Joint interface device for liquid chromatograph and mass spectrometer

Abstract

The utility model discloses a liquid chromatograph and mass spectrometer coupling interface device which comprises an air passage which is vertically arranged and has a cavity structure, the air passage is composed of an expansion air passage and a contraction air passage at intervals, and the expansion air passage penetrates through a pressure relief pipe and is provided with an exchange hole and a first pressure relief valve; a liquid inlet pipe connected with a liquid chromatograph is arranged at the top of the air passage; an atomizing needle is arranged in the center of a port of the liquid inlet pipe; an electric field opposite to the atomization needle in charge and a sampling cone are arranged at the bottom; and a hot nitrogen cavity is wrapped outside the expansion air passage. During working, liquid is atomized and heated by the hot nitrogen cavity to vaporize and discharge a solvent, an additive is removed by gas impact, and a charged target compound is attracted and enriched by an electric field, is collected by a sampling cone and is fed into a mass spectrometer. The device creatively fuses a plurality of processes, is high in universality and compatibility, and can be adapted to liquid chromatographs and mass spectrometers of any model; the hot nitrogen cavity has the functions of heat supply and heat preservation, the electric field achieves attraction and enrichment of target compounds, the sampling cone generates the suction effect, and the problems of liquid chromatogram effluent separation and supply of gaseous molecules to a mass spectrometer are effectively solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to liquid chromatograph and mass spectrometer field, especially liquid chromatograph and mass spectrometer interface device for combination. BACKGROUND

[0002] Liquid chromatograph and mass spectrometer are two commonly used devices for detecting substance composition, and usually the detection of substances needs to be used separately. Although there are devices for combination of liquid chromatograph and mass spectrometer on the market at present, the cost is high, and it is required that the liquid chromatograph and mass spectrometer are products of the same company. If the models of different products are different, it is difficult to be universal and compatible.

[0003] Since the substance composition flowed out of the liquid chromatograph mainly includes the target compound after separation, mobile phase solvent (such as methanol, acetonitrile, water) and additive (buffer salt, acid / alkali), the mobile phase solvent and additive need to be removed. Moreover, the target compound needs to be formed into gaseous molecules.

[0004] In order to solve the problem of complete separation of the substance flowed out of the liquid chromatograph and direct supply of gaseous molecules to the mass spectrometer, the utility model designs a universal combination device. UTILITY MODEL CONTENT

[0005] The utility model provides a liquid chromatograph and mass spectrometer interface device for combination, in order to solve the problem of complete separation of the substance flowed out of the liquid chromatograph and direct supply of gaseous molecules to the mass spectrometer. In order to realize the above-mentioned purpose, the utility model adopts the following technical scheme:

[0006] A liquid chromatograph and mass spectrometer interface device for combination, comprising a gas channel vertically arranged in an internal cavity structure, wherein the gas channel comprises an expansion gas channel and a contraction gas channel arranged at intervals, and the internal diameter of the contraction gas channel is smaller than that of the expansion gas channel; the expansion part of the expansion gas channel vertically penetrates a plurality of pressure relief pipes, the lower end of the pressure relief pipe is sealed, the upper end is provided with a first pressure relief valve, and the pressure relief pipe in the expansion part is provided with a plurality of exchange holes penetrating the pressure relief pipe;

[0007] The liquid inlet pipe penetrates the top of the gas channel and extends into the gas channel, the free end of the liquid inlet pipe extending into the gas channel is provided with an atomizing needle at the jet opening, and the other end is connected with the liquid chromatograph;

[0008] The bottom of the gas channel is provided with an electric field opposite in charge to the atomizing needle and a sampling cone;

[0009] The outer surface of the expansion gas channel is provided with a heat nitrogen cavity of cavity structure, and the heat nitrogen cavity wraps the expansion gas channel; a plurality of heat gas holes penetrating the heat nitrogen cavity and the expansion gas channel are arranged at the intersection of the heat nitrogen cavity and the expansion gas channel; the heat nitrogen cavity is further provided with an air inlet in communication with a heat nitrogen gas source.

[0010] Further, the tip of the atomizing needle is arranged at the center of the liquid inlet pipe port.

[0011] Further, the liquid inlet pipe port is provided with a trumpet-shaped liquid outlet.

[0012] Further, the atomizing mode of the atomizing needle is high-voltage electric atomization, and the polarity of the electric field and the charge of the liquid droplets after high-voltage electric atomization are different.

[0013] Further, the hot nitrogen cavity is further provided with a second pressure relief valve.

[0014] Further, the number of pressure relief pipes is four.

[0015] Further, the sampling tip of the sampling cone is arranged in the electric field.

[0016] Compared with the prior art, the utility model has the advantages that: in the utility model, the hot nitrogen cavity not only provides hot nitrogen gas with balanced temperature, but also realizes the purpose of heat preservation for the inflation air duct because it is wrapped in the inflation air duct. The electric field not only attracts the molecules of the target compound with charge, but also locks the molecules of the target compound in the electric field, so that the molecule concentration in the electric field is most concentrated. The sampling cone and the secondary vacuum environment are connected, and the target compound can be retained for a certain suction effect.

[0017] The utility model integrates a series of processes such as separation, removal, migration, collection and transportation of the target compound. The whole is very innovative, and has strong universality and compatibility, and can be suitable for any type of liquid chromatograph and mass spectrometer. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is an external structure schematic view of the utility model;

[0019] Figure 2 It is an internal structure schematic view;

[0020] Figure 3 It is a position relation schematic view of the liquid inlet pipe and the atomizing needle.

[0021] 1 inflation air duct, 10 upper cover, 11 lower cover, 2 contraction air duct, 3 pressure relief pipe, 31 first pressure relief valve, 32 exchange hole, 4 hot nitrogen cavity, 41 air inlet, 42 second pressure relief valve, 43 hot air hole, 5 sampling cone, 6 electric field, 7 liquid inlet pipe, 71 liquid outlet, 8 atomizing needle DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below, examples of the embodiments are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0023] In order to screen out target compounds in the liquid material flowing out of the liquid chromatograph and change the compounds into gaseous molecules, generally the size of the gaseous molecules is nanometer level, the utility model discloses a liquid chromatograph and mass spectrometer combined interface device. Figure 1 、 Figure 2 and Figure 3 As shown in the scheme, it comprises a gas channel arranged vertically and comprising an expansion gas channel 1 and a contraction gas channel 2 arranged at intervals, the inner cavity volume of the expansion gas channel 1 is also larger than that of the contraction gas channel 2, and the upper and lower parts of the gas channel are respectively sealed by an upper cover 10 and a lower cover 11.

[0024] As shown in the scheme, Figure 2 The expansion part of the expansion gas channel 1 vertically penetrates through a plurality of pressure relief pipes 3, specifically four, the lower end of the pressure relief pipe 3 is sealed, and the upper end is provided with a first pressure relief valve 31, and the pressure relief pipe 3 in the expansion part is provided with a plurality of exchange holes 32 penetrating through the pressure relief pipe 3.

[0025] A liquid inlet pipe 7 is arranged at the top center of the gas channel, the free end of the liquid inlet pipe 7 extends into the expansion gas channel 1, and the other end of the liquid inlet pipe 7 is connected with the liquid outlet end of the liquid chromatograph. In order to better atomize the liquid, a horn-shaped liquid discharge port 71 is arranged at the port nozzle of the liquid inlet pipe 7, and an atomizing needle 8 is arranged at the center of the liquid discharge port 71, and the atomizing mode of the atomizing needle 8 is high-voltage electric atomization. The liquid is atomized into charged microdroplets by high-voltage electric field, the diameter is about 1-10 mu m, and the voltage of the high-voltage electric field is 3-6 kV.

[0026] An electric field 6 and a sampling cone 5 are arranged at the bottom of the gas channel, the sampling tip of the sampling cone 5 is arranged in the electric field 6, and the polarity of the electric field 6 is different from the charge of the liquid droplets after high-voltage electric atomization. The different charges can accelerate the charged molecules to enter the sampling cone 5 as soon as possible.

[0027] Figure 2As shown, a cavity-shaped hot nitrogen chamber 4 is provided on the outer surface of the expansion channel 1, enclosing the expansion channel 1. Several through-holes 43 are provided where the hot nitrogen chamber 4 and the expansion channel 1 intersect. The hot nitrogen chamber 4 also has an inlet 41 connected to a hot nitrogen gas source. The inlets 41 of the hot nitrogen chambers 4 at different heights are connected to nitrogen gas at different temperatures. For example, the temperature of the nitrogen gas entering the inlet 41 of the highest hot nitrogen chamber 4 is 50-150℃. The purpose of the low temperature is to gently heat the gas to evaporate the solvent and avoid the decomposition of thermally unstable compounds (such as proteins and peptides). The temperature at the lowest point can be 300-500℃, rapidly converting the liquid sample into gaseous molecules, ensuring complete evaporation of the analyte to participate in subsequent chemical ionization. The hot nitrogen chamber 4, enclosing the expansion channel 1, also provides insulation for the expansion channel 1. A second pressure relief valve 42 is provided on the hot nitrogen chamber 4, mainly to prevent high internal pressure caused by blockage of the hot gas holes 43.

[0028] The working principle of this utility model:

[0029] The liquid entering through the inlet pipe 7 is ejected from the outlet 71, and then the high-voltage atomizing needle 8 directly atomizes the liquid into small droplets. Since the nitrogen gas entering the first hot nitrogen chamber 4 at a temperature of 50–150°C directly vaporizes and evaporates the solvents in the droplets, such as methanol, acetonitrile, and water, the expanded gas volume after vaporization enters the pressure relief pipe 3 through the exchange hole 32. As the pressure gradually increases, the first pressure relief valve 31 opens, thereby venting the excess gas. All the gas in the expansion gas passage 1 can be discharged through the pressure relief pipe 3.

[0030] Because the internal diameters of the expanding airway 1 and the contracting airway 2 are different, and their internal cavity volumes also differ, when gas enters from above, it is subjected to continuous impact. With each impact, the additives originally fused to the small droplets adhere to the inner walls of the airways. Through multiple stages of continuous impact, most of the additives can be completely adsorbed.

[0031] As the charged gas is attracted by the oppositely charged electric field 6, it accelerates into the electric field 6. Many target compounds accumulate in the electric field 6, and are then collected by the sampling cone 5 and transferred to the vacuum environment of the mass spectrometer.

[0032] In this invention, the hot nitrogen chamber 4 not only provides hot nitrogen gas at a uniform temperature, but also, because it is wrapped around the expansion channel 1, it can keep the expansion channel 1 warm.

[0033] The electric field 6 not only attracts charged molecules of the target compound but also locks them within it, ensuring the highest molecular concentration. Furthermore, the connection between the sampling cone 5 and the sub-vacuum environment allows for a degree of suction on the target compound.

Claims

1. A coupling interface device for a liquid chromatograph and a mass spectrometer, characterized in that: The air passage includes an internal cavity structure and is vertically arranged. The air passage includes an expansion air passage (1) arranged at intervals and a contraction air passage (2) with an inner diameter smaller than that of the expansion air passage (1). The expansion portion of the expansion air passage (1) is vertically connected to several pressure relief pipes (3). The lower end of the pressure relief pipe (3) is sealed, and the upper end is provided with a first pressure relief valve (31). The pressure relief pipe (3) in the expansion portion is provided with several exchange holes (32) that penetrate the pressure relief pipe (3). The liquid inlet pipe (7) passes through the top of the gas passage and extends into the gas passage. An atomizing needle (8) is provided at the free end nozzle of the liquid inlet pipe (7) that extends into the gas passage, and the other end is connected to the liquid chromatograph. The bottom of the airway is provided with an electric field (6) and a sampling cone (5) opposite to the charge of the atomizing needle (8); The outer surface of the expansion duct (1) is provided with a cavity-shaped hot nitrogen cavity (4), which encloses the expansion duct (1); a number of through hot air holes (43) are provided at the intersection of the hot nitrogen cavity (4) and the expansion duct (1); the hot nitrogen cavity (4) is also provided with an air inlet (41) that is connected to the hot nitrogen gas source.

2. The interface device for coupling a liquid chromatograph and a mass spectrometer according to claim 1, characterized in that: The tip of the atomizing needle (8) is located at the center of the inlet port of the liquid inlet tube (7).

3. The interface device for coupling a liquid chromatograph and a mass spectrometer according to claim 1 or 2, characterized in that: The inlet pipe (7) is provided with a funnel-shaped outlet (71).

4. The interface device for coupling a liquid chromatograph and a mass spectrometer according to claim 1, characterized in that: The atomizing needle (8) uses high-voltage electric atomization, and the polarity of the electric field (6) is different from the charge of the droplets after high-voltage electric atomization.

5. The interface device for coupling a liquid chromatograph and a mass spectrometer according to claim 1, characterized in that: The hot nitrogen chamber (4) is also equipped with a second pressure relief valve (42).

6. The interface device for coupling a liquid chromatograph and a mass spectrometer according to claim 1, characterized in that: The number of pressure relief pipes (3) is 4.

7. The interface device for coupling a liquid chromatograph and a mass spectrometer according to claim 1, characterized in that: The sampling tip of the sampling cone (5) is arranged in an electric field (6).

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