Mass spectrum device integrating microextraction and electrospray ionization

Abstract

The invention discloses a mass spectrum device integrating microextraction and electrospray ionization, comprising: a sampling device for adsorbing and collecting a sample to be detected; the extraction device is used for extracting a sample to be detected from the sampling device; and the ionization device is used for ionizing the sample to be detected and sending charged ions into a mass spectrometer for analysis. Compared with the prior art, on-site sampling and instant analysis and detection can be directly carried out through the sampling device, analysis can be carried out without complex pretreatment and sample loading, the detection speed is high, and the on-site detection requirement of the portable mass spectrometer is met.

Description

Technical Field

[0001] The invention relates to the field of mass spectrometry analysis, in particular to a mass spectrometry device integrating microextraction and electrospray ionization. Background Art

[0002] In chemical analysis, on-site, rapid and reliable detection of trace compounds such as pollutants, toxic substances, drugs of abuse and illegal additives is becoming increasingly important.

[0003] Traditional compound analysis and detection requires complex pre-treatment processes, such as filtration (a method of removing solid particles from liquids or performing solid-liquid separation to obtain solid substances, the process includes filtration, centrifugation, and precipitation), solvent extraction (using the difference in solubility or distribution coefficient of mixed components in solvents to separate them, common ones are liquid-liquid extraction, liquid-solid extraction, and liquid-gas extraction), distillation, etc.

[0004] Currently, portable mass spectrometers for non-volatile compounds have been developed, which can perform on-site analysis of non-volatile samples through direct sampling and ionization techniques. For example, the wiping method uses a sampling cloth strip to wipe solids or dip into liquids, and heats the sample to be dried out. Although it is highly portable, it has poor detection limits due to high impurity interference.

[0005] There is also a direct sampling method, which uses a capillary to dip into the solution of the object to be tested, but the object to be tested needs to be pre-treated first (solids need to be dissolved first, and then filtered by filtration before they can be sampled for analysis; liquids need to be extracted);

[0006] The operation flow of the above process is complicated, and requires prior processing to obtain the liquid of the object to be tested, and then processing the liquid of the object to be tested for mass spectrometry analysis.

[0007] Therefore, how to design a mass spectrometry device that integrates microextraction and electrospray ionization to simplify the operation process and reduce pre-processing time is a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0008] In view of the fact that in the prior art, compound analysis and detection requires a complex pre-treatment process, the present invention proposes a mass spectrometry device integrating microextraction and electrospray ionization.

[0009] The technical solution of the present invention is to propose a mass spectrometry device integrating microextraction and electrospray ionization, comprising:

[0010] A sampling device, the sampling device is used to adsorb the sample to be tested;

[0011] An extraction device, the extraction device is used to extract the sample to be tested from the sampling device;

[0012] Ionization device, which is used to ionize the sample to be measured and send the charged ions into a mass spectrometer for analysis.

[0013] Furthermore, the ionization device is a metal electrode.

[0014] Furthermore, the sampling device is a fiber coating provided at the end of the metal electrode.

[0015] Furthermore, the extraction device is a glass capillary containing an organic solvent liquid, and the organic solvent liquid can be used to extract the sample to be measured from the sampling device.

[0016] Furthermore, the glass capillary has a first tube portion and a second tube portion;

[0017] The first tube portion is in the shape of a hollow cylinder, and the second tube portion is in the shape of a hollow cone with an opening at the tip;

[0018] When the ionization device is inserted into the glass capillary and contacts the organic solvent liquid from which the sample to be measured has been extracted, the ionization device can ionize the sample to be measured and generate an electrospray near the tip opening of the second tube portion.

[0019] Furthermore, the fiber coating is a lotus leaf-shaped nanostructure;

[0020] A hydrophilic pattern area and a hydrophobic pattern area are constructed on the fiber coating, and the hydrophilic pattern area and the hydrophobic pattern area are used to guide the liquid penetration path.

[0021] Furthermore, it further includes a handheld structure provided at the other end of the metal electrode.

[0022] Furthermore, the handheld structure is a cylindrical sampling holder handle, and the side wall of the sampling holder handle is provided with a concave structure.

[0023] Furthermore, the length of the glass capillary is 40 - 70 mm, the diameter of the first tube portion is 1 - 2 mm, and the average diameter of the second tube portion is 50 - 80 μm.

[0024] Furthermore, the thickness of the fiber coating is 0.05 - 0.15 mm, the length is 0.3 - 0.7 mm, and the fiber coating is coated at a position 0.1 - 0.3 mm away from the end of the metal electrode.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The end of the metal electrode of the present invention is coated with a fiber coating, enabling the present invention to directly sample the sample to be measured. Meanwhile, the sample to be measured can be extracted by the organic solvent liquid in the glass capillary, and an electrospray is generated at the tip of the glass capillary under the ionization of the metal electrode for mass spectrometry analysis. The detection speed is fast, and it can be completed within several minutes from sampling to mass spectrometry detection, which is very suitable for on-site rapid detection. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 It is a schematic structural diagram of the whole of the present invention;

[0029] Figure 2 It is a schematic operation flow diagram of the present invention;

[0030] Figure 3 It is a mass spectrometry diagram of the present invention under a certain example. Detailed Embodiments

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Therefore, a feature pointed out in this specification will be used to illustrate one of the features of one embodiment of the present invention, rather than implying that each embodiment of the present invention must have the illustrated feature. In addition, it should be noted that this specification describes many features. Although certain features may be combined to show possible system designs, these features can also be used in other combinations not explicitly described. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0033] The principle and structure of the present invention will be described in detail below with reference to the drawings and embodiments.

[0034] Traditional compound analysis and detection requires complex pretreatment processes. Among them, SPME is a simple, rapid, and sensitive sample pretreatment technique that combines the three steps of extraction, concentration, and injection into one. Its basic principle is to use an adsorbent coated on a fused silica fiber to selectively extract the sample to be measured. When in use, insert the SPME syringe into the bottle, push the handle to extend the fiber head out of the syringe. The fiber head can be immersed in the solution or placed above the sample. Extract for 2 - 30 minutes, retract the fiber head, and remove the sample bottle. Then insert the SPME syringe into the injection port of the GC / GCMS instrument, push the handle rod to extend the fiber head, thermally desorb the sample into the chromatographic column (or rinse it into the liquid chromatographic column with the HPLC mobile phase), retract the fiber head, and remove the syringe.

[0035] The above-mentioned SPME only requires simple pretreatment for sample injection and analysis. However, when it is used for mass spectrometry analysis, it still needs to go through adsorption (fiber coating), desorption (thermal / solvent), and then transfer to the chromatograph or mass spectrometer for the analysis process, and the operation is still relatively complex.

[0036] The idea of the present invention is to further optimize on the basis of the above-mentioned SPME. After completing the extraction of the sample to be measured, ionize the organic solvent liquid of the sample to be measured obtained by extraction through a metal electrode, generate an electrospray at the tip of the glass capillary through the polarization effect, and directly use this electrospray for mass spectrometry analysis, omitting the desorption process of the traditional SPME and improving the detection speed.

[0037] Based on the above design idea, the present invention proposes a mass spectrometry device integrating microextraction and electrospray ionization, which includes:

[0038] A sampling device for adsorbing the sample to be measured;

[0039] An extraction device for extracting the sample to be measured from the sampling device;

[0040] An ionization device for ionizing the sample to be measured and sending the charged ions into the mass spectrometer for analysis.

[0041] Its specific working process is to directly sample the sample to be measured through the sampling device on-site, then put the sampling device into the extraction device for extraction to obtain the sample to be measured, and then ionize the sample to be measured through the ionization device to obtain charged ions and send the charged ions into mass spectrometry analysis.

[0042] It can be seen that the mass spectrometry device integrating microextraction and electrospray ionization proposed by the present invention, after extracting the sample to be measured, does not need to go through the desorption process and can be directly used for mass spectrometry analysis. Its operation process is more concise and the detection speed is faster.

[0043] Please refer to Figure 1, in the present invention, the ionization device is a metal electrode;

[0044] The sampling device is a fiber coating provided at the end of the metal electrode;

[0045] The extraction device is a glass capillary containing an organic solvent liquid, and the organic solvent liquid can be used to extract the sample to be measured from the sampling device.

[0046] Here, the principles of the fiber coating and the organic solvent liquid are the same as those for sampling and extracting the sample to be measured in SPME, and will not be elaborated here;

[0047] On this basis, the present invention is provided with an ionization device, which is set as a metal electrode. At the same time, the structure of the extraction device is adjusted accordingly to have a tip. The direct current high-voltage electric field near the tip of the metal electrode polarizes the solution in the glass capillary, that is, the cations and anions in the solution move towards each other, so that an electrospray is generated at the tip of the glass capillary, making the ions of the sample to be measured charged and entering the mass spectrometer for mass spectrometry analysis, and the mass spectrometry information of the sample to be measured is obtained according to the different mass-to-charge ratios of substances.

[0048] Please refer to Figure 1 , in the present invention, to achieve the above electrospray effect, the glass capillary is provided with a first tube portion and a second tube portion;

[0049] The shape of the first tube portion is a hollow cylinder, and the shape of the second tube portion is a hollow cone with an opening at the tip;

[0050] When the ionization device is inserted into the glass capillary and contacts the organic solvent liquid that extracts the sample to be measured, the ionization device after applying a direct current high voltage can ionize the sample to be measured and generate an electrospray near the tip opening of the second tube portion.

[0051] Here, the first tube portion is a normal component of the glass capillary, and setting it as a cylinder is convenient for picking and placing;

[0052] One reason for setting the second tube portion as a cone is that it has a tip opening and can form an electrospray at the opening through the polarization effect of the electrode electric field on the solution. Another reason is that the bottom of the cone can be perfectly connected to the first tube portion without affecting the overall structure of the glass capillary.

[0053] Based on the above setting of the glass capillary, it can be seen that Figure 2 , the operation process of the present invention is as follows: First, obtain a glass capillary having the above structural composition;

[0054] Then use the glass capillary to dip into the organic solvent liquid, and the organic solvent liquid needs to be able to effectively extract the sample to be measured. It can dip into the organic solvent liquid through the capillary, or inject the organic solvent liquid through a syringe;

[0055] Then insert the metal electrode of the sample to be tested obtained by sampling into the glass capillary. A fiber coating is provided at the end of the metal electrode. The fiber coating can directly sample the sample to be tested. When the metal electrode is inserted into the glass capillary, the sample to be tested on the fiber coating can come into contact with the organic solvent liquid and be extracted; during the actual sampling process, to ensure sufficient acquisition of the sample to be tested, it is generally necessary to ensure that the fiber coating is in contact with the sample to be tested for about 20 s. Similarly, to ensure the extraction of the sample to be tested by the organic solvent liquid, the metal electrode generally needs to be placed in the organic solvent liquid and left standing for 2 - 3 minutes;

[0056] Finally, charge the metal electrode, and then place the glass capillary at the mass spectrometry analysis inlet of the mass spectrometer. At this time, the organic solvent liquid in the glass capillary will be ionized and polarized to generate an electrospray, and enter the mass spectrometry analysis inlet for mass spectrometry analysis.

[0057] Further, in a preferred embodiment of the present invention, the above-mentioned fiber coating is set as a lotus leaf-shaped Wiener structure;

[0058] A hydrophilic pattern area and a hydrophobic pattern area are constructed on the fiber coating. The hydrophilic pattern area and the hydrophobic pattern area are used to guide the penetration path of the liquid.

[0059] Here, the Wiener structure is the general composition structure of the fiber coating, which is basically the same as the setting of the fiber head in SPME. The hydrophilic pattern area is the area conducive to the flow of the liquid, and the hydrophobic pattern area is the area not conducive to the flow of the liquid. Through this setting, the penetration path of the organic solvent liquid can be directionally guided, the utilization rate of the organic solvent liquid can be improved, and the residue of the sample to be tested can be reduced.

[0060] Please refer to Figure 2 , the mass spectrometry device integrating microextraction and electrospray ionization proposed by the present invention further includes a handheld structure provided at the other end of the metal electrode;

[0061] The handheld structure is a cylindrical sampling tray handle, and the side wall of the sampling tray handle is provided with a concave structure.

[0062] The purpose of setting the sampling tray handle in the present invention is to facilitate the user to pick up and place. The concave structure is used to ensure the comfort of the user when picking up and placing. When setting the handheld structure, it is also necessary to ensure the insulation of the handheld structure to avoid the risk of electric shock to the user when the metal electrode is powered.

[0063] Further, in an example of the present invention, the length of the glass capillary is 40 - 70 mm, the diameter of the first tube part is 1 - 2 mm, and the average diameter of the second tube part is 50 - 80 μm.

[0064] Further, the thickness of the fiber coating is 0.05 - 0.15 mm, and the length is 0.3 - 0.7 mm. The fiber coating is applied at a position 0.1 - 0.3 mm away from the end of the metal electrode.

[0065] The above settings are for the detection of sildenafil parent ions. In other embodiments of the present invention, the relevant parameters of the above glass capillary and fiber coating can be adjusted adaptively;

[0066] In this example, the organic solvent liquid is methanol.

[0067] Figure 3 This is the ion information spectrogram for the detection of sildenafil parent ions in the present invention. The specific process is as follows:

[0068] Use a glass capillary with a length of 55 mm, an inner diameter of the first tube part of 1.5 mm, and an average inner diameter of the second tube part of 80 μm to dip 1 - 2 μL of methanol organic solution;

[0069] Then insert a metal electrode with a diameter of 0.3 mm, coated with a fiber coating at a position 0.3 mm away from the end, the fiber coating having a thickness of 0.1 mm and a length of 0.5 mm, and equipped with a sampling tray handle, into the pulverized health product containing sildenafil and scrape it back and forth 3 - 5 times;

[0070] Then insert the end of the fiber coating dipped with the sample to be tested into the glass capillary for extraction, and let it stand for 2 minutes;

[0071] Finally, place it together with the sampling tray handle and the glass capillary at the mass spectrometry inlet. Align the tip of the glass capillary with the mass spectrometry inlet, apply a 3000 V DC high voltage to the metal electrode, polarize the organic solvent liquid in the glass capillary to generate electrospray, and the ions with the sample to be tested enter the mass spectrometer for analysis and detection.

[0072] The above is the operation process of the present invention in this example. Compared with the traditional compound analysis and detection, the detection speed is faster, the sample injection operation process is simple, and it can be completed within a few minutes from adsorbing the sample to be tested to completing the mass spectrometry analysis;

[0073] The pre - treatment time is shorter, no complex pre - treatment process is required, and immediate sampling can be directly carried out, which is very suitable for on - site rapid detection;

[0074] The application field is wider, and it can detect macromolecular substances such as proteins, while traditional SPME cannot detect due to the limitation of the desorption process.

[0075] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A mass spectrometry device integrating microextraction and electrospray ionization, characterized in that, Comprising: A sampling device for adsorbing and collecting a sample to be measured; An extraction device for extracting the sample to be measured from the sampling device; An ionization device for ionizing the sample to be measured and sending the ionized sample ions into a mass spectrometer for analysis.

2. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 1, wherein The ionization device is a metal electrode.

3. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 2, characterized in that, The sampling device is a fiber coating provided at the end of the metal electrode.

4. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 1, characterized in that, The extraction device is a glass capillary containing an organic solvent liquid, and the organic solvent liquid can be used to extract the sample to be measured from the sampling device.

5. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 4, characterized in that, The glass capillary has a first tube portion and a second tube portion; The first tube portion is in the shape of a hollow cylinder, and the second tube portion is in the shape of a hollow cone with an opening at the tip; When the ionization device is inserted into the glass capillary and contacts the organic solvent liquid from which the sample to be measured has been extracted, the ionization device can ionize the sample to be measured and generate an electrospray near the tip opening of the second tube portion.

6. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 3, characterized in that, The fiber coating is a lotus leaf-shaped wavy structure; A hydrophilic pattern area and a hydrophobic pattern area are constructed on the fiber coating, and the hydrophilic pattern area and the hydrophobic pattern area are used to guide the liquid penetration path.

7. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 3, characterized in that, It further includes a hand-held structure provided at the other end of the metal electrode.

8. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 7, characterized in that, The hand-held structure is a cylindrical sampling holder handle, and the side wall of the sampling holder handle is provided with a concave structure.

9. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 4, wherein The length of the glass capillary is 40 - 70 mm, the diameter of the first tube portion is 1 - 2 mm, and the average diameter of the second tube portion is 50 - 80 μm.

10. The mass spectrometry device integrating microextraction and electrospray ionization according to claim 3, characterized in that, The thickness of the fiber coating is 0.05 - 0.15 mm, the length is 0.3 - 0.7 mm, and the fiber coating is coated at a position 0.1 - 0.3 mm away from the end of the metal electrode.

Images