Droplet microextraction-flow type electrospray ionization device

Abstract

The utility model discloses a droplet microextraction-flow type electrospray ionization device, which belongs to the technical field of chemical analysis and comprises a digital peristaltic pump, a direct-current high-voltage power supply, a stainless steel two-way connector and a conductive metal transmitting tube. A transmission hose is arranged on the digital peristaltic pump, one end of the conductive metal transmitting tube is connected with the transmission hose of the digital peristaltic pump through a stainless steel two-way connector, the other end of the conductive metal transmitting tube corresponds to a mass spectrometer inlet and is used for generating electrospray, and the direct-current high-voltage power supply is electrically connected with the conductive metal transmitting tube. The direct-current high-voltage power supply applies voltage to the conductive metal transmitting tube; according to the droplet microextraction-flow type electrospray ionization device adopting the structure, micro-droplet flow type sample injection and non-contact flow type sample injection are combined, and electrospray can be stably generated under the condition of not depending on gas assistance.

Description

Technical Field

[0001] This utility model relates to the field of chemical analysis technology, and in particular to a droplet microextraction-flow electrospray ionization device. Background Technology

[0002] Electrospray ionization (ESI) has become an indispensable part of mass spectrometry analysis. Currently, traditional ESI devices suffer from several problems regarding sample introduction. On the one hand, in microdroplet injection, common devices struggle to precisely control the injection effect at different flow rates. For example, when using a large-diameter injection tube, achieving high flow rates often results in unstable liquid flow and uneven microdroplet formation, preventing the sample from efficiently and stably entering the mass spectrometer as microdroplets, severely impacting the accuracy and repeatability of the analytical results. On the other hand, in non-contact flow cytometry, existing equipment either struggles to effectively integrate with microdroplet flow cytometry, or during the integration process, due to unreasonable design of the connection or relative position between the emission tube and the mass spectrometer inlet, the emission tube is either directly inserted into the mass spectrometer inlet, easily causing contamination and limiting the effective utilization of the internal space of the mass spectrometer; or, although a certain distance is maintained, the lack of suitable voltage control and sample introduction structure design makes it impossible to stably eject microdroplets formed by the high-voltage electric field into the mass spectrometer, resulting in low sample introduction efficiency.

[0003] Therefore, developing a droplet microextraction-flow electrospray ionization device that can effectively combine microdroplet flow injection and non-contact flow injection, while having advantages in flow rate regulation, voltage control, and component connection, is of great practical significance. Utility Model Content

[0004] The purpose of this invention is to provide a droplet microextraction-flow electrospray ionization device to solve the above-mentioned problems.

[0005] To achieve the above objectives, this invention provides a Droplet Microextraction-Flow Electrospray Ionization (DME-Flow ESI) device, combining microdroplet flow injection with non-contact flow injection. The specific structure includes a digital peristaltic pump, a DC high-voltage power supply, a stainless steel two-way connector, and a conductive metal emission tube. The digital peristaltic pump is equipped with a transfer hose. One end of the conductive metal emission tube is connected to the transfer hose of the digital peristaltic pump via the stainless steel two-way connector, and the other end corresponds to the mass spectrometer inlet, used to generate electrospray. The DC high-voltage power supply is electrically connected to the conductive metal emission tube, applying voltage to it. The end of the conductive metal emission tube is aligned with the mass spectrometer inlet but maintained at a certain distance, not directly inserted into or in contact with the mass spectrometer inlet. The liquid sample is ejected into the mass spectrometer through microdroplets formed by the high-voltage electric field, realizing the combination of microdroplet flow injection and non-contact flow injection.

[0006] Preferably, in the above-mentioned droplet microextraction-flow electrospray ionization device, the conductive metal emitter tube includes a conductive metal emitter tube with an inner diameter of 250 μm and a conductive metal emitter tube with an inner diameter of 25 μm. When using the conductive metal emitter tube with an inner diameter of 250 μm, the flow rate of the digital peristaltic pump is above 10 μL / min, and when using the conductive metal emitter tube with an inner diameter of 25 μm, the flow rate of the digital peristaltic pump is below 500 nL / min.

[0007] Preferably, in the above-mentioned droplet microextraction-flow electrospray ionization device, the DC high-voltage power supply applies a voltage of 1.5 to 3.5 kV.

[0008] Preferably, in the above-mentioned droplet microextraction-flow electrospray ionization device, the diameter of the stainless steel two-way connector is 1 / 16 inch.

[0009] Preferably, the above-mentioned droplet microextraction-flow electrospray ionization device further includes a sample plate, the digital peristaltic pump is provided with a sample inlet tube, the inlet end of the sample inlet tube is located inside the sample plate, and the sample plate is provided with a flow path containing a control valve for introducing the extraction solution.

[0010] Therefore, this utility model, employing the aforementioned structure, provides a droplet microextraction-flow electrospray ionization device. Through a configured conductive metal emitter tube and a digital peristaltic pump flow control mechanism, it achieves continuous flow-based sample introduction, meeting the requirements for rapid analysis of high-throughput samples. This solves the problems of unstable flow rate control and uneven droplet formation in traditional devices with different inner diameter pipes, breaking through the application limitations of a single flow rate range. It can operate within a wide flow range, meeting the needs of high-flow-rate analysis and is suitable for high-throughput sample analysis, overcoming the flow rate limitations of traditional nanoLC (nano liquid chromatography) systems. The non-contact alignment design between the conductive metal emitter tube end and the mass spectrometer inlet avoids the contamination and space occupation problems of traditional contact sample introduction. Combined with the precise voltage output of a 1.5–3.5 kV DC high-voltage power supply, microdroplets can be stably formed and sprayed onto the mass spectrometer through a high-voltage electric field without gas assistance, significantly improving the persistence and stability of the electrospray process and solving the problem of low ionization efficiency caused by the mismatch between the sample introduction structure and voltage parameters in traditional devices. The device features a simple structure, is easy to operate, and supports continuous injection and ionization of multiple droplets, improving analytical efficiency and reducing analysis time. It has wide applications in mass spectrometry, single-cell analysis, tissue imaging, and other fields, demonstrating significant application value.

[0011] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of an embodiment of the droplet microextraction-flow electrospray ionization device of this utility model;

[0013] Figure 2 This is a line graph showing the effect of liquid flow rate variation on electrospray duration in an embodiment of the droplet microextraction-flow electrospray ionization device of this utility model.

[0014] Figure reference numerals: 1. Peristaltic pump; 2. DC high voltage power supply; 3. Stainless steel two-way connector; 4. Conductive metal emission tube; 5. Mass spectrometer inlet; 6. Sample plate; 7. Flow path. Detailed Implementation

[0015] To better understand the above technical solutions, a detailed description of the solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0016] The terminology used in the embodiments of this utility model is for the purpose of describing particular embodiments only and is not intended to limit the utility model. The singular forms “a,” “the,” and “the” used in the embodiments of this utility model and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0017] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0018] See appendix Figure 1 As shown, this application provides a droplet microextraction-flow electrospray ionization (DME-Flow ESI) device, which combines microdroplet flow injection with non-contact flow injection. The specific structure includes a digital peristaltic pump 1, a DC high-voltage power supply 2, a stainless steel two-way connector 3, and a conductive metal emission tube 4. The digital peristaltic pump 1 is equipped with a transfer hose. One end of the conductive metal emission tube 4 is connected to the peristaltic pump's transfer hose via the stainless steel two-way connector 3, and the other end corresponds to the mass spectrometer inlet 5, used to generate electrospray. The DC high-voltage power supply 2 is electrically connected to the conductive metal emission tube 4, applying voltage to it. The end of the conductive metal emission tube 4 is aligned with the mass spectrometer inlet 5, but maintained at a certain distance, not directly inserted into or in contact with the mass spectrometer inlet. The liquid sample is ejected into the mass spectrometer through microdroplets formed by the high-voltage electric field, realizing the combination of microdroplet flow injection and non-contact flow injection.

[0019] The conductive metal emitter 4 includes a conductive metal emitter with an inner diameter of 250 μm and a conductive metal emitter with an inner diameter of 25 μm. When using the conductive metal emitter with an inner diameter of 250 μm, the flow rate of the digital peristaltic pump 1 is above 10 μL / min, and when using the conductive metal emitter with an inner diameter of 25 μm, the flow rate of the digital peristaltic pump 1 is below 500 nL / min. The DC high voltage power supply 2 applies a voltage of 1.5 to 3.5 kV, and the applied voltage of the DC high voltage power supply 2 can be adjusted according to the actual situation. The diameter of the stainless steel two-way connector 3 is 1 / 16 inch. It also includes a sample plate 6. The digital peristaltic pump 1 is provided with a sample inlet tube, and the inlet end of the sample inlet tube is located inside the sample plate 6. The sample plate 6 is provided with a flow path 7 containing a control valve for introducing the extraction solution.

[0020] Working principle: The flow path 7, located above the sample plate 6 and containing a control valve, is used to introduce the extraction solution, ensuring precise application onto the sample plate 6. The droplet microextraction process takes place on the sample plate, achieving efficient contact between the sample and the extraction solution through precise control of the solution flow rate in the flow path. This method enables efficient extraction on the sample plate surface. The extraction solution is typically methanol-water (4 / 1 volume ratio), and the solution can be optimized according to the analyte. The extracted liquid sample is drawn in through the inlet tube of the digital peristaltic pump 1 and transported along the transfer hose to the conductive metal emission tube 4. A DC high voltage is applied outside the conductive metal emission tube 4, ionizing the liquid solvent and generating a spray. This process does not rely on gas-assisted spraying; instead, it utilizes an electric field to directly drive the liquid to form a stable electrospray, overcoming the complexity and instability inherent in traditional methods that require gas support.

[0021] When DME-Flow ESI is applied in other fields such as mass spectrometry analysis and single-cell analysis, a conductive metal emission tube with an inner diameter of 25 μm is used. At this time, the inner diameter of the conductive metal emission tube 4 is small enough that the flow rate can be lower than 500 nL / min.

[0022] This device combines microdroplet injection with non-contact flow cytometry; further analysis was conducted on the electrospray duration of the DME-Flow ESI device under different peristaltic pump flow rates and droplet volumes. Figure 2 The experimental results curve of the electrospray duration versus flow rate were obtained after the actual device was built, with the droplet volume fixed at 5 μL.

[0023] Therefore, this utility model, employing the aforementioned structure, provides a droplet microextraction-flow electrospray ionization device. Through a configured conductive metal emitter tube and a digital peristaltic pump flow control mechanism, it achieves continuous flow-based sample introduction, meeting the requirements for rapid analysis of high-throughput samples. This solves the problems of unstable flow rate control and uneven microdroplet formation in traditional devices with different inner diameter pipes, breaking through the application limitations of a single flow rate range. It can operate within a wide flow rate range, meeting the needs of high-flow-rate analysis and is suitable for high-throughput sample analysis, overcoming the flow rate limitations of traditional nanoLC systems. The non-contact alignment design between the conductive metal emitter tube end and the mass spectrometer inlet avoids the mass spectrometer inlet contamination and space occupation problems caused by traditional contact sample introduction. Combined with the precise voltage output of a 1.5–3.5 kV DC high-voltage power supply, microdroplets can be stably formed and sprayed onto the mass spectrometer through a high-voltage electric field without gas assistance, significantly improving the persistence and stability of the electrospray process and solving the problem of low ionization efficiency caused by the mismatch between the sample introduction structure and voltage parameters in traditional devices. The device features a simple structure, is easy to operate, and supports continuous injection and ionization of multiple droplets, improving analytical efficiency and reducing analysis time. It has wide applications in mass spectrometry, single-cell analysis, tissue imaging, and other fields, demonstrating significant practical value.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A droplet microextraction-flow electrospray ionization device, characterized in that: This invention combines microdroplet injection with non-contact flow cytometry. The specific structure includes a digital peristaltic pump, a DC high-voltage power supply, a stainless steel two-way connector, and a conductive metal emission tube. The digital peristaltic pump is equipped with a transfer hose. One end of the conductive metal emission tube is connected to the transfer hose of the digital peristaltic pump via the stainless steel two-way connector, while the other end corresponds to the mass spectrometer inlet for generating electrospray. The DC high-voltage power supply is electrically connected to the conductive metal emission tube and applies voltage to it. The end of the conductive metal emission tube is aligned with the mass spectrometer inlet but maintained at a certain distance, without directly inserting into or contacting the inlet. The liquid sample is injected into the mass spectrometer through microdroplets formed by the high-voltage electric field, thus combining microdroplet injection with non-contact flow cytometry.

2. The droplet microextraction-flow electrospray ionization device according to claim 1, characterized in that: The conductive metal emitter includes a conductive metal emitter with an inner diameter of 250 μm and a conductive metal emitter with an inner diameter of 25 μm. When using the conductive metal emitter with an inner diameter of 250 μm, the flow rate of the digital peristaltic pump is above 10 μL / min. When using the conductive metal emitter with an inner diameter of 25 μm, the flow rate of the digital peristaltic pump is below 500 nL / min.

3. The droplet microextraction-flow electrospray ionization device according to claim 1, characterized in that: The DC high-voltage power supply applies a voltage of 1.5 to 3.5 kV.

4. The droplet microextraction-flow electrospray ionization device according to claim 1, characterized in that: The stainless steel two-way connector has a diameter of 1 / 16 inch.

5. The droplet microextraction-flow electrospray ionization device according to claim 1, characterized in that: It also includes a sample plate, the digital peristaltic pump is equipped with a sample inlet tube, the inlet end of the sample inlet tube is located inside the sample plate, and the sample plate is provided with a flow path containing a control valve for introducing the extraction solution.

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