Rapid determination method for volatile organic acid in electronic atomized liquid

Abstract

The invention provides a method for rapidly determining volatile organic acids in electronic atomized liquid, which comprises the following steps: respectively adding a derivatization reagent, an internal standard solution and a solvent into the electronic atomized liquid, extracting, carrying out derivatization reaction on the obtained sample liquid to be detected, and then determining by using a gas chromatography-mass spectrometry method, and determining the content of at least one volatile organic acid component in the liquid to be detected. According to the rapid determination method for the volatile organic acid in the electronic atomized liquid, provided by the invention, the volatile organic acid in the electronic atomized liquid can be rapidly, simply, conveniently and efficiently determined at low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical composition analysis, and relates to a method for rapidly determining the content of volatile organic acids in electronic atomization liquid, and specifically to a method for rapidly determining the content of multiple volatile organic acids in electronic atomization liquid by using headspace thermal assisted derivatization-gas chromatography-mass spectrometry. Background Art

[0002] Electronic atomizing liquid is an important component of electronic cigarette products, which is atomized by the device to produce inhalable aerosol. Acidulants are one of the most commonly used additives in electronic atomizing liquid, especially in fruit-flavored atomizing liquid. The naturalness of fruit flavor and the outstanding reduction of fruity aroma are the ultimate pursuit of the taste of atomizing liquid in the industry. The type and ratio of volatile organic acids in the acidulant can greatly affect the naturalness and three-dimensionality of the aroma and taste of the atomizing liquid.

[0003] At present, the methods for determining organic acids mainly include gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. When analyzing organic acids by gas chromatography-mass spectrometry, since the direct determination method requires pre-treatment such as filtration and extraction, the loss of the target is prone to occur, and it is necessary to purchase a special chromatographic column for organic acid determination. The cost of the special column is high compared to the conventional column. Some volatile organic acids are unstable under gas chromatography conditions, and the peak shape is generally poor and the sensitivity is low. Therefore, the current traditional determination method is generally to derive them into silanized or esterified compounds with better peak shape, higher sensitivity and more stable properties. However, this method requires cumbersome pre-treatment such as saponification, hydrolysis, esterification, extraction, etc., which is troublesome and time-consuming to operate, and the loss of the target is prone to occur during the pre-treatment process, especially volatile organic acids, causing measurement errors. Liquid chromatography-mass spectrometry does not require derivatization, which can relatively reduce the errors caused by the pre-treatment steps, but the liquid chromatography-mass spectrometer is expensive, the test cost is high, and it is more inclined to the determination of non-volatile organic acids.

[0004] For example, the patent with publication number CN115656369A describes a method for simultaneously determining organic acids in electronic atomization liquid by liquid chromatography-tandem mass spectrometry. This method requires the use of LC / MSMS, and the instrument is expensive and the testing cost is high. In addition, the test objects of this patent method are mainly non-volatile acids such as malic acid, citric acid, tartaric acid, etc.

[0005] For another example, Harvanko et al. used gas chromatography-mass spectrometry to perform methyl esterification derivatization determination of organic acids in electronic atomization liquid in the article "Characterization of Nicotine Salts in 23 Electronic Cigarette Refill Liquids". The sample processing method in this article is relatively complicated, requiring multiple steps such as saponification, hydrolysis, esterification, and extraction. There is a large measurement error, and only qualitative analysis of organic acids is performed, and quantitative analysis of the target is not achieved.

[0006] For example, Tang Xiaodong et al. used gas chromatography-mass spectrometry to perform online methylation derivatization determination of oleic acid in tobacco flavors and fragrances in the article "Online Methyl Derivatization-Gas Chromatography-Mass Spectrometry" to determine the oleic acid in tobacco flavors and fragrances. However, the article was aimed at tobacco flavors and fragrances, not electronic atomization liquids, and the sample matrices were quite different. At the same time, this method was only applicable to the determination of non-volatile organic acids such as oleic acid, which was too single and could not meet the determination of the types of organic acids in actual samples. In addition, the use of the injection port for online methylation determination of organic acids also has the following problems, such as the need to filter and extract the samples before loading them onto the machine, which may easily lead to the loss of the target; too much sample matrix enters the instrument, which greatly interferes with the screening and determination of organic acids and affects the recovery rate of the target; the injection port derivatization reagent residue is serious, which may easily interfere with the subsequent sample determination; the organic acid esterification reaction cannot control the reaction time, and there are problems such as incomplete reaction, serious acid residue at the injection port, poor reproducibility of sample determination, peak tailing, low sensitivity and accuracy.

[0007] In the prior art, the traditional derivatization methods used to determine organic acids in electronic cigarette aerosol liquid are mostly cumbersome, time-consuming and troublesome to operate, and require treatments such as heating, nitrogen blowing, and filtration. However, the boiling points of volatile organic acids are not high, and they are easily volatilized and lost in this process, so the extraction recovery effect is poor.

[0008] In order to better study the composition of acidulants in electronic cigarette atomizer liquid, it is necessary to develop a low-cost method that can simultaneously, simply and efficiently determine multiple volatile organic acids in electronic cigarette atomizer liquid, so as to improve the accuracy of qualitative and quantitative results of volatile organic acids in electronic cigarette atomizer liquid. Summary of the invention

[0009] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for rapid determination of volatile organic acids in electronic atomization liquid, which is used to better study the types of volatile organic acids in electronic cigarette liquid, and at the same time, simply and efficiently determine the content of volatile organic acids, and can achieve low cost.

[0010] To achieve the above-mentioned purpose and other related purposes, the present invention provides a method for rapid determination of volatile organic acids in electronic atomized liquid, comprising: respectively adding a derivatization reagent, an internal standard solution, and a solvent to the electronic atomized liquid for extraction, subjecting the obtained sample test liquid to a derivatization reaction and then subjecting the sample test liquid to gas chromatography-mass spectrometry determination to determine the content of at least one volatile organic acid component in the test liquid.

[0011] Preferably, the electronic atomization liquid is also called electronic cigarette oil or electronic cigarette liquid, which is used in conjunction with an electronic atomizer. Specifically, the electronic atomization liquid can produce mist like a cigarette by heating the electronic atomizer. The main components of the electronic atomization liquid are food-grade or medical-grade propylene glycol, 1,2-propylene glycol, flavors, nicotine, nicotine salts or nicotine derivatives.

[0012] Preferably, the volatile organic acid is selected from at least one of acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid or dodecanoic acid.

[0013] Preferably, the volatile organic acids include 13 kinds, including acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid and dodecanoic acid.

[0014] Preferably, the derivatization reagent is selected from a methyl esterification reagent or a non-methyl esterification reagent.

[0015] Preferably, the derivatization agent is selected from at least one of tetramethylammonium hydroxide, trimethylphenylammonium hydroxide, trimethylsulfur hydroxide, tetramethylammonium acetate, tetraethylammonium hydroxide and tetrabutylammonium hydroxide.

[0016] More preferably, the derivatization agent is selected from at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide or tetrabutylammonium hydroxide.

[0017] More preferably, the methylating agent is tetramethylammonium hydroxide.

[0018] Among the above derivatization reagents, tetramethylammonium hydroxide, trimethylphenylammonium hydroxide, trimethylsulfur hydroxide, and tetramethylammonium acetate are methyl esterification reagents, and tetraethylammonium hydroxide or tetrabutylammonium hydroxide is a non-methyl esterification reagent.

[0019] Preferably, the internal standard solution is a methanol solution of deuterated pentanoic acid (pentanoic acid-D9).

[0020] Preferably, the concentration of deuterated pentanoic acid in the internal standard solution is 500-1000 mg / L.

[0021] Preferably, the solvent is a commonly used organic solvent, specifically at least one selected from methanol, ethanol, isopropanol, ethyl acetate, etc., preferably methanol.

[0022] Preferably, the ratio of the added mass g of the electronic atomization liquid to the added volume μL of the derivatization reagent is 0.1-1:1.25-400, specifically 0.1-1:1.25-12.5, 0.1-1:12.5-40, 0.1-1:40-400, 1:12.5-400, 1:200-400, 1:300-400, 1:200-300, preferably 1:300-400, more preferably 1:300.

[0023] Preferably, the ratio of the added mass g of the electronic atomization liquid to the added volume μL of the internal standard solution is 0.1-1:1.25-400, specifically 0.1-1:1.25-12.5, 0.1-1:12.5-40, 0.1-1:40-400, 1:12.5-400, 1:200-400, 1:300-400, 1:200-300, preferably 1:200-300, more preferably 1:200.

[0024] Preferably, the ratio of the added mass g of the electronic atomization liquid to the added volume mL of the solvent is 0.1-1:1-100, specifically 0.1-1:1-10, 0.1-1:10-100, 1:1-10, 1:10-100, preferably 1:10.

[0025] Preferably, the extraction is selected from ultrasonic extraction, oscillation extraction or microwave extraction, preferably oscillation extraction.

[0026] Preferably, the oscillation extraction time is 5-15 min, specifically 5-10 min, 10-15 min, preferably 10 min.

[0027] Preferably, the sample liquid to be tested is subjected to a derivatization reaction and then subjected to a gas chromatography-mass spectrometry determination, comprising the following steps:

[0028] 1) preparing a standard solution: providing a standard solution, wherein the standard solution comprises at least one selected from the group consisting of acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid, and dodecanoic acid, and a blank matrix reagent, a derivatization reagent, an internal standard solution, and a solvent;

[0029] 2) Determination: The sample solution and the standard solution obtained in step 1) are subjected to derivatization reaction injection respectively, and then subjected to gas chromatography-mass spectrometry determination, and the retention time is compared for qualitative determination, and the internal standard curve method is used for quantitative determination to determine the content of at least one of the 13 volatile organic acid components in the solution.

[0030] In step 1), the blank matrix reagent is a mixed solution of propylene glycol (PG) and vegetable glycerin (VG) (referred to as PG-VG mixed solution), and the mass ratio of propylene glycol (PG) to vegetable glycerin (VG) in the PG-VG mixed solution is 1:1. The PG-VG mixed solution is the base solvent used in the electronic atomization liquid.

[0031] In step 1), the derivatization reagent is selected from a methyl esterification reagent or a non-methyl esterification reagent.

[0032] Preferably, the derivatization agent is selected from at least one of tetramethylammonium hydroxide, trimethylphenylammonium hydroxide, trimethylsulfur hydroxide, tetramethylammonium acetate, tetraethylammonium hydroxide and tetrabutylammonium hydroxide.

[0033] More preferably, the derivatization agent is selected from at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide or tetrabutylammonium hydroxide.

[0034] More preferably, the methylating agent is tetramethylammonium hydroxide.

[0035] In step 1), the internal standard solution is a methanol solution of deuterated pentanoic acid (pentanoic acid-D9).

[0036] Preferably, the concentration of deuterated pentanoic acid in the internal standard solution is 500-1000 mg / L.

[0037] In step 1), the solvent is a commonly used organic solvent, specifically at least one selected from methanol, ethanol, isopropanol, ethyl acetate, etc., preferably methanol.

[0038] In step 1), the standard solution is obtained by adding a standard of at least one of the 13 volatile organic acids to a solvent to obtain a mixed stock solution, and after gradual dilution, adding a blank matrix reagent, a derivatization reagent, and an internal standard solution, and then adding a solvent to dissolve and fix the volume.

[0039] Preferably, the concentration of each volatile organic acid component in the standard solution is 5-100 mg / L.

[0040] Preferably, the concentration of the blank matrix reagent in the standard solution is 0.1-2 g / 10 mL, such as 0.1-0.5 g / 10 mL, 0.5-1 g / 10 mL, 1-2 g / 10 mL, and preferably 1 g / 10 mL.

[0041] Preferably, the concentration of the derivatization reagent in the standard solution is 12.5-400 μL / 10 mL, specifically 12.5-200 μL / 10 mL, 200-300 μL / 10 mL, 300-400 μL / 10 mL, preferably 300 μL / 10 mL.

[0042] Preferably, the concentration of the internal standard solution in the standard solution is 12.5-400 μL / 10 mL, such as 12.5-200 μL / 10 mL, 200-300 μL / 10 mL, 300-400 μL / 10 mL, and preferably 200 μL / 10 mL.

[0043] In step 2), in the derivatization reaction injection, the injection volume of the sample solution is 1-20 μL, such as 1-5 μL, 5-10 μL, 10-15 μL, 15-20 μL, preferably 10 μL.

[0044] In step 2), the injection mode of the derivatization reaction is selected from one of headspace thermal assisted derivatization injection and injection port online derivatization injection.

[0045] Preferably, the derivatization reaction is a headspace thermal assisted derivatization method.

[0046] In the above-mentioned derivatization reaction, compared with the headspace thermal-assisted derivatization method, the peak tailing of low molecular weight organic acids such as acetic acid, propionic acid, butyric acid, and valeric acid is serious, and the sensitivity and accuracy are low. Therefore, the headspace thermal-assisted derivatization method is better than the inlet online derivatization method.

[0047] More preferably, in the headspace thermal assisted derivatization method, the sample solution and the standard solution are both placed in a headspace bottle and then placed in a headspace injector. After the sample solution and the standard solution are both placed in the headspace bottle, the bottle cap is quickly pressed, mixed evenly, and then allowed to stand for 45-75 seconds, preferably 60 seconds.

[0048] More preferably, in the headspace thermal assisted derivatization method, the reaction temperature of the heating box is lower than the temperature of the quantitative loop, and the temperature of the quantitative loop is lower than the temperature of the transmission line.

[0049] More preferably, in the headspace thermally assisted derivatization method, the reaction temperature of the heating box is 60-240°C, such as 60-90°C, 90-120°C, 120-140°C, 140-160°C, 160-180°C, 180-200°C, 200-210°C, 210-230°C, 230-240°C, preferably 210-220°C, 220-230°C, more preferably 220°C.

[0050] More preferably, in the headspace thermal assisted derivatization method, the quantitative loop temperature is 220-240°C, such as 220-230°C, 230-240°C, preferably 230°C.

[0051] More preferably, in the headspace thermal assisted derivatization method, the transfer line temperature is 230-250°C, such as 230-240°C, 240-250°C, preferably 240°C.

[0052] More preferably, in the headspace thermal-assisted derivatization method, the injection time is 0.1-1 min, such as 0.1-0.5 min, 0.5-1 min, and preferably 0.5 min.

[0053] More preferably, in the headspace thermal-assisted derivatization method, the equilibration time is 0.5-30 min, such as 0.5-1 min, 1-3 min, 3-5 min, 5-6 min, 6-10 min, 10-30 min, preferably 6-8 min, 8-10 min, 10-15 min, 15-20 min, 20-25 min, 25-30 min, and more preferably 8 min.

[0054] More preferably, in the headspace thermal-assisted derivatization method, the derivatization reaction time is 0.5-30 min, such as 0.5-1 min, 1-3 min, 3-5 min, 5-6 min, 6-10 min, 10-30 min, preferably 6-8 min, 8-10 min, 10-15 min, 15-20 min, 20-25 min, 25-30 min, and more preferably 8 min.

[0055] More preferably, in the headspace thermal-assisted derivatization method, the equilibration and derivatization reactions are carried out simultaneously.

[0056] More preferably, in the headspace thermal assisted derivatization method, the filling pressure is 10-30 psi, such as 10-15 psi, 15-30 psi, and preferably 15 psi.

[0057] In step 2), in the gas chromatography measurement conditions, the chromatographic column is selected from one of a DB-5 capillary column, a DB-624 capillary column or a DB-WAX capillary column, preferably a DB-624 capillary column (length 30m×inner diameter 250μm×film thickness 1.4μm); the injection port temperature is 240-260°C, preferably 250°C; the transmission line temperature is 240-260°C, preferably 250°C; the carrier gas is high-purity helium, the carrier gas purity is ≥99.999%; the carrier gas flow rate is 0.5-2.0mL / min, preferably 1.0mL / min; the split ratio is 10-50:1, preferably 30:1.

[0058] In step 2), in the measurement conditions of the gas chromatography, the temperature rising program of the gas chromatography is: initial temperature 30-50°C, preferably 40°C, maintained for 2-4min, preferably 3min; at a rate of 4-6°C / min, preferably 5°C / min, increased to 80-100°C, preferably 90°C; then at a rate of 9-11°C / min, preferably 10°C / min, increased to 140-160°C, preferably 150°C; then at a rate of 19-21°C / min, preferably 20°C / min, increased to 240-260°C, preferably 250°C, maintained for 11-13min, preferably 12min.

[0059] In step 2), the mass spectrometry conditions are as follows: ionization mode: electron impact (EI) ion source; ionization energy: 70 eV; ion source temperature: 150°C; quadrupole temperature: 230°C; solvent delay: 0-6 min, preferably 3.6 min; scanning mode: full scan (Scan) and selected ion monitoring (SIM); scanning range of full scan mode: 29-350 m / z.

[0060] Preferably, when the scanning mode is selected ion monitoring (SIM), the corresponding mass spectrometry parameter conditions are shown in Table 1 below.

[0061] Table 1

[0062]

[0063] In step 2), the internal standard curve method comprises the following steps:

[0064] i) preparing a series of standard solutions of different concentrations, performing GC-MS detection respectively, obtaining a linear relationship between the chromatographic peak area ratio of at least one volatile organic acid component / internal standard and the concentration ratio of the corresponding volatile organic acid component / internal standard, drawing a corresponding standard working curve, and calculating a regression equation of the standard working curve of at least one volatile organic acid component;

[0065] ii) subjecting the sample to be tested to GC-MS detection, substituting the obtained chromatographic peak area ratio of at least one volatile organic acid component to the internal standard into the regression equation of the standard working curve of at least one volatile organic acid component in step i), and calculating the content of at least one volatile organic acid component in the sample to be tested based on the known concentration of the internal standard.

[0066] More preferably, in the standard working curve, the quantitative ion chromatographic peak area ratio of at least one volatile organic acid component to the internal standard is used as the ordinate (Y-axis), and the corresponding concentration ratio of at least one volatile organic acid component to the internal standard is used as the abscissa (X-axis).

[0067] As described above, the present invention provides a rapid determination method for volatile organic acids in electronic atomization liquid, and develops a qualitative and quantitative analysis method for 13 volatile organic acid components in electronic atomization liquid. It has the following beneficial effects:

[0068] (1) The present invention provides a rapid determination method for volatile organic acids in electronic atomization liquid. Compared with the prior art, the method makes up for the lack of derivatization determination method for volatile organic acids in electronic cigarette atomization liquid by headspace thermal assisted methyl esterification derivatization GC / MS determination.

[0069] (2) The present invention provides a method for rapid determination of volatile organic acids in electronic atomization liquid. After the electronic cigarette atomization liquid sample is extracted with methanol containing internal standard liquid and derivatization liquid, the temperature and time of the derivatization reaction are controlled by a headspace sampling furnace so that the methyl esterification derivatization reagent can completely derivatize the volatile organic acid, and then the methyl esterification product is passed into GC / MS for analysis. That is, after headspace thermal assisted methyl esterification derivatization, GC-MS is used for determination. Compared with the traditional derivatization method which requires cumbersome pre-treatment such as saponification, hydrolysis, esterification, extraction, filtration, etc., the sample pre-treatment process is simple and rapid.

[0070] (3) The present invention provides a method for rapid determination of volatile organic acids in electronic atomized liquid. It only requires sample solvent extraction and can be put into the machine without derivatization before being put into the machine. It is easy to operate and also reduces the loss of target substances caused by a series of tedious pretreatments, thereby improving the accuracy of sample testing.

[0071] (4) The present invention provides a method for rapid determination of volatile organic acids in electronic atomized liquid. Compared with the method of methyl esterification derivatization through the injection port, this method has less residual derivatization liquid and sample matrix, higher reproducibility, better peak shape of target chromatographic peak, higher separation and sensitivity, and can also take into account the determination of multiple volatile organic acids, which can better meet the requirements for the determination of organic acid types in actual samples; compared with the direct determination method without derivatization, the cost is lower.

[0072] (5) The present invention provides a method for rapid determination of volatile organic acids in electronic atomized liquid, which has the effect of rapid determination. Specifically, on the one hand, there is no need to perform derivatization treatment before loading the sample on the machine, and derivatization can be performed online, so that multiple samples can be tested uninterruptedly, that is, while the previous sample is being tested, the next sample is being derivatized and prepared, thereby shortening the analysis time; on the other hand, the headspace sampling method is suitable for volatile substances, which can reduce the contamination of the sample matrix itself to the instrument, and there is no need to perform sample pretreatment such as extraction, purification and other steps, thereby improving the detection efficiency, simplifying the processing steps and shortening the processing time.

[0073] (6) The present invention provides a method for rapid determination of volatile organic acids in electronic atomization liquid, which can achieve low-cost, simultaneous, rapid, simple and efficient determination of volatile organic acids in electronic atomization liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1a , 1b , 1c shows the comparative chromatograms for different column selections, where Figure 1a This is a comparison chart of different scanning modes of DB-WAX chromatographic column, where the upper picture is the SCAN full scan picture, and the lower picture is the SIM selective scan picture; Figure 1b This is a comparison chart of different scanning modes of DB-5 chromatographic column, where the upper picture is the SCAN full scan picture, and the lower picture is the SIM selective scan picture; Figure 1c This is a comparison chart of different scanning modes of the DB-624 chromatographic column, where the upper picture is the SCAN full scan picture and the lower picture is the SIM selective scan picture.

[0075] Figure 2 Shown are comparative chromatograms under different thermal-assisted reaction modes, where the upper figure is the SCAN full scan and the lower figure is the SIM selective scan.

[0076] Figure 3a , 3b Shown are comparative chromatograms of different types of derivatization reagents, where: Figure 3a The comparison diagram of derivatization with different methyl esterification agents, where the upper diagram is the SCAN full scan diagram and the lower diagram is the SIM selective scan diagram; Figure 3b This is a comparison chart of derivatization with different esterification reagents.

[0077] Figure 4a , 4b , 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l, and 4m are chromatograms showing different types of volatile organic acid methyl esterification derivatives, wherein: Figure 4a is the chromatogram of the methyl esterification derivative of acetic acid; Figure 4b is the chromatogram of the derivative product of propionic acid methyl esterification; Figure 4c is the chromatogram of the derivative product of methyl esterification of isobutyric acid; Figure 4d is the chromatogram of the butyric acid methyl esterification derivative product; Figure 4e is a chromatogram of the methyl esterification derivative of 2-methylbutyric acid; Figure 4f is the chromatogram of the methyl esterification derivative of isovaleric acid; Figure 4g is the chromatogram of the methyl esterification derivative of valeric acid; Figure 4h is a chromatogram of the derivative product of methyl esterification of 2-methylpentanoic acid; Figure 4i is the chromatogram of the hexanoic acid methyl esterification derivative product; Figure 4j is the chromatogram of the product derived from the methyl esterification of heptanoic acid; Figure 4k is the chromatogram of the methyl esterification derivative of octanoic acid; Figure 4l is the chromatogram of the methyl esterification derivative of decanoic acid; Figure 4m This is the chromatogram of the product derived from the methyl esterification of dodecanoic acid. DETAILED DESCRIPTION

[0078] The present invention is further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention.

[0079] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0080] The materials, reagents and instruments used in the following examples are all conventionally used in the art and can be obtained commercially.

[0081] Example 1

[0082] 1. Sample pretreatment

[0083] Weigh 1 g of electronic atomization liquid and place it in a 10 mL volumetric flask. Add 300 μL of tetramethylammonium hydroxide as a derivatization reagent and 200 μL of 1000 mg / L deuterated pentanoic acid methanol solution as an internal standard solution. Make up to volume with methanol, oscillate and extract for 10 min to obtain the sample solution.

[0084] 2. Preparation of standard solution

[0085] Accurately weigh the standard samples of acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid, and dodecanoic acid, and add methanol to prepare a mixed stock solution of a certain concentration. Then take a certain volume of the mixed stock solution and dilute it step by step, place it in a 10mL volumetric flask, add a PGVG mixed solution with a mass ratio of 1:1 of propylene glycol (PG) and vegetable glycerin (VG) as a blank matrix reagent; tetramethylammonium hydroxide is used as a derivatization reagent, add 1000 mg / L of deuterated valeric acid in methanol as an internal standard solution, and then add methanol to dissolve and fix the volume to obtain a standard solution. The concentration of each volatile organic acid component in the standard solution is 5-100 mg / L, the concentration of the blank matrix reagent in the standard solution is 1g / 10mL, the concentration of the derivatization reagent in the standard solution is 300μL / 10mL, and the concentration of the internal standard solution in the standard solution is 200μL / 10mL.

[0086] 3. Determination

[0087] 10 μL of sample solution and 10 μL of standard solution were injected by headspace thermal-assisted derivatization method, and then determined by gas chromatography-mass spectrometry. The retention time was compared for qualitative analysis, and the internal standard curve method was used for quantitative analysis to determine the contents of 13 volatile organic acid components in the sample solution.

[0088] In the headspace thermal assisted derivatization method, the reaction temperature of the heating box was 220°C, the temperature of the quantitative loop was 230°C, the temperature of the transfer line was 240°C, the injection time was 0.5 min, the equilibrium time was 8 min, the derivatization reaction time was 8 min, and the filling pressure was 15 psi.

[0089] The conditions for the gas chromatography test are as follows: chromatographic column: DB-624 capillary column (length 30m×inner diameter 250μm×film thickness 1.4μm); injection port temperature: 250℃; transmission line temperature: 250℃; carrier gas: high-purity helium, carrier gas purity ≥99.999%; carrier gas flow rate: 1.0mL / min; split ratio: 30:1. The temperature program for the gas chromatography is: initial temperature 40℃, maintained for 3min; increased to 90℃ at 5℃ / min; then increased to 150℃ at 10℃ / min; then increased to 250℃ at 20℃ / min, maintained for 12min.

[0090] The mass spectrometry conditions include: ionization mode: electron impact (EI) ion source; ionization energy: 70 eV; ion source temperature: 150°C; quadrupole temperature: 230°C; solvent delay: 3.6 min; scanning mode: full scan (Scan) and selected ion monitoring (SIM); scanning range of full scan mode: 29-350 m / z. When the scanning mode is selected ion monitoring (SIM), the corresponding mass spectrometry parameter conditions are shown in Table 1.

[0091] In the specific determination, a series of standard solutions with concentrations ranging from 5 to 100 mg / L are prepared, and GC-MS detection is performed respectively to obtain the linear relationship between the chromatographic peak area ratio of 13 volatile organic acid components / internal standard and the concentration ratio of the corresponding volatile organic acid components / internal standard, and the corresponding standard working curve is drawn to calculate the regression equation of the standard working curve of the 13 volatile organic acid components. Then, the sample liquid to be tested is subjected to GC-MS detection, and the chromatographic peak area ratio of the 13 volatile organic acid components to the internal standard is substituted into the regression equation of the standard working curve of the 13 volatile organic acid components, and the content of the 13 volatile organic acid components in the sample liquid to be tested is calculated based on the known concentration of the internal standard.

[0092] Example 2

[0093] 1. Sample pretreatment

[0094] Weigh 1 g of electronic atomization liquid and place it in a 10 mL volumetric flask. Add 350 μL of tetramethylammonium hydroxide as a derivatization reagent and 250 μL of 1500 mg / L deuterated pentanoic acid methanol solution as an internal standard solution. Make up to volume with methanol and extract by oscillation for 9 minutes to obtain the sample solution.

[0095] 2. Preparation of standard solution

[0096] Accurately weigh the standard samples of acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid, and dodecanoic acid, and add methanol to prepare a mixed stock solution of a certain concentration. Then take a certain volume of the mixed stock solution and dilute it step by step, place it in a 10mL volumetric flask, add a PGVG mixed solution with a mass ratio of PG (propylene glycol) to VG (vegetable glycerin) of 1:1 as a blank matrix reagent, tetramethylammonium hydroxide as a derivatization reagent, add 1500mg / L of deuterated valeric acid in methanol as an internal standard solution, and then add methanol to dissolve and fix the volume to obtain a standard solution. The concentration of each volatile organic acid component in the standard solution is 5-100mg / L, the concentration of the blank matrix reagent in the standard solution is 0.5g / 10mL, the concentration of the derivatization reagent in the standard solution is 200μL / 10mL, and the concentration of the internal standard solution in the standard solution is 250μL / 10mL.

[0097] 3. Determination

[0098] 10 μL of sample solution and 10 μL of standard solution were injected by headspace thermal-assisted derivatization method, and then determined by gas chromatography-mass spectrometry. The retention time was compared for qualitative analysis, and the internal standard curve method was used for quantitative analysis to determine the contents of 13 volatile organic acid components in the sample solution.

[0099] In the headspace thermal assisted derivatization method, the reaction temperature of the heating box was 215°C, the temperature of the quantitative loop was 225°C, the temperature of the transfer line was 235°C, the injection time was 0.6 min, the equilibrium time was 8.5 min, the derivatization reaction time was 8.5 min, and the filling pressure was 18 psi.

[0100] The gas chromatography measurement conditions are as follows: chromatographic column: DB-624 capillary column (length 30m×inner diameter 250μm×film thickness 1.4μm); injection port temperature: 245℃; transmission line temperature: 245℃; carrier gas: high-purity helium, carrier gas purity ≥99.999%; carrier gas flow rate: 1.1mL / min; split ratio: 28:1. The temperature program of the gas chromatography is: initial temperature 45℃, maintained for 2min; increased to 85℃ at 4℃ / min; then increased to 145℃ at 11℃ / min; then increased to 245℃ at 18℃ / min, maintained for 13min.

[0101] The mass spectrometry conditions include: ionization mode: electron impact (EI) ion source; ionization energy: 70 eV; ion source temperature: 150°C; quadrupole temperature: 230°C; solvent delay: 3.5 min; scanning mode: full scan (Scan) and selected ion monitoring (SIM); scanning range of full scan mode: 29-350 m / z. When the scanning mode is selected ion monitoring (SIM), the corresponding mass spectrometry parameter conditions are shown in Table 1.

[0102] In the specific determination, a series of standard solutions with concentrations ranging from 5 to 100 mg / L are prepared, and GC-MS detection is performed respectively to obtain the linear relationship between the chromatographic peak area ratio of 13 volatile organic acid components / internal standard and the concentration ratio of the corresponding volatile organic acid components / internal standard, and the corresponding standard working curve is drawn to calculate the regression equation of the standard working curve of the 13 volatile organic acid components. Then, the sample liquid to be tested is subjected to GC-MS detection, and the chromatographic peak area ratio of the 13 volatile organic acid components to the internal standard is substituted into the regression equation of the standard working curve of the 13 volatile organic acid components, and the content of the 13 volatile organic acid components in the sample liquid to be tested is calculated based on the known concentration of the internal standard.

[0103] Comparative Example 1: Chromatographic column selection

[0104] Comparative Example 1: The separation effects of different chromatographic columns on the target organic acid derivatives were compared; a weakly polar DB-5 capillary column, a medium-polarity DB-624 capillary column, and a strongly polar DB-WAX capillary column were selected, and the detection was performed under the conditions of Example 1. The results are shown in FIG. Figure 1a , 1b , 1c. The results show that the weak polar DB-5 capillary column, the medium polar DB-624 capillary column, and the strong polar DB-WAX capillary column can all separate some or all of the 13 target substances.

[0105] from Figure 1a It can be seen that when the sample uses a DB-5 capillary column, although the separation of 13 volatile organic acid derivatives is good, some volatile organic acid derivatives have severe peak tailing, making it impossible to accurately quantify the sample.

[0106] from Figure 1b It can be seen that when the sample is chromatographically analyzed using the DB-WAX column, not only are the peaks of some target derivatives severely tailed, but the derivatives of acetic acid, propionic acid, and isobutyric acid cannot be separated and eluted, and the corresponding target peaks cannot be found.

[0107] from Figure 1cIt can be seen that when the DB-624 chromatographic column is used in Example 1, compared with the other two chromatographic columns, the derivatives of the 13 targets can be well separated, and the peak shapes of the corresponding target peaks are good, which enables more accurate sample quantification.

[0108] Selection of thermal assisted derivatization reaction mode in comparative example 2

[0109] Comparative Example 2 analyzed and compared the effects of different thermally assisted derivatization reactions on the derivatization and separation detection of the target; the injection port thermally assisted derivatization method and the head space heating furnace thermally assisted derivatization method were selected for derivatization treatment, and then the detection was performed according to the conditions of Example 1. In the injection port thermally assisted derivatization method, the sample liquid to be tested was directly subjected to gas chromatography determination, and the thermally assisted derivatization was performed using the injection port temperature, wherein the injection port temperature was the same as the injection port temperature (250° C.) of the gas chromatography determination in Example 1.

[0110] Results Figure 2 , Figure 2 The chromatograms of the target compound derivative products under two thermal-assisted derivatization conditions are compared. The results show that after the 13 target compounds were treated with the two thermal-assisted derivatization methods, the peak elution and separation effects were relatively good. However, after treatment with the injection port thermal-assisted derivatization method, the peaks of the derivatives of low molecular weight organic acids such as acetic acid, propionic acid, butyric acid, and valeric acid were severely tailed, which was not conducive to the subsequent quantification of the sample content. The target compound treated with the headspace heating furnace thermal-assisted derivatization method in Example 1 had a good peak shape and could be quantitatively detected more accurately.

[0111] Comparative Example 3 Derivatization Reagent Selection

[0112] Comparative Example 3: The derivatization effects of different derivatization reagents on the target organic acid were compared; the derivatization reaction effects of different derivatization reagents were tested under the conditions of 60°C and 0.5min, and the generation of reaction products was observed. The results are shown in Table 2. Figure 3a , 3b From Table 6, Figure 3a , 3b The results show that the following reagents can be used for derivatization, but the response size of the derivative products in the methylation reagents is ranked from large to small as follows: tetramethylammonium hydroxide > phenyltrimethylammonium hydroxide > tetramethylsulfur hydroxide > tetramethylammonium acetate. At the same time, the product response values ​​of ammonium hydroxide methylation (tetramethylammonium hydroxide) and ethylation (tetraethylammonium hydroxide) and butylation (tetrabutylammonium hydroxide) reagents are not much different, but considering that there may be a large number of ethyl and butyl components in the actual measured samples, tetramethylammonium hydroxide is a better derivatization reagent. It should be noted that before all derivatization reactions reach saturation, the response size of the derivative product represents the difficulty of derivatization, and further indicates the speed of the derivatization reaction.

[0113] Table 2

[0114]

[0115] Selection of reaction temperature for derivatization in comparative example 4

[0116] Comparative Example 4 analyzed and compared the derivatization effects of different derivatization reactions on the target organic acid; the reaction temperatures of the derivatization in Table 3 were selected respectively, and the test was carried out according to the conditions of Example 1, and the results are shown in Table 3. From the results in Table 3, it can be seen that the following temperatures can be used for derivatization, but the response value of the reaction product increases with the increase of the reaction temperature only at a certain temperature, and the derivatization reaction is complete at 220°C. After exceeding 220°C, the effect of the derivatization reaction of some target organic acids is reduced, so 220°C is a better reaction temperature.

[0117] Table 3

[0118]

[0119] Comparative Example 5 Derivatization Reaction Time Selection

[0120] Comparative Example 5 analyzed and compared the derivatization effects of different derivatization reaction times on the target organic acid; the derivatization reaction times in Table 4 were selected respectively, and other conditions were tested according to the conditions of Example 1, and the results are shown in Table 4. From the results in Table 4, it can be seen that the following times can ensure derivatization, but the response value of the reaction product increases with the extension of the reaction time within a certain period of time, and the derivatization reaction is complete at 8 minutes. After exceeding 8 minutes, the effect of the derivatization reaction decreases. Therefore, considering the life loss of the instrument and accessories and the sample testing efficiency, 8 minutes is selected as the best reaction time.

[0121] Table 4

[0122]

[0123] Selection of dosage of derivative solution in group 6 of comparative example

[0124] Comparative Example 6 groups analyzed and compared the derivatization effects of different derivatization reagent dosages on the target organic acid; different derivatization liquid dosages were selected, specifically, the ratio of the amount of derivatization liquid to the amount of organic acid substance (derivation liquid dosage): 0.125:1 (12.5 μL), 0.25:1 (25 μL), 0.5:1 (50 μL), 1:1 (100 μL), 1.5:1 (150 μL), 2:1 (200 μL), 2.5:1 (250 μL), 3:1 (300 μL), 3.5:1 (350 μL), 4:1 (400 μL). Other conditions were tested according to the conditions of Example 1, and the results are shown in Table 5. From the results in Table 5, it can be seen that the following amounts of derivatization reagents can ensure derivatization, but the response value of the reaction product is within a certain range and increases with the increase of the derivatization reaction reagent. When the ratio of the amount of the derivatization reagent to the organic acid substance reaches 3:1, the derivatization reaction tends to be complete. When it exceeds 3:1, the effect of the derivatization reaction decreases. Therefore, considering the reaction saturation degree, a ratio of the amount of the derivatization reagent to the organic acid substance of 3:1 is selected as the reaction amount, that is, the amount of the derivatization reagent used each time is preferably 300 μL.

[0125] Table 5

[0126]

[0127] Comparative Example 7 Groups of Sample Matrix Solvent Content Selection

[0128] Since the content of matrix solvent in the electronic atomization liquid accounts for more than 80%, it is necessary to evaluate the effect of matrix solvent on the derivatization of the target compound to be detected. The comparative example 7 groups analyzed and compared the derivatization effect of sample matrix with different contents on the target, and the target organic acid + 0.1g PG-VG mixed solution, target organic acid + 0.5g PG-VG mixed solution, and target organic acid + 1.0g PG-VG mixed solution were used as test samples. The other reaction conditions were tested according to the conditions of Example 1, and the results are shown in Table 6. It can be seen from the results in Table 6 that different contents of sample matrix have no significant effect on the derivatization reaction of volatile organic acids, indicating that organic acids are more susceptible to derivatization reactions than PG-VG mixed solutions. Therefore, considering the sensitivity of the detection limit and other conditions of the method, it is better to choose 1g as the sample weight.

[0129] Table 6

[0130]

[0131] Stability of the derivatized products in Comparative Example 8

[0132] Comparative Example 8 analyzed and compared the derivatization effects of different post-derivation stabilization times on the target organic acid; the organic acid derivative products were placed for a certain period of time: 0h, 24h, and 72h, and then tested according to the conditions of Example 1, and the results are shown in Table 7. From the results in Table 7, it can be seen that the organic acid derivative products are stable within 0-72h after preparation, so there is no need to place them for a period of time, and they can be prepared and used immediately for immediate testing.

[0133] Table 7

[0134]

[0135] Method validation example 1

[0136] 10 μL of each of the standard solutions of different concentrations prepared in step 2 of Example 1 was taken and added to the headspace bottle. The bottle cap was quickly pressed and mixed well. After standing for 60 seconds, the solution was placed in the headspace sampler and detected by headspace-gas chromatography-mass spectrometry according to step 3 of Example 1.

[0137] The quantitative ion chromatographic peak area ratio of the 13 volatile organic acid components and the internal standard is used as the ordinate (Y axis), and the concentration ratio of the corresponding volatile organic acid components and the internal standard is used as the abscissa (X axis). The regression equations and correlation coefficients of the 13 volatile organic acid components are obtained, as shown in Table 8 below. As can be seen from Table 8, the linear relationship of the standard curves of the 13 volatile organic acid components is good, and the correlation coefficient R 2 ≥0.990.

[0138] In addition, the limit of detection (LOD) refers to the concentration of the substance to be measured corresponding to the detection limit of the method according to the detection method. The limit of quantitation (LOQ) refers to the concentration of the substance to be measured corresponding to the lower limit of quantitation according to the detection method. In chromatographic analysis, the EPASW-846 standard can be referred to, and multiple groups (n≥7) of low-concentration spiked samples can be determined. The standard deviation method is used to define the limit of detection and the limit of quantification, MDL=3.14SD (n=7), MQL=10SD (n=7). Specifically, the standard solution with the lowest concentration was repeated 7 times for HS-GC / MS parallel detection and analysis, with the concentration corresponding to 3 times the standard deviation as the detection limit and the concentration corresponding to 10 times the standard deviation as the quantification limit. The detection limits of 13 volatile organic acid components were between 0.4-5.7 mg / kg, and the quantification limits of 13 volatile organic acid components were between 1.3-18.1 mg / kg. The specific results are shown in Table 9. It can be seen from Table 9 that it has a high sensitivity.

[0139] Table 8

[0140]

[0141] Table 9

[0142]

[0143] Method Verification Example 2

[0144] One electronic atomization liquid sample was selected, and six parallel measurements were performed according to the steps in Example 1, and the contents of 13 volatile organic acids in the sample were calculated respectively. The results are shown in Table 10. As can be seen from Table 10, this method has good precision.

[0145] Table 10

[0146]

[0147] Method Verification Example 3

[0148] Two electronic atomization liquid samples of different flavors were selected, and three concentration levels of low, medium and high were added to the standard curve, and single injection was performed according to the steps in Example 1, and the recovery rates of 13 volatile organic acids in the samples were calculated respectively. The results are shown in Table 11. As can be seen from Table 11, this method has good accuracy.

[0149] Table 11

[0150]

[0151] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for rapid determination of volatile organic acids in electronic atomization liquid, comprising: The electronic atomized liquid is respectively added with a derivatization reagent, an internal standard solution, and a solvent for extraction, and the obtained sample test liquid is subjected to a derivatization reaction and then measured by gas chromatography-mass spectrometry to determine the content of at least one volatile organic acid component in the test liquid.

2. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 1, characterized in that: The volatile organic acid is selected from at least one of acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid or dodecanoic acid; preferably, the volatile organic acid includes acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid and dodecanoic acid.

3. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 1, characterized in that: Includes any one or more of the following conditions: A1) the derivatization agent is selected from one of a methyl esterification agent or a non-methyl esterification agent; preferably, the derivatization agent is selected from at least one of tetramethylammonium hydroxide, trimethylphenylammonium hydroxide, trimethylsulfur hydroxide, tetramethylammonium acetate, tetraethylammonium hydroxide or tetrabutylammonium hydroxide; A2) the internal standard solution is a methanol solution of deuterated pentanoic acid; preferably, the concentration of deuterated pentanoic acid in the internal standard solution is 500-1000 mg / L; A3) the solvent is selected from at least one of methanol, ethanol, isopropanol and ethyl acetate; A4) the ratio of the added mass of the electronic atomization liquid to the added volume of the derivatization reagent is 0.1-1:1.25-400, g / μL; A5) the ratio of the added mass of the electronic atomization liquid to the added volume of the internal standard solution is 0.1-1:1.25-400, g / μL; A6) The ratio of the added mass of the electronic atomization liquid to the added volume of the solvent is 0.1-1:1-100, g / mL; A7) The extraction is selected from one of ultrasonic extraction, oscillation extraction or microwave extraction; preferably, the extraction is oscillation extraction, and the oscillation extraction time is 5-15 min.

4. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 1, characterized in that: The sample liquid to be tested is subjected to a derivatization reaction and then subjected to a gas chromatography-mass spectrometry determination, comprising the following steps: 1) preparing a standard solution: providing a standard solution, wherein the standard solution comprises at least one selected from the group consisting of acetic acid, propionic acid, isobutyric acid, butyric acid, 2-methylbutyric acid, isovaleric acid, valeric acid, 2-methylvaleric acid, hexanoic acid, heptanoic acid, octanoic acid, decanoic acid, and dodecanoic acid, and a blank matrix reagent, a derivatization reagent, an internal standard solution, and a solvent; 2) Determination: The sample solution and the standard solution obtained in step 1) are subjected to derivatization reaction injection respectively, and then subjected to gas chromatography-mass spectrometry determination, and the retention time is compared for qualitative determination, and the internal standard curve method is used for quantitative determination to determine the content of at least one of the 13 volatile organic acid components in the solution.

5. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 4, characterized in that: In step 1), any one or more of the following conditions are included: B1) the blank matrix reagent is a mixed solution of propylene glycol PG and vegetable glycerin VG, and the mass ratio of propylene glycol to vegetable glycerin in the PG-VG mixed solution is 1:1; B2) the derivatization agent is selected from one of a methyl esterification agent or a non-methyl esterification agent; preferably, the derivatization agent is selected from at least one of tetramethylammonium hydroxide, trimethylphenylammonium hydroxide, trimethylsulfur hydroxide, tetramethylammonium acetate, tetraethylammonium hydroxide or tetrabutylammonium hydroxide; B3) the internal standard solution is a methanol solution of deuterated pentanoic acid; preferably, the concentration of deuterated pentanoic acid in the internal standard solution is 500-1000 mg / L; B4) the solvent is selected from at least one of methanol, ethanol, isopropanol and ethyl acetate; B5) The standard solution is obtained by adding a standard of at least one of the 13 volatile organic acids to a solvent to obtain a mixed stock solution, and then adding a blank matrix reagent, a derivatization reagent, and an internal standard solution after gradual dilution, and then adding a solvent to dissolve and fix the volume.

6. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 5, characterized in that: B5) includes any one or more of the following conditions: B51) The concentration of each volatile organic acid component in the standard solution is 5-100 mg / L; B52) the concentration of the blank matrix reagent in the standard solution is 0.1-2 g / 10 mL; B53) The concentration of the derivatization reagent in the standard solution is 12.5-400 μL / 10 mL; B54) The concentration of the internal standard solution in the standard solution is 12.5-400 μL / 10 mL.

7. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 4, characterized in that: In step 2), any one or more of the following conditions are included: C1) In the derivatization reaction, the injection volume of the sample solution is 1-20 μL; C2) The derivatization reaction injection mode is selected from one of headspace thermal assisted derivatization injection and injection port online derivatization injection; preferably, the derivatization reaction is headspace thermal assisted derivatization injection.

8. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 7, characterized in that: In item C2), the headspace thermal assisted derivatization method includes any one or more of the following conditions: C21) The reaction temperature of the heating box is 60-240°C; C22) The temperature of the quantitative loop is 220-240°C; C23) The transmission line temperature is 230-250°C; C24) injection time is 0.1-1min; C25) the equilibration time is 0.5-30min; the derivatization reaction time is 0.5-30min; the equilibration and derivatization reactions are carried out simultaneously; C26) Filling pressure is 10-30psi.

9. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 4, characterized in that: In step 2), the gas chromatography measurement conditions include any one or more of the following conditions: D1) Chromatographic column: selected from one of DB-5 capillary chromatographic column, DB-624 capillary chromatographic column or DB-WAX capillary chromatographic column; preferably, the chromatographic column is a DB-624 capillary chromatographic column, with a length of 30 m× an inner diameter of 250 μm× a film thickness of 1.4 μm; D2) injection port temperature is 240-260°C; D3) The transmission line temperature is 240-260°C; D4) The carrier gas is high-purity helium, with a carrier gas purity of ≥99.999%; D5) carrier gas flow rate is 0.5-2.0 mL / min; D6) split ratio is 10-50:1; D7) The temperature program of gas chromatography is as follows: initial temperature 30-50°C, maintained for 2-4 minutes; increased to 80-100°C at a rate of 4-6°C / min; then increased to 140-160°C at a rate of 9-11°C / min; then increased to 240-260°C at a rate of 19-21°C / min, maintained for 11-13 minutes.

10. The method for rapid determination of volatile organic acids in electronic atomized liquid according to claim 4, characterized in that: In step 2), the mass spectrometry measurement conditions include any one or more of the following conditions: E1) The ionization method is electron bombardment EI ion source; E2) ionization energy is 70 eV; E3) The ion source temperature is 150°C; E4) The temperature of the quadrupole is 230°C; E5) solvent delay is 0-6min; E6) The scanning modes include full scan Scan and selected ion monitoring SIM; preferably, the scanning range of the full scan mode is 29-350 m / z.

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