Shunting-in-situ matrix purification liquid-liquid electric extraction device, method and application

Abstract

The invention relates to a shunting-in-situ matrix purification liquid-liquid electric extraction device and method and application, and relates to the technical field of chemical analysis. The extraction assembly comprises a push-and-pull device, an injector electrode and a shunt tube, the injector electrode comprises an injector electrode wire and an injector which are connected, the injector is used for containing conductive liquid, the push-and-pull device drives a piston of the injector to do push-and-pull motion, one end of the injector electrode wire is connected with the injector, and the other end of the injector electrode wire is grounded or connected with a power supply; one end of the shunt tube is communicated with the injector, and the other end is used for immersing a to-be-extracted object; the sample assembly comprises a sample container and a sample electrode wire, one end of the sample electrode wire is used for immersing an object to be extracted, and the other end is grounded or connected with a power supply; the sample container is used for accommodating a to-be-extracted substance; the equipment can reduce the risk of bubble generation through shunting, and improve the baseline stability and the electric extraction efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical analysis, and in particular to a split-flow in-situ matrix purification liquid-liquid electric extraction device, method and application. Background Art

[0002] Liquid-liquid electroextraction technology has shown many attractive advantages, but in the actual application process, it also encounters some challenges in the face of complex matrix interference. On the one hand, although in theory the extraction speed of liquid-liquid electroextraction technology can be greatly improved by increasing the electric field (such as increasing the voltage) without limit, in fact, the sample matrix will increase the conductivity of the electroextraction system, causing the current to rise and the Joule heat to increase. The increase in the local temperature of the system will cause bubbles to be generated, thereby interfering with or even interrupting the extraction. At the same time, the increasingly violent electrode reaction will also become a source of bubble generation. The bubble problem greatly limits the improvement of electroextraction efficiency. On the other hand, complex matrix components will interfere with the electroextraction process, resulting in a decrease in extraction rate and poor stability. Co-extracted impurities will also cause matrix effects. These problems will directly lead to long electroextraction time, low extraction recovery, poor extraction precision and accuracy, and it is difficult to achieve exhaustion extraction.

[0003] Therefore, establishing a liquid-liquid electroextraction technology and its device with simple operation, low cost, excellent enrichment effect, strong matrix purification ability and avoidance of bubble generation for the further development and promotion of the practical application of electroextraction technology has important practical significance. Summary of the invention

[0004] In view of the above problems, the present invention provides a flow splitting-in-situ matrix purification liquid-liquid electric extraction device, which can reduce the risk of bubble generation through flow splitting and improve the electric extraction efficiency and extraction stability.

[0005] In order to achieve the above object, the present invention provides a split-flow in-situ matrix purification liquid-liquid electroextraction device, comprising:

[0006] An extraction assembly, comprising a push-pull device, a syringe electrode and a shunt tube, wherein the syringe electrode comprises a connected syringe electrode wire and a syringe, the syringe is used to contain an electroconductive liquid, the push-pull device drives the piston of the syringe to push and pull, one end of the syringe electrode wire is connected to the syringe, and the other end is grounded or connected to a power source; one end of the shunt tube is connected to the syringe, and the other end is used to immerse the object to be extracted; and

[0007] The sample assembly comprises a sample container and a sample electrode wire. One end of the sample electrode wire is used to immerse the object to be extracted, and the other end is used to be grounded or connected to a power source. The sample container is used to contain the object to be extracted.

[0008] The inventors discovered during the research process that, in order to address the above-mentioned bubble problem, the risk of bubble generation can be reduced by increasing the number of pipes in the shunt pipe. Specifically, increasing the number of pipes in the shunt pipe can reduce the actual current passing through each pipe under the same conditions, thereby reducing the temperature rise of each pipe, and ultimately reducing the risk of bubble generation.

[0009] At the same time, the device connects the syringe electrode wire to the syringe to form a "syringe electrode" structure, so that the collection of the solution and the cleaning of the device are conveniently controlled by the syringe pump, and the sufficient conductive liquid in the syringe can be used for multiple samples for electrical extraction, thereby improving the efficiency of electrical extraction. In addition, the cross-sectional area of ​​the conventional sample container and the shunt tube is quite different, which is conducive to accelerating the diffusion mass transfer in the sample container while significantly inhibiting the diffusion mass transfer in the shunt tube, and inhibiting the target object in the tube (including the sample to be tested or the standard sample) from back-diffusion back to the sample container. When the device is used for shunt-in-situ matrix purification liquid-liquid electroextraction, the target object in the sample container can gradually form a target enrichment zone in the shunt tube after electrical extraction. The zone is far away from the contact surface of the sample container and the shunt tube, and the target object in the shunt tube can be prevented from back-diffusion back to the sample container.

[0010] In one embodiment, the other end of the syringe electrode wire is grounded or connected to the high voltage output end of a power supply; the other end of the sample electrode wire is used to be grounded or connected to the high voltage output end of a power supply.

[0011] In one embodiment, the number of pipes of the shunt pipe is ≥1.

[0012] In one embodiment, the number of the diversion pipes is 1 to 11.

[0013] In one embodiment, the number of the diversion pipes is 3 to 10.

[0014] In one embodiment, the number of pipes in the diversion pipe is 5.

[0015] In one embodiment, one end of the syringe electrode wire is inserted into the tail of the syringe piston rod and exposed at the head of the piston rod.

[0016] The syringe electrode wire is exposed from the head of the piston rod and can be immersed in the conductive liquid.

[0017] In one embodiment, the object to be extracted includes a sample to be extracted or a standard.

[0018] In one embodiment, the shunt tube is connected to the syringe via a Luer connector or a hollow plastic cone.

[0019] In one embodiment, the shunt tube is an insulating shunt tube with a length of 35 to 45 cm and an inner diameter of 0.3 to 1.0 mm.

[0020] In one embodiment, the sample container is an insulated sample container with a capacity of 5 to 15 mL, a height of 6 to 8 cm, and an inner diameter of 1 to 2 cm.

[0021] In one embodiment, the power supply is a positive high voltage power supply of 0 to 30 kV or a negative high voltage power supply of -30 to 0 kV.

[0022] In one embodiment, the syringe electrode wire is a stainless steel electrode wire, the sample electrode wire is a platinum upper and lower double ring electrode wire, and the diameters of the syringe electrode wire and the sample electrode wire are both 0.3 to 0.7 mm.

[0023] In one embodiment, the push-pull device is a syringe pump, the flow rate of the syringe pump is 150-250 μL / min, and the capacity of the syringe is 5-10 mL.

[0024] The present invention also provides a split flow-in-situ matrix purification liquid-liquid electro-extraction method, comprising the following steps: preparing a sample to be extracted and a standard product, using the split flow-in-situ matrix purification liquid-liquid electro-extraction device described in any one of claims 1 to 3 to electro-extract the sample to be extracted and the standard product to obtain a sample to be tested and a standard sample; the sample to be tested is enriched in a split flow tube;

[0025] The step of preparing the sample to be extracted comprises: mixing the sample with a purifier and extracting with a solvent to obtain the sample to be extracted;

[0026] The step of preparing the standard product comprises: mixing the standard solution with a purifier, and extracting with a solvent to obtain the standard product.

[0027] The above-mentioned two-phase liquid-liquid electroextraction method achieves the effect of matrix purification and selective extraction by adding a purifier, thereby achieving efficient concentration and enrichment, and is simple to operate, low cost, and excellent enrichment effect. During extraction, the target will undergo a continuous deceleration migration effect in the diverter tube and tend to stagnate, achieving regional enrichment and ultimately producing an enrichment zone.

[0028] In one embodiment, the sample to be tested can be pushed out of the shunt tube by a syringe driven by a push-pull device, and analyzed and tested by an online combined analytical device or collected in a container for analysis and testing.

[0029] In one embodiment, the conditions of the electrical extraction include: immersing the shunt tube and the sample electrode wire into the object to be extracted, the extraction voltage is -100kV to 100kV, the extraction voltage is not 0, and the extraction time is ≤200min.

[0030] In one embodiment, the extraction voltage is 0 to 60 kV or 0 to -60 kV, and the extraction voltage is not 0.

[0031] In one embodiment, the purifier includes at least one of silica gel, bonded silica gel, porous carbon material, metal oxide, metal salt, metal organic framework, covalent organic framework, microporous organic polymer, functional polymer material, ionic liquid, low eutectic solvent, supramolecular solvent, surfactant, adsorption resin, anion exchange resin, cation exchange resin, molecular imprinting polymer, magnetic nanomaterial, activated carbon, activated carbon fiber, graphitized carbon black, graphene, graphene oxide, carbon nanotube, carbon nanoparticle, melamine sponge, hydrogel, metal hydroxide, metal complex, complexing agent, chitosan, chitin, N-propylethylenediamine bonded silica gel adsorbent, magnesium sulfate, cyclodextrin, urea, zirconium oxide, titanium dioxide, polyethylene glycol, polystyrene or octadecyl silica, and the mass ratio of the sample or standard solution to the purifier is 10000:1 to 1:10;

[0032] The solvent includes methanol, acetonitrile, ethanol, water, ethyl acetate, butyl acetate, isoamyl acetate, isopropyl acetate, benzyl acetate, isoborneol acetate, borneol acetate, linalyl acetate, geranyl acetate, cinnamyl acetate, ethyl benzoate, methyl benzoate, butyl benzoate, isoamyl benzoate, isopropyl benzoate, isopropanol, n-butanol, tert-butanol, isoamyl alcohol, benzyl alcohol, geraniol, linalool, higher fatty alcohols, ether, methyl ether, methyl tert-butyl ether, tetrahydrofuran, ether, benzaldehyde, cinnamaldehyde, vanillin, citral, dichloromethane, chloroform, carbon tetrachloride, n-hexane, n-heptane, n-octane, isooctane, cyclohexane, methylcyclohexane, petroleum ether, formic acid, acetic acid, fat At least one of fatty acid, ammonia, dimethyl sulfoxide, butanone, trifluoroacetic acid, ethyl trifluoroacetate, methyl trifluoroacetate, isopropyl trifluoroacetate, isobutyl trifluoroacetate, isopentyl trifluoroacetate, isohexyl trifluoroacetate, isoheptyl trifluoroacetate, isooctyl trifluoroacetate, isodecyl trifluoroacetate, ethylene glycol trifluoroacetate, propylene glycol trifluoroacetate, butylene glycol trifluoroacetate, pentanediol trifluoroacetate, hexanediol trifluoroacetate, octanediol trifluoroacetate, decanediol trifluoroacetate, pentaerythritol trifluoroacetate, sorbitol trifluoroacetate, mannitol trifluoroacetate, dimethylformamide, pyridine, benzene, toluene, carbon disulfide, dimethyl carbonate, diethyl carbonate, 1,4-dioxane, and acetone;

[0033] The electro-extraction conductive liquid comprises a conductive liquid solvent and an electrolyte. The concentration of the electrolyte in the conductive liquid is 0-1 mol / L. The electrolyte comprises an acid, a base or a salt.

[0034] The above-mentioned conductive solution can also achieve electro-extraction when the electrolyte concentration is 0, but the electro-extraction effect is better after adding electrolyte.

[0035] In one embodiment, the magnesium sulfate is anhydrous magnesium sulfate.

[0036] In one embodiment, the conductive liquid solvent includes methanol.

[0037] In one embodiment, the acid comprises an organic acid, and the organic acid comprises at least one of malonic acid, phthalic acid, acetic acid, and formic acid; the base comprises an organic base, and the organic base comprises at least one of triethylamine, diethylamine, and ammonium acetate.

[0038] The present invention also provides an electrical extraction analysis method, comprising the following steps: using the split flow-in-situ matrix purification liquid-liquid electrical extraction method to extract the object to be tested to obtain a sample to be tested or a standard sample, using an online combined analysis device to perform analysis and detection or collecting the sample in a container for analysis and detection, and comparing the spectra obtained by the detection.

[0039] In one embodiment, the comparison includes: comparing and analyzing the liquid phase spectrum of the sample to be tested with the liquid phase spectrum or mass spectrum of the standard sample, and calculating the content of the target component in the sample to be tested.

[0040] The present invention also provides application of the electrical extraction analysis method in detecting shellfish toxins and / or sulfonamide drugs.

[0041] The present invention also provides a method for detecting shellfish toxins, comprising the following steps: using the electrical extraction analysis method to detect the object to be detected;

[0042] The purifier includes chitosan, the mass ratio of the object to be tested to the purifier is 10000:1 to 1:10; and the solvent includes acetonitrile.

[0043] In one embodiment, in the method for detecting shellfish toxins, the extraction voltage is -4.5 to -3.5 kV, and the extraction time is 10-16 min.

[0044] In one embodiment, in the method for detecting shellfish toxins, the analyte includes a tissue sample of shellfish, and the shellfish toxin includes at least one of scallop-like toxin, scallop toxin, okadaic acid or cyanotoxin.

[0045] The present invention also provides a method for detecting sulfonamide drugs, comprising the following steps: using the electrical extraction analysis method to detect the object to be detected;

[0046] The purifier includes magnesium sulfate, and the mass ratio of the analyte to the purifier is 10000:1 to 1:10; and the solvent includes acetonitrile.

[0047] In one embodiment, in the detection method of sulfonamide drugs, the extraction voltage is -8.5 to -6.5 kV, and the extraction time is 10-16 min.

[0048] In one embodiment, in the detection method of sulfonamide drugs, the test object includes animal meat, and the sulfonamide drugs include at least one of sulfathiazole, sulfamethoxazole, sulfachloropyridazine, sulfaphenazole, sulfacetamide or sulfadimethoxazole.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention discloses a shunt-in-situ matrix purification liquid-liquid electro-extraction device, method and application. The device can reduce the risk of bubble generation by shunt flow, improve baseline stability and electro-extraction efficiency. The method achieves the effects of matrix purification and selective extraction by adding a purifier, thereby realizing efficient concentration and enrichment, and is simple to operate, low in cost and excellent in enrichment effect. During extraction, the target will undergo a continuous deceleration migration effect in the shunt tube and tend to stagnate, achieving regional enrichment and ultimately producing an enrichment zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Schematic diagram of the structure of the shunt-in-situ matrix purification liquid-liquid electroextraction device of Example 1, wherein 10 is a high-voltage power supply, 20 is a precision injection pump, 30 is a syringe, 31 is a conductive liquid, 40 is a stainless steel electrode wire, 50 is a platinum upper and lower double ring electrode wire, 60 is a shunt tube, 70 is a sample bottle, and 71 is a sample solution;

[0052] Figure 2 Schematic diagram of the state of the split-flow-in-situ matrix purification liquid-liquid electroextraction device in Example 1 during the electroextraction process, wherein 50 is a platinum upper and lower double-ring electrode wire, 60 is a split tube, 70 is a sample bottle, 71 is a sample solution, and 72 is a target enrichment zone;

[0053] Figure 3 The current variation diagram of different numbers of shunt pipes in Example 2 within 300s at 10kV, wherein Sample 1, Sample 2, Sample 3, and Sample 4 are parallel experiments under the same conditions;

[0054] Figure 4 is a graph showing the relationship between the crystal violet extraction rate and time for different numbers of diversion pipes in Example 2;

[0055] Figure 5This is a graph showing the relationship between the shellfish toxin extraction rate and time at -4 kV for different numbers of diversion pipes in Example 3;

[0056] Figure 6 This is a graph showing the relationship between the extraction rate of sulfonamide antibiotics and time for different numbers of shunt pipes at -7 kV in Example 4. DETAILED DESCRIPTION

[0057] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0058] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0060] source:

[0061] Unless otherwise specified, the reagents, materials, and equipment used in this example are all commercially available; the experimental methods are all conventional experimental methods in the art unless otherwise specified.

[0062] Example 1

[0063] A split-flow in-situ matrix purification liquid-liquid electroextraction device.

[0064] 1. The structural diagram of the device is as follows Figure 1 shown.

[0065] The device includes an extraction component and a sample component: the extraction component includes a push-pull device, a syringe electrode and a shunt tube. The syringe electrode is composed of a syringe electrode wire and a syringe. The push-pull device drives the piston of the syringe to push and pull. One end of the syringe electrode wire is inserted from the tail of the syringe piston rod, and penetrates and exposes the rubber head at the head of the piston rod to form a "syringe electrode" structure; the other end of the syringe electrode wire is connected to the ground wire. The injection port of the syringe is connected to the shunt tube, and the other end of the shunt tube is immersed in the object to be extracted.

[0066] In this embodiment, the syringe electrode wire is a stainless steel electrode wire, the push-pull device is a precision syringe pump, and the syringe is injected with an electroconductive liquid containing an organic electrolyte and fixed on the precision syringe pump.

[0067] The sample assembly comprises a sample container and a sample electrode wire. One end of the sample electrode wire is connected to a power source, and the other end extends into the sample container containing the object to be extracted and is immersed in the object to be extracted.

[0068] In this embodiment, the sample container is a sample bottle, the sample electrode wire is a platinum upper and lower double ring electrode wire, and the power supply is a high voltage power supply.

[0069] 2. Assembly of split-flow-in-situ matrix purification liquid-liquid electroextraction device.

[0070] 1. Insert the stainless steel electrode wire 40 into the piston rod of the syringe 30 and pass through the rubber head on the piston rod to form a "syringe electrode" structure. The stainless steel electrode wire 40 is connected to the ground wire.

[0071] 2. Inject a conductive liquid 31 containing electrolyte components into the syringe 30, and then fix the syringe 30 on the precision injection pump 20; the conductive liquid 31 is a methanol solution or a methanol aqueous solution with a volume fraction of 2:1, which contains a certain concentration of organic electrolyte; the organic electrolyte is 3mmol / L malonic acid or other organic acids with similar acidity (for example, at least one of phthalic acid, acetic acid, and formic acid) and 3mmol / L triethylamine or other organic bases with similar alkalinity (for example, at least one of triethylamine, diethylamine, and ammonium acetate).

[0072] 3. Use a Luer connector or a hollow plastic cone to tightly connect the syringe 30 to one end of the shunt tube 60, and push the syringe pump 20 to fill the shunt tube 60 with the conductive liquid.

[0073] 4. Extend the other end of the shunt tube 60 and the platinum upper and lower double-ring electrode wire 50 connected to the high-voltage power supply 10 into the sample bottle 70 containing the sample solution 71 and immerse them in the sample solution 71 .

[0074] In this embodiment, the shunt tube 60 is made of insulating material, has a length of 40 cm, and an inner diameter of 0.46 mm. The sample bottle 70 is made of insulating material, has a capacity of 10 mL, a height of 8 cm, and an inner diameter of 1.4 cm. The cross-sectional areas of the sample bottle 70 and the shunt tube 60 are quite different, which is beneficial to accelerate the osmotic mass transfer in the sample bottle while significantly inhibiting the diffusion mass transfer in the shunt tube, and inhibiting the target in the tube from diffusing back into the bottle.

[0075] The high voltage power supply 10 is a positive high voltage power supply of 0 to 30 kV or a negative high voltage power supply of -30 to 0 kV. The diameters of the stainless steel electrode wire 40 and the platinum upper and lower double ring electrode wire 50 are both 0.5 mm. The flow rate of the precision injection pump 20 is 200 μL / min, and the syringe capacity is 5 mL or 10 mL.

[0076] 3. An electrical extraction analysis method.

[0077] The above-mentioned split-flow-in-situ matrix purification liquid-liquid electroextraction device is used for electroextraction, and its state schematic diagram is shown as follows: Figure 2 The specific steps are as follows.

[0078] 1. Prepare the sample solution to be tested: Mix the sample with the purifier and use a polar solvent to extract the target substance in the sample. The volume of the polar solvent is 3 mL.

[0079] 2. Prepare a series of standard sample solutions: Mix the standard solution with the purifier, dilute the standard solution step by step into a series of standard solutions of known concentrations, and use 3 mL of polar solvent to extract the target substance.

[0080] In this embodiment, the purifier includes at least one of chitosan, magnesium sulfate, polyethylene glycol, C18, PSA or chitin, and the mass ratio of the sample or standard solution to the purifier is 10000:1 to 1:10 (the amount of the purifier is determined according to the change of the target extraction rate with the amount of the purifier, the amount of the purifier added is from 0 to 100 mg, and the target extraction rate and the amount of the purifier are plotted into a line graph to select the best amount of the purifier); the polar solvent includes at least one of methanol, acetonitrile, ethanol, ethyl acetate, isopropanol, and acetone

[0081] After the platinum upper and lower double-ring electrode wires and the shunt tube of the electro-extraction device are immersed in the standard sample solution, the power is turned on to start the electro-extraction. After a certain period of time, the power is turned off and a series of concentration standard sample solutions are obtained by pushing the syringe pump. The sample solution in the initial state is as follows Figure 2 As shown in state a.

[0082] 3. Assemble the electric extraction device, immerse the shunt tube and platinum upper and lower double-ring electrode wires in the electric extraction device into the sample solution, adjust the voltage to 2-7 kV or -7--2 kV, turn on the power, and the sample solution will be Figure 2 The state b is shown in the figure; the duration of the electroextraction is 2 to 20 minutes; when the extraction is finished, the sample solution is as follows Figure 2 As shown in state c, the target is enriched in the tube, and the target enrichment zone 72 is clearly visible and is in the color of the target. The zone is far away from the contact surface between the sample bottle and the shunt tube. The sample solution to be tested and the standard series sample solution are extracted respectively.

[0083] 4. After the extraction is completed, Figure 2 As shown in state d, the syringe pump is used to push the sample to be tested or the standard sample to be tested (i.e., the target enrichment zone 72 portion) to be directly analyzed and tested online or after collecting 200 μL of the sample solution or the standard solution in the shunt tube.

[0084] 5. Compare the liquid phase spectrum of the enriched sample solution with the liquid phase spectrum or mass spectrum of each concentration enriched standard solution. The characteristic peak of the corresponding component with the same retention time as that in the liquid phase spectrum of the enriched standard solution is the characteristic peak of the substance identical to the component; calculate the content of the target substance in the sample according to the peak area of ​​the characteristic peak using the accompanying standard curve.

[0085] Example 2

[0086] Electroextraction enrichment of crystal violet in methanol.

[0087] 1. The instruments used in this embodiment include the split-flow-in-situ matrix purification liquid-liquid electroextraction device of embodiment 1, 1 / 10000 electronic balance, micropipette, LC-20A high performance liquid chromatograph (SPD-M20A diode array detector), SHIMADZU C18 chromatographic column (250×4.6mm, 5μm). The reagents used include: methanol and acetonitrile (chromatographic grade), malonic acid (analytical grade).

[0088] 2. Prepare different numbers of diversion pipes in advance, according to Figure 3 From the current change time-current change curves of single channel (a), dual channel (b), triple channel (c), quad channel (d), quintuple channel (e), septuple channel (f) and eleven channel (g) at 10 kV within 300 s, it can be seen that when the number of shunt pipes is 1 and 2, due to the generation of bubbles in the pipes, a sudden current drop will occur during the extraction process, causing the electro-extraction process to be interrupted. With the increase in the number of shunt pipes, the electro-extraction process gradually stabilizes, and the current shows a steady downward trend over time. When the number of shunt pipes reaches 11, the current almost no longer decreases during the electro-extraction process, which in turn causes a sharp drop in the electro-extraction efficiency. In the experiment of the extraction rate of crystal violet, Figure 4 As shown in the figure, when the number of split channels is 1, the extraction rate is low. As the number of channels increases, the extraction efficiency of crystal violet increases. However, when the number of channels reaches 11, the extraction efficiency decreases. In summary, 5 channels are finally selected as the optimal number of split channels.

[0089] 3. The sample to be tested in this example: methanol suspected of being contaminated by crystal violet; standard substance: crystal violet, analytical grade, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., batch number CAS: 548-62-9.

[0090] Weigh 100 mg of crystal violet into a 100 mL volumetric flask, dilute to the mark with methanol, and shake to prepare a 1000 μg / L crystal violet standard solution.

[0091] The split-flow-in-situ matrix purification liquid-liquid electroextraction device of Example 1 is used to electro-extract the crystal violet enriched with methanol, and the specific steps are as follows:

[0092] 1. Prepare the sample injection solution to be tested.

[0093] Assemble the electro-extraction device. Then take 3mL of the methanol to be tested and add it to the sample bottle. Shake well to obtain the sample solution to be tested. After immersing the platinum upper and lower double-ring electrode wires and the shunt tube of the electro-extraction device into the sample solution to be tested, adjust the voltage to +5kV, turn on the power to start electro-extraction. Turn off the power after 10 minutes, push through the injection pump, and collect 200μL of the sample injection solution to be tested in the shunt tube.

[0094] 2. Prepare standard injection solution.

[0095] Assemble the electroextraction device. Then dilute the crystal violet standard solution step by step into a series of standard sample solutions with concentrations of 0, 200, 400, 600, 800 and 1000 μg / L. After immersing the platinum upper and lower double-ring electrode wires and the shunt tube of the electroextraction device into the standard sample solution, adjust the voltage to +5kV, turn on the power to start electroextraction. After 10 minutes, turn off the power, push through the syringe pump, collect 200 μL of solution in the shunt tube, and obtain a series of concentration standard injection solutions.

[0096] 3. High performance liquid chromatography detection.

[0097] Mobile phase: By volume, the mobile phase consists of 60% phase A and 40% phase B.

[0098] Among them, phase A is acetonitrile, phase B is an aqueous solution of 5mmol / L ammonium acetate + 0.1% formic acid, and phase B is prepared by the following method: 0.771g of ammonium acetate is weighed with a 1 / 1000 electronic balance and placed in a 500mL volumetric flask, dissolved with 400mL of water, and then 0.5mL of formic acid is added, and then the volume is adjusted to 500mL, filtered, and ultrasonically degassed for use.

[0099] HPLC detection conditions: flow rate 1.0 mL / min, injection volume 10 μL. Crystal violet detection wavelength 588 nm.

[0100] 4. Detection data processing.

[0101] After the system is balanced, the sample solution to be tested and a series of standard solution concentrations are injected separately, and the chromatograms of the sample solution and the standard solution are recorded.

[0102] A scatter plot of the crystal violet standard injection solution was made with the peak area measured for each standard injection solution as the ordinate and the concentration of the standard injection solution as the abscissa, and then a two-variable linear regression analysis of the peak area and concentration value of each standard injection solution was performed on the obtained scatter plot to obtain a standard curve equation, wherein x is the concentration of the standard injection solution (μg / L), y is the peak area (mAU*s), and a and b are constants; the peak position of the sample injection solution was confirmed according to the retention time of the peak of the standard injection solution, and the peak area measured for the sample injection solution was substituted into the above-mentioned related equation for calculation to obtain the crystal violet content in the sample to be tested.

[0103] After detection and calculation, the content of crystal violet in the sample to be tested in this embodiment is 816 μg / L.

[0104] Example 3

[0105] 1. The instruments used in this example include the split-flow-in-situ matrix purification liquid-liquid electroextraction device of Example 1, a 1 / 1000 electronic balance, a 1 / 10000 electronic balance, a 50 mL measuring cylinder, a micropipette, a Vortex-Genie adjustable vortex mixer, a Milli-QELement ultrapure water treatment system, a CT15RT desktop centrifuge, an LC-20A high performance liquid chromatograph, and a 4000Q Triple quadrupole mass spectrometer, Poroshell 120SB C18 chromatographic column (100 mm × 4.6 mm, 2.7 μm, Agilent).

[0106] The reagents used are: methanol, acetonitrile, triethylamine (chromatographic grade); malonic acid (analytical grade).

[0107] 2. Prepare different numbers of diversion pipes in advance, according to Figure 5 From the time-extraction rate variation curves of single channel (a), dual channel (b), triple channel (c), quadruple channel (d), quintuple channel (e), septuple channel (f) and eleven channel (g) at -4kV, it can be seen that, compared with other pathways, when the number of shunt channels is 5, the four shellfish toxins all reach exhaustion extraction in a very short time and have good stability. Therefore, 5 channels are selected as the optimal number of shunt channels.

[0108] 3. The samples to be tested in this embodiment are:

[0109] Shellfish samples to be tested: shellfish samples suspected of containing shellfish toxins; blank shellfish samples: shellfish samples without shellfish toxins; standard substances: dinophysistoxin-1 (DTX1), okadaic acid (OA), yessotoxin (YTX), and 1-homoyessotoxin (hYTX) were purchased from the Canadian National Research Center.

[0110] Extracting shellfish toxins from shellfish samples using the split-flow-in-situ matrix purification liquid-liquid electroextraction device of Example 1 comprises the following steps:

[0111] 1. Prepare the sample injection solution to be tested.

[0112] Assemble the electroextraction device. Accurately weigh 20 mg of shellfish sample into a 10 mL polypropylene tube, add 40 μL of water, vortex mix for 60 seconds, then add 70 mg of chitosan and 3 mL of acetonitrile, ultrasonicate for 10 minutes, and centrifuge at 13000 rpm for 5 minutes. Immerse the upper and lower double-ring electrode wires of the cathode and the Teflon tube in the sample solution for electroextraction, set the high-voltage power supply parameters to -4 kV, set the precision syringe pump injection volume to 200 μL, turn on the high-voltage power supply for electroextraction for 15 minutes, turn off the power and run the syringe pump, collect 200 μL of the receiving phase solution in the Teflon tube in the glass liner, mix well, and perform LC-MS / MS detection.

[0113] 2. Prepare standard injection solution.

[0114] Assemble the electroextraction device. Add the standard solution of shellfish toxins to a 10mL centrifuge tube to prepare a series of standard solutions with concentrations of 0, 10, 20, 30, 40, 50, 60, and 70 μg / kg. Add 60 μL of water, vortex mix for 60 seconds, then add 70 mg of chitosan and 3 mL of acetonitrile, ultrasonicate for 10 minutes, and centrifuge at 13000 rpm for 5 minutes. Immerse the upper and lower double-ring electrode wires and Teflon tubes of the cathode into the sample solution for electroextraction, set the high-voltage power supply parameters to -4kV, set the precision syringe pump injection volume to 200 μL, turn on the high-voltage power supply for electroextraction for 15 minutes, turn off the power and run the syringe pump, collect 200 μL of the receiving phase solution in the Teflon tube in a glass liner, mix well, and perform LC-MS / MS detection. A series of concentration standard injection solutions are obtained.

[0115] 3. Liquid chromatography-mass spectrometry detection.

[0116] Mobile phase: The mobile phase consists of acetonitrile (A) and an aqueous solution of 10 mmol / L ammonium formate containing 0.1% formic acid (B). Phase B is prepared by the following method: accurately weigh 0.315 g of ammonium formate using a 1 / 1000 electronic balance, dissolve it in ultrapure water and transfer it to a 500 mL volumetric flask, add 500 μL of formic acid, make up to the scale with ultrapure water, then filter and ultrasonically degas for use.

[0117] Liquid chromatography detection conditions: flow rate 0.4 mL / min, injection volume 35 μL, column temperature 40 °C.

[0118] Mass spectrometry detection conditions: ionization mode is negative ion mode, scanning mode is multiple reactions monitoring (MRM). Collision gas (CAD): medium, curtain gas (CUR): 15.0psi, ionization voltage (IS): -4200.0V, ion source temperature (TEM): 500.0℃, nebulizer gas (GS1): 60.0psi, heating gas (GS2): 50.0psi, entrance voltage (EP): -10.0V, collision chamber exit voltage (CXP): -15.0V. The corresponding declustering voltage, collision energy, precursor ion and product ion of each other analyte are listed in the table below. The residence time of all analytes was set to 100ms.

[0119] Table 1 Chromatographic retention time, parent ion, daughter ion, declustering voltage, collision energy parameters of target

[0120]

[0121] a. For quantitative analysis

[0122] 4. Detection data processing.

[0123] After the system is balanced, the sample solution to be tested and a series of concentrations of standard solution are injected separately.

[0124] By inputting the concentrations of the series of standard solutions into the software, the peak area-concentration standard curve equation can be obtained, and the software can calculate the content of each shellfish toxin component in the sample to be tested.

[0125] Results: The concentration of okanamic acid in the tested shellfish samples was 99.3 μg / kg, and the concentration of ichthyophthirius toxin was 37.4 μg / kg. No other shellfish toxin components were detected.

[0126] In addition, to further demonstrate the effectiveness and accuracy of this method for detecting shellfish toxins, the detection limit, lower limit of quantification, accuracy and precision of each shellfish toxin in shellfish samples were evaluated according to the EU Food Safety Regulation 2021 / 808 / EC (European Commission 2021) Analytical Method Validation Guidelines. The sample concentration value with a signal-to-noise ratio of 3 was calculated as the detection limit of the sample, and the shellfish sample concentration value with a signal-to-noise ratio of 10 was calculated as the lower limit of quantification of the shellfish sample. The detection limit and lower limit of quantification of the shellfish sample are shown in Table 2. The accuracy and precision were evaluated by calculating the intra-day and inter-day recoveries and relative standard deviations (RSDs), where the inter-day difference was obtained by measuring six parallel samples of three concentrations on the same day, and the intra-day difference was obtained by measuring six parallel samples of three concentrations each day for a total of three days, as shown in Table 3.

[0127] Table 2 Detection limit and quantification limit of shellfish toxins extracted by electroextraction

[0128]

[0129] Table 3 Accuracy and precision data of electro-extraction of shellfish toxins in shellfish samples

[0130]

[0131] Example 4

[0132] 1. The instruments used in this example include the split-flow-in-situ matrix purification liquid-liquid electroextraction device of Example 1, a 1 / 1000 electronic balance, a 50 mL measuring cylinder, a micropipette, a Vortex-Genie adjustable vortex mixer, a Milli-Q ELement ultrapure water treatment system, a CT15RT desktop centrifuge, an LC-20A high performance liquid chromatograph, and a 4000Q Triple quadrupole mass spectrometer, Poroshell 120SB C18 chromatographic column (100 mm × 4.6 mm, 2.7 μm, Agilent).

[0133] The reagents used are: methanol, acetonitrile, triethylamine (chromatographic grade); malonic acid (analytical grade).

[0134] 2. Different numbers of diversion pipes prepared in advance, different numbers of diversion pipes prepared in advance, according to Figure 6 From the time-extraction rate variation curves of single channel (a), dual channel (b), triple channel (c), quadruple channel (d), quintuple channel (e), septuple channel (f) and eleven channel (g) at -7KV, it can be seen that compared with other pathways, when the number of shunt channels is 5, the six sulfonamide antibiotics all reach exhaustion extraction in a very short time and have good stability. Therefore, 5 channels are selected as the optimal number of shunt channels.

[0135] 3. The samples to be tested in this embodiment are:

[0136] Meat samples to be tested: meat samples suspected of containing sulfonamide antibiotic residues; blank meat samples: normal meat samples without sulfonamide antibiotic residues; standard substances: Sulfathiazole (STZ), Sulfamethizole (SMT), Sulfachloropyridazine (SCP), Sulfaphenazolum (SPZ), Sulfacetamide (SFM), and Sulfisoxazole (SSZ) were purchased from Beijing Myrida Technology Co., Ltd.

[0137] The extraction of sulfonamide antibiotics from meat samples using the split-flow-in-situ matrix purification liquid-liquid electroextraction device of Example 1 comprises the following steps:

[0138] 1. Prepare the sample injection solution to be tested.

[0139] Assemble the electric extraction device. Accurately weigh 20 mg of meat sample in a 10 mL polypropylene tube, accurately weigh 20 mg of meat sample in a 10 mL polypropylene tube, vortex mix for 1 min, then add 30 mg of anhydrous magnesium sulfate and 3 mL of acetonitrile, ultrasonicate for 7 min, and centrifuge at 13000 rpm for 5 min. Immerse the upper and lower double-ring electrode wires of the cathode and the Teflon tube in the sample solution for electric field-assisted extraction, extract at -8 kV high voltage for 15 min, turn off the power and run the syringe pump, collect 200 μL of the receiving phase solution in the Teflon tube in a glass liner, mix well and perform LC-MS / MS detection.

[0140] 2. Prepare standard injection solution.

[0141] Assemble the electric extraction device. Add the standard solution of sulfonamide antibiotics to a 10mL centrifuge tube to prepare a series of standard solutions with concentrations of 0, 1, 2, 3, 4, 5, 6, and 7 μg / kg, respectively. Vortex mix for 60 seconds, then add 30 mg of anhydrous magnesium sulfate and 3 mL of acetonitrile, sonicate for 7 minutes, and centrifuge at 13000 rpm for 5 minutes. Immerse the upper and lower double-ring electrode wires of the cathode and the Teflon tube in the sample solution for electric field-assisted extraction, extract at -8KV high voltage for 15 minutes, turn off the power and run the syringe pump, collect 200 μL of the receiving phase solution in the Teflon tube in a glass liner, mix well, and perform LC-MS / MS detection to obtain a series of concentration standard injection solutions.

[0142] 3. Liquid chromatography-mass spectrometry detection.

[0143] Mobile phase: The mobile phase consists of acetonitrile (A) and an aqueous solution of 20 mmol / L ammonium acetate containing 0.1% formic acid (B). Phase B is prepared by the following method: accurately weigh 0.771 g of ammonium acetate using a 1 / 1000 electronic balance, dissolve it in ultrapure water and transfer it to a 500 mL volumetric flask, add 500 μL of formic acid, make up to the scale with ultrapure water, then filter and ultrasonically degas for use.

[0144] Liquid chromatography detection conditions: flow rate 0.4 mL / min, injection volume 10 μL, column temperature 40 °C.

[0145] Mass spectrometry detection conditions: ionization mode is positive ion mode, scanning mode is multiple reactions monitoring (MRM). Collision gas (CAD): medium, curtain gas (CUR): 10.0 psi, ionization voltage (IS): 5500.0 V, ion source temperature (TEM): 400.0 ° C, nebulizer gas (GS1): 60.0 psi, heating gas (GS2): 60.0 psi, entrance voltage (EP): 10.0 V, collision chamber exit voltage (CXP): 15.0 V. The corresponding declustering voltage, collision energy, precursor ion and product ion of each other analyte are listed in Table 4. The residence time of all analytes was set to 100 ms.

[0146] Table 4 Chromatographic retention time, parent ion, daughter ion, declustering voltage, collision energy parameters of target

[0147]

[0148]

[0149] a. For quantitative analysis

[0150] 4. Detection data processing.

[0151] After the system is balanced, the sample solution to be tested and a series of concentrations of standard solution are injected separately.

[0152] By inputting the concentrations of the series of standard solutions into the software, the peak area-concentration standard curve equation can be obtained, and the content of each sulfonamide antibiotic in the sample to be tested can be calculated by the software.

[0153] Result: No sulfonamide antibiotics were detected in the tested meat samples.

[0154] In addition, to further demonstrate the effectiveness and accuracy of this method for detecting the sulfonamide antibiotics, the detection limit, lower limit of quantification, accuracy and precision of each sulfonamide antibiotic in meat samples were evaluated according to the EU Food Safety Regulation 2021 / 808 / EC (European Commission 2021) Analytical Method Validation Guidelines. The sample concentration value with a signal-to-noise ratio of 3 was calculated as the detection limit of the sample, and the meat sample concentration value with a signal-to-noise ratio of 10 was calculated as the lower limit of quantification of the meat sample. The detection limit and lower limit of quantification of the meat sample are shown in Table 5. The accuracy and precision were evaluated by calculating the intra-day and inter-day recoveries and relative standard deviations (RSDs), where the inter-day difference was obtained by measuring six parallel samples of three concentrations on the same day, and the intra-day difference was obtained by measuring six parallel samples of three concentrations each day for a total of three days, as shown in Table 6.

[0155] Table 5 Detection limit and quantification limit of electroextraction sulfonamide antibiotics

[0156]

[0157] Table 6 Accuracy and precision data of electroextraction of sulfonamide antibiotics in meat samples

[0158]

[0159] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0160] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A split-flow in-situ matrix purification liquid-liquid electroextraction device, characterized in that: include: The extraction assembly comprises a push-pull device, a syringe electrode and a shunt tube, wherein the syringe electrode comprises a connected syringe electrode wire and a syringe, the syringe is used to contain an electroconductive liquid, the push-pull device drives the piston of the syringe to push and pull, one end of the syringe electrode wire is connected to the syringe, and the other end is grounded or connected to a power source; one end of the shunt tube is connected to the syringe, and the other end is used to immerse the object to be extracted; as well as The sample assembly comprises a sample container and a sample electrode wire. One end of the sample electrode wire is used to immerse the object to be extracted, and the other end is used to be grounded or connected to a power source. The sample container is used to contain the object to be extracted.

2. The split-flow in-situ matrix purification liquid-liquid electroextraction device according to claim 1, characterized in that: The number of pipes of the diversion pipe is ≥1.

3. The split-flow in-situ matrix purification liquid-liquid electroextraction device according to claim 1, characterized in that: One end of the syringe electrode wire is inserted into the tail of the syringe piston rod and exposed at the head of the piston rod.

4. A split-flow in-situ matrix purification liquid-liquid electroextraction method, characterized in that: The following steps are involved: Prepare a sample to be extracted and a standard product, and use the split-flow-in-situ matrix purification liquid-liquid electric extraction device described in any one of claims 1 to 3 to perform electric extraction on the sample to be extracted and the standard product to obtain a sample to be tested and a standard sample; The sample to be tested is enriched in the shunt tube; The step of preparing the sample to be extracted comprises: mixing the sample with a purifier and extracting with a solvent to obtain the sample to be extracted; The step of preparing the standard product comprises: mixing the standard solution with a purifier, and extracting with a solvent to obtain the standard product.

5. The split-flow in-situ matrix purification liquid-liquid electroextraction method according to claim 4, characterized in that: The conditions of the electric extraction include: immersing the shunt tube and the sample electrode wire into the object to be extracted, the extraction voltage is -100kV to 100kV, the extraction voltage is not 0, and the extraction time is ≤200min.

6. The split-flow in-situ matrix purification liquid-liquid electroextraction method according to claim 4, characterized in that: The purifier includes at least one of silica gel, bonded silica gel, porous carbon material, metal oxide, metal salt, metal organic framework, covalent organic framework, microporous organic polymer, functional polymer material, ionic liquid, deep eutectic solvent, supramolecular solvent, surfactant, adsorption resin, anion exchange resin, cation exchange resin, molecular imprinting polymer, magnetic nanomaterial, activated carbon, activated carbon fiber, graphitized carbon black, graphene, graphene oxide, carbon nanotube, carbon nanoparticle, melamine sponge, hydrogel, metal hydroxide, metal complex, complexing agent, chitosan, chitin, N-propylethylenediamine bonded silica gel adsorbent, magnesium sulfate, cyclodextrin, urea, zirconium oxide, titanium dioxide, polyethylene glycol, polystyrene or octadecyl silica, and the mass ratio of the sample or standard solution to the purifier is 10000:1 to 1:10; The solvent includes methanol, acetonitrile, ethanol, water, ethyl acetate, butyl acetate, isoamyl acetate, isopropyl acetate, benzyl acetate, isoborneol acetate, borneol acetate, linalyl acetate, geranyl acetate, cinnamyl acetate, ethyl benzoate, methyl benzoate, butyl benzoate, isoamyl benzoate, isopropyl benzoate, isopropanol, n-butanol, tert-butanol, isoamyl alcohol, benzyl alcohol, geraniol, linalool, higher fatty alcohols, ether, methyl ether, methyl tert-butyl ether, tetrahydrofuran, ether, benzaldehyde, cinnamaldehyde, vanillin, citral, dichloromethane, chloroform, carbon tetrachloride, n-hexane, n-heptane, n-octane, isooctane, cyclohexane, methylcyclohexane, petroleum ether, formic acid, acetic acid, fat At least one of fatty acid, ammonia, dimethyl sulfoxide, butanone, trifluoroacetic acid, ethyl trifluoroacetate, methyl trifluoroacetate, isopropyl trifluoroacetate, isobutyl trifluoroacetate, isopentyl trifluoroacetate, isohexyl trifluoroacetate, isoheptyl trifluoroacetate, isooctyl trifluoroacetate, isodecyl trifluoroacetate, ethylene glycol trifluoroacetate, propylene glycol trifluoroacetate, butylene glycol trifluoroacetate, pentanediol trifluoroacetate, hexanediol trifluoroacetate, octanediol trifluoroacetate, decanediol trifluoroacetate, pentaerythritol trifluoroacetate, sorbitol trifluoroacetate, mannitol trifluoroacetate, dimethylformamide, pyridine, benzene, toluene, carbon disulfide, dimethyl carbonate, diethyl carbonate, 1,4-dioxane, and acetone; The electro-extraction conductive liquid comprises a conductive liquid solvent and an electrolyte. The concentration of the electrolyte in the conductive liquid is 0-1 mol / L. The electrolyte comprises an acid, a base or a salt.

7. An electrical extraction analysis method, characterized in that: The method comprises the following steps: extracting the analyte by the split-flow-in-situ matrix purification liquid-liquid electroextraction method described in any one of claims 4 to 6 to obtain a sample to be tested or a standard sample, analyzing and detecting the sample by an online coupled analytical device, or collecting the sample in a container for analysis and detection, and comparing the spectra obtained by the detection.

8. Application of the electrical extraction analysis method according to claim 7 in the detection of shellfish toxins and / or sulfonamide drugs.

9. A method for detecting shellfish toxins, characterized in that: The method comprises the following steps: using the electric extraction analysis method according to claim 7 to detect the object to be detected; The purifier includes chitosan, the mass ratio of the object to be tested to the purifier is 10000:1 to 1:10; and the solvent includes acetonitrile.

10. A method for detecting sulfonamides, characterized in that: The method comprises the following steps: using the electric extraction analysis method according to claim 7 to detect the object to be detected; The purifier includes magnesium sulfate, and the mass ratio of the analyte to the purifier is 10000:1 to 1:10; and the solvent includes acetonitrile.

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