrum may not accurately reflect the true state of the sample solution. Additionally, a portion of the current generated by the applied voltage is used for these unrelated electrochemical reactions, reducing the spray current and resulting in incomplete ionization. This decreases the number of ions entering the mass spectrometer, leading to inaccurate detection results. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an electro-spray nozzle whose signal is not suppressed and whose generated spray is fully ionized.

[0008] The present invention also provides an electrospray ionization device, which utilizes the above-mentioned electrospray nozzle, and the detection sensitivity of the sample solution is not reduced when using the electrospray ionization device.

[0009] The present invention also provides an electrospray needle ionization analysis method, which, by utilizing the above-mentioned electrospray ionization device, can improve the detection sensitivity.

[0010] To achieve this objective, the present invention adopts the following technical solution: An electrospray nozzle is provided, which is made of an organic polymer material, wherein the polymer material contains at least one of hydroxyl, carboxyl, sulfonic acid, amino, and halogen polar functional groups.

[0011] Preferably, the polymeric material includes any one of polyvinyl alcohol, phenolic resin, cellulose and its derivatives, polyacrylic acid, polyvinyl acid, polybutyric acid, polyamic acid, carboxymethyl cellulose, polystyrene sulfonate, polyacrylic acid sulfonate, polyurethane, amino resin, polyethyleneamine, polyimide, and nylon.

[0012] Preferably, the inner diameter of the electro-spray needle ranges from 10μm to 500μm, and the length ranges from 1cm to 5cm. The difference between the outer and inner diameters of the tip of the electro-spray needle is 5μm-100μm.

[0013] An electrospray ionization device is also provided, including the aforementioned electrospray nozzle, three-way connector, electrode, sample tube, gas tube, and sleeve; The three-way connector includes a first interface, a second interface, and a third interface. The electrode is connected to the first interface, the sample tube is connected to the second interface, and the tail end of the electrospray needle is connected to the third interface. The central axis of the electrospray needle is at a preset angle to the central axis of the mass spectrometer inlet; The tip of the electrospray needle is spaced at a predetermined distance from the inlet of the mass spectrometer along the central axis of the mass spectrometer. The sample solution inside the electrospray needle forms an electrospray under the action of the electrode, and the electrospray can be ionized and enter the inlet of the mass spectrometer. One end of the sleeve is provided with an end cap, and the end cap has a mounting hole coaxial with the sleeve. The electro-spray needle passes through the mounting hole and the sleeve, and the inner diameter of the sleeve is larger than the maximum diameter of the electro-spray needle. An air inlet is provided on the end cap, and the air inlet is connected to a gas pipe.

[0014] Preferably, the preset included angle range is 0°-90°.

[0015] Preferably, the preset distance range is 0.1cm-6cm.

[0016] Preferably, the difference between the inner diameter of the sleeve and the maximum diameter of the electro-spray needle is in the range of 5mm-20mm.

[0017] Another electrospray mass spectrometry analysis method is provided, which is performed using the aforementioned electrospray ionization device, including: S1. Place the electrospray needle of polymer material inside the sleeve, connect the electrode to the first interface of the three-way connector, connect the sample tube to the second interface of the three-way connector, connect the tail end of the electrospray needle to the third interface of the three-way connector, and make the tip of the electrospray needle face the inlet of the mass spectrometer, and turn on the mass spectrometer. S2. The gas tube is connected to the tail end of the sleeve; S3. The sample solution is delivered to the polymer material electrospray nozzle, and the gas is delivered to the tip of the electrospray nozzle through the sleeve; S4. The electrode applies a voltage to the sample solution inside the electrospray needle, the electrode forms a circuit with the inlet of the mass spectrometer, and the tip of the electrospray needle forms an electrospray; S5. The ions generated by the electrospray ionization are detected at the entrance of the mass spectrometer.

[0018] Preferably, the gas is nitrogen, and the flow rate of the gas is in the range of 0-600 L / h.

[0019] Preferably, the voltage range released by the electrode is 1kV-5kV.

[0020] Compared with existing technologies, this invention has the following advantages: The use of a non-conductive electrospray nozzle in this invention significantly reduces signal suppression caused by discharge. The positive ion signal intensity of the organic polymer nozzle is 1-2 orders of magnitude higher than that of the metal capillary nozzle, and the negative ion signal intensity is two orders of magnitude higher, solving the long-standing problem of low signal in the negative ion mode of electrospray mass spectrometry and improving the performance and efficiency of the instrument.

[0021] Furthermore, because metal capillary nozzles undergo anodic oxidation or cathodic reduction reactions under high voltage, they generate a large number of metal ions originating from the nozzle material itself, as well as byproduct ions from solvents or buffer salts. Therefore, compared to electrospray produced by metal capillary nozzles, electrospray nozzles made of organic polymer materials can significantly reduce the complex chemical reactions caused by electrochemical reactions, simplifying the spectra.

[0022] The reactive species (such as free radicals and ions) generated by these electrochemical reactions can undergo secondary reactions with analyte molecules, leading to unexpected adducts (such as oxidation products and solvadducts), fragmentation, or polymer formation, thereby interfering with the obtained mass spectra. In contrast, the electrospray nozzle made of organic polymer materials in this invention generates higher electrospray energy than that produced by metal capillary nozzles, thus reducing various addition reactions that occur during the vaporization and ionization of sample molecules and more accurately reflecting sample information.

[0023] Electrospray nozzles made of organic polymer materials containing at least one of the above-mentioned hydroxyl, carboxyl, sulfonic acid, amino, and halogen polar tube groups can greatly reduce the complex reactions caused by electrochemical reactions, thereby reducing the signals of background ions, adduct ions, and fragment ions on the mass spectrum obtained after mass spectrometry detection. The signal attribution of target analyte ions is clearer, the resolution is higher, the target peak is easier to identify, there is less interference, and the quantitative analysis is more accurate.

[0024] The current generated by the applied voltage is entirely used to form the electrospray, with little or no diversion to electrochemical side reactions. At the same voltage, the effective current for generating charged droplets is greater, resulting in a higher density and greater charge in the generated droplets. The efficiency of generating gaseous ions from droplet evaporation and fragmentation is also higher, significantly improving the efficiency of converting the target analyte into detectable gaseous ions. This also greatly enhances the ionization effect, thereby significantly improving the overall detection sensitivity of mass spectrometry.

[0025] Furthermore, the organic polymer materials used in electrospray nozzles, by introducing specific functional groups, can regulate the surface wettability of the nozzles to form a more uniform liquid film and generate more stable charged droplets. Polymer surfaces containing acidic and basic functional groups can act as proton donors or acceptors, directly participating in the protonation or deprotonation of analyte molecules, thereby facilitating ionization and charge separation of the analyte molecules and ultimately improving the intensity of the mass spectrometry signal.

[0026] Electrospray nozzles made of organic polymers can avoid electrolytic corrosion or the limitations imposed by the pH of the liquid passing through them. Furthermore, using organic polymers with moderate conductivity as electrospray nozzles can suppress harmful electrochemical reactions, allowing more current to be used for the effective formation of charged droplets. This results in more and smaller initial droplets, ultimately improving ionization efficiency and the production efficiency of analyte ions, thereby enhancing overall detection sensitivity. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the electrospray ionization device in this invention.

[0028] Figure 2This is a positive ion mode electrospray mass spectrum of the acetylphosphine metal capillary nozzle in this invention.

[0029] Figure 3 This is a positive ion mode electrospray mass spectrum of the acetamiprid polyvinyl chloride electrospray nozzle of the present invention.

[0030] Figure 4 This is a positive ion mode electrospray mass spectrum of the acetamiprid polyvinyl alcohol electrospray needle in this invention.

[0031] Figure 5 This is a positive ion mode electrospray mass spectrum of the acetaminophen nylon electrospray nozzle of the present invention.

[0032] Figure 6 This is a positive ion mode electrospray mass spectrum of the sodium polystyrene sulfonate electrospray needle used in this invention.

[0033] Figure 7 This is a positive ion mode electrospray mass spectrum of the acetaminophen carboxymethyl cellulose electrospray needle used in this invention.

[0034] Figure 8 This is a negative ion mode electrospray mass spectrum of the acetylphosphine metal capillary nozzle in this invention.

[0035] Figure 9 This is a negative ion mode electrospray mass spectrum of the acetamiprid polyvinyl chloride electrospray nozzle of the present invention.

[0036] Figure 10 This is a negative ion mode electrospray mass spectrum of the acetamiprid polyvinyl alcohol electrospray nozzle in this invention.

[0037] Figure 11 This is a negative ion mode electrospray mass spectrum of the acetaminophen nylon electrospray nozzle of the present invention.

[0038] Figure 12 This is a negative ion mode electrospray mass spectrum of the sodium polystyrene sulfonate electrospray needle used in this invention.

[0039] Figure 13 This is a negative ion mode electrospray mass spectrum of the acetaminophen carboxymethyl cellulose electrospray needle of the present invention.

[0040] Figure 14 This is a positive ion mode electrospray mass spectrum of the fluopyram metal capillary nozzle of the present invention.

[0041] Figure 15 This is a positive ion mode electrospray mass spectrum of the fluopyram-polyvinyl chloride electrospray nozzle of the present invention.

[0042] Figure 16This is a positive ion mode electrospray mass spectrum of the fluopyram-polyvinyl alcohol electrospray needle in this invention.

[0043] Figure 17 This is a positive ion mode electrospray mass spectrum of the fluopyram nylon electrospray nozzle of the present invention.

[0044] Figure 18 This is a positive ion mode electrospray mass spectrum of the sodium fluopyramidal polystyrene sulfonate electrospray needle used in this invention.

[0045] Figure 19 This is a positive ion mode electrospray mass spectrum of the fluopyram-carboxymethyl cellulose electrospray needle of the present invention.

[0046] Figure 20 This is a negative ion mode electrospray mass spectrum of the fluopyram metal capillary nozzle of the present invention.

[0047] Figure 21 This is a negative ion mode electrospray mass spectrum of the fluopyram-polyvinyl chloride electrospray nozzle of the present invention.

[0048] Figure 22 This is a negative ion mode electrospray mass spectrum of the fluopyram-polyvinyl alcohol electrospray needle in this invention.

[0049] Figure 23 This is a negative ion mode electrospray mass spectrum of the fluopyram nylon electrospray nozzle of the present invention.

[0050] Figure 24 This is a mass spectrum of the negative ion mode electrospray spectroscopy for a sodium fluopyramidal polystyrene sulfonate electrospray nozzle.

[0051] Figure 25 Mass spectra of the negative ion mode electrospray ionization of fluopyram-carboxymethyl cellulose electrospray nozzle.

[0052] Figure 26 This is a positive ion mode electrospray mass spectrum of the imidacloprid metal capillary nozzle in this invention.

[0053] Figure 27 This is a positive ion mode electrospray mass spectrum of the imidacloprid polyvinyl chloride electrospray needle of the present invention.

[0054] Figure 28 This is a positive ion mode electrospray mass spectrum of the imidacloprid polyvinyl alcohol electrospray needle in this invention.

[0055] Figure 29 This is a positive ion mode electrospray mass spectrum of the imidacloprid nylon electrospray nozzle of the present invention.

[0056] Figure 30 This is a positive ion mode electrospray mass spectrum of the sodium polystyrene sulfonate electrospray needle used in this invention.

[0057] Figure 31 This is a positive ion mode electrospray mass spectrum of the imidacloprid carboxymethyl cellulose electrospray needle of the present invention.

[0058] Figure 32 This is a negative ion mode electrospray mass spectrum of the imidacloprid metal capillary nozzle in this invention.

[0059] Figure 33 This is a negative ion mode electrospray mass spectrum of the imidacloprid polyvinyl chloride electrospray needle of the present invention.

[0060] Figure 34 This is a negative ion mode electrospray mass spectrum of the imidacloprid polyvinyl alcohol electrospray needle in this invention.

[0061] Figure 35 This is a negative ion mode electrospray mass spectrum of the imidacloprid nylon electrospray needle of the present invention.

[0062] Figure 36 This is a negative ion mode electrospray mass spectrum of the sodium polystyrene sulfonate electrospray needle used in this invention.

[0063] Figure 37 This is a negative ion mode electrospray mass spectrum of the imidacloprid carboxymethyl cellulose electrospray needle of the present invention.

[0064] Figure 38 This is a positive ion mode electrospray mass spectrum of the metal capillary nozzle of the present invention.

[0065] Figure 39 This is a positive ion mode electrospray mass spectrum of the polyvinyl chloride electrospray nozzle used in this invention.

[0066] Figure 40 This is a positive ion mode electrospray mass spectrum of the polyvinyl alcohol electrospray needle used in this invention.

[0067] Figure 41 This is a positive ion mode electrospray mass spectrum of the cytotoxic nylon electrospray nozzle of the present invention.

[0068] Figure 42 This is a positive ion mode electrospray mass spectrum of the sodium polystyrene sulfonate electrospray nozzle used in this invention.

[0069] Figure 43 This is a positive ion mode electrospray mass spectrum of the carboxymethyl cellulose electrospray nozzle used in this invention.

[0070] Figure 44 This is a negative ion mode electrospray mass spectrum of the pymetrozine metal capillary nozzle in this invention.

[0071] Figure 45This is a negative ion mode electrospray mass spectrum of the pymetrozine polyvinyl chloride electrospray nozzle of the present invention.

[0072] Figure 46 This is a negative ion mode electrospray mass spectrum of the pymetrozine polyvinyl alcohol electrospray nozzle of the present invention.

[0073] Figure 47 This is a negative ion mode electrospray mass spectrum of the pymetrozine nylon electrospray nozzle of the present invention.

[0074] Figure 48 This is a negative ion mode electrospray mass spectrum of the sodium pymetrozine polystyrene sulfonate electrospray nozzle of the present invention.

[0075] Figure 49 This is a negative ion mode electrospray mass spectrum of the pymetrozine carboxymethyl cellulose electrospray needle of the present invention.

[0076] The components include: 1. Inlet; 2. Electrospray needle; 3. Sheath; 4. Electrode; 5. Sample tube; 6. Gas tube; and 7. T-connector. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0078] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0079] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0080] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0081] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0082] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0083] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0084] This embodiment provides an electro-spray nozzle, the polymer material containing at least one of hydroxyl, carboxyl, sulfonic acid, amino, and halogen polar functional groups.

[0085] In this embodiment, a non-conductive electrospray nozzle is used, which can greatly reduce signal suppression caused by discharge. Compared with metal capillary nozzles, the electrospray nozzle produces positive ion signals with an intensity 1-2 orders of magnitude higher and negative ion signals with an intensity 2 orders of magnitude higher, solving the long-standing problem of low negative ion signals in electrospray mass spectrometry and improving the performance and efficiency of the instrument.

[0086] Furthermore, because metal capillary nozzles undergo anodic oxidation or cathodic reduction reactions under high voltage, they generate a large number of metal ions originating from the nozzle material itself, as well as byproduct ions from solvents or buffer salts. Therefore, compared to electrospray produced by metal capillary nozzles, electrospray nozzles made of organic polymer materials can significantly reduce the complex chemical reactions caused by electrochemical reactions, simplifying the spectra.

[0087] The reactive substances generated by these electrochemical reactions, such as free radicals and ions, can undergo secondary reactions with analyte molecules, leading to the formation of unexpected adducts (such as oxidation products and solvadducts), fragment ions, or polymers, thereby interfering with the obtained mass spectra. In this embodiment, the electrospray nozzle made of organic polymer materials generates higher electrospray energy than the electrospray generated by a metal capillary nozzle, thus reducing various addition reactions that occur during the vaporization and ionization of sample molecules, and more accurately reflecting sample information.

[0088] Electrospray nozzles made of organic polymer materials containing at least one of the above-mentioned hydroxyl, carboxyl, sulfonic acid, amino, and halogen polar tube groups can greatly reduce the complex reactions caused by electrochemical reactions, thereby reducing the signals of background ions, adduct ions, and fragment ions on the mass spectrum obtained after mass spectrometry detection. The signal attribution of target analyte ions is clearer, the resolution is higher, the target peak is easier to identify, there is less interference, and the quantitative analysis is more accurate.

[0089] The current generated by the applied voltage is entirely used to form the electrospray, with little or no diversion to electrochemical side reactions. At the same voltage, the effective current for generating charged droplets is greater, resulting in a higher density and greater charge in the generated droplets. The efficiency of generating gaseous ions from droplet evaporation and fragmentation is higher, significantly improving the efficiency of converting the target analyte into detectable gaseous ions. Ionization is also greatly enhanced, thus significantly improving the overall detection sensitivity of mass spectrometry. This detection sensitivity refers to the lowest amount or concentration of sample that the mass spectrometer can reliably detect, or the signal intensity generated at a specific concentration.

[0090] Furthermore, the organic polymer material used in the electrospray nozzle 2, by introducing specific functional groups, can regulate the surface wettability of the nozzle 2 to form a more uniform liquid film and generate more stable charged droplets. The polymer surface containing acidic and basic tube groups can act as a proton donor or acceptor, directly participating in the protonation or deprotonation of the analyte molecules, thereby facilitating the ionization and charge separation of the analyte molecules and ultimately improving the intensity of the mass spectrometry signal.

[0091] Electrospray nozzles made of organic polymers can avoid electrolytic corrosion or the limitations imposed by the pH of the liquid passing through them. Furthermore, using organic polymers with moderate conductivity as electrospray nozzles can suppress harmful electrochemical reactions, allowing more current to be used for the effective formation of charged droplets. This results in more and smaller initial droplets, ultimately improving ionization efficiency and the production efficiency of analyte ions, thereby enhancing overall detection sensitivity.

[0092] Preferably, the polymeric material includes any one of polyvinyl alcohol, phenolic resin, cellulose and its derivatives, polyacrylic acid, polyvinyl acid, polybutyric acid, polyamic acid, carboxymethyl cellulose, polystyrene sulfonate, polyacrylic acid sulfonate, polyurethane, amino resin, polyethyleneamine, polyimide, and nylon.

[0093] For example, polyvinyl alcohol in the above materials contains hydroxyl groups (-OH), and carboxyl groups (-COOH) can also be introduced. Cellulose derivatives contain hydroxyl groups (-OH), and carboxyl / sulfonic acid groups can also be introduced.

[0094] Polyacrylic acid contains a carboxyl group (-COOH) and can also have carboxyl groups introduced. Polyvinylamine contains an amino group (-NH2) and can also have sulfonic acid groups introduced.

[0095] Polyimide contains an amino group (-NH2), which can also introduce halogens. Polystyrene sulfonate contains a sulfonic acid group (-SO3H), which can also introduce halogens.

[0096] Polyurethanes contain urethane esters (-NHCOO-) and can also have hydroxyl / carboxyl groups introduced. Amino resins contain amino groups (-NH2) and can also have hydroxyl groups introduced.

[0097] Preferably, the inner diameter of the electrospray needle is in the range of 10μm-500μm, the length is in the range of 1cm-5cm, and the difference between the outer diameter and the inner diameter of the tip of the electrospray needle 2 is in the range of 5μm-100μm.

[0098] This embodiment also provides an electrospray ionization device, including the above-mentioned electrospray needle, three-way connector 7, electrode 4, sample tube 5, gas tube 6 and sleeve 3.

[0099] The aforementioned three-way connector 7 includes a first interface, a second interface, and a third interface. The electrode 4 is connected to the first interface, the sample tube 5 is connected to the second interface, and the tail end of the electrospray needle 2 is connected to the third interface. The central axis of the electrospray needle 2 and the central axis of the mass spectrometer inlet 1 are at a preset angle.

[0100] The tip of the electrospray needle 2 is spaced at a preset distance from the inlet 1 of the mass spectrometer. The sample liquid inside the electrospray needle 2 forms an electrospray under the action of the electrode 4. The electrospray can be ionized and enter the inlet 1 of the mass spectrometer.

[0101] One end of the sleeve 3 is provided with an end cap, and the end cap has a mounting hole coaxial with the sleeve 3. The electro-spray needle 2 passes through the mounting hole and the sleeve 3. The inner diameter of the sleeve 3 is larger than the maximum diameter of the electro-spray needle 2.

[0102] An air inlet is provided on the end cap, and the air inlet is connected to the gas pipe 6.

[0103] Preferably, the angle between the central axis of the electrospray needle 2 and the central axis of the inlet 1 of the mass spectrometer is in the range of 0°-90°.

[0104] When the angle between the two is 0°, the direction of the electric field force is completely consistent with the ion's path of motion, allowing for linear acceleration of the ions without deflection, and achieving a transmission efficiency of over 90%. However, solvent vapors or neutral particles can directly bombard the mass spectrometer's inlet 1, especially at high flow rates, contaminating the mass spectrometer's vacuum system.

[0105] When the angle between the two is 90°, neutral particles are blocked by their inertial linear motion, and only charged ions are deflected by the electric field to enter the mass spectrometer inlet. Therefore, the background noise (such as solvent vapor and neutral particles) is reduced by more than 90%. However, ions need to undergo a 90° deflection before entering the mass spectrometer inlet, and the loss of kinetic energy leads to a decrease in efficiency.

[0106] Preferably, the distance between the tip of the electrospray needle 2 and the inlet 1 of the mass spectrometer is in the range of 0.1-6 cm.

[0107] One end of the sleeve 3 is provided with an end cap, on which a mounting hole coaxial with the sleeve 3 is opened. The electro-spray needle 2 passes through the mounting hole and the sleeve 3. The inner diameter of the sleeve 3 is larger than the maximum diameter of the electro-spray needle 2. An air inlet is provided on the end cap, which is connected to the gas pipe 6.

[0108] In this embodiment, because the electrospray needle 2 is made of organic polymer material, which contains at least one of polar functional groups such as hydroxyl, carboxyl, sulfonic acid, amino, and halogen, the electrospray generated under the high voltage of electrode 4 when the electrospray needle 2 is working will reduce the complex reactions caused by electrochemical reactions, making the signal attribution of the target analyte ions on the mass spectrum obtained after mass spectrometry detection clearer, with higher resolution and more accurate quantitative analysis.

[0109] The current generated by the applied voltage is entirely used to form the electrospray, with little or no diversion to electrochemical side reactions. Under the same voltage, the effective current used to generate charged droplets is greater, resulting in a higher density and more charge in the generated droplets.

[0110] As the electrospray moves toward the inlet 1 of the mass spectrometer, the small droplets evaporate and break up to generate gaseous ions more efficiently, thus significantly improving the efficiency of converting the target analyte into detectable gaseous ions. The ionization effect is greatly improved, thereby greatly enhancing the overall detection sensitivity of mass spectrometry analysis.

[0111] The distance between the tip of the electrospray needle 2 and the inlet 1 of the mass spectrometer along the central axis of the mass spectrometer ranges from 0.1 cm to 6 cm. This setting is because the charged droplets in the electrospray ejected from the tip of the electrospray needle 2 need to undergo multiple cycles of solvent evaporation and droplet splitting before finally releasing gaseous ions.

[0112] If the distance between the two is less than 0.1 cm, the charged droplet will not evaporate completely, and the solvent molecules will encapsulate the target molecule, resulting in incomplete ionization. After detection by a mass spectrometer, the mass spectrum will show many peaks of the adduct and a weak signal.

[0113] If the distance between the two is greater than 6 cm, ions will be lost due to diffusion, and the signal strength will decrease.

[0114] Therefore, the distance between the tip of the electrospray needle 2 and the inlet 1 of the mass spectrometer is set in the range of 0.1cm-6cm, which allows the droplet to move into the path of the inlet 1 of the mass spectrometer under the traction force of the electric field, giving it enough time to expand with the ambient gas, evaporate the solvent, and finally form free ions.

[0115] Preferably, the gas is nitrogen, and the gas flow rate is in the range of 0-600 L / h. At this flow rate, the role of nitrogen as the spray gas is to cut the electrospray solution into small fragments to form an aerosol, thereby assisting in the formation of a stable and uniform aerosol and realizing the electrospray process.

[0116] The actual flow rate of nitrogen is adjusted based on the flow rate of the electrospray and the composition of the sample solution. Higher sample solution flow rates, or increases in the proportion of water in the sample solution, typically require a higher nitrogen flow rate to ensure spray stability. When the sample solution flow rate is extremely low, electrospray generation can be achieved solely through the electric field, in which case nitrogen assistance is unnecessary.

[0117] Preferably, the voltage range released by electrode 4 is 1kV-5kV, within which the highest ionization efficiency can be achieved with the lowest energy input.

[0118] This embodiment also provides an electrospray mass spectrometry analysis method, which is performed using the aforementioned electrospray ionization device, and the specific steps include: S1. Place the electrospray needle 2 of polymer material inside the sleeve 3, connect the electrode to the first interface of the three-way connector 7, connect the sample tube to the second interface of the three-way connector 7, connect the tail end of the electrospray needle 2 to the third interface of the three-way connector 7, and the tip of the electrospray needle 2 is directly opposite the inlet 1 of the mass spectrometer, and turn on the mass spectrometer. S2, Gas pipe 6 is connected to the tail of sleeve 3; S3. The sample solution is delivered to the polymer material electrospray needle 2. The gas in the gas tank is delivered to the tip of the electrospray needle 2 through the sleeve 3. The tip of the electrospray needle 2 will generate a spray. S4. Electrode 4 applies voltage to the sample solution in the electrospray needle 2. Electrode 4 forms a circuit with the inlet 1 of the mass spectrometer. The tip of the electrospray needle 2 sprays out an electrospray. S5. Ions generated by electrospray ionization enter the inlet 1 of the mass spectrometer and are detected.

[0119] In this embodiment, the electrospray needle 2 of the organic polymer material is placed inside the sleeve 3 and does not directly contact the electrode 4, which can prevent metal from dissolving into the spray sprayed by the electrospray needle 2 and interfering with the detection.

[0120] Electrodes are typically made of metal, such as platinum or stainless steel. Under the high-voltage electric field of electrospray, the interface between the electrode and the solution becomes an electrode in an "electrolytic cell," where an irreversible redox reaction occurs. In this embodiment, the current is transmitted only through the spray droplets and ion conduction, preventing metal ions and other products generated by the corrosion of electrode 4 from entering the electrospray flow and interfering with the detection results.

[0121] In addition, the gas at the tail end of the sleeve 3 blows directly to the tip of the electro-spray needle 2, which helps to cut the electro-spray solution in the electro-spray needle 2 into small fragments to form an aerosol, i.e., auxiliary spraying.

[0122] By adjusting the gas flow rate and temperature, the evaporation of the solvent in the spray can be accelerated. At the same time, the continuous airflow can prevent crystallization at the tip of the electro-spray needle 2 for polymer materials.

[0123] Although organic polymer materials are not conductive, they become highly conductive after being wetted by a solvent. Specifically, the organic polymer material in step S2 is an insulator in its dry state, but after wetting, the solvent forms a continuous liquid film on the inner wall of the electrospray needle 2. Electrolyte ions in the solution migrate along the liquid film, forming ion-conducting channels.

[0124] A voltage is applied at the electrospray needle 2. This voltage is transmitted through the electrode 4, the solution inside the electrospray needle 2, the liquid film formed on the inner wall of the electrospray needle 2, and the path formed by the charged spray, thus creating a circuit, rather than through the conductivity of the polymer material itself. Because the mass spectrometer is grounded, a potential difference is formed between the tip of the electrospray needle 2 and the inlet 1 of the mass spectrometer, thereby creating an electric field. This is a prerequisite for the ionization of the sample solution in the electrospray needle 2.

[0125] When the sample solution flow rate is high or the water content is high, the electric field alone cannot produce a spray of the sample solution. Introducing nitrogen gas can assist in vaporization. The nitrogen flow rate is related to the ease of sample solution vaporization. Generally, a higher flow rate and a higher water content result in a higher nitrogen flow rate, and vice versa. The nitrogen flow rate can be lower or even completely shut off.

[0126] In electrospray ionization, when the flow rate of the sample solution is high (greater than 20 μL / min) or the water content is high (e.g., greater than 90%), the electric field force cannot effectively overcome the liquid cohesion. At high flow rates, the inertial force of the liquid exceeds the electric field's traction force, causing droplets to fall without being liquefied. High-speed nitrogen gas is introduced into the tip of the electrospray needle 2 through a coaxially arranged sleeve 3, forming a gas flow.

[0127] Nitrogen gas is mixed with the ionized sample solution in the electrospray nozzle 2, forming an electrospray at the tip of the nozzle 2. The electrospray consists of a series of charged droplets. These charged droplets move towards the inlet 1 of the mass spectrometer under the action of an electric field. During this process, the solvent on the surface of the droplets evaporates continuously, the droplet diameter decreases, and the number of surface charges on the droplets remains unchanged. When the repulsive force of the surface charge on the droplet equals the surface tension of the droplet, the droplet begins to burst, forming even smaller droplets. This process is repeated until sample ions are finally formed. The sample ions enter the inlet 1 of the mass spectrometer and are detected.

[0128] Example 1 Fabrication of Electrospray Needle 2 for Organic High-Analysis Materials: Take organic polymer materials, including polyvinyl chloride, polyvinyl alcohol, nylon, sodium polystyrene sulfonate, and carboxymethyl cellulose, and cut them into short rods with a length of 4 cm. Drill a hole in the center of this short rod to obtain a capillary of the organic polymer material. Trim the tip of the capillary into a pointed shape so that its outer diameter is as close as possible to its inner diameter, thus obtaining the electrospray needle 2 for the organic polymer material.

[0129] Preferably, the electrospray needle 2 includes a tube section of the same diameter and a tip connected to the tube section of the same diameter. The length of the tip is 1 / 5 to 1 / 3 of the length of the electrospray needle. The length of the electrospray needle ranges from 1 cm to 5 cm. The inner diameter of the tube section and the tip is the same, and its inner diameter ranges from 10 μm to 500 μm.

[0130] More preferably, the difference between the outer diameter and the inner diameter of the tip of the electrospray needle 2 is 5-100 μm. This difference ensures that the sample solution inside the needle can form an electrospray at the tip of the electrospray needle 2.

[0131] like Figure 1 As shown, an electrospray ionization device using an electrospray nozzle made of organic polymer material includes an electrospray nozzle 2 made of organic polymer material, a three-way connector 7, an electrode 4, a sample tube 5, a gas tube 6, and a sleeve 3.

[0132] The mass spectrometer inlet 1 is located at the far right end, and the left end is an electrospray needle 2 for organic polymer materials. The tip of the electrospray needle 2 is directly opposite the mass spectrometer inlet 1, and the distance from the mass spectrometer inlet 1 ranges from 0.1cm to 6cm. The angle between the electrospray needle 2 and the axis of the mass spectrometer inlet 1 is 0-90°. The electrode is connected to the first interface of the three-way connector 7, the sample tube is connected to the second interface of the three-way connector 7, and the tail end of the electrospray needle 2 is connected to the third interface of the three-way connector 7, with the tip of the electrospray needle 2 directly opposite the mass spectrometer inlet 1.

[0133] A high voltage is applied directly to electrode 4. The nozzle 2 is fixed inside the sleeve 3 and arranged coaxially and in the same direction as the sleeve 3. The inner diameter of the sleeve 3 is larger than the outer diameter of the nozzle to facilitate gas passage. The front end of the sleeve 3 is open to allow the spray from the tip of the nozzle 2 to move towards the mass spectrometer inlet. The rear end of the sleeve 3 is closed, but allows the tail of the nozzle 3 to pass through and connect to the tee 7. Additionally, the rear end of the sleeve 3 is connected to the gas tube 6 to facilitate gas inflow into the sleeve 3.

[0134] Detailed test and analysis process: 1) Apply voltage to the electro-spray nozzle 2 of the organic polymer material; 2) Turn on the mass spectrometer and scan the mass spectrometry signal; 3) Turn on the sample introduction system and deliver the sample solution through the sample tube 5 and the three-way connector 7 to the electrospray nozzle 2 for the organic polymer material. Turn on the gas switch and deliver nitrogen gas through the gas tube 6 to the tip of the electrospray nozzle 2 for the organic polymer material. Adjust the position and gas flow rate of the electrospray nozzle 2 for the organic polymer material to achieve the strongest signal. 4) Record the scanning data to obtain the mass spectrum of the sample ions.

[0135] Example 2 In this embodiment, the electrospray nozzle is made of polyvinyl chloride (PVC). In positive ion mode, 0.1 μg / ml of acephate methanol solution was aspirated into the PVC electrospray nozzle using a syringe, and the acephate methanol solution was analyzed using a Thermo LCQ Fleet mass spectrometry system. In negative ion mode, 10 μg / ml of acephate methanol solution was aspirated, and the electrospray generated by the nozzle was compared with that generated by a metal capillary nozzle.

[0136] from Figures 2-7 It can be seen that polyvinyl chloride (PVC) is used. Figure 3 ), polyvinyl alcohol ( Figure 4 ), Nylon (5), Carboxymethyl cellulose ( Figure 7 The intensity of the acephate signal (m / z 206) obtained by the electrospray needle in positive ion mode was higher than that of the electrospray produced by the conventional metal capillary needle. Figure 2 It is an order of magnitude higher than that, using sodium polystyrene sulfonate ( Figure 6 The acephate signal intensity obtained by the nozzle is two orders of magnitude higher than that obtained by the metal capillary nozzle.

[0137] The functional group of polyvinyl chloride is chlorine atom (-Cl), the functional group of polyvinyl alcohol is hydroxyl group (-OH), the functional group of nylon is amide group (-CONH-), and the functional group of sodium polystyrene sulfonate is sulfonic acid group (-SO3). - The functional group of carboxymethyl cellulose is carboxymethyl (-CH2COOH). These functional groups are highly electronegative and can combine with hydrogen protons (H+) generated during electrospray ionization in positive ionization mode. When the analyte molecule comes into contact with these groups, it can transfer hydrogen protons to the analyte molecule to form an analyte ion. This ionization efficiency based on hydrogen proton transfer exceeds that based on electron transfer, therefore the signal intensity is higher than that of metal capillary nozzles. In particular, sulfonic acid is a strong acid with a very strong proton-donating ability, so its mass spectrometry signal intensity is two orders of magnitude higher than that of metal capillary nozzles.

[0138] from Figures 8-13 It can be seen that the acephate signal (m / z 182) detected by the electrospray generated using the metal capillary nozzle in negative ion mode is very weak. Figure 8 ), while using polyvinyl chloride ( Figure 9 ), polyvinyl alcohol (10), nylon ( Figure 11 Sodium polystyrene sulfonate ( Figure 12 The acephate signal intensity detected by the electrospray nozzle 2 made of carboxymethyl cellulose material in negative ion mode was two orders of magnitude higher than that of the electrospray produced by the metal capillary nozzle. The negative ion signal intensity of acephate detected by the electrospray nozzle 2 made of carboxymethyl cellulose material was ( Figure 13 The electrospray quality is an order of magnitude higher than that produced by a metal capillary nozzle. This is because, in negative ion mode, metal capillary nozzles discharge very easily under high voltage, thus severely suppressing the electrospray mass spectrometry signal. Meanwhile, the polar functional groups (-Cl, -OH, -CONH-, SO3-) in organic polymer materials... - The negative ion (-CH₂COOH) reacts or combines with the negative ions generated by electrolysis to produce a negative charge. When this negative charge comes into contact with the analyte molecule, it can absorb hydrogen protons from the analyte molecule, thereby transferring the negative charge to the analyte molecule. This proton transfer-induced ionization efficiency is higher than that caused by electron transfer, and the discharge effect is not significant, avoiding signal suppression in electrospray mass spectrometry. The superposition of these two effects results in a significantly higher signal enhancement in the negative ion mode compared to the positive ion mode.

[0139] Example 3 This embodiment employs electrospray ionization devices using electrospray nozzles made of organic polymer materials such as polyvinyl chloride, polyvinyl alcohol, and nylon. In positive ion mode, a 0.1 μg / ml fluopyram methanol solution is aspirated using a syringe and injected into the polyvinyl alcohol, polyvinyl alcohol, and nylon electrospray nozzles, respectively, and analyzed using a Thermo LCQ Fleet mass spectrometry system. In negative ion mode, a 10 μg / ml fluopyram methanol solution is aspirated, and the electrospray generated is compared with that generated by a metal capillary nozzle. The electrospray ionization device using the electrospray nozzles of Example 1 (…) Figure 1 In the comparative experiment, the metal capillary nozzle was used as the electrospray device for generating ion sources. This electrospray device is a built-in device of the commercial electrospray mass spectrometer (Thermo LCQ Fleet), and the metal capillary nozzle is made of stainless steel.

[0140] The sample solution was placed in a syringe and injected through sample tube 5 and three-way connector 7 into an electrospray needle 2 made of polyvinyl chloride, polyvinyl alcohol, or nylon, or a metal capillary needle, at a sample flow rate of 10 μL / min. To compare the performance of both, the auxiliary gas was not turned on, and other parameters were adjusted to the strongest signal. The electrospray needle operation method was the same as in Example 1, using positive and negative ion electrospray modes respectively.

[0141] Depend on Figure 14-19 It can be seen that polyvinyl chloride (PVC) is used. Figure 15 ), polyvinyl alcohol ( Figure 16 ), Nylon (17), Sodium polystyrene sulfonate (18), Carboxymethyl cellulose ( Figure 19 The fluopyram signal (m / z 691, 731, 385, 346) intensity obtained by the nozzle in positive ion mode was higher than that of the electrospray produced by a traditional metal capillary nozzle. Figure 14 It is an order of magnitude higher.

[0142] from Figure 20-25 It can be seen that the fluopyram signal (m / z 344) detected by electrospray generated using a metal capillary nozzle in negative ion mode is very weak. Figure 20 ), while using polyvinyl chloride ( Figure 21 ), polyvinyl alcohol (22), nylon ( Figure 23 Sodium polystyrene sulfonate ( Figure 24 ), carboxymethyl cellulose ( Figure 25 The electrospray produced by the electrospray needle made of [a specific material], after being detected by mass spectrometry in negative ion mode, showed that the intensity of the fluopyram signal was significantly higher than that of the electrospray produced by the metal capillary needle. Figure 20 It is two orders of magnitude higher.

[0143] Example 4 This embodiment uses an electrospray ionization device with an electrospray nozzle made of organic polymer materials such as polyvinyl chloride, polyvinyl alcohol, and nylon. In positive ion mode, a 0.01 μg / ml imidacloprid methanol solution is aspirated into the nylon electrospray nozzle using a syringe, and the imidacloprid methanol solution is analyzed using a Thermo LCQ Fleet mass spectrometry system. In negative ion mode, a 10 μg / ml imidacloprid methanol solution is aspirated, and the electrospray generated is compared with that generated by a metal capillary nozzle. The electrospray ionization device using the electrospray nozzle of Example 1 (… Figure 1 The electrospray device for the metal capillary nozzle is a stainless steel electrospray mass spectrometer provided by Thermo LCQ Fleet.

[0144] The sample solution was placed in a syringe and injected through sample tube 5 and three-way connector 7 into either a polyvinyl chloride, polyvinyl alcohol nylon electrospray needle 2, or a metal capillary needle at a flow rate of 10 μL / min. To compare the performance of both, the auxiliary gas was not turned on, and other parameters were adjusted to maximize the signal. The electrospray needle operation method was the same as in Example 1, using both positive and negative ion electrospray modes.

[0145] Depend on Figure 26-31 It can be seen that polyvinyl chloride (PVC) is used. Figure 27 ), polyvinyl alcohol ( Figure 28 ),nylon( Figure 29 Sodium polystyrene sulfonate ( Figure 30 ), carboxymethyl cellulose ( Figure 31 The intensity of the imidacloprid signal (m / z 256, 278) obtained by the spray needle in positive ion mode is higher than that of the electrospray generated by a traditional metal capillary spray needle. Figure 26 It is an order of magnitude higher.

[0146] from Figure 32-37 It can be seen that the imidacloprid signal (m / z 254) detected by electrospraying generated using a metal capillary nozzle in negative ion mode is very weak. Figure 32 ), while using polyvinyl chloride ( Figure 33 ), polyvinyl alcohol ( Figure 34 ),nylon( Figure 35 Sodium polystyrene sulfonate ( Figure 36 ), carboxymethyl cellulose ( Figure 37 The signal intensity of imidacloprid detected by the nozzle in negative ion mode was lower than that of the electrospray produced by the metal capillary nozzle. Figure 20 It is two orders of magnitude higher.

[0147] Example 5 This embodiment employs an electrospray ionization device for electrospray nozzles made of organic polymer materials such as polyvinyl chloride, polyvinyl alcohol, nylon, sodium polystyrene sulfonate, and carboxymethyl cellulose. Figure 1 A 0.1 μg / ml solution of propoxur methanol was aspirated using a syringe and injected into electrospray needles for polyvinyl chloride, polyvinyl alcohol, nylon, sodium polystyrene sulfonate, and carboxymethyl cellulose, respectively, and analyzed using a Thermo LCQ Fleet mass spectrometry system. The results were compared with those generated by a metal capillary needle. The electrospray ionization device of the electrospray needle described in Example 1 was used. In the comparative experiment, the metal capillary needle was used as the electrospray device for generating ion sources. This electrospray device was a component of the commercial electrospray mass spectrometer (Thermo LCQ Fleet), and the metal capillary needle was made of stainless steel.

[0148] The sample solution was placed in a syringe and injected through the sample tube 5 and the three-way connector 7 into either the polymer electrospray needle 2 or the metal capillary needle at a flow rate of 10 μL / min. To compare the performance of both, the auxiliary gas was not turned on, and other parameters were adjusted to maximize the signal. The electrospray needle operation method was the same as in Example 1, using the positive ion electrospray mode.

[0149] from Figures 38-43 It can be seen that polyvinyl chloride (PVC) is used. Figure 39 ), polyvinyl alcohol ( Figure 40 ),nylon( Figure 41 Sodium polystyrene sulfonate ( Figure 42 ), carboxymethyl cellulose ( Figure 43 The intensity of the cytotoxic signal (m / z 232) obtained by the nozzle in positive ion mode is higher than that of the electrospray generated by a traditional metal capillary nozzle. Figure 26 It is an order of magnitude higher. The cytotoxic molecule contains hydrophobic amino groups, which do not show peaks in the negative spectrum.

[0150] Example 6 This embodiment employs an electrospray ionization device for electrospray nozzles made of organic polymer materials such as polyvinyl chloride, polyvinyl alcohol, nylon, sodium polystyrene sulfonate, and carboxymethyl cellulose. Figure 1 A 10 μg / ml solution of pymetrozine in methanol was aspirated using a syringe and injected into electrospray needles for polyvinyl chloride, polyvinyl alcohol, nylon, sodium polystyrene sulfonate, and carboxymethyl cellulose, respectively. The solutions were then analyzed using a Thermo LCQ Fleet mass spectrometer system, and compared with the electrospray generated by a metal capillary needle. The electrospray ionization device of the electrospray needle described in Example 1 was used. In the comparative experiment, the metal capillary needle was used as the electrospray device for generating ion sources. This electrospray device was a component of the commercial electrospray mass spectrometer (Thermo LCQ Fleet), and the metal capillary needle was made of stainless steel.

[0151] The sample solution was placed in a syringe and injected through sample tube 5 and three-way connector 7 into either the polymer electrospray needle 2 or the metal capillary needle at a flow rate of 10 μL / min. To compare the performance of both, the auxiliary gas was not turned on, and other parameters were adjusted to maximize the signal. The electrospray needle operation method was the same as in Example 1, using the negative ion electrospray mode.

[0152] Pymetrozine molecules contain five amino groups. These amino groups have a very strong proton affinity, causing them to rapidly add to hydrogen protons in solution to form ions. Therefore, in positive ion mode, the pymetrozine signal intensity detected using polymer materials is only slightly improved (1.5-6 times) compared to metal capillary nozzles. However, the effect is significantly improved in negative ion mode. Figure 44-49 It can be seen that polyvinyl chloride (PVC) is used. Figure 45 ), polyvinyl alcohol ( Figure 46 ), sodium polystyrene sulfonate (48), carboxymethyl cellulose ( Figure 49 The intensity of the pymetrozine signal (m / z 216) obtained by the electrospray needle in negative ion mode was higher than that of the electrospray produced by the traditional metal capillary needle. Figure 26 ) is an order of magnitude higher. Nylon ( Figure 47 The intensity of the pymetrozine signal (m / z 216) detected was higher than that of the electrospray produced by a conventional metal capillary nozzle. Figure 26The difference is two orders of magnitude higher because the amino groups on nylon have a stronger affinity for hydrogen protons on pymetrozine.

[0153] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An electro-spray nozzle, characterized in that, Made of organic polymer materials, wherein the polymer materials contain at least one of hydroxyl, carboxyl, sulfonic acid, amino, and halogen polar functional groups.

2. The electro-spray nozzle according to claim 1, characterized in that, The polymeric material includes any one of polyvinyl alcohol, phenolic resin, cellulose and its derivatives, polyacrylic acid, polyvinyl acid, polybutyric acid, polyamic acid, carboxymethyl cellulose, polystyrene sulfonate, polyacrylic acid sulfonate, polyurethane, amino resin, polyethyleneamine, polyimide, and nylon.

3. The electro-spray nozzle according to claim 1 or 2, characterized in that, The inner diameter of the electro-spray nozzle ranges from 10μm to 500μm, and the length ranges from 1cm to 5cm. The difference between the outer diameter and the inner diameter of the tip of the electrospray needle (2) is 5μm-100μm.

4. An electrospray ionization device, characterized in that, Includes the electrospray nozzle, tee connector (7), electrode (4), sample tube (5), gas tube (6) and sleeve (3) as described in any one of claims 1-3; The three-way connector (7) includes a first interface, a second interface and a third interface. The electrode (4) is connected to the first interface, the sample tube (5) is connected to the second interface, and the tail end of the electrospray needle (2) is connected to the third interface. The central axis of the electrospray needle (2) and the central axis of the mass spectrometer inlet (1) are at a preset angle; The tip of the electrospray needle (2) is spaced at a predetermined distance from the inlet (1) of the mass spectrometer along the central axis of the mass spectrometer. The sample solution in the electrospray needle (2) forms an electrospray under the action of the electrode (4), and the electrospray can be ionized and enter the inlet (1) of the mass spectrometer. One end of the sleeve (3) is provided with an end cap, and the end cap is provided with an installation hole coaxial with the sleeve (3). The electro-spray needle (2) passes through the installation hole and the sleeve (3). The inner diameter of the sleeve (3) is greater than the maximum diameter of the electro-spray needle (2). An air inlet is provided on the end cap, and the air inlet is connected to the gas pipe (6).

5. The electrospray ionization device according to claim 4, characterized in that, The preset included angle range is 0°-90°.

6. The electrospray ionization device according to claim 4, characterized in that, The preset distance range is 0.1cm-6cm.

7. The electrospray ionization device according to claim 4, characterized in that, The difference between the inner diameter of the sleeve (3) and the maximum diameter of the electro-spray needle (2) is 5mm-20mm.

8. An electrospray mass spectrometry analysis method, characterized in that, Performed using the electrospray ionization device according to any one of claims 4-7, comprising: S1. Place the electrospray needle (2) of polymer material inside the sleeve (3), connect the electrode (4) to the first interface of the three-way connector (7), connect the sample tube to the second interface of the three-way connector (7), connect the tail end of the electrospray needle (2) to the third interface of the three-way connector (7), and make the tip of the electrospray needle (2) face the inlet (1) of the mass spectrometer, and turn on the mass spectrometer. S2, the gas tube (6) is connected to the tail of the sleeve (3); S3. The sample solution is delivered to the polymer material electrospray needle (2), and the gas is delivered to the tip of the electrospray needle through the sleeve (3); S4. The electrode (4) applies a voltage to the sample solution in the electrospray needle (2). The electrode (4) forms a circuit with the inlet (1) of the mass spectrometer, and the tip of the electrospray needle (2) forms an electrospray. S5, The ions generated by the electrospray enter the inlet (1) of the mass spectrometer and are detected.

9. The electrospray mass spectrometry analysis method according to claim 8, characterized in that, The gas is nitrogen, and the flow rate of the gas is in the range of 0-600 L / h.

10. The electrospray mass spectrometry analysis method according to claim 8, characterized in that, The voltage range released by the electrode (4) is 1kV-5kV.

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