A method for detecting etomidate in e-liquid

Abstract

The present application belongs to the technical field of etomidate, and particularly relates to a detection method of etomidate in electronic cigarette oil, comprising the following steps: adding electronic cigarette oil, deionized water, polar organic solvent and inorganic salt solid powder into a container, oscillating and mixing uniformly, standing, centrifuging the supernatant after standing; taking the supernatant after centrifuging, adding an acidic reagent, oscillating and mixing uniformly, centrifuging again; taking the supernatant after centrifuging again, adding an alkaline reagent, oscillating and mixing uniformly, centrifuging, and taking the supernatant as a to-be-tested liquid; mixing the to-be-tested liquid, nano gold sol and a coagulation accelerator, and detecting by using a Raman spectrometer; wherein the coagulation accelerator comprises an inorganic acid aqueous solution. The present application is based on Raman spectroscopy technology, and can accurately determine whether etomidate exists in electronic cigarette from the molecular level. The method is rapid, simple, high-precision, and suitable for on-site rapid detection.

Description

Technical Field

[0001] This invention belongs to the field of etomidate technology, specifically relating to a method for detecting etomidate in e-cigarette liquid. Background Technology

[0002] Currently, the main methods for detecting etomidate include liquid chromatography and liquid chromatography-tandem mass spectrometry. These methods require large-scale laboratory testing equipment, involve complex pretreatment, require professional operators, and have high testing costs, making them inconvenient for grassroots testing personnel and thus limiting their use. In addition, according to research, there is currently no rapid detection method for etomidate in e-cigarette liquids. Only Orient Bio launched an etomidate urine test kit in July 2023, but it cannot be applied to the rapid on-site detection of etomidate in e-cigarette liquids. Summary of the Invention

[0003] The purpose of this invention is to provide a method for detecting etomidate in e-cigarette liquids. Based on Raman spectroscopy, this method can accurately determine the presence of etomidate in e-cigarettes at the molecular level. This method is fast, simple, and highly accurate, and is suitable for rapid on-site detection.

[0004] A method for detecting etomidate in e-cigarette liquid, comprising the following steps:

[0005] Add e-cigarette liquid, deionized water, polar organic solvent, and inorganic salt solid powder to a container, shake to mix, let stand, and centrifuge the supernatant after standing.

[0006] Take the supernatant after centrifugation, add acidic reagent, shake to mix, and centrifuge again;

[0007] Take the supernatant after centrifugation, add alkaline reagent, shake to mix, centrifuge, and take the supernatant as the test solution;

[0008] The test solution, gold nanoparticle sol, and coagulant were mixed and then detected using a Raman spectrometer.

[0009] The coagulant comprises an aqueous solution of an inorganic acid. The polar organic solvent comprises at least one of ethyl acetate, chloroform, and acetonitrile.

[0010] Preferably, the inorganic acid in the inorganic acid aqueous solution includes at least one of hydrochloric acid, sulfuric acid, and nitric acid.

[0011] Preferably, the acidic reagent includes at least one of dilute hydrochloric acid aqueous solution, dilute sulfuric acid aqueous solution, and dilute nitric acid aqueous solution.

[0012] Preferably, the alkaline reagent includes at least one of sodium hydroxide aqueous solution and potassium hydroxide aqueous solution, and the concentration of the alkaline reagent is 0.5-3 mol / L.

[0013] Preferably, the preparation method of the nano-gold sol is as follows: take an aqueous solution of chloroauric acid and a sodium citrate solution, mix and stir to obtain a mixture, heat the mixture until the color of the mixture changes to the color of nano-gold, and cool at room temperature to obtain the nano-gold sol.

[0014] The inorganic salt crystalline solid powder includes at least one of sodium chloride, potassium chloride, sodium sulfate, and magnesium chloride.

[0015] Preferably, the chloroauric acid aqueous solution has a mass fraction of 0.01-0.1%.

[0016] Preferably, the volume ratio of the aqueous chloroauric acid solution to the sodium citrate solution is 100:0.5-1.5.

[0017] Preferably, the concentration of the inorganic acid aqueous solution is 0.5-3 mol / L.

[0018] Preferably, the volume ratio of the supernatant after centrifugation to the acidic reagent is 1:0.2-1.5; the volume ratio of the supernatant after re-centrifugation to the added alkaline reagent is 1:0.2-1.5.

[0019] Preferably, the volume ratio of the test solution, the gold nanoparticle sol, and the coagulant is 1:0.1-0.4:0.1-0.4.

[0020] Preferably, the Raman spectroscopy used in this application to detect the spectral information of etomidate in e-cigarette oil contains the following characteristic peak: 984 cm⁻¹ -1 1195cm -1 1722cm -1 .

[0021] It should be noted that, since nicotine in e-liquid can significantly interfere with the experiment, this application utilizes the differences in the chemical properties of nicotine and etomidate, as well as their differences in solubility in water, acid and alkali reagents, and organic solvents. By adding water for dilution, extracting with organic solvents, and using inorganic salt powder to improve the efficiency of liquid-liquid extraction and separation, the aim is to first extract etomidate from the e-liquid as much as possible while minimizing the interference of nicotine. Subsequently, acidic and alkaline reagents are added to further reduce the interference of nicotine and other interfering components that may be added to the e-liquid, thereby minimizing the content of interfering substances in the final reaction solution.

[0022] The beneficial effects of this invention are:

[0023] This application utilizes Raman spectroscopy to precisely determine the presence of etomidate in e-cigarettes at the molecular level. Detection using the method described in this application can achieve a molecular level of 984 cm⁻¹. -1 1195cm -1 1722cm-1 A distinct Raman spectral peak was observed. The detection limit of this application is as low as 0.5 mg / L. In step c, only 1 mL of e-cigarette oil needs to be processed, and after subsequent steps, a better detection effect can be achieved. In addition, by setting up comparative examples 1 to 3, it can be seen that steps a to g of this application have good coordination and correlation. The obviousness of the peak in the detection spectrum can also affect the accuracy of the results. The peak in Example 1 of this application is obvious and easy to observe, which can improve the accuracy and effect of detecting etomidate in e-cigarette oil. In addition, the detection time of this application does not exceed 10 minutes, and can even be as low as 10-30 seconds, which can quickly detect trace samples. Moreover, the steps are not complicated, the detection cost is low, the requirements for detection personnel are low, and there is no need to rely on large detection equipment, which is conducive to the operator's preliminary and rapid detection of etomidate in e-cigarette oil on site. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 These are comparative spectra of Embodiment 1 and Embodiment 2 of the present invention;

[0026] Figure 2 This is a comparative spectrum of Comparative Example 1 of the present invention;

[0027] Figure 3 This is a comparative spectrum of Comparative Example 2 of the present invention;

[0028] Figure 4 This is a comparative spectrum of Comparative Example 3 of the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Unless otherwise specified, the equipment and materials used in the embodiments can be readily obtained from commercial companies. The following is a partial description:

[0031] Electronic cigarettes, manufacturer and model: Philt's Sweet and Sour Berry, or you can choose Pear Mist's Green Bean Popsicle flavor or RELX's RELX Green Feather.

[0032] Portable Raman spectrometer, manufacturer and model: Polaris Scientific Instruments (Suzhou) Co., Ltd., Polaris-R80.

[0033] This invention provides a method for detecting etomidate in e-cigarette liquid, comprising the following steps:

[0034] a. Take a 0.01-0.1% chloroauric acid aqueous solution and a 1-10% sodium citrate solution and mix them in a volume ratio of 100:0.5-1.5 to obtain a mixture. Heat the mixture to 100°C. The color of the mixture changes to the color of nano-gold. Cool it to room temperature to obtain nano-gold sol.

[0035] b. Prepare an aqueous solution of inorganic acid of 0.5-3 mol / L as a coagulation accelerator. The inorganic acid in the aqueous solution includes at least one of hydrochloric acid, sulfuric acid, and nitric acid.

[0036] c. Take 0.5-3 mL of e-cigarette liquid into a 10 mL centrifuge tube, add 1-4 mL of deionized water, 2-4 mL of polar organic solvent, and 0.5 g of inorganic salt crystalline solid powder to the centrifuge tube, shake to mix, and let stand for 0.5-3 minutes; wherein, the inorganic salt crystalline solid powder includes at least one of sodium chloride, potassium chloride, sodium sulfate, and magnesium chloride;

[0037] d. Take 0.3-2 mL of the supernatant from step c and centrifuge at 10,000 rpm for 10-60 seconds;

[0038] e. Take 0.3-1.5 mL of the supernatant after centrifugation in step d, add an acidic reagent to this supernatant at a volume ratio of 1:0.2-1.5, shake to mix, and centrifuge at 10,000 rpm for 2-30 seconds; wherein, the acidic reagent includes at least one of dilute hydrochloric acid aqueous solution, dilute sulfuric acid aqueous solution, and dilute nitric acid aqueous solution;

[0039] f. Take 0.2-1.5 mL of the supernatant after centrifugation in step e, add an alkaline reagent to this supernatant at a volume ratio of 1:0.2-1.5, shake to mix, centrifuge at 10000 rpm for 2-30 seconds, and the supernatant is the test solution; wherein, the alkaline reagent includes at least one of sodium hydroxide aqueous solution and potassium hydroxide aqueous solution.

[0040] g. Mix the gold nanoparticle sol from step a, the test solution obtained in step f, and the coagulation accelerator prepared in step b at a volume ratio of 1:0.1-0.4:0.1-0.4, and detect the mixture using a portable Raman spectrometer for 10-30 seconds.

[0041] The detection parameters of the portable Raman spectrometer in this invention are: excitation wavelength 785 nm, laser power 300 mW, integration time 3 seconds, number of scans 1, and spectral resolution ≤ 6 cm⁻¹.-1 .

[0042] Example 1

[0043] A method for detecting etomidate in e-cigarette liquid, comprising the following steps:

[0044] a. Mix 0.01% chloroauric acid aqueous solution and 2% sodium citrate solution in a volume ratio of 100:0.7 to obtain a mixture. Heat the mixture to 100°C. The mixture turns into the color of nano-gold. Cool to room temperature to obtain nano-gold sol.

[0045] b. Prepare a 2 mol / L inorganic acid aqueous solution as a coagulation accelerator. The inorganic acid in the inorganic acid aqueous solution is hydrochloric acid.

[0046] c. Take 1 mL of e-cigarette liquid into a 10 mL centrifuge tube, add 3 mL of deionized water, 3 mL of polar organic solvent, and 0.5 g of inorganic salt crystalline solid powder to the centrifuge tube, shake to mix, and let stand for 1 minute; the inorganic salt crystalline solid powder is sodium chloride; the polar organic solvent is ethyl acetate;

[0047] d. Take 1 mL of the supernatant from step c and centrifuge at 10,000 rpm for 30 seconds;

[0048] e. Take 0.8 mL of the supernatant after centrifugation in step d, add an acidic reagent to this supernatant at a volume ratio of 1:0.5, shake to mix, and centrifuge at 10,000 rpm for 10 seconds; wherein, the acidic reagent is a dilute hydrochloric acid aqueous solution;

[0049] f. Take 0.6 mL of the supernatant after centrifugation in step e, add an alkaline reagent to this supernatant at a volume ratio of 1:0.5, shake to mix, centrifuge at 10000 rpm for 10 seconds, and the supernatant is the test solution; wherein, the alkaline reagent is an aqueous solution of sodium hydroxide.

[0050] g. Mix the gold nanoparticle sol from step a, the test solution obtained in step f, and the coagulation accelerator prepared in step b at a volume ratio of 1:0.1:0.2;

[0051] After the cg step, both spiked e-liquid and blank e-liquid samples were placed in a portable Raman spectrometer for detection. The entire detection process took 10-30 seconds. Etomidate standard solution was then analyzed using the same procedure as step g. The results showed that the spiked e-liquid sample and the etomidate standard solution both showed a similar reading at 984 cm⁻¹. -1 1195cm -1 1722cm -1 There is a distinct Raman spectral peak at this location, as referenced. Figure 1In Example 1, the concentration of etomidate spiked in the e-liquid was 0.5 mg / L.

[0052] Example 2

[0053] Unlike Example 1, in this example, the concentration of etomidate spiked in the e-liquid was 20 mg / L, and the results were as follows: Figure 1 The remaining steps are the same as in Example 1.

[0054] Results analysis: From Figure 1 It is evident that the method of this application is applicable to both high and low concentrations of etomidate in e-liquid. Furthermore, based on using three times the intensity of the background as the criterion for determining the validity of the characteristic peak, the detection limit of this method for etomidate in e-liquid can be as low as 0.5 mg / L. In addition, using etomidate in 0 mg / L e-liquid as a control further accurately reveals the peak values ​​in Examples 1 and 2.

[0055] Comparative Example 1

[0056] A method for detecting etomidate in e-cigarette liquid, comprising the following steps:

[0057] Steps a through e are the same as in Example 1.

[0058] f. Take 0.6 mL of the supernatant after centrifugation in step e, add deionized water to this supernatant at a volume ratio of 1:0.5, shake to mix, centrifuge at 10000 rpm for 10 seconds, and the supernatant is the test solution;

[0059] g. Mix the gold nanoparticle sol from step a, the test solution obtained in step f, and the coagulation accelerator prepared in step b at a volume ratio of 1:0.1:0.2;

[0060] The spiked e-liquid from Comparative Example 1, after undergoing the CG step, and the spiked e-liquid from Example 1 were both placed in a portable Raman spectrometer for analysis. The entire analysis process took no more than 10 minutes. The results are as follows: Figure 2 .

[0061] Results Analysis: The spiked samples of etomidate in Example 1 and Comparative Example 1 were at 984 cm⁻¹ -1 1195cm -1 1722cm -1 All samples showed distinct Raman spectral peaks, but under the same spiking concentration, Example 1 showed a peak at 984 cm⁻¹. -1 The characteristic peak at 1026 cm⁻¹ is significantly higher than that of Comparative Example 1, and the intensity of characteristic peaks at other positions is also improved to some extent. Furthermore, compared to Comparative Example 1, Example 1 shows a higher intensity at 1026 cm⁻¹. -1The interference peak at that location is significantly weaker. This indicates that for the detection method of this application, in step f, adding an alkaline reagent to the supernatant provides a better detection effect than adding deionized water to the supernatant in this step.

[0062] Comparative Example 2

[0063] A method for detecting etomidate in e-cigarette liquid, comprising the following steps:

[0064] Steps a to b are the same as in Example 1.

[0065] c. Mix the nano-gold sol from step a, the e-cigarette oil, and the coagulation accelerator prepared in step b at a volume ratio of 1:0.1:0.2;

[0066] Both the spiked e-liquid from Comparative Example 2 and the spiked e-liquid from Example 1, after undergoing step c above, were analyzed using a portable Raman spectrometer. The entire detection process took no more than 10 minutes. The results were referenced... Figure 3 .

[0067] Results Analysis: The spiked sample of etomidate in Example 1 was at 984 cm⁻¹ -1 1195cm -1 1722cm -1 While there were obvious Raman spectral peaks at these locations, in Comparative Example 2, no effective peaks were observed at these three locations under the same spiking concentration; only obvious Raman spectral data for nicotine were observed. This demonstrates that pre-treating the e-cigarette oil according to the method described in this application can improve the detection effect and accuracy.

[0068] Comparative Example 3

[0069] A method for detecting etomidate in e-cigarette liquid, comprising the following steps:

[0070] Steps ab of Example 1 are removed, while step cf is the same as in Example 1.

[0071] g. Take all the supernatant liquid from step f after centrifugation and place it in a test bottle;

[0072] After undergoing the above CG step, both the spiked e-liquid of Comparative Example 3 and the spiked e-liquid of Example 1 were analyzed using a portable Raman spectrometer. The results were compared with those of Comparative Example 3. Figure 4 .

[0073] Results Analysis: The spiked sample of etomidate in Example 1 was at 984 cm⁻¹ -1 1195cm -1 1722cm -1While there were obvious Raman spectral peaks at these locations, in Comparative Example 3, no effective peaks were observed at these three locations under the same spiking concentration; only the Raman spectral data of the extraction solvent was clearly observed. This indicates that the detection method of this application, which mixes the nano-gold sol, the coagulation accelerator, and the e-cigarette oil before detection, can improve the detection effect and accuracy.

[0074] In summary, according to the testing method of this application, it is possible to detect [a substance] at 984cm. -1 1195cm -1 1722cm -1 A distinct Raman spectral peak was observed. The detection limit of this application is as low as 0.5 mg / L. In step c, only 1 mL of e-cigarette oil needs to be processed, and after subsequent steps, a better detection effect can be achieved. In addition, by setting up comparative examples 1 to 3, it can be seen that steps a to g of this application have good coordination and correlation. The obviousness of the peak in the detection spectrum can also affect the accuracy of the results. The peak in Example 1 of this application is obvious and easy to observe, which can improve the accuracy and effect of detecting etomidate in e-cigarette oil. In addition, the detection time of this application does not exceed 10 minutes, and can even be as low as 10-30 seconds, which can quickly detect trace samples. Moreover, the steps are not complicated, the detection cost is low, the requirements for detection personnel are low, and there is no need to rely on large detection equipment, which is conducive to the operator's preliminary and rapid detection of etomidate in e-cigarette oil on site.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting etomidate in e-cigarette liquid, characterized in that, Includes the following steps: Add e-cigarette liquid, deionized water, polar organic solvent, and inorganic salt solid powder to a container, shake to mix, let stand, and centrifuge the supernatant after standing. Take the supernatant after centrifugation, add acidic reagent, shake to mix, and centrifuge again; Take the supernatant after centrifugation, add alkaline reagent, shake to mix, centrifuge, and take the supernatant as the test solution; The test solution, gold nanoparticle sol, and coagulant were mixed and then detected using a Raman spectrometer. The coagulant comprises an aqueous solution of an inorganic acid; the alkaline reagent comprises at least one of an aqueous solution of sodium hydroxide and an aqueous solution of potassium hydroxide, wherein the concentration of the alkaline reagent is 0.5-3 mol / L; the concentration of the aqueous solution of the inorganic acid is 0.5-3 mol / L; the volume ratio of the supernatant after centrifugation to the acidic reagent is 1:0.2-1.5; and the volume ratio of the supernatant after re-centrifugation to the added alkaline reagent is 1:0.2-1.

5.

2. The method for detecting etomidate in e-cigarette liquid according to claim 1, characterized in that, The inorganic acid in the aqueous solution includes at least one of hydrochloric acid, sulfuric acid, and nitric acid. The polar organic solvent includes at least one of ethyl acetate, chloroform, and acetonitrile.

3. The method for detecting etomidate in e-cigarette liquid according to claim 1, characterized in that, The acidic reagent includes at least one of dilute hydrochloric acid aqueous solution, dilute sulfuric acid aqueous solution, and dilute nitric acid aqueous solution.

4. The method for detecting etomidate in e-cigarette liquid according to claim 1, characterized in that, The preparation method of the nano-gold sol is as follows: take chloroauric acid aqueous solution and sodium citrate solution, mix and stir to obtain a mixture, heat the mixture until the color of the mixture changes to the color of nano-gold, and cool at room temperature to obtain the nano-gold sol; The inorganic salt crystalline solid powder includes at least one of sodium chloride, potassium chloride, sodium sulfate, and magnesium chloride.

5. The method for detecting etomidate in e-cigarette liquid according to claim 4, characterized in that, The mass fraction of the chloroauric acid aqueous solution is 0.01-0.1%.

6. The method for detecting etomidate in e-cigarette liquid according to claim 4, characterized in that, The volume ratio of chloroauric acid aqueous solution to sodium citrate solution is 100:0.5-1.

5.

7. The method for detecting etomidate in e-cigarette liquid according to claim 1, characterized in that, The volume ratio of the test solution, the gold nanoparticle sol, and the coagulant is 1:0.1-0.4:0.1-0.4; The information of the obtained etomidate in the electronic cigarette oil detected by the Raman spectrometer contains the following characteristic peaks: 984 cm -1 , 1195 cm -1 , 1722 cm -1 .

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