Efficient sample injection system for improving liquid sample injection efficiency

Abstract

The invention relates to the technical field of analytical chemistry sample pretreatment, in particular to an efficient sample injection system for improving liquid sample injection efficiency. Comprising an injection pump, an enrichment cavity, an organic filter membrane, a closed heating pipe and a capillary tube, the organic filter membrane is arranged in the enrichment cavity and divides the enrichment cavity into a chamber I and a chamber II, the injection pump injects a liquid sample into the chamber I through a first pipeline, and the liquid sample is enriched in the chamber II through the organic filter membrane; the chamber II is sequentially connected with a closed heating tube and a capillary tube through a second pipeline, an outlet of the capillary tube is connected with a time-of-flight mass spectrum, the chamber II injects purging gas through a first purging gas pipeline, an enriched sample in the chamber II is purged into the closed heating tube to be gasified and heated, and then the enriched sample is introduced into the time-of-flight mass spectrum through the capillary tube to be analyzed. The device has the characteristics of compact structure, high integration level and high enrichment and gasification efficiency, realizes efficient conversion and sample introduction from a liquid sample to gas, and remarkably improves the sensitivity and efficiency of mass spectrometry.

Description

Technical Field

[0001] This invention relates to the field of analytical chemistry sample pretreatment technology, and in particular to a high-efficiency sample introduction system for improving liquid sample introduction efficiency. Background Technology

[0002] In mass spectrometry, direct injection of liquid samples suffers from low ionization efficiency, significant matrix interference, and low sensitivity. Typically, liquid samples need to be converted into gases and enriched to improve injection efficiency and detection sensitivity. However, traditional liquid vaporization devices often suffer from incomplete vaporization, high transmission losses, easy condensation, and difficulty in efficiently coupling with mass spectrometers.

[0003] Enrichment membrane technology, especially devices using organic filter membranes, can selectively enrich volatile organic compounds through the principle of permeation-diffusion-adsorption. However, existing devices are mostly designed for gas samples and have limited capacity to process liquid samples. There is a lack of efficient and integrated solutions for vaporization-enrichment-sample introduction.

[0004] Therefore, there is an urgent need to develop a sample introduction device that can efficiently convert liquids to gases, integrate enrichment functions, and be seamlessly connected to a mass spectrometer. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a high-efficiency liquid injection system that improves liquid injection efficiency. This system integrates liquid circulation enrichment, vaporization, dehumidification, flow control, and mass spectrometry injection, significantly improving the injection efficiency and detection sensitivity of liquid samples.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a high-efficiency sample introduction system for improving liquid sample introduction efficiency, comprising an injection pump, an enrichment chamber, an organic filter membrane, a sealed heating tube, and a capillary. The organic filter membrane is disposed within the enrichment chamber, which is divided into chamber I and chamber II. The injection pump is connected to chamber I via a first conduit, and injects a liquid sample into chamber I. After contacting the organic filter membrane, the liquid sample is enriched in chamber II. Chamber II is connected to the sealed heating tube and the capillary in sequence via a second conduit. The outlet of the capillary is connected to a time-of-flight mass spectrometer. Chamber II is connected to a first purge gas conduit, which injects purge gas to purge the enriched sample in chamber II into the sealed heating tube for vaporization and heating, and then introduces it into the time-of-flight mass spectrometer for analysis via the capillary.

[0008] The chamber II is provided with port A and port B. Port A is connected to the first purge gas pipeline, port B is connected to the first interface of the three-way valve c, the second interface of the three-way valve c is connected to the second pipeline, and the third interface of the three-way valve c is the vent port.

[0009] The chamber I is provided with port E and port F. Port E is connected to the first interface of three-way valve a, the second interface of three-way valve a is connected to the first pipeline, port F is connected to the first interface of three-way valve b, the second interface of three-way valve b is connected to the discharge pipeline, and the third interface of three-way valve b is connected to the third interface of three-way valve a. When the liquid surface in the chamber I comes into contact with the organic filter membrane, the three-way valve b connected to port F is opened to form a circulation path for the liquid sample, so that the liquid continuously flows over the surface of the organic filter membrane, thereby enriching the liquid sample in the chamber II.

[0010] The chamber I is provided with port C and port D. Port C is connected to the second purge gas pipeline, port D is connected to the first interface of the three-way valve d, the second interface of the three-way valve d is connected to the sealed heating tube, and the third interface of the three-way valve d is the vent port.

[0011] When analyzing a gas sample, the gas sample is introduced into chamber II through the first purge gas line, and then the three-way valve c connected to port B is opened, so that the gas sample in chamber II flows through the organic filter membrane, thereby enriching the gas sample in chamber I.

[0012] After sample injection, purge gas is introduced into chamber I through the second purge gas line. Then, the three-way valve d connected to port D is opened to purge the enriched sample in chamber I through the sealed heating tube and capillary into the time-of-flight mass spectrometer.

[0013] The second pipeline is equipped with a dehumidifier and a flow meter, which are located between the sealed heating tube and the capillary tube. The dehumidifier is used to dehumidify the enriched sample, and the flow meter is used to monitor and control the gas flow rate in real time.

[0014] The flow control range of the flow meter is 1 mL / min to 1 L / min.

[0015] The enrichment chamber includes two hemispherical cavities, and the mating surface of the two hemispherical cavities is a flat plate structure. One of the hemispherical cavities has an O-ring groove on its mating surface, and an O-ring is embedded in the O-ring groove. The organic filter membrane is placed on the O-ring, and the mating surfaces of the two hemispherical cavities are connected by bolts to compress the organic filter membrane and achieve a fixed seal.

[0016] The organic filter membrane is an enrichment membrane made of polydimethylsiloxane.

[0017] The maximum temperature reached by the sealed heating tube is 200 degrees Celsius.

[0018] The diameter of the capillary is 0.1 mm.

[0019] The advantages and beneficial effects of the present invention are as follows: The present invention provides a high-efficiency sample introduction system that improves the efficiency of liquid sample introduction. It integrates liquid circulation enrichment, vaporization, dehumidification, flow control and mass spectrometry sample introduction into one system, which significantly improves the sample introduction efficiency and detection sensitivity of liquid samples. It is especially suitable for introducing liquid samples into time-of-flight mass spectrometry for detection after efficient vaporization and enrichment.

[0020] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of the high-efficiency sample introduction system for improving liquid sample introduction efficiency according to the present invention.

[0024] In the diagram: 1-Injection pump, 2-Three-way valve a, 3-Enrichment chamber, 4-Organic filter membrane, 5-Sealed heating tube, 6-Dehumidifier, 7-Flow meter, 8-Capillary tube, 9-Time-of-flight mass spectrometer, 10-Three-way valve b, 11-Three-way valve c, 12-Three-way valve d. Detailed Implementation

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] like Figure 1As shown, this invention provides a high-efficiency sample introduction system for improving liquid sample introduction efficiency, including a syringe pump 1, an enrichment chamber 3, an organic filter membrane 4, a sealed heating tube 5, and a capillary tube 8. The organic filter membrane 4 is disposed in the enrichment chamber 3, which is divided into chamber I and chamber II. Chamber I is connected to the syringe pump 1 through a first pipeline. The syringe pump 1 injects liquid sample into chamber I. After the liquid sample comes into contact with the organic filter membrane 4, it is enriched in chamber II. Chamber II is connected to the sealed heating tube 5 and the capillary tube 8 in sequence through a second pipeline. The outlet of the capillary tube 8 is connected to a time-of-flight mass spectrometer 9. Chamber II is connected to a first purge gas pipeline. The first purge gas pipeline injects purge gas to purge the enriched sample in chamber II into the sealed heating tube 5 for vaporization and heating, and then introduces it into the time-of-flight mass spectrometer 9 through the capillary tube 8 for analysis.

[0028] In an embodiment of the present invention, chamber II is provided with vertical ports A and B. Port A is connected to the first purge gas pipeline, port B is connected to the first interface of the three-way valve c11, the second interface of the three-way valve c11 is connected to the second pipeline, and the third interface of the three-way valve c11 is an air vent.

[0029] In an embodiment of the present invention, chamber I is provided with port E and port F. Port E is connected to the first interface of three-way valve a2, the second interface of three-way valve a2 is connected to the first pipeline, port F is connected to the first interface of three-way valve b10, the second interface of three-way valve b10 is connected to the discharge pipeline, and the third interface of three-way valve b10 is connected to the third interface of three-way valve a2. When three-way valve a2 is opened, the liquid sample is injected into the chamber I of enrichment chamber 3 by injection pump 1. When the liquid surface contacts the organic filter membrane 4, three-way valve b10 connected to port F is opened to form a circulation path for the liquid sample, so that the liquid continuously flows over the surface of the organic filter membrane 4, thereby enriching the liquid sample in chamber II.

[0030] Furthermore, chamber I is also equipped with port C and port D. Port C is connected to the second purge gas line, and port D is connected to the first interface of the three-way valve d12. The second interface of the three-way valve d12 is connected to the sealed heating tube 5, and the third interface of the three-way valve d12 is the vent. When analyzing gas samples, gas samples are introduced into chamber II through the first purge gas line. Then, the three-way valve c11 connected to port B is opened, allowing the gas samples in chamber II to flow through the organic filter membrane 4, thereby enriching the gas samples in chamber I. After the sample introduction is completed, purge gas is introduced into chamber I through the second purge gas line. Then, the three-way valve d12 connected to port D is opened, allowing the enriched gas samples in chamber I to be purged through the sealed heating tube 5 and the capillary tube 8 into the time-of-flight mass spectrometer 9.

[0031] Furthermore, a dehumidifier 6 and a flow meter 7 are installed on the second pipeline. The dehumidifier 6 and flow meter 7 are located between the sealed heating tube 5 and the capillary tube 8. The dehumidifier 6 is used to remove moisture from the sample gas, reducing interference with mass spectrometry analysis. The flow meter 7 is used to monitor and control the gas flow rate in real time. The flow control range of the flow meter 7 is 1 mL / min to 1 L / min.

[0032] In an embodiment of the present invention, the enrichment cavity 3 is a spherical structure, including two hemispherical cavities. The mating surface of the two hemispherical cavities is a flat plate structure. An O-ring groove is provided on the mating surface of one of the hemispherical cavities. An O-ring is embedded in the O-ring groove. The organic filter membrane 4 is placed on the O-ring. The mating surfaces of the two hemispherical cavities are connected by bolts, thereby pressing the organic filter membrane 4 to achieve a fixed seal.

[0033] Preferably, the organic filter membrane 4 is an enrichment membrane made of polydimethylsiloxane. The sealed heating tube 5 is used to heat the purge gas and the vaporized sample to prevent condensation; the maximum temperature can reach 200 degrees Celsius. The capillary tube 8, with a diameter of 0.1 mm, serves as a transfer interface to efficiently introduce the sample into the time-of-flight mass spectrometer 9. The syringe pump 1 is connected to a sample vial for holding liquid samples.

[0034] This invention provides a high-efficiency liquid sample introduction system. Its working principle is as follows: A three-way valve a2 is opened, allowing the liquid sample to enter chamber I of the enrichment chamber 3 from the syringe pump 1. When the liquid surface contacts the organic filter membrane 4, a three-way valve b10 connected to port F is opened, forming a circulating flow path for the liquid sample. This allows the liquid to continuously flow over the surface of the organic filter membrane 4, achieving sample enrichment in chamber II. After enrichment, purge gas is introduced through the first purge gas line, carrying the sample from chamber II into the sealed heating tube 5. Under heating conditions, the liquid is ensured to be completely vaporized. Subsequently, moisture is removed by a dehumidifier 6, and the flow rate is precisely controlled by a flow meter 7. Finally, the sample is directly introduced into the time-of-flight mass spectrometer 9 via a capillary tube 8 for analysis.

[0035] The gas sample can be directly introduced into chamber II of enrichment chamber 3 through port A. Then, the three-way valve c11 connected to port B is opened, allowing the gas sample to flow through the organic filter membrane 7 and be enriched in chamber I. After the sample is introduced, purge gas is introduced from the second purge gas line connected to port C. Then, the three-way valve d12 connected to port D is opened, and the enriched sample in chamber I is purged through the sealed heating tube 5 and capillary tube 8 into the time-of-flight mass spectrometer 9.

[0036] This invention features a compact structure, high integration, and high enrichment and vaporization efficiency. It enables universal processing of liquid and gas samples, especially achieving efficient liquid-to-gas conversion and injection, while also possessing enrichment capabilities, thus greatly improving injection efficiency and mass spectrometry analysis sensitivity.

[0037] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A high-efficiency sample introduction system for improving liquid sample introduction efficiency, characterized in that, It includes an injection pump (1), an enrichment chamber (3), an organic filter membrane (4), a sealed heating tube (5), and a capillary tube (8). The organic filter membrane (4) is disposed in the enrichment chamber (3), and the enrichment chamber (3) is divided into chamber I and chamber II. Chamber I is connected to the injection pump (1) through a first pipeline. The injection pump (1) injects a liquid sample into chamber I. After the liquid sample comes into contact with the organic filter membrane (4), it is enriched in chamber II. Chamber II is connected to the sealed heating tube (5) and capillary tube (8) in sequence through the second pipeline. The outlet of the capillary tube (8) is connected to the time-of-flight mass spectrometer (9). Chamber II is connected to the first purge gas pipeline. Purge gas is injected through the first purge gas pipeline to purge the enriched sample in chamber II into the sealed heating tube (5) for vaporization and heating, and then introduced into the time-of-flight mass spectrometer (9) through the capillary tube (8) for analysis.

2. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 1, characterized in that, The chamber II is provided with port A and port B. Port A is connected to the first purge gas pipeline, and port B is connected to the first interface of the three-way valve c (11). The second interface of the three-way valve c (11) is connected to the second pipeline, and the third interface of the three-way valve c (11) is the vent port.

3. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 2, characterized in that, The chamber I is provided with port E and port F. Port E is connected to the first interface of three-way valve a (2), the second interface of three-way valve a (2) is connected to the first pipeline, port F is connected to the first interface of three-way valve b (10), the second interface of three-way valve b (10) is connected to the discharge pipeline, and the third interface of three-way valve b (10) is connected to the third interface of three-way valve a (2). When the liquid surface in chamber I comes into contact with the organic filter membrane (4), the three-way valve b (10) connected to port F is opened to form a circulation path for the liquid sample, so that the liquid continuously flows over the surface of the organic filter membrane (4) to achieve enrichment of the liquid sample in chamber II.

4. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 2, characterized in that, The chamber I is provided with port C and port D. Port C is connected to the second purge gas pipeline, and port D is connected to the first interface of the three-way valve d (12). The second interface of the three-way valve d (12) is connected to the sealed heating tube (5), and the third interface of the three-way valve d (12) is the vent. When analyzing a gas sample, a gas sample is introduced into chamber II through the first purge gas line, and then the three-way valve c (11) connected to port B is opened so that the gas sample in chamber II flows through the organic filter membrane (4) to achieve enrichment of the gas sample in chamber I; After the sample is injected, purge gas is introduced into the chamber I through the second purge gas line. Then, the three-way valve d (12) connected to port D is opened to purge the enriched sample in the chamber I through the sealed heating tube (5) and capillary tube (8) into the time-of-flight mass spectrometer (9).

5. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 1, characterized in that, The second pipeline is equipped with a dehumidifier (6) and a flow meter (7). The dehumidifier (6) and the flow meter (7) are located between the sealed heating tube (5) and the capillary tube (8). The dehumidifier (6) is used to dehumidify the enriched sample, and the flow meter (7) is used to monitor and control the gas flow in real time.

6. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 5, characterized in that, The flow control range of the flow meter (7) is 1 mL / min-1 L / min.

7. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 1, characterized in that, The enrichment cavity (3) includes two hemispherical cavities. The mating surfaces of the two hemispherical cavities are flat. An O-ring groove is provided on the mating surface of one of the hemispherical cavities. An O-ring is embedded in the O-ring groove. The organic filter membrane (4) is placed on the O-ring. The two hemispherical cavities are fastened together and the mating surfaces are connected by bolts, thereby pressing the organic filter membrane (4) to achieve a fixed seal.

8. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 1, characterized in that, The organic filter membrane (4) is a enrichment membrane made of polydimethylsiloxane.

9. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 1, characterized in that, The maximum temperature heated by the sealed heating tube (5) is 200 degrees Celsius.

10. The high-efficiency sample introduction system for improving liquid sample introduction efficiency according to claim 1, characterized in that, The diameter of the capillary (8) is 0.1 mm.

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