Mass spectrum automatic sample injection system for microwell plate high-throughput analysis

Abstract

The utility model discloses a mass spectrum automatic sampling system for high-throughput analysis of a microwell plate, which comprises an eluent delivery pipe connected with a high-voltage electrode, an atomizing gas pipe communicated with an atomizing gas source, a microwell plate sampling probe, an electrospray ion source and a liquid suction capillary communicated with the microwell plate sampling probe and the electrospray ion source, and a sample moving system. A coaxial capillary probe with an open port in the microplate sampling probe can directly suck a liquid sample, and mass spectrometry is performed after electrospray ionization, so that the tedious steps of chromatographic separation and sample transfer are avoided, the sample preparation and analysis time is shortened, and the speed and flux of mass spectrometry of the microplate sample are effectively improved. A high-flow-rate elution solvent flows into the liquid suction capillary tube from a gap between the coaxial capillary tubes to realize automatic elution after sampling, so that the phenomena of cross contamination and signal overlapping between samples are avoided, and continuous sample introduction analysis of a large number of microwell plate samples can be realized.

Description

Technical Field

[0001] The utility model belongs to the field of high-throughput sample analysis, relates to a sampling system, and particularly relates to an automatic mass spectrometry sampling system for high-throughput analysis of microplates. Background Art

[0002] High-throughput analysis methods based on microplates have been widely used in various scientific fields such as drug discovery, enzyme activity determination, toxicity testing, molecular diagnosis, immunological research, food safety, agriculture, and environmental monitoring. Based on the commonly used 96-well microplates, 384-well and 1536-well high-density microplates have been developed to improve the analysis throughput. However, currently, such methods mainly detect the optical properties of analytes such as color, absorbance, fluorescence, turbidity, and transparency, with limited sensitivity and specificity, narrow application range, and difficulty in exploring new unknown compounds.

[0003] Mass spectrometry technology performs qualitative and quantitative analysis based on the mass-to-charge ratio of the analyte molecules, with advantages such as high specificity, high sensitivity, universality, trace amount, and non-labeling. By combining different types of ion sources such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), precise analysis of molecules such as proteins, polypeptides, metabolites, and drugs can be achieved. However, in order to improve the selectivity of mass spectrometry analysis and reduce the matrix interference of complex biological samples, separation steps such as gas or liquid chromatography are usually required before mass spectrometry analysis, which undoubtedly increases the complexity of sample preparation and analysis time, thereby reducing the throughput and efficiency of high-throughput analysis of microplates.

[0004] In response to the above problems, direct ionization mass spectrometry technology without complex separation or sample pretreatment has been proposed. Among them, matrix-assisted laser desorption ionization (MALDI) uses a laser bombardment in a vacuum for sample desorption and ionization, and can achieve an analysis throughput of about one sample per second. However, this technology requires mixing the microplate sample with the matrix and spotting it on a dedicated metal target plate. This process may introduce interference from matrix background peaks, and the spotting process also increases the time and complexity of sample preparation. Open mass spectrometry technologies such as desorption electrospray ionization (DESI) and liquid extraction surface analysis (LESA) allow direct and rapid analysis of solid samples in an atmospheric pressure environment, but these technologies usually rely on an automated liquid handling platform to accurately titrate trace liquid samples from the microplate onto a dedicated substrate to form a high-density sample array suitable for large-scale analysis. This process not only increases the equipment cost and the time required for sample preparation, but also easily causes cross-contamination and signal overlap between samples in the case of high sample spot density.

[0005] Recently, methods for directly introducing microplate samples into mass spectrometry for analysis through media such as lasers and ultrasounds have received attention. These direct sampling mass spectrometry techniques avoid cumbersome sample transfer steps and significantly shorten the time for sample preparation and analysis. Among them, the infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) technique can desorb liquid samples in a microplate through a laser, followed by ionization in the electrospray ionization region, and finally introduce the ions into a mass spectrometer for high-throughput analysis. The acoustic mist ionization technique (AMI) uses sound waves to atomize the samples in the microplate into tiny droplets and directly introduces them into the mass spectrometer for ionization and detection, improving the speed of mass spectrometry analysis of microplates. In addition, the acoustic droplet ejection system (ADE) can be combined with the open port interface (OPI) technique. The sample droplets are ejected onto a liquid flow interface through sound waves, then diluted and transported to the mass spectrometer for analysis, thus achieving efficient sample processing and detection. The above techniques combined with an automated control system can perform row-by-row scanning of microplate samples and enable high-throughput analysis of microplates without additional sample preparation steps. However, such analysis techniques require additional commercial equipment for sample desorption, such as the ECHO 555 droplet emission device and infrared lasers, etc. These devices are usually expensive and have high maintenance costs. In addition, due to the limitations of the working principle, the amount of sample ejected each time by this type of technique is limited, and large-volume continuous sampling of the same sample cannot be performed, which has limitations in applications that require continuous and real-time monitoring of the same sample. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, the utility model provides a mass spectrometry automatic sampling system for high-throughput analysis of microplates.

[0007] The above object of the utility model is achieved by the following technical solutions:

[0008] A mass spectrometry automatic sampling system for high-throughput analysis of microplates includes an elution solution delivery tube connected to a high-voltage electrode and an atomization gas tube communicated with an atomization gas source, and also includes a microplate sampling probe, an electrospray ion source, a liquid suction capillary connecting the microplate sampling probe and the electrospray ion source, and a sample moving system; wherein:

[0009] The microplate sampling probe includes a sampling probe three-way tube and a liquid supply capillary; the sampling probe three-way tube includes a first branch of the sampling probe three-way tube, a second branch of the sampling probe three-way tube, and a third branch of the sampling probe three-way tube; one end of the liquid supply capillary is communicated with the elution solution delivery tube, forming a liquid supply channel in the first branch and the second branch of the sampling probe three-way tube, and the other end of the liquid supply capillary extends out from the end of the second branch of the sampling probe three-way tube;

[0010] The electrospray ion source includes an ion source tee and a sheath gas tube; the ion source tee includes a first branch of the ion source tee, a second branch of the ion source tee, and a third branch of the ion source tee; one end of the sheath gas tube is communicated with the atomization gas tube, and a gas supply channel is formed in the second branch and the third branch of the ion source tee, and the other end of the sheath gas tube extends out from the end of the second branch of the ion source tee;

[0011] One end segment of the liquid suction capillary penetrates through the second branch and the third branch of the sampling probe tee, and the other end segment penetrates through the first branch and the second branch of the ion source tee; the part of the liquid suction capillary located in the second branch of the sampling probe tee is sleeved inside the part of the liquid supply capillary located in the second branch of the sampling probe tee, and a space for the elution solution to flow is left between the outer wall of the liquid suction capillary and the inner wall of the liquid supply capillary, and the sleeved part of the liquid suction capillary is shorter than the liquid supply capillary; the part of the liquid suction capillary located in the second branch of the ion source tee is sleeved inside the part of the sheath gas tube located in the second branch of the ion source tee, and a space for the atomization gas to flow is left between the outer wall of the liquid suction capillary and the inner wall of the sheath gas tube, and the sleeved part of the liquid suction capillary is longer than the sheath gas tube;

[0012] The sample moving system includes a microplate holder for fixing the microplate and a translation and lifting mechanism for controlling the movement of the microplate holder to adjust the sampling position, sampling depth, and sampling duration of the microplate sampling probe on the microplate.

[0013] Preferably, the second branch of the sampling probe tee is perpendicular to the microplate.

[0014] Preferably, the second branch of the ion source tee is aligned with the sample inlet of the mass spectrometer at a certain angle.

[0015] More preferably, the angle is 30 - 60°.

[0016] Preferably, the translation and lifting mechanism includes an XY-axis horizontal moving stage and a Z-axis lifting stage. The Z-axis lifting stage is fixedly connected to the XY horizontal moving stage, and the microplate holder is fixedly connected to the Z-axis lifting stage.

[0017] Preferably, the length of the liquid suction capillary is 5 - 50 cm.

[0018] Preferably, the type of the microplate is a 96-well plate, a 384-well plate, or a 1536-well plate.

[0019] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0020] (1) The coaxial capillary probe with an open port can directly aspirate liquid samples in a microplate, and after electrospray ionization, perform mass spectrometry analysis, avoiding the cumbersome steps of chromatographic separation and sample transfer, shortening the time for sample preparation and analysis, and effectively improving the speed and throughput of mass spectrometry analysis of microplate samples;

[0021] (2) Using a high-flow elution solvent flowing into the aspiration capillary through the gap between the coaxial capillaries to achieve automatic elution after sampling, avoiding cross-contamination and signal overlap between samples, and facilitating continuous injection analysis of a large number of microplate samples;

[0022] (3) Using the aspiration capillary to directly connect two three-way tubes, simultaneously achieving sampling of the microplate and subsequent ionization, with the advantages of low cost, simple structure, easy maintenance and replacement;

[0023] (4) By means of the Z-axis lift to make the sampling probe extend into the microplate well for direct sampling, continuous, real-time and on-line detection of the same sample can be achieved. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of a mass spectrometry automatic sampler for high-throughput analysis of microplates;

[0025] Figure 2 It is Figure 1 A partial enlarged schematic diagram of the device;

[0026] Figure 3 It is Figure 2 A cross-sectional view of the device;

[0027] Figure 4 It is the extracted ion current result of analyzing androstenedione (A), androstadienedione (B) and methyl diketone (C) using the mass spectrometry automatic sampler of the present utility model;

[0028] Figure 5 It is the extracted ion current and linear fitting result of analyzing androstenedione (A), androstadienedione (B) and methyl diketone (C) with different concentrations using the mass spectrometry automatic sampler of the present utility model;

[0029] Figure 6 It is the extracted ion current result of analyzing the steroid standards and blank solvents arranged at intervals in the microplate using the mass spectrometry automatic sampler of the present utility model, where A is androstenedione, B is androstadienedione, and C is methyl diketone;

[0030] Wherein: 1. Microwell plate sampling probe; 2. Elution solvent delivery tube; 3. High-voltage electrode; 4. Microwell plate holder; 5. Microwell plate; 6. Z-axis lifting stage; 7. XY-axis horizontal moving stage; 8. Electrospray ionization source; 9. Atomizing gas tube; 10. Mass spectrometer inlet; 11. Liquid absorption capillary; 12. First branch of the sampling probe tee; 13. Second branch of the sampling probe tee; 14. Third branch of the sampling probe tee; 15. First branch of the ion source tee; 16. Second branch of the ion source tee; 17. Third branch of the ion source tee; 18. Liquid supply capillary; 19. Sheath gas tube. Detailed implementation mode

[0031] The following combines the embodiments to specifically introduce the substantial content of the present invention, but does not limit the protection scope of the present invention hereby.

[0032] In the following embodiments, Embodiments 1-3 are the specific structures and connection relationships of the patent device, and Embodiments 4-6 are the application effects of the patent device. In the following embodiments: Androstenedione (AD), androstadienedione (ADD), methyl diketone (NONE), Girard reagent P (GirP) are all purchased from Shanghai Yuanye Bio-Technology Co., Ltd.; Analytical grade acetonitrile and methanol reagents are purchased from Fisher Scientific; Ultrapure water is obtained from the MilliQ system; In the application embodiment, after the patent device automatically samples and ionizes the microwell plate sample, an LTQ XL (Thermo Fisher Scientific Inc., USA) mass spectrometer can be selected for high-throughput analysis, with a mass range of m / z 100-1000, and the positive ion mode is selected during analysis.

[0033] Embodiment 1: Device embodiment

[0034] As Figures 1 to 3 shown, a mass spectrometry automatic sampling system for high-throughput analysis of microwell plates includes an elution solution delivery tube 2 connected to the high-voltage electrode 3 and an atomizing gas tube 9 connected to the atomizing gas source, and also includes a microwell plate sampling probe 1, an electrospray ionization source 8, a liquid absorption capillary 11 connecting the microwell plate sampling probe 1 and the electrospray ionization source 8, and a sample moving system.

[0035] The microwell plate sampling probe 1 includes a sampling probe tee and a liquid supply capillary 18. The sampling probe tee includes a first branch 12 of the sampling probe tee, a second branch 13 of the sampling probe tee, and a third branch 14 of the sampling probe tee. One end of the liquid supply capillary 18 is connected to the elution solution delivery tube 2 to form a liquid supply channel in the first branch 12 and the second branch 13 of the sampling probe tee, and the other end of the liquid supply capillary 18 extends out from the end of the second branch 13 of the sampling probe tee.

[0036] The electrospray ion source 8 includes an ion source tee and a sheath gas tube 19. The ion source tee includes a first branch 15 of the ion source tee, a second branch 16 of the ion source tee, and a third branch 17 of the ion source tee. One end of the sheath gas tube 19 communicates with the nebulizer gas tube 9, and a gas supply channel is formed in the second branch 16 and the third branch 17 of the ion source tee. The other end of the sheath gas tube 19 extends out from the end of the second branch 16 of the ion source tee.

[0037] One end section of the liquid suction capillary 11 passes through the second branch 13 and the third branch 14 of the sampling probe tee, and the other end section passes through the first branch 15 and the second branch 16 of the ion source tee. The part of the liquid suction capillary 11 located in the second branch 13 of the sampling probe tee is sleeved inside the part of the liquid supply capillary 18 located in the second branch 13 of the sampling probe tee. A space for the elution solution to flow is left between the outer wall of the liquid suction capillary 11 and the inner wall of the liquid supply capillary 18, and the sleeved part of the liquid suction capillary is shorter than the liquid supply capillary. The part of the liquid suction capillary 11 located in the second branch 16 of the ion source tee is sleeved inside the part of the sheath gas tube 19 located in the second branch 16 of the ion source tee. A space for the nebulizing gas to flow is left between the outer wall of the liquid suction capillary 11 and the inner wall of the sheath gas tube 19, and the sleeved part of the liquid suction capillary is longer than the sheath gas tube. The second branch 16 of the ion source is aligned with the mass spectrometer inlet 10 (mass spectrometer sample inlet) at a certain angle.

[0038] The sample moving system includes a microplate holder 4, a Z-axis lifting stage 6, and an XY-axis horizontal moving stage 7. The microplate holder 4 is fixedly connected to the Z-axis lifting stage 6, the Z-axis lifting stage 6 is fixedly connected to the top surface of the XY-axis horizontal moving stage 7, and the microplate holder 4 is located below the microplate sampling probe 1. The microplate sampling probe 1 is located above the microplate holder 4, and the second branch 13 of the sampling probe tee is perpendicular to the microplate on the microplate holder 4.

[0039] In a specific embodiment, the liquid supply capillary 18 is a PEEK tube with an inner diameter of 1 mm and an outer diameter of 1.6 mm, and its preferred length is 3 cm; the liquid suction capillary 11 is a quartz capillary with an inner diameter of 250 μm and an outer diameter of 365 μm, and its preferred length is 25 cm. The inlet of the liquid suction capillary 11 retracts slightly 1 mm from the tip of the coaxially arranged liquid supply capillary 18; the sheath gas tube 19 is a PEEK tube with an inner diameter of 0.5 mm and an outer diameter of 1.6 mm, and its preferred length is 3.2 cm. The outlet of the liquid suction capillary 11 extends slightly 1.5 mm from the coaxially arranged sheath gas tube 19.

[0040] In a specific embodiment, the microplate sampling probe 1 is perpendicular to the microplate 5, the second branch 13 of the sampling probe tee is vertically aligned with the hole of the microplate 5, and the distance between the tip of the liquid supply capillary 18 and the microplate 5 is 1 cm. The liquid suction capillary 11 is bent at an angle of 30-60° so that the outlet of the second branch 16 of the ion source tee is aligned with the mass spectrometer inlet 10 at a certain angle, the angle range is 30-60°, and the distance between it and the mass spectrometer inlet 10 is 1 cm.

[0041] In a specific embodiment, the maximum travel range of the XY axis horizontal moving stage 7 is 10×10 cm, and the maximum travel distance of the Z axis lifting stage 6 is 5 cm. The Z axis lifting stage 6 drives the microplate 5 on the microplate holder 4 to lift 1.5 cm, and positions the liquid aspiration capillary 11 at the microplate sampling probe 1 into the microplate hole for sample aspiration. Among them, the moving speed of the XY axis horizontal moving stage 7 is 0.6 cm / s, and the lifting and lowering speed of the Z axis lifting stage 6 is 1 cm / s.

[0042] Workflow and principle: Cut the PEEK tube and quartz capillary of the above lengths as the liquid supply capillary 18, the liquid suction capillary 11 and the sheath gas tube 19, respectively, according to Figures 1 - 3 Connect as shown. Connect the high-voltage electrode 3 to the elution solvent delivery pipe 2, and set the voltage to 3-5kV according to the experimental requirements. Inject the elution solution into the elution solution delivery pipe 2, such as methanol, acetonitrile, water, or a mixture of methanol / acetonitrile / water in any proportion, and adjust the flow rate to the optimal elution effect, such as 450μL / h. Introduce high-flow nitrogen into the atomization air pipe 9, and adjust the nitrogen flow rate to the optimal, such as 2-4L / min. After completing the above parameter settings, place the microplate 5 containing the liquid sample into the microplate holder 4, and the single-chip microcomputer automatically controls the Z-axis lifting platform 6 to drive the microplate 5 on the microplate holder 4 to lift 1.5cm, so that the tips of the liquid supply capillary 18 and the liquid aspiration capillary 11 in the microplate sampling probe 1 extend into the microplate holes. The high-flow nitrogen gas introduced into the atomizing air pipe 9 passes through the narrow gap between the outer wall of the liquid-absorbing capillary 11 and the inner wall of the sheath air pipe 19 at the second branch 16 of the ion source three-way pipe, and forms a self-priming effect at its tip, so that the liquid sample enters from the entrance of the liquid-absorbing capillary 11 in the microplate sampling probe 1, and enters the mass spectrometer entrance 10 after being ionized by the electrospray ion source. After completing the sample sampling and analysis, the single-chip microcomputer controls the Z-axis lifting platform 6 to drive the microplate support 4 to descend to the initial height, and controls the XY-axis horizontal moving platform 7 to drive the microplate 5 to move, so that the microplate sampling probe 1 is aligned with the next hole. At the same time, the elution solvent is transported into the liquid supply capillary 18 through the high-voltage electrode 3, and flows into the liquid absorption capillary 11 from the gap between the inner wall of the liquid supply capillary 18 and the outer wall of the liquid absorption capillary 11, realizing automatic elution after sampling.

[0043] Those skilled in the art know that the core utility model point of the present utility model creation lies in directly sucking the liquid sample in the microplate 5 by using coaxial capillary probes (liquid supply capillary 18, liquid suction capillary 11) with open ports, ionizing it through an electrospray ion source 8 and then performing mass spectrometry analysis, avoiding the cumbersome steps of chromatographic separation and sample transfer, and shortening the time for sample preparation and analysis. At the same time, a high-flow elution solvent flows into the liquid suction capillary 11 from the gap between the coaxial capillaries to achieve automatic elution after sampling, avoiding cross-contamination and signal overlap between samples. In addition, the liquid suction capillary 11 is directly connected to two three-way tubes to simultaneously achieve sampling from the microplate and subsequent ionization, having the advantages of low cost, simple structure, easy maintenance and replacement. Therefore, Figures 1 to 3 It is only a specific implementation manner for explaining the core invention point of the present utility model, and any simple replacement based on this cannot deviate from the protection scope of the present utility model creation.

[0044] Example 2: Application Example

[0045] This example aims to illustrate the analysis throughput and stability of the device shown in Example 1 by continuously analyzing different steroid compounds in a microplate to extract the extracted ion chromatogram (XIC). Figures 1 to 3

[0046] Before using the present utility model, 50 μL of standard solutions of different steroid compounds (such as AD, ADD, NONE) were mixed with 50 μL of BY4741 yeast solution to simulate a complex matrix environment. 100 μL of GirP derivatization reagent with a concentration of 1 mg / mL was mixed with the above-mentioned analytes and reacted at 60 °C for 4 hours to improve the sensitivity of mass spectrometry detection. The above samples were appropriately diluted to form an analyte solution with a final concentration of 125 ng / mL, and each analyte was added to 6 consecutive holes of a 96-well microplate for high-throughput analysis. During the analysis, the device of this patent scanned and analyzed the liquid samples in the microplate one by one according to the set path at a speed of 6.5 seconds / sample. After the scanning and analysis were completed, the Xcalibur 3.0 software was used to monitor the m / z values of the target ions to draw the corresponding XIC spectra, and the peak areas of the target substances in the spectra were analyzed to further quantify the content of the target substances in the samples. As Figure 4 shown, AD (m / z 420), ADD (m / z 418), and NONE (m / z 406) [M] + ​The XIC results of the ion peaks indicate that when the device of this patent is combined with mass spectrometry to analyze different steroid compounds, the peak width is narrow and there is no tailing phenomenon, showing good baseline separation effect. It only takes 39 seconds to continuously analyze 6 samples, and the average analysis time for each sample is 6.5 seconds. At the same time, the coefficients of variation (CV) of the peak areas of continuously analyzed AD (A), ADD (B), and NONE (C) are 3.37%, 5.10%, and 5.45% respectively, indicating that this method has high analysis throughput and stability, and can provide consistent and reliable results in a short time.

[0047] Example 3: Application Example

[0048] This example aims to continuously analyze different concentrations of steroid compounds in a microplate, and use the XIC and linear fitting results to illustrate the Figures 1 to 3 quantitative ability of the device shown in Example 1, specifically as follows:

[0049] Into 50 μL of yeast solution, add 50 μL of a series of standard solutions of AD, ADD, and NONE with different concentrations. Mix 100 μL of GirP derivatization reagent with a concentration of 1 mg / mL with the above-mentioned analytes, and add 5 μL of 2 mg / mL corticosterone internal standard solution (IS), and react at 60 °C for 4 hours. After dilution of the above reaction solution, analyte solutions with concentration gradients of 0.1, 0.5, 1, 2.5, 5, 10, 50, 100, and 150 ng / mL are formed. Solutions of each concentration are respectively added into 3 consecutive holes in a 96-well microplate, and then the high-throughput analysis is carried out using the device of this patent. As Figure 5 shown, in the concentration range of 1500 times, the peak areas of AD (A), ADD (B), and NONE (C) in the XIC diagram show good linear relationships with the concentrations (R 2 are 0.999, 0.999, and 0.998 respectively), indicating that this utility model can accurately characterize the concentration of samples in the microplate and can be used for high-precision quantitative analysis.

[0050] Example 4: Application Example

[0051] This example aims to continuously analyze the steroid compounds and blank solvents arranged at intervals in a microplate, and use the XIC and sample residue rate results to illustrate the Figures 1 to 3 automatic sample elution effect of the device shown in Example 1, specifically as follows:

[0052] 50 μL of AD, ADD, and NONE standard solutions were mixed with 50 μL of yeast solution. After adding 100 μL of 1 mg / mL GirP solution, the reaction was carried out at 60 °C for 4 hours. The above reaction solution was diluted to form an analyte solution with a concentration of 150 ng / mL (the upper limit of quantification concentration), and it was alternately added into the wells of a 96-well microplate with a blank solvent (methanol: water = 1:1, V:V). Subsequently, high-throughput analysis was performed using the device of this patent. After the scanning analysis was completed, the m / z values of the target ions were monitored by Xcalibur 3.0 software to plot the corresponding XIC chromatogram and analyze the peak area of the target substance in the figure. The calculation formula for the sample residual rate (ECI%) is as follows: ECI% = absolute residue (AC) × concentration difference (DC) × 100%. AC refers to the ratio of the peak area of the residue in the blank sample to the peak area of the previous highest limit of quantification sample (ULOQ); DC is the ratio of the peak area of the previous sample to the peak area of the next sample. As Figure 6 shown, this utility model shows good sample elution effect when detecting different types of steroid compounds, basically avoiding cross-contamination and residue phenomena between samples. The sample residual rates of AD (A), ADD (B), and NONE (C) are 1.06%, 4.51%, and 0.53% respectively.

[0053] It can be seen from the above embodiments that compared with the prior art, this utility model has the following advantages: (1) The device of this patent uses a coaxial capillary probe with an open port to directly aspirate the liquid sample in the microplate, avoiding the complex steps of chromatographic separation and sample transfer, effectively improving the throughput and stability of the mass spectrometry analysis of the microplate. Its analysis speed is about 6.5 seconds / sample, and the coefficient of variation of the peak areas of continuously analyzed different analytes is less than 6%. (2) The device of this patent uses a liquid aspiration capillary to directly connect two three-way tubes, realizing both microplate sampling and subsequent ionization at the same time. This design not only has low cost and simple maintenance, but also has good quantification ability when analyzing different samples, and shows good linear relationships (R 2 values are 0.999, 0.999, and 0.998 respectively) within a 1500-fold concentration range. (3) The device of this patent uses a high-flow elution solvent to flow into the liquid aspiration capillary from the gap between the coaxial capillaries to achieve automatic elution after sampling, avoiding cross-contamination and signal overlap phenomena between samples. The residual rates of continuously analyzed different samples are 1.06%, 4.51%, and 0.53% respectively.

[0054] The role of the above embodiments is to specifically introduce the substantial content of this utility model. However, those skilled in the art should know that the protection scope of this utility model should not be limited to this specific embodiment.

Claims

1. A mass spectrometry automatic sampling system for microplate high-throughput analysis, comprising an elution solution delivery pipe connected to a high-voltage electrode and an atomization gas pipe connected to an atomization gas source, characterized in that: It also includes a microplate sampling probe, an electrospray ion source, a liquid aspiration capillary connecting the microplate sampling probe and the electrospray ion source, and a sample moving system; wherein: The microplate sampling probe comprises a sampling probe tee and a liquid supply capillary; the sampling probe tee comprises a first branch of the sampling probe tee, a second branch of the sampling probe tee and a third branch of the sampling probe tee; one end of the liquid supply capillary is connected to the elution solution delivery tube, and a liquid supply channel is formed in the first branch of the sampling probe tee and the second branch of the sampling probe tee, and the other end of the liquid supply capillary extends from the end of the second branch of the sampling probe tee; The electrospray ion source comprises an ion source three-way pipe and a sheath gas pipe; the ion source three-way pipe comprises a first branch of the ion source three-way pipe, a second branch of the ion source three-way pipe and a third branch of the ion source three-way pipe; one end of the sheath gas pipe is connected to the atomization gas pipe, and a gas supply channel is formed in the second branch of the ion source three-way pipe and the third branch of the ion source three-way pipe, and the other end of the sheath gas pipe extends from the end of the second branch of the ion source three-way pipe; One distal section of the liquid-pipetting capillary penetrates the second branch of the sampling probe tee and the third branch of the sampling probe tee, and the other distal section penetrates the first branch of the ion source tee and the second branch of the ion source tee; the portion of the liquid-pipetting capillary located in the second branch of the sampling probe tee is sleeved in the portion of the liquid-supply capillary located in the second branch of the sampling probe tee, a space for the flow of elution solution is reserved between the outer wall of the liquid-pipetting capillary and the inner wall of the liquid-supply capillary, and the sleeved portion of the liquid-pipetting capillary is shorter than the liquid-supply capillary; the portion of the liquid-pipetting capillary located in the second branch of the ion source tee is sleeved in the portion of the sheath gas tube located in the second branch of the ion source tee, a space for the flow of atomizing gas is reserved between the outer wall of the liquid-pipetting capillary and the inner wall of the sheath gas tube, and the sleeved portion of the liquid-pipetting capillary is longer than the sheath gas tube; The sample moving system comprises a microplate support for fixing the microplate and a translation and lifting mechanism for controlling the movement of the microplate support to adjust the sampling point, sampling depth and sampling duration of the microplate sampling probe on the microplate.

2. The mass spectrometry automatic sampling system according to claim 1, characterized in that: The second branch of the sampling probe three-way tube is perpendicular to the microplate.

3. The mass spectrometry automatic sampling system according to claim 1, characterized in that: The second branch of the ion source three-way pipe is aligned with the sample inlet of the mass spectrometer at a certain angle.

4. The mass spectrometry automatic sampling system according to claim 3, characterized in that: The angle is 30-60°.

5. The mass spectrometry automatic sampling system according to claim 1, characterized in that: The translation and lifting mechanism comprises an XY axis horizontal moving platform and a Z axis lifting platform, the Z axis lifting platform is fixedly connected to the XY horizontal moving platform, and the microplate bracket is fixedly connected to the Z axis lifting platform.

6. The mass spectrometry automatic sampling system according to claim 1, characterized in that: The length of the liquid-absorbing capillary is 5-50 cm.

7. The mass spectrometry automatic sampling system according to claim 1, characterized in that: The type of the microplate is a 96-well plate, a 384-well plate or a 1536-well plate.

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