A rapid detection method for a non-opiate sedative, methotrimeprazine

Abstract

The application discloses a rapid detection method of non-opiate sedative agent methaqualone, and belongs to the technical field of forensic toxicant safety detection. The method comprises the following steps: firstly, preparing melamine foam material of surface modified dopamine-polyacetylene imine copolymer; then, cutting the melamine foam material and placing it into the head of a pipette gun, compacting to obtain a treated head; enriching methaqualone in the head; and detecting the sample by ion mobility spectrometry after ionization of the sample.

Description

Technical Field

[0001] The present invention belongs to the technical field of forensic poison safety detection, and in particular relates to a rapid detection method for non-opioid sedative xylazine. Background Art

[0002] Xylazine, a powerful sedative, was approved by the FDA in 1972 for use in animals, typically as a sedative and analgesic, in horses, cattle, sheep, and other non-human mammals. It is not currently approved for use in humans. Because it is colorless and odorless when dissolved in water, it has been reported to be added to beverages, leading to criminal violations [Microchimica Acta (2022) 189:465]. Therefore, monitoring xylazine is of paramount importance.

[0003] Currently, gas chromatography-mass spectrometry, high-performance liquid chromatography, and ultra-high-performance liquid chromatography-mass spectrometry are commonly used to detect xylazine. These technologies are not suitable for emergency detection and rapid screening due to their high cost, expensive instruments, the need for professional operation, and are very time-consuming. To achieve rapid on-site detection, Fiorentin et al. used a portable gas chromatography-mass spectrometry (GC-MS) to screen for a variety of prohibited substances, with a detection limit of 40 μg / ml for xylazine [Forensic Science International 313(2020)110342]. However, when faced with complex biological samples, such instruments are expensive and have high detection limits, making it difficult to meet the requirements. Lucas et al. used an electrochemical sensing method to detect it, with a detection limit of approximately 300 ng / ml [Microchimica Acta(2022)189:465]. However, this method is complex to set up and has poor selectivity. There is still a need to develop more sensitive and accurate methods for rapid detection of xylazine.

[0004] Ion mobility spectrometry (IMS) has been successfully used for the determination of volatile organic compounds in the environment due to its ease of operation, rapid detection, and miniaturization, making it easily applicable for rapid on-site screening. It has also become a viable option for the rapid detection of psychotropic drugs. However, the use of IMS for the detection of these drugs remains a technical gap. Summary of the Invention

[0005] To address the above-mentioned problems in the prior art, the present invention proposes a rapid detection method for the non-opioid sedative xylazine. This method has a short detection time and high sensitivity, enabling rapid on-site screening of xylazine in multiple matrices.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A rapid detection method for non-opioid sedative xylazine comprises the following steps:

[0008] S1, dissolving dopamine hydrochloride (PDA) and polyimide (PEI) in a buffer solution of tris(hydroxymethyl)aminomethane to obtain a copolymer solution; placing a melamine foam material into the copolymer solution and stirring to obtain a melamine foam material having a surface modified with a dopamine-polyimide copolymer;

[0009] S2. Cutting a melamine foam material having a surface modified dopamine-polyacetimide copolymer and placing it into a pipette tip, compacting it, and obtaining a treated pipette tip; inserting the pipette tip into an aqueous solution containing a non-opioid sedative, xylazine, and performing a first "pump-and-push" cycle; and then continuously placing the pipette tip into an elution solvent and performing a second "pump-and-push" cycle to obtain an eluate enriched with the non-opioid sedative, xylazine;

[0010] S3. The eluate enriched with the non-opioid sedative xylazine is added dropwise to the sample injection test paper, which is then inserted into the ion mobility spectrometer injection port. After the sample is ionized, it is detected by the Faraday disk detector through the migration tube.

[0011] Furthermore, in S1, the mass ratio of dopamine hydrochloride to polyacetimide is 1:1.

[0012] Furthermore, in S1, the stirring time is 24 hours, and the temperature during stirring is 25°C.

[0013] Furthermore, in S1, the concentration of the tris(hydroxymethyl)aminomethane buffer solution is 10 mmol / L and the pH is 8.5.

[0014] Furthermore, in S2, the first "absorption-expulsion" cycle number is 5-50 times, and the second "absorption-expulsion" cycle number is 5-30 times. The elution solvent can be an organic solvent such as methanol, acetonitrile, n-hexane, chloroform, ethyl acetate, etc.

[0015] Furthermore, in S3, the amount of the eluent for enriching the non-opioid sedative xylazine added dropwise onto the sample test paper is 1-10 μL.

[0016] Furthermore, in S3, the parameters of the ion mobility spectrometer host are set as follows: inlet temperature: 150-220°C, preferably 150°C, 180°C and 220°C; corona voltage: 1.0-3.0kV, preferably 2.0-3.0kV, more preferably 2.0kV, 2.5kV, 3.0kV; migration tube temperature: 100-180°C, preferably 100°C, 150°C, 180°C; spectral width 20ms, ion gate pulse 150-450μs, preferably 150μs, 300μs, 450μs; migration gas and carrier gas flow rates are 300-1000mL / min, preferably 300mL / min, 600mL / min, 1000mL / min.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] In the present invention, dopamine and polyimide undergo a copolymerization reaction under weakly alkaline conditions. During the copolymerization of dopamine and polyimide, the active hydrogen at the carbonyl and carbonyl α positions in the structure can react with amino groups to generate imine and amine groups, which can gradually form a thin PDA-PEI polymer layer on the surface of the melamine foam, thus obtaining a surface-modified melamine foam material. The alkyl groups, amine groups, and conjugated structures in the polymer coating can generate van der Waals forces, dipole-dipole interactions, and π-π interactions, thereby achieving effective enrichment of the target xylazine. Because the target xylazine contains groups such as amino groups that are easy to obtain protons, the compound can be ionized into positively charged ions when detected by IMS. Under the action of the electric field, the ions are ultimately received by the Faraday disk of the detector to generate signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0020] Figure 1 Schematic diagram of the PDA-PEI polymerization reaction mechanism in Examples 1-3 of the present invention;

[0021] Figure 2 This is the IMS spectrum of enrichment and detection of xylazine in drinking water in Example 1;

[0022] Figure 3 This is the IMS spectrum of enrichment and detection of xylazine in tea water in Example 2;

[0023] Figure 4 This is the IMS spectrum of enrichment and detection of xylazine in alcoholic beverages in Example 3;

[0024] Figure 5 This is an operation flow chart of the present invention;

[0025] Figure 6 SEM image of MF@PDA-PEI of Example 1 of the present application;

[0026] Figure 7 Elemental distribution image of MF@PDA-PEI of Example 1 of the present application;

[0027] Figure 8 Electron spectroscopy image of PDA-PEI coating of Example 1 of the present application. DETAILED DESCRIPTION

[0028] Various illustrative embodiments of the present application are described in detail below, with reference to the attached drawings. These embodiments are not intended to be exhaustive or to limit the application to the precise form disclosed. Rather, the description is intended to highlight certain aspects and features of the present application, and to provide an enabling description for the various embodiments of the present application.

[0029] It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for a range of values of a parameter, unless otherwise stated, the inclusion of either extremity of the range is understood to describe the exclusion of that extremity in a claim. Thus, "less than or equal to 25" is specifically intended to exclude 25 itself, unless otherwise stated. Additionally, for ranges of values of a parameter, unless otherwise stated, the inclusion of either extremity of the range is understood to describe the exclusion of that extremity in a claim. Thus, "less than or equal to 25" is specifically intended to exclude 25 itself, unless otherwise stated.

[0030] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All patents, patent applications, publications, and descriptions mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the patents, patent applications, publications, and descriptions are cited.

[0031] Many modifications and variations of this application can be made in the light of the above teachings without departing from the spirit and scope thereof. Other implementations of this application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The examples and embodiments described herein are intended to be illustrative only and are presented by way of example to provide what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the application. Other embodiments apparent to those of ordinary skill in the art are intended to be encompassed by the claims.

[0032] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", "containing", or variations thereof, are intended to be open-ended terms that mean including, but not limited to.

[0033] As used herein, the term "room temperature" means 25 ± 2 °C, unless otherwise specified.

[0034] The raw materials used in the following examples of the present application are commercially available.

[0035] A rapid detection method for non-opioid sedative xylazine comprises the following steps:

[0036] S1. Melamine foam material with surface modified dopamine-acetimide copolymer (PDA-PEI): Dissolve 40 mg of dopamine hydrochloride and 40 mg of polyacetimide in 20 mL of 10 mmol / L tris(hydroxymethyl)aminomethane buffer solution (pH of the solution is about 8.5) until fully dissolved to obtain a copolymer solution; place the melamine foam material into the prepared copolymer solution, react at a temperature of 25°C, and stir for 24 hours. Dopamine and polyacetimide undergo copolymerization under weak alkaline conditions (polymerization reaction mechanism as shown in FIG. Figure 1 ), which can gradually form a thin PDA-PEI polymer layer on the surface of the melamine foam, that is, a melamine foam material with surface modified dopamine-polyacetimide copolymer (denoted as MF@PDA-PEI);

[0037] S2. Enrich the sample based on the pipette extraction method: Cut 1-10 mg of the melamine foam material of the surface-modified dopamine-polyimide copolymer prepared above and put it into the pipette tip, compact it with tweezers, the tension of the foam material can fix it inside the tip, insert the pipette into the treated tip, add xylazine to water (or beverage sample), take out 1-20 mL of sample liquid and put it into a 20 mL disposable centrifuge tube, insert the tip into the test solution and "absorb-push" for 5-50 cycles, then put 100-800 uL of blank eluent into a 2 mL disposable centrifuge tube, and also use a pipette to "absorb-push" for 5-30 cycles to obtain an eluent enriched with xylazine; the elution solvent can be an organic solvent such as methanol, acetonitrile, n-hexane, chloroform, ethyl acetate, etc. The eluent used in the following examples of the present invention is methanol

[0038] S3. IMS Detection: 1-10 μL of eluent is added dropwise to the sample strip, which is then inserted into the ion mobility spectrometer inlet. After ionization, the sample passes through the migration tube and is detected by the Faraday disk detector. The ion mobility spectrometer mainframe parameters are: inlet temperature: 150-220°C, corona voltage: 1.0-3.0 kV, migration tube temperature: 100-180°C, spectrum width: 20 ms, ion gate pulse: 150-450 μs, migration gas and carrier gas flow rates: 300-1000 mL / min.

[0039] The following examples serve as further illustrations of the technical solutions of the present invention.

[0040] Example 1

[0041] Detection of Xylazine in Drinking Water:

[0042] 1) Preparation and loading of pretreatment material: 40 mg of dopamine hydrochloride and 40 mg of polyacetylimine were dissolved in 20 mL of 10 mmol / L tris-hydroxymethyl aminomethane buffer solution (pH of the solution was 8.5), and were fully dissolved to obtain a copolymer solution; 5 mg of melamine foam material was placed into the prepared copolymer solution, the reaction temperature was 25℃, and the stirring reaction was performed for 24 hours to obtain melamine foam material with surface modified dopamine-polyacetylimine copolymer; the material was cut into 1 mg and was loaded into a pipette gun head, and was compacted by using tweezers, and the tension of the foam material could fix it in the gun head.

[0043] 2) Pretreatment method: the pipette gun was inserted into the above treated gun head; 100 ng of toluene sulfochloride was added into 10 mL of water to obtain a sample liquid, 1 mL of the sample liquid was taken into a 20 mL disposable centrifuge tube, the gun head was inserted into the sample liquid to perform "suction-pushing" circulation for 50 times, then 100 uL of eluent was taken into a 2 mL disposable centrifuge tube, and the same "suction-pushing" circulation was performed for 5 times by using the pipette gun to obtain toluene sulfochloride enriched eluent.

[0044] 3) Ion mobility spectrometry was performed to detect the enriched sample: 10 uL of the eluent was dropped on the sample paper, and was inserted into the ion mobility spectrometry sample inlet, and after the sample was ionized, it was detected by the Faraday disc detector through the migration tube. The parameter setting of the ion mobility spectrometry host was as follows: sample inlet temperature: 150℃, corona voltage: 2.0 kV, migration tube temperature: 150℃, spectrum width: 20 ms, ion gate pulse: 150 us, and migration gas and carrier gas flow rate: 300 mL / min.

[0045] Figure 2 The IMS spectrum of Example 1 for the enrichment and detection of toluene sulfochloride in drinking water was shown in the figure, and the peak signal of toluene sulfochloride was obvious (marked star).

[0046] Example 2

[0047] Toluene sulfochloride in tea water was detected:

[0048] 1) Preparation and loading of pretreatment material: 40 mg of dopamine hydrochloride and 40 mg of polyacetylimine were dissolved in 20 mL of 10 mmol / L tris-hydroxymethyl aminomethane buffer solution (pH of the solution was 8.5), and were fully dissolved to obtain a copolymer solution; 5 mg of melamine foam material was placed into the prepared copolymer solution, the reaction temperature was 25℃, and the stirring reaction was performed for 24 hours to obtain melamine foam material with surface modified dopamine-polyacetylimine copolymer; the material was cut into 1 mg and was loaded into a pipette gun head, and was compacted by using tweezers, and the tension of the foam material could fix it in the gun head.

[0049] 2) Pretreatment method: Insert a pipette into the treated tip; add 100 ng of xylazine to 20 mL of tea to obtain a sample liquid. Remove 10 mL of the sample liquid and place it in a 20 mL disposable centrifuge tube. Insert the pipette tip into the sample liquid and perform a "pump-and-push" cycle 30 times. Then, place 500 uL of the eluate into a 2 mL disposable centrifuge tube and perform a "pump-and-push" cycle 30 times using the pipette to obtain an eluate enriched with xylazine.

[0050] 3) Ion mobility spectrometry was used to detect the enriched sample. 1 μL of eluent was added to a sample strip, which was then inserted into the ion mobility spectrometer inlet. After ionization, the sample passed through the migration tube and was detected by a Faraday disk detector. The ion mobility spectrometer mainframe parameters were set as follows: inlet temperature: 220°C, corona voltage: 3.0 kV, migration tube temperature: 180°C, spectral width: 20 ms, ion gate pulse: 450 μs, and migration and carrier gas flow rates of 1000 mL / min.

[0051] Figure 3 This is the IMS spectrum of the enrichment and detection of xylazine in tea water in Example 2. It can be seen from the figure that the matrix substances in the tea water do not interfere with the detection of xylazine.

[0052] Example 3

[0053] Detection of Xylazine in Alcoholic Beverages:

[0054] 1) Preparation and loading of pretreatment materials: 40 mg of dopamine hydrochloride and 40 mg of polyacetimide were dissolved in 20 mL of a 10 mmol / L tris(hydroxymethyl)aminomethane buffer solution (pH 8.5) until fully dissolved to obtain a copolymer solution; 15 mg of melamine foam material was placed in the prepared copolymer solution, stirred at a reaction temperature of 25° C. for 24 hours to obtain a melamine foam material with a surface modified dopamine-acetimide copolymer; 10 mg of the material was cut into a pipette tip and compacted with tweezers; the tension of the foam material was sufficient to secure it to the inside of the pipette tip.

[0055] 2) Pretreatment Method: Insert a pipette into the treated tip; add 50 ng of xylazine to 10 mL of alcoholic beverage to obtain a sample liquid. Remove 5 mL of the sample liquid and place it in a 20 mL disposable centrifuge tube. Insert the pipette tip into the sample liquid and perform a "pipette-and-push" cycle five times. Then, place 800 μL of the eluate into a 2 mL disposable centrifuge tube and perform a "pipette-and-push" cycle 15 times using the same pipette to obtain an eluate enriched in xylazine.

[0056] 3) Ion mobility spectrometry detection of the enriched sample: 5 μL of the eluent was dropped on the sample paper, and then inserted into the ion mobility spectrometry sample inlet. After ionization of the sample, the ions were detected by the Faraday disk detector through the drift tube. The parameters of the ion mobility spectrometry host were set as follows: sample inlet temperature: 180℃, corona voltage: 2.5 kV, drift tube temperature: 100℃, spectral width: 20 ms, ion gate pulse: 300 μs, and flow rate of the drift gas and carrier gas: 600 mL / min.

[0057] Figure 4 The IMS spectrum of toluazamide enriched in the alcoholic beverage of Example 3 is shown in the figure. It can be seen from the figure that the alcoholic matrix does not affect the detection of toluazamide.

[0058] Figure 5 The operation flowchart of the application.

[0059] Figure 6 The scanning electron microscope image of MF@PDA-PEI in Example 1 of the application is shown in the figure. It can be seen from the figure that the material has a porous skeleton structure inside, which increases the contact area with the to-be-detected liquid, thereby improving the extraction efficiency.

[0060] Figure 7 The element distribution map of MF@PDA-PEI in Example 1 of the application is shown in the figure. It can be seen from the figure that after the surface modification of the material, the coating corresponding to the three elements N, C and O is uniformly distributed on the surface of the material, and the PDA-PEI coating is uniformly covered on the surface thereof.

[0061] Figure 8 The PDA-PEI coating electron spectrogram in Example 1 of the application is shown in the figure. It can be seen from the figure that the PDA-PEI polymer coating contains a higher N-containing functional group on the surface than the single PDA coating, and can more easily realize specific adsorption of toluazamide.

[0062] Control group

[0063] The detection method of toluazamide in the prior art such as the background art:

[0064] 1.0 mg of the beverage sample was dissolved in 10 mL of methanol, and 0.4 mg of toluazamide was added to obtain a sample solution. 1 μL of the sample solution was directly detected by the portable GC-MS, and toluazamide in the sample was successfully detected, and the detection limit was 0.04 mg / mL.

[0065] Comparative Example 1

[0066] The same as Example 1, except that the mass of dopamine hydrochloride was 80 mg.

[0067] Comparative Example 2

[0068] The same as Example 1, except that the amount of the eluent for enriching the non-opioid sedative xylazine added dropwise to the sample test paper is 0.5 μL.

[0069] Comparative Example 3

[0070] The same as Example 1, except that the parameters of the ion mobility spectrometer host are set as follows: injection port temperature: 300°C, corona voltage: 4 kV, migration tube temperature: 200°C, spectrum width 20 ms, ion gate pulse 100 μs, migration gas and carrier gas flow rate of 2000 mL / min.

[0071] Table 1 shows the detection limits for xylazine using the methods of Examples 1-3, the control group, and Comparative Examples 1-3. Three replicates were performed, and the average values ​​were recorded. During the testing process, the detection limit for each test method was used as the detection limit for each test method.

[0072] Table 1

[0073]

[0074]

[0075] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A rapid detection method for non-opioid sedative xylazine, characterized in that: The following steps are involved: S1, dissolving dopamine hydrochloride and polyacetimide in a buffer solution of tris(hydroxymethyl)aminomethane to obtain a copolymer solution; placing a melamine foam material into the copolymer solution and stirring to obtain a melamine foam material having a surface modified dopamine-polyacetimide copolymer; S2. Cutting a melamine foam material having a surface modified dopamine-polyacetimide copolymer and placing it into a pipette tip, compacting it, and obtaining a treated pipette tip; inserting the pipette tip into an aqueous solution containing the non-opioid sedative xylazine to perform a first "pump-and-push" cycle, and then continuously placing the pipette tip into an elution solvent to perform a second "pump-and-push" cycle, thereby obtaining an eluate enriched in the non-opioid sedative xylazine; S3. The eluate enriched with the non-opioid sedative xylazine is added dropwise to the sample injection test paper, which is then inserted into the ion mobility spectrometer injection port. After the sample is ionized, it is detected by the Faraday disk detector through the migration tube.

2. The method for rapid detection of non-opioid sedative xylazine according to claim 1, characterized in that: In S1, the mass ratio of dopamine hydrochloride to polyacetimide is 1:

1.

3. The rapid detection method for non-opioid sedative xylazine according to claim 1, characterized in that: In S1, the stirring time is 24 h, and the temperature during stirring is 25°C.

4. The method for rapid detection of non-opioid sedative xylazine according to claim 1, characterized in that: In S2, the number of the first "suck-and-push" cycles is 5-50 times, and the number of the second "suck-and-push" cycles is 5-30 times.

5. The rapid detection method for non-opioid sedative xylazine according to claim 1, characterized in that: In S3, the amount of the eluent for enriching the non-opioid sedative xylazine added dropwise to the sample injection test paper is 1-10 μL.

6. The rapid detection method for non-opioid sedative xylazine according to claim 1, characterized in that: In S3, the parameters of the ion mobility spectrometer host were set as follows: inlet temperature: 150-220°C, corona voltage: 1.0-3.0 kV, migration tube temperature: 100-180°C, spectrum width 20 ms, ion gate pulse 150-450 μs, migration gas and carrier gas flow rates of 300-1000 mL / min.

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