Ammonia synthesis method and device based on gas-liquid interface reaction and application

Abstract

The invention provides an ammonia synthesis method and device based on gas-liquid interface reaction and application. According to the ammonia synthesis method, an aqueous solution and N2-containing gas are used as raw materials, the aqueous solution is atomized into micro-droplets by the N2-containing gas in a flowing state under the atomization air pressure larger than 50 psi, meanwhile, a gas-liquid interface with an electric field of 108-109 V / m is formed, under the action of the electric field of the gas-liquid interface, N2 molecules are activated at the normal temperature, and then the micro-droplets are formed. And combining with hydrogen free radicals in H2O molecules in the aqueous solution to synthesize ammonia molecules. The device comprises a microliter liquid supply unit, an N2 gas source and a three-way spraying assembly, and is simple in structure and easy and convenient to operate. Therefore, according to the synthesis method and device provided by the invention, the NH3 can be efficiently synthesized at normal temperature through high-pressure gas atomization without additional addition of a catalyst or additional conditions and other auxiliary means, and further, the synthesis method and device can be applied to saccharide isomer distinguishing and quantitative analysis, food detection, medicine research and development and biomics research.

Description

Technical Field

[0001] The present invention relates to the fields of green chemistry technology and biomass omics, and specifically to a method, device and application for ammonia synthesis through the reaction at the gas-liquid interface of water microdroplets. Background Art

[0002] Ammonia (NH3) is the cornerstone of modern agriculture and industry, and is widely used in agricultural fertilizers, pharmaceutical manufacturing, and fine chemical fields, supporting the development of the global modern industry. At the same time, NH3 is also expected to become an energy carrier and hydrogen storage molecule for future sustainable development. In the chemical process of the origin of life, NH3 also plays a crucial role. It is not only a precursor of key biomolecules such as amino acids and nucleotides, but also plays an important role in many primitive metabolic pathways. Currently, the industrial production of ammonia mainly relies on the Haber-Bosch process. Even though this process has greatly increased the production of nitrogen fertilizers in the past century, due to the need to react high-purity nitrogen gas (N2) with hydrogen gas (H2) at high temperature (300–500 °C) and high pressure (100–300 atmospheres) under the action of a catalyst to produce ammonia. However, this process has significant problems such as high energy consumption, large carbon emissions, and strong dependence on fossil fuels, making it difficult to meet the requirements of sustainable development and restricting its long-term application in the context of sustainable development. Therefore, the development of low-energy-consuming, environmentally friendly, and renewable ammonia synthesis technologies has become the focus of common concern in the current scientific and industrial communities.

[0003] In recent years, with the rapid development of chemical reactions in microdroplets, ammonia synthesis technologies based on the gas-liquid interface have gradually become a research hotspot. In particular, the unique reaction environment at the gas-liquid interface of water microdroplets provides new ideas for ammonia synthesis. Due to its ultra-high surface area-to-volume ratio, spontaneous high electric field (up to 10 9 V / m), and the significant increase in the reaction rate occurring at the interface, some reactions that are difficult to carry out or have extremely slow reaction rates in the bulk solution can be efficiently carried out at the microdroplet interface. These technologies use water as the hydrogen source, replacing the need for high-purity hydrogen gas in traditional processes, significantly reducing the complexity of raw material preparation and transportation. Microdroplet technology not only provides a new tool for basic research at the laboratory scale, but also lays an important theoretical foundation and technical support for the popularization of future industrial ammonia synthesis technologies. Currently, on this basis, researchers have found that when water microdroplets are sprayed onto the surface of catalyst coating materials (such as Fe3O4, Nafion, etc.), nitrogen molecules are effectively activated under the action of the catalyst, and at the same time, water molecules provide a hydrogen source, further promoting the efficient synthesis of ammonia. In the contact electrification mechanism, an aqueous solution and solid particles such as polytetrafluoroethylene (PTFE) form a strong electric field at the interface, and the reduction reaction of nitrogen molecules is achieved through the charge transfer process, thereby generating ammonia.

[0004] In addition, CN 118125468 A discloses a method for ammonia synthesis based on plasma / inorganic solvent interface reaction. This method uses a nanoliter electrospray device as an interfacial microreactor. During the application of negative high voltage, corona discharge occurs at the capillary tip, and the plasma excitation generated by the corona discharge can generate reactive nitrogen species (such as N*, N2*, N2⁺) at the gas-liquid interface. These reactive nitrogen species rapidly generate ammonia during the interaction with water molecules. The method disclosed in this invention patent application requires an additional applied voltage and is applicable to plasma-assisted ammonia synthesis reactions, and does not involve its application in the differential analysis of disaccharide isomers such as maltose, isomaltose, sucrose, palatinose, melibiose, and turanose. Summary of the Invention

[0005] In view of this, to solve the above problems, the main object of the present invention is to provide a method, device, and application for ammonia (NH3) synthesis based on gas-liquid interface reaction, which can achieve efficient synthesis of NH3 at room temperature without the need for additional catalysts or external conditions (such as temperature, voltage, etc.) as auxiliary means, and can thus be applied to the differential analysis of disaccharide isomers.

[0006] To achieve the above object, the present invention provides the following technical solutions: The first aspect of the present invention provides a method for ammonia (NH3) synthesis based on gas-liquid interface reaction, including: using an aqueous solution and a gas containing N2 as raw materials. Under the condition that the aqueous solution is in a flowing state, it is atomized into micro-droplets by the gas containing N2 under an atomization air pressure greater than 50 psi, and at the same time, a gas-liquid interface with an electric field of 10 8 -10 9 V / m is formed. Under the action of the electric field at this gas-liquid interface, N2 molecules are activated at room temperature and combine with hydrogen free radicals in H2O molecules in the aqueous solution to synthesize ammonia molecules.

[0007] The aqueous solution described in the present invention refers to a solution containing water molecules H2O, which can be a pure aqueous solution or an inorganic aqueous solution. Among them, the "pure aqueous solution" described in the present invention includes tap water, distilled water, etc., and the inorganic aqueous solution refers to a solution containing inorganic substances and water, and the inorganic substances therein do not chemically react with NH3, such as inorganic base aqueous solutions, inorganic salt aqueous solutions, etc.

[0008] Based on the above, the atomization air pressure is 60-120 psi, so that water can be fully atomized into droplets, further realizing efficient and energy-saving ammonia synthesis.

[0009] Based on the above, the flow rate of the aqueous solution is 10-15 µL / min, so as to facilitate the formation of uniform micro-droplets at the gas-liquid interface and realize efficient and continuous synthesis of ammonia.

[0010] The second aspect of the present invention provides a water micro-droplet atomization device for ammonia synthesis, comprising: a microliter liquid supply unit, an N2 gas source, and a three-way spray assembly. Among them, the microliter liquid supply unit includes a capillary tube, and an aqueous solution can be continuously supplied to the three-way spray assembly through the capillary tube; The N2 gas source is used to supply N2-containing gas with a pressure greater than 50 psi to the three-way spray assembly and atomize the aqueous solution into micro-droplets; The three-way spray assembly includes a liquid inlet end, a gas inlet end, and an outlet end through which N2-containing gas can escape. The gas inlet end is connected to the N2 gas source. One end of the capillary tube is inserted into the three-way spray assembly from the liquid inlet end and penetrates through it, and extends out from the outlet end to form a spray port for spraying the micro-droplets; When the micro-droplets are sprayed out, a gas-liquid interface with an electric field of 10 8 -10 9 V / m is formed. Under the action of the electric field at this gas-liquid interface, N2 is activated at room temperature and combines with the hydrogen free radicals in the H2O molecules in the aqueous solution to synthesize ammonia.

[0011] Based on the above, the microliter liquid supply unit further includes a sampling needle and an injection pump installed on the capillary tube. The capillary tube is respectively connected to the sampling needle and the three-way spray assembly.

[0012] The third aspect of the present invention provides a method for synthesizing ammonia using the above water micro-droplet atomization device, including supplying an aqueous solution to the three-way spray assembly at a flow rate of 10-15 µL / min through the microliter liquid supply unit, and simultaneously supplying N2-containing gas with a pressure greater than 50 psi to the three-way spray assembly through the N2 gas source. The three-way spray assembly atomizes the aqueous solution therein into micro-droplets, forming a gas-liquid interface with an electric field of 10 8 -10 9 V / m. Under the action of the electric field at this gas-liquid interface, N2 molecules are activated at room temperature and combine with the hydrogen free radicals in H2O molecules to synthesize ammonia.

[0013] Research shows that in the micro-droplet interface environment, the binding effect between ammonia and disaccharide isomers is significantly enhanced. Using these characteristics, qualitative and quantitative analysis of disaccharide isomers can be achieved quickly and efficiently. Therefore, the fourth aspect of the present invention provides an application of the above ammonia synthesis method combined with mass spectrometry detection or a water micro-droplet atomization device combined with a mass spectrometer in the differentiation of sugar isomers, quantitative analysis of sugar isomers, food detection, pharmaceutical research and development, and biological omics research.

[0014] Compared with the prior art, the above technical solutions protected by the present invention have the following characteristics: 1) The above ammonia synthesis method provided by the present invention uses high-pressure N2-containing gas as the atomizing gas to atomize the aqueous solution into micro-droplets. Under normal temperature conditions, without any catalyst and external conditions (temperature, voltage, etc.), the water micro-droplets will have a high electric field at the gas-liquid interface. N2 can be activated at this interface and further react with the H radicals generated by water to complete the synthesis of ammonia; that is, the synthesis of NH3 can be achieved at the gas-liquid interface with a self-generated high electric field, providing a brand-new technical path for NH3 synthesis, breaking through the limitations of traditional processes in terms of energy consumption, temperature, pressure, etc., showing significant advantages of green, low-carbon, and sustainable, and having characteristics such as environmental protection and high energy efficiency.

[0015] 2) The above water micro-droplet atomization device provided by the present invention does not require external high temperature and high voltage. Through high-pressure gas atomization, NH3 can be generated at the water micro-droplet gas-liquid interface, with a simple structure and easy operation.

[0016] 3) The above ammonia synthesis method provided by the present invention combined with mass spectrometry detection technology can be used for the discrimination and quantitative analysis of sugar isomers, and then applied to food detection, pharmaceutical research and development, and biomics research.

[0017] Therefore, the above methods and devices provided by the present invention provide a new technical path for efficient, simple, and energy-saving ammonia synthesis, showing broad application potential in the fields of green chemistry and food science. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the water micro-droplet atomization device provided in Embodiment 1 of the present invention.

[0019] Figure 2 Disaccharide isomer detection and analysis device provided in Embodiment 2 of the present invention.

[0020] Figure 3 High-resolution mass spectrometry diagram after maltose reacts with ammonia at the water micro-droplet gas-liquid interface by using the method provided by the present invention.

[0021] Figure 4 For the device provided in Embodiment 2 of the present invention, according to the reaction distance and the pressure of the atomizing gas nitrogen, the influence results of the signal intensity and yield of [M+NH4] generated at the water micro-droplet gas-liquid interface +

[0022] Figure 5 Overall device structure for experimental characterization of the nitrogen source in the micro-droplet gas-liquid interface by the mixed gas system of the present invention.

[0023] Figure 6 In the gas-liquid interface formed by spraying in the water micro-droplet atomization device provided in Embodiment 4 of the present invention, 6 disaccharide isomers [M+NH4] +( m / z MS / MS mass spectrum at a collision energy of 20 eV is 360.15).

[0024] Figure 7 PCA and OPLS-DA analysis of multi-data of MS / MS fragment ions of six disaccharide isomers provided in Example 4 of the present invention.

[0025] Figure 8 Linear calibration curves constructed for relative quantification of disaccharide isomers in a binary mixture system based on the intensity ratio of fragment ion peaks provided in Examples 5-7 of the present invention.

[0026] Among them, the component symbols in the above figures: injection needle 1, quartz capillary 2, XYZ three-axis moving platform 3, X-axis 3-1, Z-axis 3-2, Y-axis 3-3, tee spray assembly 4, gas inlet end 4-1, liquid inlet end 4-2, outlet end 4-3, reaction distance 5, mass spectrometer 6, gas supply unit 7, CO2 gas source 7-1, N2 gas source 7-2, mixed gas 7-3, reaction chamber 8. Detailed implementation manners

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0028] Unless otherwise specified, the terms used in the present invention are all common terms in the art. The technical means adopted in the embodiments, such as preparation processes, analysis methods, etc., are all conventional means well-known to those skilled in the art. The reagents and products used are also commercially available. The sources, trade names of the reagents and those that need to list their composition components are indicated when they first appear.

[0029] At the gas-liquid interface of water microdroplets, the present invention first discovered that without a catalyst coating material, N2 molecules are effectively activated at the gas-liquid interface and directly react with protons provided by water molecules to generate ammonia molecules. Compared with the traditional Haber-Bosch process, it can be carried out under normal temperature and pressure conditions, avoiding the high energy consumption and safety hazards brought by high temperature and pressure. The high electric field of water microdroplets can not only promote the synthesis of ammonia, but also be used for the characteristic research of complex organic molecules such as disaccharides. As a basic molecule, ammonia has a strong binding ability with oxygen-containing molecules, especially forming a stable adduct with disaccharides ([M+NH4] + ). Through mass spectrometry analysis, after ammonia binds to disaccharides, it will show a characteristic fragment ion distribution. The [M+NH4] of different disaccharide isomers (such as maltose, isomaltose, and sucrose, etc.) +Unique ion signals are generated in the MS / MS fragmentation mode, and these signals can be used as effective fingerprint information to distinguish disaccharide isomers. Research shows that in the microdroplet interface environment, the binding effect of ammonia with disaccharide isomers is significantly enhanced, and these characteristics can be used to quickly and efficiently achieve the qualitative and quantitative analysis of disaccharide isomers.

[0030] In a first aspect of the present invention, a method for synthesizing ammonia (NH3) based on a gas-liquid interface reaction is provided, including: using an aqueous solution and a gas containing N2 as raw materials, the aqueous solution in a flowing state is atomized into microdroplets by the gas containing N2 under an atomization pressure greater than 50 psi, and at the same time, a gas-liquid interface with an electric field of 10 8 -10 9 V / m is formed. Under the action of the electric field at this gas-liquid interface, N2 molecules are activated at room temperature and combine with hydrogen free radicals in H2O molecules in the aqueous solution to synthesize ammonia molecules.

[0031] In this way, in this ammonia synthesis method, by using a high-pressure gas containing N2 as the atomizing gas, the aqueous solution is atomized into microdroplets. At room temperature, without any catalyst and external conditions (such as temperature, voltage, etc.), the water microdroplets will have a high electric field at the gas-liquid interface by themselves. N2 can be activated at this interface and further react with the H free radicals generated by water to complete the synthesis of ammonia; that is, the synthesis of NH3 can be achieved at the gas-liquid interface with a high electric field by itself, providing a new technical path for NH3 synthesis, breaking through the limitations of traditional processes in terms of energy consumption, temperature, pressure, etc., and showing significant advantages of being green, low-carbon, and sustainable, with characteristics such as environmental protection and high energy efficiency.

[0032] Among them, the aqueous solution described in the present invention includes tap water, distilled water, inorganic aqueous solutions, etc.

[0033] In the present invention, the atomization pressure is 60 - 120 psi, such as 60 psi, 70 psi, 80 psi, 90 psi, 100 psi, 110 psi, 120 psi. In this way, water can be fully atomized into droplets, and further achieve efficient and energy-saving synthesis of ammonia.

[0034] In the present invention, the gas containing N2 is air or nitrogen with a purity of 99.99%.

[0035] In the present invention, the flow rate of the aqueous solution is 10 - 15 µL / min, such as 10 µL / min, 11 µL / min, 12 µL / min, 13 µL / min, 14 µL / min, 15 µL / min, etc. In this way, it is convenient to form uniform microdroplets at the gas-liquid interface and achieve efficient and continuous synthesis of ammonia.

[0036] The second aspect of the present invention provides a water micro-droplet atomization device for ammonia synthesis. Without the need for externally applied high temperature and high voltage, NH3 can be generated at the gas-liquid interface of water micro-droplets. The structure is simple and the operation is easy and feasible.

[0037] Specifically, a water micro-droplet atomization device includes: a microliter liquid supply unit, an N2 gas source, and a three-way spray assembly. Among them, the microliter liquid supply unit includes a capillary tube, which can continuously supply an aqueous solution to the three-way spray assembly through the capillary tube; the N2 gas source is used to supply N2-containing gas with a pressure greater than 50 psi to the three-way spray assembly and atomize the aqueous solution into micro-droplets; the three-way spray assembly includes a liquid inlet end, a gas inlet end, and an outlet end from which N2-containing gas can escape. The gas inlet end is connected to the N2 gas source. One end of the capillary tube is inserted into the three-way spray assembly from the liquid inlet end and penetrates through it, and extends out from the outlet end to form a spray nozzle for spraying the micro-droplets; when the micro-droplets are sprayed out, a gas-liquid interface with an electric field of 10 8 -10 9 V / m is formed. Under the action of the electric field at this gas-liquid interface, N2 is activated at room temperature and combines with the hydrogen radicals in the H2O molecules in the aqueous solution to synthesize ammonia.

[0038] The microliter liquid supply unit further includes a sampling needle and an injection pump installed on the capillary tube. The capillary tube is respectively connected to the sampling needle and the three-way spray assembly. Among them, the injection pump can accurately control the flow rate of the aqueous solution to ensure that the aqueous solution in the sampling needle forms uniform micro-droplets when flowing through the outlet of the capillary tube.

[0039] The inner diameter of the outlet end is larger than the outer diameter of the capillary tube. In particular, the inner diameter of the outlet end is larger than the outer diameter of the spray nozzle of the capillary tube, which can ensure that nitrogen escapes from the outlet end and provides raw materials for synthesizing ammonia at the gas-liquid interface.

[0040] The inner diameter of the capillary tube can be 50-100 µm, such as 50 µm, 75 µm, 100 µm, etc., to ensure that micro-droplet sprays with smaller particle sizes can be generated to form a gas-liquid interface. The material of the capillary tube can be glass, quartz, etc. Quartz capillary tubes are preferably used to reduce impurities and improve product purity.

[0041] The third aspect of the present invention provides a method for synthesizing ammonia using the above-mentioned water micro-droplet atomization device, including supplying an aqueous solution to the three-way spray assembly through the microliter liquid supply unit at a flow rate of 10-15 µL / min, and simultaneously supplying N2-containing gas with a pressure greater than 50 psi to the three-way spray assembly through the N2 gas source. The three-way spray assembly atomizes the aqueous solution therein into micro-droplets and sprays them out from the capillary outlet at the outlet end, forming a gas-liquid interface with an electric field of 10 8-10 9 The gas-liquid interface of an electric field of V / m. Under the action of the electric field at this gas-liquid interface, N2 molecules are activated at room temperature and combine with hydrogen free radicals in H2O molecules to synthesize ammonia, which is ejected from the capillary outlet at the outlet end. Preferably, the air pressure of the gas containing N2 is 60 - 120 psi.

[0042] Ammonia, as a basic molecule, has a strong binding ability with oxygen-containing molecules, especially forming a stable adduct with disaccharides ([M+NH4] + ). Through mass spectrometry analysis, ammonia will show a characteristic fragment ion distribution after binding with disaccharides. The [M+NH4] + of different disaccharide isomers (such as maltose, isomaltose, and sucrose, etc.) generates unique ion signals in the MS / MS fragmentation mode. These signals can be used as effective fingerprint information to distinguish disaccharide isomers. Research shows that in the microdroplet interface environment, the binding effect of ammonia with disaccharide isomers is significantly enhanced. Using these characteristics, qualitative and quantitative analysis of disaccharide isomers can be achieved quickly and efficiently.

[0043] Therefore, the present invention further combines the adduct reaction of ammonia with target molecules and develops a method for distinguishing and relatively quantifying disaccharide isomers based on the microdroplet gas-liquid interface technology. NH3 is generated by atomizing an aqueous solution with high-purity N2. NH3 molecules bind to disaccharide molecules at the gas-liquid interface to form a stable [M+NH4] + adduct. Subsequently, the characteristic fragment ion abundances of the [M+NH4] + adduct are analyzed in the tandem secondary mass spectrometry MS / MS mode, successfully distinguishing six common disaccharide isomers, including maltose, isomaltose, sucrose, palatinose, melibiose, and turanose. In the relative quantification of disaccharide isomers, the present invention establishes a calibration curve by regulating the mixing ratio of disaccharides and based on the variation law of the signal intensity ratio of target fragment ions for quantitative analysis of disaccharide isomers in a binary mixed system.

[0044] Specifically, the fourth aspect of the present invention provides a method for distinguishing disaccharide isomers, including the steps: [M+NH4] + Adduct generation: Using a disaccharide aqueous solution as the sample solution and a gas containing N2 as the atomizing gas. The disaccharide aqueous solution is injected into the capillary and continuously flows in the capillary. The disaccharide aqueous solution in the capillary is atomized into microdroplets and ejected from the ejection port of the capillary at a gas pressure greater than 50 psi, while forming a self-contained 10 8 -10 9At the gas-liquid interface of an electric field of V / m, under the action of the electric field at the gas-liquid interface, N2 molecules are activated at room temperature and combine with hydrogen free radicals in H2O molecules in the disaccharide aqueous solution to synthesize NH3 molecules. The NH3 molecules combine with the disaccharide molecules in the disaccharide aqueous solution to form [M+NH4]. + adduct; Mass spectrometry detection: Using a mass spectrometer to fragment the adduct [M+NH4]. + to form characteristic fragment ions and detect the intensity and abundance distribution of the characteristic fragment ions; Disaccharide isomer discrimination: Distinguish disaccharide isomers according to the intensity and abundance distribution rules of the characteristic fragment ions of different disaccharide isomers.

[0045] Among them, the steps for generating the [M+NH4]. + adduct include: The disaccharide aqueous solution flows at a flow rate of 10-20 µL / min and is atomized into the microdroplets by the N2-containing gas under a pressure of 60-120 psi.

[0046] In the gas-liquid interface environment, the generation of ammonia and the binding effect with disaccharide molecules are significantly enhanced. The mass spectrometry signal intensity of the [M+NH4]. + conjugate is closely related to the spatial structure of the disaccharide isomer. The distance between the inlet of the mass spectrometer and the ejection port (the formation outlet of the microdroplets) of the capillary is adjustable, and this distance is defined as the reaction distance. By optimizing the reaction distance and the gas pressure of the atomizing gas, the mass spectrometry signal intensity and the discrimination accuracy are further improved; preferably, the reaction distance is 5-20 mm.

[0047] The method for forming the characteristic fragment ions includes: For higher ion selectivity and less interference, and to be able to analyze the target ion [M+NH4]+ more precisely, the isolation width is set to a narrow width, such as 1-2. m / z and a collision energy of 10-30 eV is used to fragment the adduct [M+NH4]. + That's it. The disaccharides in the disaccharide aqueous solution include but are not limited to: maltose, isomaltose, sucrose, palatinose, melibiose, turanose and their mixtures. The characteristic fragment ions include but are not limited to m / z 342.14, 325.11, 163.06, 145.05, 127.04, 97.03, 85.03, etc.

[0048] Among them, the steps for disaccharide isomer discrimination distinguish the disaccharide isomers by comparing the peak values and relative abundances of the characteristic fragment ions.

[0049] The steps for identifying the disaccharide isomers further include: combining principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to perform multivariate statistical analysis on the distribution of the characteristic fragment ions, and further verifying the accuracy of differentiating the disaccharide isomers.

[0050] The fifth aspect of the present invention provides a method for relative quantitative detection of disaccharide isomers in a binary mixed system. Based on the above method for differentiating disaccharide isomers, this detection method can quickly and efficiently achieve quantitative detection and analysis of disaccharide isomers.

[0051] Specifically, a method for relative quantitative detection of disaccharide isomers in a binary mixed system based on the above differentiation method includes the steps: Prepare a series of binary mixed aqueous solutions with different ratios of disaccharide isomers, and the total concentrations of the two disaccharide isomers in the binary mixed aqueous solution are the same; Utilize the above microdroplet gas-liquid interface reaction to generate ammonia molecules, and react with the disaccharide isomers in the binary mixed aqueous solution respectively to form corresponding [M+NH4] + adducts; Utilize a mass spectrometer to fragment the adduct [M+NH4] in the binary mixed aqueous solution + to form characteristic fragment ions; use the mass spectrometer to detect the intensities of the characteristic fragment ions in the binary mixed aqueous solution, and calculate the relative ratios of the intensities of the characteristic fragment ions therein; Establish a calibration curve according to the following formula to calculate the relative molar content of the disaccharide isomers in the binary mixed aqueous solution: , , ; wherein, RI mix is the relative ratio of the intensities of the characteristic fragment ions in the binary mixed aqueous solution; RI a and RI b respectively represent the relative intensities of the corresponding characteristic fragment ions when the disaccharide isomers a and b exist alone; α a and α b are respectively the molar (or mass) percentages of the disaccharide isomers a and b in the binary mixed aqueous solution, and satisfy α a + α b = 1, C a and C bThe configuration ratio of disaccharide isomers a and b at a known concentration ratio, where k and t are constants obtained by linear fitting.

[0052] Using the calibration curve, convert the characteristic fragment ion signal of the unknown sample into the relative content of the isomers.

[0053] Among them, the mass ratio or molar ratio of disaccharide isomers a and b in the binary mixed aqueous solution is 20:1 - 1:100, and the relative intensity ratios of characteristic fragment ions for different disaccharide isomer combinations include but are not limited to: palatinose and turanose: m / z 145 / 259, isomaltose and palatinose: m / z 145 / 325, sucrose and melibiose: m / z 145 / 163.

[0054] The sixth aspect of the present invention provides a disaccharide isomer detection and analysis device, which includes a water microdroplet atomization device. Without high temperature and external high voltage, [M+NH4] can be generated at the water microdroplet gas-liquid interface + , and the operation is simple and easy; there is no need to add any additional derivatization reagents to react with the sample compounds, nor to introduce metal or non-metal ligands with complex structures to form complexes with sugars. Only the sample solution to be measured needs to be directly injected, omitting the complicated pretreatment steps in the traditional method; the isomers can be quickly distinguished through tandem mass spectrometry technology, and the time for collision-induced dissociation is at the millisecond level. There is no need for separation equipment such as liquid chromatography or ion mobility spectrometry, thus making the separation method of disaccharide isomers efficient and simple.

[0055] Specifically, a disaccharide isomer detection and analysis device includes: The above-mentioned water microdroplet atomization device is used to generate ammonia molecules through the reaction at the microdroplet gas-liquid interface and react with disaccharide isomers to form [M+NH4] + adducts; A mass spectrometer includes an inlet port opposite to the ejection port of the capillary, which is used to monitor in real time the mass spectrometry detection signal of the [M+NH4] + adducts generated by the reaction at the microdroplet gas-liquid interface.

[0056] Based on the above detection and analysis device, it further includes an XYZ three-axis moving platform, which is used to fixedly install the three-way spray assembly and adjust the relative position of the ejection port of the capillary and the inlet port of the mass spectrometer; so that the ejection port of the capillary in the three-way spray assembly is coaxially arranged with the inlet port of the mass spectrometer, that is, at the same height, realizing adjustable and controllable reaction distance. To ensure the best reaction distance of nitrogen at the gas-liquid interface, the position of the platform can be precisely adjusted through the XYZ three-axis moving platform, which can optimize the desolvation efficiency of the sample and the reaction conditions, thereby significantly improving the accuracy and repeatability of the disaccharide isomer discrimination detection.

[0057] Among them, the mass spectrometer is an existing mass spectrometry detection device, preferably a high-resolution mass spectrometer, which can perform MS / MS analysis of [M+NH4] in real time. + adducts.

[0058] In short, ammonia combines with disaccharide molecules in the solution at the gas-liquid interface of microdroplets to form stable [M+NH4] + adducts, which exhibit characteristic fragment ion distributions in the tandem secondary mass spectrometry MS / MS mode. Using these characteristic ions, rapid differentiation and quantitative analysis of disaccharide isomers of maltose, isomaltose, sucrose, palatinose, melibiose, and turanose can be achieved.

[0059] Therefore, the seventh aspect of the present invention provides an application of any one of the above ammonia synthesis methods, water microdroplet atomization devices, disaccharide isomer differentiation methods, relative quantitative detection methods, and disaccharide isomer detection and analysis devices in ammonia synthesis, carbohydrate isomer differentiation and quantitative analysis, food detection, pharmaceutical research and development, or biomics research.

[0060] The above method provided by the present invention realizes the efficient synthesis of NH3 under normal temperature and catalyst-free conditions by adopting a gas-liquid interface reaction device of microdroplets and adjusting the optimal reaction distance on the XYZ three-axis moving platform, without relying on traditional high-temperature and high-pressure processes. This process not only avoids the need for high-purity hydrogen in traditional ammonia synthesis methods, but also significantly reduces carbon dioxide emissions and energy consumption generated by hydrogen production, storage, and transportation, reflecting the characteristics of green and sustainable development. In addition, the present invention does not require the use of catalysts or complex electrochemical and photochemical devices, simplifies the ammonia synthesis process flow, and reduces equipment investment and operating costs. With the help of the high-intensity electric field (~10 9 V / m) formed at the gas-liquid interface of microdroplets, the generation efficiency of ammonia and its binding ability with disaccharides are significantly improved. By optimizing the gas-liquid interface conditions of microdroplets, the present invention realizes the efficient in-situ generation and enrichment of ammonia, and provides a unique technical means for the rapid separation and quantitative analysis of disaccharide isomers.

[0061] The above water microdroplet atomization device and disaccharide isomer detection and analysis device provided by the present invention have a simple structure, do not require complex modification of existing mass spectrometry devices, are easy to operate, and are easy to promote and apply. This technology provides a new technical path for efficient, simple, and energy-saving ammonia synthesis and disaccharide isomer separation, demonstrating broad application potential in the fields of green chemistry and food science.

[0062] The technical solutions of the present invention will be further described in detail below through specific embodiments. Among them, the water microdroplet atomization device and the disaccharide isomer detection and analysis device used in the following examples are shown in Example 1 and Example 2 respectively.

[0063] Example 1 Water Microdroplet Atomization Device and Ammonia Synthesis As Figure 1 shown, this example provides a water microdroplet atomization device for synthesizing ammonia (NH3), which mainly consists of a microliter liquid supply unit, an N2 gas source 7-2, and a three-way spray assembly 4. The microliter liquid supply unit is mainly used to provide an aqueous solution to the three-way spray assembly 4, including a sampling needle 1, a capillary 2 for connecting the sampling needle 1 and the three-way spray assembly 4, and an injection pump installed on the capillary 2. The inner diameter of the capillary 4 can be 50-100 µm, and its material can be glass, quartz, etc. In this example, the capillary 4 is a quartz capillary with an inner diameter of 75 µm.

[0064] The three-way spray assembly 4 includes a liquid inlet end 4-2 connected to the sampling needle 1, an outlet end 4-3, and an air inlet end 4-1 connected to the N2 gas source 7-2, with the capillary 2 passing through it internally. One end of the capillary 2 is inserted into the three-way spray assembly 4 from the liquid inlet end 4-2 and passes through it, and the outlet end 4-3 extends to form a spray port for spraying microdroplets. The injection pump can accurately control the flow rate of the aqueous solution to ensure that the aqueous solution in the sampling needle 1 forms uniform microdroplets when flowing through the outlet of the capillary 2. The N2 gas source 7-2 is used to provide a gas containing N2 with a pressure greater than 50 psi to the three-way spray assembly. Among them, the N2 gas source 7-2 includes air or pure nitrogen (purity 99.99%). In this example, the N2 gas source 7-2 is pure nitrogen.

[0065] The three-way spray assembly 4 can atomize the aqueous solution into microdroplets and simultaneously form a gas-liquid interface with an electric field of 10 8 -10 9 V / m. Under the action of the electric field at this gas-liquid interface, N2 is activated at room temperature and combines with the hydrogen radicals in the H2O molecules in the aqueous solution to synthesize ammonia.

[0066] This example also provides a method for synthesizing NH3 based on the above device. The specific method includes the following steps: S1) Use an injection pump to transport pure water H2O to the three-way spray assembly 4 through the sampling needle 1 at a flow rate of 10-15 µL / min; at the same time, connect the air inlet end 4-1 of the three-way spray assembly 4 to the N2 gas source 7-2 through a gas pipeline to provide a pure nitrogen gas source to the pure water H2O; the nitrogen enters the three-way spray assembly 4 under a pressure of 60-120 psi and atomizes the pure water H2O flowing in the capillary 2 it passes through into microdroplets; S2) Under normal temperature, without a catalyst and without applying an external voltage or other auxiliary components to the capillary 2, N2 with a pressure of 60 - 120 psi is ejected from the outlet end 4 - 3 and forms a high-speed gas-liquid interface together with the micro-droplets formed by the atomization of purified H2O; the micro-droplets have a strong electric field as high as 10 9 V / m at the interface, reducing the activation energy of the N≡N bond, so that N2 molecules are more likely to break and be activated at this interface; the activated nitrogen atoms (or nitrogen-containing free radicals) react with the hydrogen atoms (or hydrogen free radicals) provided by water molecules to generate NH3 and accumulate at the gas-liquid interface. Among them, during the synthesis of NH3, the flow rate of the pure water H2O can be 10, 11, 12, 13, 14, 15 µL / min, etc., and the pressure of nitrogen can be 60 psi, 70 psi, 80 psi, 90 psi, 100 psi, 110 psi, 120 psi, etc.

[0067] Therefore, the above water micro-droplet atomization device for synthesizing ammonia provided in this embodiment is an efficient system for generating a gas-liquid interface of micro-droplets. The core design of this device includes a three-way connector (three-way spray assembly 4), the two ends of which are connected by a precisely machined capillary. The upper end is connected to a nitrogen source as the atomizing gas. By precisely controlling the nitrogen flow rate, it is ensured that the solution in the sampling needle forms uniform micro-droplets when flowing through the capillary outlet, thereby realizing the rapid, efficient, and green synthesis of ammonia.

[0068] Example 2 Disaccharide Isomer Detection and Analysis Device Please refer to Figure 2 , this embodiment provides a disaccharide isomer detection and analysis device, which includes the water micro-droplet atomization device provided in Example 1, an XYZ three-axis moving platform 3, and a mass spectrometer 6. The water micro-droplet atomization device is used to generate ammonia molecules through the reaction of the gas-liquid interface of micro-droplets and react with disaccharide isomers to form [M + NH4] + adducts; the XYZ three-axis moving platform 3 is mainly used to precisely adjust the relative positions of the three-way spray assembly 4 and the mass spectrometer; the mass spectrometer is mainly used to real-time monitor the mass spectrometry detection signals of the ammonia molecules and [M + NH4] + adducts generated by the reaction of the gas-liquid interface of micro-droplets. In this embodiment, the mass spectrometer 6 is a high-resolution mass spectrometer.

[0069] The capillary 2 passing through the three-way spray assembly 4 extends from the outlet end 4-3, and the injection port formed faces the injection port of the mass spectrometer 6. The distance between the injection port of the capillary 2 and the injection port of the mass spectrometer 6 is defined as the reaction distance 5. The three-way spray assembly 4 is fixedly installed on an acrylic plate with dimensions of 5 cm × 8 cm, and the acrylic plate is perpendicular to the XY plane of the XYZ three-axis moving platform 3. By adjusting the positions of the X-axis 3-1, Z-axis 3-2, and Y-axis 3-3 in the XYZ three-axis moving platform 3, the desolvation efficiency of the detected sample and the reaction conditions, the optimal reaction conditions for ammonia synthesis, can be optimized, thereby significantly improving the accuracy and repeatability of the detection and differentiation of disaccharide isomers.

[0070] Preliminary Mass Spectrometry Characterization of NH3 Synthesis Experiments found that NH3 generated at the gas-liquid interface of microdroplets shows high solubility in aqueous solutions and is prone to combine with protons to form ammonium ions under non-alkaline conditions. In addition, NH3 tends to form stable bonds with oxygen-containing molecules, especially sugar compounds, through non-covalent interactions such as hydrogen bonds. Therefore, maltose (MT) was selected as a marker for NH3, and high-resolution mass spectrometry technology was used to qualitatively analyze the generated NH3 to verify the synthesis of ammonia.

[0071] Combined Figure 2 , the specific verification method for ammonia includes the following steps: S1) Use a syringe pump to deliver a 100 μmol / L aqueous solution of maltose to the three-way spray assembly 4 through the injection needle 1 at a flow rate of 15 μL / min; at the same time, connect the inlet end 4-1 of the three-way spray assembly 4 to the N2 gas source 7-2 through a gas pipeline to provide a pure nitrogen gas source for the aqueous solution of maltose; the nitrogen gas enters the three-way spray assembly 4 at a pressure of 100 psi and atomizes the aqueous sugar solution flowing through the capillary 2 therein into microdroplets. S2) Under the conditions of normal temperature, without a catalyst, and without applying an external voltage to the capillary 2, N2 at a pressure of 100 psi is ejected from the outlet end 4-3 through the capillary and forms a high-speed gas-liquid interface together with the microdroplets atomized from the aqueous solution of maltose; the microdroplets have a strong electric field of up to 10 9 V / m at the interface, reducing the activation energy of the N≡N bond, so that nitrogen molecules are more likely to break and be activated at this interface; the activated nitrogen atoms (or nitrogen-containing free radicals) react with the hydrogen atoms (or hydrogen free radicals) provided by water molecules to generate NH3 and accumulate at the gas-liquid interface. S3) Precisely adjust the relative positions of the injection port of the capillary 2 and the injection port of the mass spectrometer 6 through the XYZ three-axis moving platform 3 to achieve precise adjustment of the reaction distance 5. The adjustment accuracy in the X direction 3-1, Y direction 3-3, and Z direction 3-2 is all 10 μm.

[0072] Furthermore, under the conditions of the optimal reaction distance and atomizing gas pressure, the mass spectrometer can accurately detect the generated ammonia and the related mass spectrometry signals of its adduct ions with maltose, significantly improving the reproducibility and accuracy of the ammonia synthesis process.

[0073] Based on the above, a pure aqueous solution of maltose without any added ions forms microdroplets under the action of N2 and enters the mass spectrometer for detection. In the high-resolution mass spectrometry Figure 3 as shown, an obvious m / z signal peak of 360.1499 can be observed, and this signal peak is considered to be [MT + NH4] + , and the calculated exact mass number is 360.1500. The deviation (Δ m ) between the two values is only 0.28 ppm, which fully meets the error range allowed by the high-resolution mass spectrometer. In addition, a small amount of [MT + Na] + ( m / z 365.1053) and [MT + K] + ( m / z 381.0794) signal peaks are also detected. The result of [MT + NH4] + is further verified by tandem mass spectrometry in the positive ion mode with a collision energy of 20 eV ( Figure 6 a), and the generated fragment ions m / z are 342.14, 325.11, 163.06, 145.05, 127.04, 97.03, 85.03, etc. The generation of these fragments is mainly due to the stepwise hydrolysis of the disaccharide and the common consecutive ring-opening reactions in the carbohydrate fragmentation pathway. Among them, m / z the peak with a value of 325.11 is generated by the m / z loss of one molecule of NH3 (17 Da) from the fragment ion of 342.14, further verifying the generation of NH3. Therefore, the water microdroplet gas-liquid interface method of this device successfully realizes the synthesis of NH3.

[0074] Effect test of atomizing gas pressure on [MT + NH4] + The following combines Figure 4 the results shown in (left) and the relevant test data to illustrate the effect of atomizing gas pressure on the generation of [MT + NH4] + . Those skilled in the art can understand the regulation principle of the gas-liquid interface reaction efficiency in the microdroplet of the present invention according to the following content, but it is not limited to this embodiment.

[0075] To evaluate the generation efficiency of [MT + NH4] + , based on Figure 3 ​For the generated ion adducts, the present invention defines the yield of the product as: (1) Wherein the content in the brackets of formula (1) represents the peak intensity of the corresponding ion in the mass spectrum.

[0076] Basically, the specific verification method of ammonia provided in "Preliminary Mass Spectrometric Characterization of NH3 Synthesis" is adopted. The main difference is that the atomization pressure in this experiment is between 60 - 100 psi, and other method steps are the same. The results are as Figure 4 (left) shows that when the atomization gas pressure is gradually increased from 60 psi to 100 psi, the peak intensity of [MT + NH4] + and the product yield both increase significantly. The main reason is that as the atomization gas pressure increases, the particle size of the micro-droplets becomes smaller, and the ratio of surface area to volume increases accordingly, thereby strengthening the water-gas interface effect, making the synthesis of ammonia and its adduct formation process with the target molecule (such as maltose) more efficient. Thus, it can be seen that by increasing the atomization gas pressure, the reaction efficiency at the gas-liquid interface of the micro-droplets can be effectively enhanced.

[0077] Experiment on the influence of reaction distance on [MT + NH4] + Basically, the specific verification method of ammonia provided in "Preliminary Mass Spectrometric Characterization of NH3 Synthesis" is adopted. The main difference is that in this experiment, the injection distance (i.e., reaction distance 5) of the micro-droplet gas-liquid interface is further adjusted within the range of 5 mm to 20 mm, and other method steps are the same, to evaluate the influence of the reaction distance on [MT + NH4] + generated. The results are as Figure 4 (right) shows that as the reaction distance increases from 5 mm to 10 mm, both the ion signal intensity and the product percentage show an upward trend and reach a peak at 10 mm, with the highest generation efficiency approaching 95%. When the distance exceeds 10 mm, both of them decrease significantly, and the product percentage drops to about 60% at 20 mm. This phenomenon indicates that the micro-droplets need sufficient flight and gas-liquid interface reaction time within a certain range to complete effective desolvation and ammonia adduct formation reactions; but when the distance is too large, the micro-droplets are prone to dispersion or secondary coalescence, resulting in a weakened gas-liquid interface, and at the same time, the longer distance affects the transmission efficiency of mass spectrometry for its detection, ultimately reducing the generation efficiency of [MT +NH4] + . Therefore, choosing an appropriate reaction distance, such as 10 mm, is crucial for achieving high ionization efficiency and product yield.

[0078] Experimental characterization of nitrogen source The following is combined with Figure 5The experimental characterization of the nitrogen source in the embodiments of the present invention will be described in detail in connection with the specific experimental procedures. It should be understood that the disclosed embodiments are only used to illustrate the principles of the present invention and are not used to limit the protection scope of the present invention.

[0079] As shown in Figure 5, in order to confirm that the nitrogen atoms in the synthesized NH3 come from the atomized gas N2, a closed reaction chamber 8 that can be connected to the inlet of the mass spectrometer 6 was designed and constructed. The capillary 2 is inserted from the front end of the reaction chamber 8 to ensure that the sample can be accurately transported to the gas-liquid interface of the micro-droplet for reaction. To maintain the pressure balance in the reaction chamber, a gas outlet 8-1 is provided at the bottom of the reaction chamber 8 to allow excess gas to escape. The gas supply unit 7 includes flow regulating valves connected to the N2 gas source 7-2 and the CO2 gas source 7-1. The mixed gas 7-3 mixed in a predetermined ratio is introduced into the reaction chamber 8 through the inlet end 4-1 of the three-way spray assembly 4 by the gas mixing device, so as to establish a controllable gas environment during the experiment. Except for the gas composition, other experimental conditions (including sample concentration, temperature, distance between the sprayer and the inlet of the mass spectrometer, sheath gas pressure, etc.) are kept consistent to systematically characterize and compare the formation process of NH3 under different gas environments. The experiment was carried out under six gas conditions: synthetic air, pure N2, and mixed gases of 80% N2 + 20% CO2, 50% N2 + 50% CO2, 20% N2 + 80% CO2, and pure CO2.

[0080] The mass spectrometry results show that + the formation of + [MT + NH4] + is significantly dependent on the presence of the N2 atomized gas. Under the condition of pure N2, the product percentage of + [MT + NH4] + is slightly higher than that under the synthetic air condition. In the mixed gas of N2 and CO2, with the increase of the CO2 ratio, the formation of + [MT + NH4] + gradually decreases. At the same time, the peak intensities of

[0081] [MT + Na] + and + [MT + K] + gradually increase, indicating that the ionization or adduct formation is enhanced in a high CO2 environment. When pure CO2 is used as the atomized gas, no signal of + [MT + NH4]

[0081] is observed. This result shows that if N2 participation is lacking, the nitrogen molecules cannot be effectively activated to synthesize ammonia, and the adduct reaction cannot form + [MT + NH4]

[0081] . It is further confirmed that N2 is the key source for the formation of NH3.The experimental results provide important evidence for the mechanism of ammonia synthesis at the gas-liquid interface of microdroplets in the present invention, and also provide a reference basis for further optimizing the reaction atmosphere and exploring the influence of other gas components on ammonia synthesis. The above embodiments do not constitute a limitation to the present invention. Those skilled in the art can make various improvements and deformations to the present invention without departing from the spirit and scope of the present invention, and still fall within the protection scope of the present invention.

[0082] Example 3 Method for distinguishing disaccharide isomers This embodiment provides a method for distinguishing disaccharide isomers, including the steps of: first, using an aqueous disaccharide solution as a sample solution, using a gas containing N2 as an atomizing gas, synthesizing NH3 by gas-liquid interface reaction, and combining NH3 molecules with disaccharide molecules in the aqueous disaccharide solution to form [M+NH4] + adduct; using a mass spectrometer to detect the [M+NH4] + adduct to obtain the mass spectrometry signal information of characteristic fragment ions; distinguishing disaccharide isomers according to the mass spectrometry signal information of characteristic fragment ions.

[0083] That is, on the basis of generating ammonia at the gas-liquid interface of microdroplets, this embodiment of the present invention further utilizes the binding characteristics of ammonia and saccharide substances to realize the distinction and analysis of disaccharide isomers. The specific implementation steps are as follows: S4) Inject the sample solution from the end of the capillary 2 through the injection needle 1, and the sample solution is an aqueous disaccharide solution; in this embodiment, disaccharides such as maltose, isomaltose, sucrose, palatinose, melibiose, and turanose are respectively prepared into aqueous solutions with a concentration of 100 µmol / L, and are transported into the three-way connector 4 through the injection pump via the injection needle 1. The atomizing pressure and the flow rate of the aqueous solution in this step are the same as those in step S1) of the aforementioned "Preliminary mass spectrometry characterization of NH3 synthesis"; S5) Under normal temperature conditions, without any catalyst and applying an external voltage to the capillary 2, a high electric field at the gas-liquid interface of microdroplets is formed after the aqueous disaccharide solution is atomized by N2. At this time, NH3 is synthesized in real time at the interface, and further NH3 combines with disaccharide molecules to form [M+NH4] + ion adduct peak, which can be visually observed in mass spectrometry detection; S6) By optimizing the reaction distance and atomizing gas pressure, the [M+NH4] + signal peak reaches the best intensity; in this embodiment, by adjusting the XYZ three-axis moving platform 3 to change the reaction distance 5, and finely adjusting the flow rate or atomizing pressure of the aqueous disaccharide solution, the [M+NH4] + peak intensity and yield reach the best values; S7) Select [M+NH4] +As the parent ion, it undergoes MS / MS fragmentation through collision-induced dissociation to form characteristic fragment ions, and the intensity and abundance distribution characteristics of the characteristic fragment ions are detected; in this embodiment, the isolation width is set to 1 m / z , the collision energy is 20 eV, and the characteristic fragment ion spectrum and its relative abundance are recorded. The results are as Figure 6 shown; S8) By comparing the distribution of characteristic fragment ions generated after collision dissociation of different disaccharides, rapid differentiation of disaccharide isomers is achieved.

[0084] From Figure 6 it can be seen that: the typical fragment ions detected for the 6 disaccharide isomers in this embodiment mainly include m / z 342.14, 343.12, 325.11, 163.06, 145.05, 127.04, 97.03, 85.03, etc. Among them, m / z 342.14 breaks m / z 325.11 shows a mass loss of about 17 Da, indicating an obvious NH3 loss process, which conforms to the common multi-step hydrolysis and step-by-step ring-opening fragmentation rules of carbohydrates. For melibiose, isomaltose, and sucrose, obvious [M + H] + peaks ( m / z 343.12) can also be detected in the experiment. Research shows that glycosidic bond types, such as the α(1→6) bond of melibiose and isomaltose and the α(1→2) non-reducing bond of sucrose, are more likely to undergo linear protonation or NH3 loss under these conditions to generate relatively stable protonated ions. Due to its special non-reducing structure, sucrose will show relatively abundant fragment peaks at m / z 198.10 and 180.09 during the collision-induced dissociation process, showing that it first forms monosaccharide fragment ions ( + 198.10) in cooperation with NH4 m / z , and then further dehydrates to generate m / z 180.09.

[0085] The fragment ions of the 6 disaccharides are visualized using principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The results are as Figure 7 shown, and different disaccharide isomers can be clearly distinguished. The relative abundances of each ion signal and the fragmentation pathways together constitute the differential discrimination characteristics. According to Figure 7 the PCA result analysis shown in a, the cumulative interpretation rate R 2 X reaches 0.995, indicating that the model can explain 99.5% of the original variable information and has a good data fitting degree; while Q 2is 0.976, indicating that the prediction ability of the model is relatively reliable during the cross-validation process. In Figure 7 In the OPLS-DA model shown in b, the cumulative interpretation rate R 2 X of the model is 1, and R 2 Y is 0.999, indicating that the fitting degree of the model to the data and the interpretation degree of the classification variables are both extremely high; at the same time, Q 2 can reach 0.998, indicating that the prediction ability for unknown samples is also extremely excellent.

[0086] Therefore, by performing MS / MS collision-induced dissociation on the [MT + NH4] + ions formed by the addition of disaccharides and ammonia at the high electric field environment of the microdroplet gas-liquid interface, and combining multivariate statistical analyses including PCA and OPLS-DA, this example can achieve rapid and efficient differentiation of six common disaccharide isomers without the need for complex derivatization or harsh conditions such as high temperature and high pressure. This method has the advantages of high sensitivity, high specificity, and good reproducibility, and can provide important technical support for the identification and analysis of carbohydrate isomers in the fields of food, medicine, and biology.

[0087] Those skilled in the art can reasonably adjust the collision energy, microdroplet size, and other parameters according to actual needs, which still fall within the protection scope of the present invention.

[0088] Example 4-6 Relative Quantitative Detection Method for Disaccharide Isomers in Binary Mixture Systems Since disaccharide isomers are highly similar in molecular structure and physical and chemical properties, traditional analytical methods often face great challenges in quantitative differentiation. To solve this problem, this example uses the [MT +NH4] + ions generated by the high electric field at the microdroplet gas-liquid interface, and combines the change rules of the intensity ratios of the characteristic ion peaks of MS / MS fragmentation to construct a relative quantitative method for binary mixture systems suitable for disaccharide isomers.

[0089] Specifically, a relative quantitative detection method for disaccharide isomers in a binary mixture system includes the following steps: First, two disaccharide isomers were respectively mixed in the following different ratios and dissolved in pure water to prepare mixed aqueous solutions: 20:1, 10:1, 5:1, 1:1, 1:5, 1:10, 1:20, and 1:100, and it was ensured that the total concentration of the binary mixture system was the same, all being 100 µmol / L; among them, the two disaccharide isomers in the binary mixture systems provided in Examples 5-7 were palatinose and turanose, isomaltose and palatinose, sucrose and melibiose, respectively; Secondly, the method for distinguishing disaccharide isomers provided in Example 4 is adopted. Ammonia molecules are generated by the reaction at the gas-liquid interface of microdroplets and react with the disaccharide isomers in the binary mixed aqueous solution respectively to form corresponding [M+NH4] + adducts; the adducts [M+NH4] in the binary mixed aqueous solution are fragmented by using a mass spectrometer to form characteristic fragment ions; the intensities of the characteristic fragment ions in the binary mixed aqueous solution are detected by using a mass spectrometer, and the relative ratio of the intensities of the characteristic fragment ions is calculated; + Then, according to the above detection results, a corresponding calibration curve is constructed. The following gives the relevant mathematical expressions for the relative quantification of disaccharide isomers in the embodiments of the present invention. It should be understood that the shown equations are only used to illustrate the method principle and do not limit the protection scope of the present invention. The relational expression (2) of the relative intensity ratio and the proportion of isomers in the binary system:

[0090] where RI mix is the relative ratio of the intensities of the characteristic fragment ions in the binary mixed aqueous solution; RI a and RI b respectively represent the relative signal intensities of the corresponding characteristic fragment ions when the disaccharide isomers a and b exist alone; α a and α b are the molar (or mass) percentages of the disaccharide isomers a and b in the binary mixed aqueous solution respectively, and satisfy α a + α b = 1.

[0091] The isomer proportion formula (3) deduced from the relative intensity ratio of the mixed system: , and through formula (3), RI mix can be measured and compared with the known C a and C b is the relative proportion of the disaccharide isomers a and b in the binary mixed system under the known concentration ratio α a / α b .

[0092] The linear relational expression (4) of the isomer proportion and the known concentration ratio: , in this formula C a and​​C b The configuration ratio of disaccharide isomers a and b at a known concentration ratio, where k and t are constants obtained by linear fitting. From this, a calibration curve can be established based on the measured values at multiple known ratios, and the relative content of the isomers in the unknown sample can be deduced.

[0093] In Example 5, palatinose (Glcα1→6Fru) and turanose (Glcα1→3Fru): Both have the same monosaccharide composition, containing glucose and fructose, but differ in the glycosidic bond positions α1→6 and α1→3. Using m / z the characteristic ion of 145 / 259 for quantitative evaluation, a calibration curve as shown in Figure 8 a was established according to the linear relationship (4) within the concentration range of 0.02 - 100 µmol / L, where y is α 帕拉金糖 / α 松二糖 , and x is C 帕拉金糖 / C 松二糖 , with R² = 0.9964.

[0094] In Example 6, isomaltose (Glcα1→6Glc) and palatinose (Glcα1→6Fru): Both have the same glycosidic bond position α1→6, but different monosaccharide compositions (glucose and fructose); using m / z the intensity ratio of the fragment ion peaks of 145 / 325 to establish a calibration curve as shown in Figure 8 b according to the linear relationship (4) within the concentration range of 0.01 - 10 µmol / L, where y is α 异麦芽糖 / α 帕拉金糖 , and x is C 异麦芽糖 / C 帕拉金糖 , with R² = 0.9982.

[0095] In Example 7, sucrose (Glcα1→2Fru) and melibiose (Galα1→6Glc): The two isomers differ not only in the glycosidic bond position and monosaccharide type, but also in the non-reducing end characteristics of sucrose. Based on m / z the ion ratio of 145 / 163 for fitting, a calibration curve as shown in Figure 8 c was established according to the linear relationship (4) within the linear range of 0.01 - 80 µmol / L, where y is α 蔗糖 / α 蜜二糖 , where x is C 蔗糖 / C 蜜二糖 , R² = 0.9996.

[0096] Therefore, the embodiments of the present invention utilize the microdroplet gas-liquid interface technology and the MS / MS fragmentation analysis method, which can not only identify the fine structures of disaccharide isomers, but also achieve high-precision relative quantification through a calibration curve in a binary mixed system. This method has the advantages of a wide linear range, strong adaptability, high selectivity, etc., and can be widely applied in the fields of food detection, pharmaceutical research and development, and glycobiology research. Those skilled in the art can make necessary adjustments to the selected fragment ions, flow rates, and other operating parameters according to actual needs.

[0097] In summary, the method and device for ammonia synthesis and disaccharide isomer differentiation based on the gas pressure interface reaction provided by the embodiments of the present invention are mainly based on the gas-liquid interface reaction of water microdroplets in a high electric field environment, and utilize the activation of nitrogen gas (N2) and the hydrogen radicals provided by water molecules to perform efficient ammonia synthesis without the need for catalysts, high temperatures, or high-pressure conditions, realizing green ammonia production at normal temperature and pressure. At the same time, the embodiments of the present invention have developed an adduct reaction method for ammonia and disaccharide molecules to generate a stable adduct [M+NH4] + , and combined with tandem mass spectrometry (MS / MS) to analyze the distribution of its characteristic fragment ions, successfully realizing the rapid differentiation and quantitative detection of disaccharide isomers. The device of the embodiments of the present invention can accurately control parameters such as the reaction distance and atomizing gas pressure, optimizing the reaction efficiency and adduct signal intensity. Therefore, the device provided by the present invention has a simple structure, and the method significantly simplifies the experimental process, reduces energy consumption and environmental pollution, provides an efficient, green and economical solution for ammonia synthesis and sugar isomer detection, opens up a new application direction for the detection of complex sugars in food chemistry and omics analysis, and is expected to become an important development direction for nitrogen fixation, ammonia synthesis and biomass analysis in the future, contributing to the global energy structure transformation and sustainable development, and having broad industrial and scientific research application potential.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. An ammonia synthesis method based on gas-liquid interface reaction, comprising: Using an aqueous solution and N2-containing gas as raw materials, the aqueous solution is atomized into micro-droplets by the N2-containing gas at an atomization air pressure greater than 50 psi in a flowing state, and at the same time, a gas-liquid interface with an electric field of 10 8 -10 9 V / m is formed. Under the action of the electric field at this gas-liquid interface, N2 molecules are activated at room temperature and combine with hydrogen free radicals in H2O molecules in the aqueous solution to synthesize ammonia molecules.

2. The synthesis method according to claim 1, characterized in that, The atomizing air pressure is 60 - 120 psi.

3. The synthesis method according to claim 1 or 2, characterized in that, The flow rate of the aqueous solution is 10 - 15 μL / min.

4. The synthesis method according to claim 1, characterized in that, The N2-containing gas is air or nitrogen with a purity of 99.99%.

5. A water micro-droplet atomization device, characterized in that, A microliter liquid supply unit, an N2 gas source, and a three-way spray assembly. Among them, the microliter liquid supply unit includes a capillary tube, and the aqueous solution can be continuously provided to the three-way spray assembly through the capillary tube; The N2 gas source is used to provide N2-containing gas with an air pressure greater than 50 psi to the three-way spray assembly and atomize the aqueous solution into micro-droplets; The three-way spray assembly includes a liquid inlet end, a gas inlet end, and an outlet end from which the N2-containing gas can escape. The gas inlet end is connected to the N2 gas source. One end of the capillary tube is inserted into the three-way spray assembly from the liquid inlet end and penetrates through it, and extends out from the outlet end to form a spray port for spraying the micro-droplets; The micro-droplets form a gas-liquid interface with an in-built electric field of 10 8 -10 9 V / m when being ejected. Under the action of the electric field at this gas-liquid interface, N2 is activated at room temperature and combines with the hydrogen radicals in the H2O molecules in the aqueous solution to synthesize ammonia.

6. The water micro-droplet atomization device according to claim 5, characterized in that, The microliter liquid supply unit further includes a sampling needle and an injection pump installed on the capillary tube. The capillary tube is respectively connected to the sampling needle and the three-way spray assembly.

7. The water micro-droplet atomization device according to claim 5 or 6, characterized in that, The inner diameter of the outlet end is greater than the outer diameter of the capillary tube.

8. The water micro-droplet atomization device according to claim 7, characterized in that, The inner diameter of the capillary tube is 50 - 100 µm.

9. A method for synthesizing ammonia using the water micro-droplet atomization device according to any one of claims 5-8, comprising supplying an aqueous solution to the three-way spray assembly at a flow rate of 10-15 µL / min through the micro-liter liquid supply unit, and simultaneously supplying a nitrogen-containing gas with a pressure greater than 50 psi to the three-way spray assembly through the N2 gas source. The three-way spray assembly atomizes the aqueous solution therein into micro-droplets, forming a gas-liquid interface with an electric field of 10 8 -10 9 V / m. Under the action of the electric field at this gas-liquid interface, N2 molecules are activated at room temperature and combine with hydrogen free radicals in H2O molecules to synthesize ammonia.

10. Use of the synthesis method according to any one of claims 1 - 4, or the water micro-droplet atomizing device according to any one of claims 5 - 8, or the method for synthesizing ammonia according to claim 9 in the discrimination of sugar isomers, quantitative analysis of sugar isomers, food detection, pharmaceutical research, or biomics research.

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