Method for detecting content of cyclosiloxane in atomized liquid and application of method

Abstract

The invention relates to a method for detecting the content of cyclosiloxane in atomized liquid and application of the method. The detection method comprises the following steps: preparing an aqueous solution containing atomized liquid and water-soluble inorganic salt, and detecting the aqueous solution by adopting a headspace gas chromatograph-mass spectrometer. The method is high in sensitivity, good in accuracy and good in reproducibility, can efficiently and accurately detect the content of cyclosiloxane in the atomized liquid, and can be used for testing the migration amount of trace cyclosiloxane in the atomized liquid of the electronic cigarette. The invention further provides application of the detection method in detection of the migration amount of cyclosiloxane in the atomized liquid of the electronic cigarette or quality detection of the electronic cigarette.

Description

Technical Field

[0001] The present application relates to the technical field of analytical chemistry, and in particular to a method for detecting the content of cyclosiloxane in atomized liquid and an application thereof. Background Art

[0002] Electronic cigarette cartridges are usually sealed with silicone to prevent leakage of atomized liquid. Cyclosiloxanes, such as octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), are important intermediates for the preparation of silicone. During the contact between silicone and atomized liquid, cyclosiloxanes may migrate into the atomized liquid. Studies have found that cyclosiloxanes such as D4, D5, and D6 are toxic to the human nervous, immune, and reproductive systems, and are carcinogenic and mutagenic. These three cyclosiloxanes have been included in the list of substances of very high concern (SVHCs) by the European Chemicals Agency (ECHA). The European Commission (EU) Amendment No. 2018 / 35 stipulates that the content of D4 and D5 in water-washable cosmetics must be less than 0.1%.

[0003] Electronic cigarette atomizers generally use alcohol organic solvents (such as propylene glycol, ethanol, etc.), and also contain flavors and fragrances such as organic acids, alcohols, esters, and aldehydes. These chemical components may increase the risk of cyclosiloxane dissolution and cause safety hazards. However, the migration amount of cyclosiloxane in electronic cigarette atomizers is very low, usually far below 1ppm. The existing detection methods for the residual amount of cyclosiloxane in products such as silica gel and textiles have low detection sensitivity and cannot meet the detection requirements of trace cyclosiloxane in electronic cigarette atomizers. In addition, this method requires the use of a large amount of organic solvents for extraction, which is harmful to the environment and health.

[0004] Therefore, it is of great significance to develop an efficient and accurate method for determining the content of cyclosiloxane in e-cigarette aerosols. Summary of the invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention provides a method for detecting the content of cyclosiloxane in atomized liquid, which has high sensitivity, good accuracy and good reproducibility, and can efficiently and accurately detect the content of cyclosiloxane, such as D4, D5 and D6, in atomized liquid.

[0006] The present invention also proposes the application of the method for detecting the content of cyclosiloxane in the atomized liquid.

[0007] Specifically, the embodiment of the first aspect of the present invention relates to a method for detecting the content of cyclosiloxane in an atomized liquid, comprising the steps of:

[0008] preparing an aqueous solution containing an atomized liquid and a water-soluble inorganic salt;

[0009] The aqueous solution is detected by using a headspace gas chromatography-mass spectrometer, wherein the heating equilibrium temperature of the headspace gas chromatography is 70-90°C.

[0010] The method for detecting the content of cyclosiloxane in the atomized liquid according to the first aspect of the present invention has at least the following beneficial effects:

[0011] The present invention adopts a headspace gas chromatography-mass spectrometry method to solve the problem that the cyclosiloxane content in the existing electronic cigarette aerosol liquid is low and cannot be measured.

[0012] The heating equilibrium temperature of the headspace gas chromatography is set at 70-90°C, and water-soluble inorganic salts are used to balance the distribution coefficient of cyclosiloxane, which promotes the diffusion of cyclosiloxane from the liquid phase into the gas phase and improves the detection sensitivity. Since the equilibrium temperature is much lower than the boiling point of water, the interference of water and the influence of water on the column efficiency of the chromatographic column are reduced, and the detection accuracy is improved.

[0013] Compared with the existing headspace gas chromatography, the present invention converts the atomized liquid into an aqueous solution for detection, does not need to use a large amount of organic solvents, adopts headspace direct sampling analysis, has a high recovery rate, and is simple and safe to operate.

[0014] This method has the advantages of good reproducibility, high sensitivity and high accuracy. The detection limit of D4, D5 and D6 in the atomized liquid is as low as 5.00 μg / kg-12.5 μg / kg (10 -2 -10 -3 ppm level, up to ppb level), it has a good linear relationship in the detection mass range of 50.0ng-500ng, the linear correlation coefficient is greater than 0.999, the recovery rates of three cyclosiloxanes D4, D5 and D6 in the atomized liquid are between 85.7% and 110%, and the repeatability experiment RSD is between 0.3% and 1.9%, which can be used for accurate testing of trace cyclosiloxane content in the atomized liquid.

[0015] According to some embodiments of the first aspect of the present invention, the water-soluble inorganic salt is selected from water-soluble sulfates or chlorides, which can play a good role in balancing the gas-liquid partition coefficient of cyclosiloxane, reducing the detection limit and improving the sensitivity. For example, the water-soluble inorganic salt can be sodium chloride, potassium chloride, sodium sulfate, ammonium sulfate, magnesium sulfate, etc.

[0016] According to some embodiments of the first aspect of the present invention, in the aqueous solution, the concentration of the water-soluble inorganic salt is the saturated solubility of the water-soluble inorganic salt in water. The saturated aqueous solution of the water-soluble inorganic salt can better balance the gas-liquid partition coefficient of the cyclosiloxane, further reduce the detection limit, and improve the sensitivity.

[0017] According to some embodiments of the first aspect of the present invention, an aqueous solution containing an atomized liquid and a water-soluble inorganic salt is prepared by: dissolving the water-soluble inorganic salt in water to prepare a water-soluble inorganic salt solution; and dissolving the atomized liquid in the water-soluble inorganic salt solution.

[0018] According to some embodiments of the first aspect of the present invention, the heating equilibrium temperature of the headspace gas chromatography is 80-90° C. If the heating equilibrium temperature is too low, it is not conducive to the detection of cyclosiloxanes, and if the heating equilibrium temperature is too high, it will accelerate the volatilization of water and increase interference and headspace bottle pressure.

[0019] According to some embodiments of the first aspect of the present invention, the heating equilibrium time of the headspace gas chromatography is not less than 20 min.

[0020] According to some embodiments of the first aspect of the present invention, the heating equilibrium time of the headspace gas chromatography is 20-60 minutes. Prolonging the heating equilibrium time appropriately is conducive to the escape of cyclosiloxane, but if the heating equilibrium time is too long, the improvement in the detection effect is not obvious, but it is not conducive to the improvement of detection efficiency.

[0021] According to some embodiments of the first aspect of the present invention, the heating equilibrium time of the headspace gas chromatography is 30-40 min.

[0022] According to some embodiments of the first aspect of the present invention, the chromatographic column of the headspace gas chromatography is selected from HP-5MS, HP-5, DB-5, DB-5MS, OV-5, BP-5, SE-52, SE-54 or Rtx-5, all of which can achieve good detection effects.

[0023] The present invention does not particularly limit the specifications of the chromatographic column, and commercially available conventional sizes can be selected. For example, the length of the chromatographic column can be 25-35m, such as a column length of 30m; the inner diameter of the chromatographic column can be 300-320μm, such as a column inner diameter of 320μm.

[0024] According to some embodiments of the first aspect of the present invention, the carrier gas of the headspace gas chromatography is helium, which can achieve better separation.

[0025] According to some embodiments of the first aspect of the present invention, the split ratio of the headspace gas chromatography is (10-50): 1. Within this split ratio range, the peak shape can be improved and the detection accuracy can be better guaranteed.

[0026] According to some embodiments of the first aspect of the present invention, the heating conditions of the headspace gas chromatography are: initial column temperature of 40-80°C, maximum column temperature of 250-300°C, and heating rate of 5-25°C / min.

[0027] The heating method can be gradient heating or uniform heating. Among them, gradient heating is more conducive to ensuring the separation degree, especially in the separation and detection of multiple components.

[0028] According to some embodiments of the first aspect of the present invention, the initial column temperature of the headspace gas chromatography is 40-60°C.

[0029] According to some embodiments of the first aspect of the present invention, the heating conditions of the headspace gas chromatography are:

[0030] The initial column temperature was 40-60°C and maintained for 0-5 min;

[0031] Raise the temperature to 150-220°C at a rate of 5-20°C / min and maintain for 0-5min;

[0032] Raise the temperature to 250-300°C at a rate of 10-25°C / min and maintain for 0-5min.

[0033] According to some embodiments of the first aspect of the present invention, the injection port temperature of the headspace gas chromatography is 200-280°C.

[0034] According to some embodiments of the first aspect of the present invention, the injection port temperature of the headspace gas chromatography is 220-250°C.

[0035] According to some embodiments of the first aspect of the present invention, the ion source of the mass spectrometer is an electron impact ionization source (EI).

[0036] According to some embodiments of the first aspect of the present invention, the interface temperature of the mass spectrometer is 250-280°C.

[0037] According to some embodiments of the first aspect of the present invention, the interface temperature of the mass spectrometer is 270-280°C.

[0038] It should be noted that the present invention has no special requirements on parameters such as the injection port temperature, carrier gas flow rate, sampling needle temperature (which may be 5-15°C higher than the equilibrium temperature) of headspace gas chromatography, and the detection conditions of mass spectrometry, which can be reasonably determined based on actual experience and detection requirements.

[0039] During the detection process, in order to eliminate the influence of the solvent on the mass spectrometer, a solvent delay time is usually set, that is, after the gas chromatograph flows out for a period of time (mainly the solvent comes out at the beginning), the mass spectrometer is turned on to measure the mass spectrum. The solvent delay time can be controlled at about 2 minutes.

[0040] According to some embodiments of the first aspect of the present invention, the scanning mode of the mass spectrometer is an ion scanning mode (SIM).

[0041] According to some embodiments of the first aspect of the present invention, the mass spectrometer selects the SIM scanning mode, and the charge-to-mass ratios of the monitored ions are: 73, 147, 207, 221, 267, 271, 295, 341, 255, and 429, which can well meet the detection requirements for D4, D5, and D6.

[0042] According to some embodiments of the first aspect of the present invention, the quantitative analysis is performed using an external standard method.

[0043] It can be understood that the external standard method is to first prepare standard solutions of target compounds (test components, such as D4, D5, D6) of different concentrations, inject the standard solutions for testing, and draw a standard curve based on the corresponding relationship between the peak area (or peak height) and concentration of the target compound. Then, inject the sample to be tested under the same test conditions, and obtain the concentration of the target compound in the sample to be tested based on the peak area (or peak height) of the target compound in the sample to be tested and the corresponding standard curve.

[0044] Among them, in the standard solution, the solvent is selected as a good solvent that does not interfere with the peak of the target compound. For example, in this method, the solvent can be methanol, ethyl acetate, n-hexane, etc.

[0045] According to some embodiments of the first aspect of the present invention, the atomized liquid is an electronic cigarette atomized liquid.

[0046] The implementation of the second aspect of the present invention relates to the application of the method for detecting the content of cyclosiloxane in atomized liquid to detecting the migration amount of cyclosiloxane in the atomized liquid of electronic cigarette.

[0047] The detection limit of this method for D4, D5, and D6 in the atomized liquid is as low as 5.00 μg / kg-12.5 μg / kg (10 -2 -10 - 3 ppm level, up to ppb level), it has a good linear relationship in the detection mass range of 50.0ng-500ng, the linear correlation coefficient is greater than 0.999, the recovery rates of the three cyclosiloxanes D4, D5 and D6 in the atomized liquid are between 85.7%-110%, and the RSD of the repeatability experiment is between 0.3%-1.9%. It has the advantages of good specificity, high sensitivity, good accuracy and good reproducibility, and can efficiently and accurately detect cyclosiloxanes in the atomized liquid. It can be used for the precise test of the migration amount of trace cyclosiloxanes in the atomized liquid of electronic cigarettes, filling the technical gap in the electronic cigarette industry that is difficult to detect the migration amount of cyclosiloxanes in the atomized liquid.

[0048] According to some embodiments of the first aspect of the present invention, the electronic cigarette atomizer liquid is in continuous contact with the silica gel for more than 1 day before detection. Specifically, the electronic cigarette atomizer liquid can be placed in an atomizer device (smoke bomb) sealed with silica gel for more than 1 day, so that the electronic cigarette atomizer liquid is in continuous contact with the silica gel to dissolve the cyclosiloxane in the silica gel.

[0049] According to some embodiments of the first aspect of the present invention, the electronic cigarette atomizer liquid is in continuous contact with silica gel for 1-30 days before detection.

[0050] According to some embodiments of the first aspect of the present invention, the migration amount of cyclosiloxane in the electronic cigarette atomizer liquid is ≤1 ppm.

[0051] According to some embodiments of the first aspect of the present invention, the migration amount of cyclosiloxane in the electronic cigarette atomizer liquid is ≤0.5 ppm.

[0052] According to some embodiments of the first aspect of the present invention, the migration amount of cyclosiloxane in the electronic cigarette atomizer liquid is ≤0.3 ppm.

[0053] The implementation of the third aspect of the present invention relates to the application of the method for detecting the content of cyclosiloxane in the atomized liquid in the quality inspection of electronic cigarettes.

[0054] The detection limit of this method for D4, D5, and D6 in the atomized liquid is as low as 5.00 μg / kg-12.5 μg / kg (10 -2 -10 - 3 ppm level, up to ppb level), it has a good linear relationship in the detection mass range of 50.0ng-500ng, the linear correlation coefficient is greater than 0.999, the recovery rates of three cyclosiloxanes D4, D5 and D6 in the atomized liquid are between 85.7%-110%, and the repeatability experiment RSD is between 0.3%-1.9%. It has the advantages of good specificity, high sensitivity, good accuracy and good reproducibility. It can accurately test the migration amount of trace cyclosiloxanes in the atomized liquid of electronic cigarettes, and can be used for the quality detection of electronic cigarettes to better ensure the safety of electronic cigarette products.

[0055] Herein, the term "trace amount" means a content not exceeding 1 ppm.

[0056] Atomizer liquid refers to the electronic atomizer liquid used with an atomizer device, specifically, electronic cigarette atomizer liquid (commonly known as electronic cigarette oil or electronic cigarette liquid). The main ingredients of electronic cigarette oil on the market are: glycerin, 1,2-propylene glycol, nicotine, tobacco flavors, etc., and may also contain ethanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is the chromatogram of the mixed standard series solution in Example 1.

[0058] Figure 2 It is the standard curve of D4 in Example 1.

[0059] Figure 3 It is the standard curve of D5 in Example 1.

[0060] Figure 4 It is the standard curve of D6 in Example 1.

[0061] Figure 5 It is the chromatogram of the atomized liquid to be tested in Example 1.

[0062] Figure 6 It is the chromatogram of the blank nebulized liquid in Example 1. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0064] Unless otherwise specified, all reagents used in this example were chromatographically pure and the weighing accuracy of the sample was 0.1 mg.

[0065] Electronic cigarette cartridges (sealing plugs: made of silicone) and atomizing liquid (electronic cigarette oil) are both common types on the market.

[0066] 1. Related experimental equipment and materials

[0067] Headspace sampler: Platinum Elmo TurboMatrix 40;

[0068] Gas chromatograph: Agilent 7890B; Chromatographic column: HP-5MS, column length 30m, column inner diameter 320μm;

[0069] Mass spectrometer: Agilent 5977B.

[0070] 2. Solution Preparation

[0071] Stock solution: Accurately weigh 0.500g of D4, D5, and D6 standards respectively into a beaker, dilute with methanol, transfer to a 100mL volumetric flask, and dilute to the mark with methanol to prepare a 5.00mg / mL stock solution.

[0072] Mixed standard intermediate solution: Take 1.00 mL of stock solution into 10 mL volumetric flasks respectively, dilute to the mark with methanol, and prepare a mixed standard intermediate solution with a single standard (D4 / D5 / D6) concentration of 500 mg / L.

[0073] Example 1

[0074] This embodiment provides a method for detecting the content of cyclosiloxane in atomized liquid, which uses a headspace gas chromatography-mass spectrometer for detection.

[0075] 1.1 Test conditions

[0076] Headspace sampler conditions: heating equilibrium temperature 85°C; heating equilibrium time 30 min; sampling needle temperature 100°C; transfer line temperature 120°C; injection time 0.2 min; needle withdrawal time 0.4 min.

[0077] Gas chromatography conditions: injection port temperature of 250°C; split ratio of 20:1; injection volume of 1 μL; programmed temperature: initial column temperature of 60°C, maintained for 2 min, then heated to 150°C at a rate of 10°C / min, maintained for 2 min, then heated to 300°C at a rate of 25°C / min, maintained for 2 min; carrier gas was helium at a flow rate of 3 mL / min.

[0078] Mass spectrometry conditions: interface temperature 280°C; ion source temperature 230°C; solvent delay 2 min; scan mode SIM was selected, and the monitored ions m / z were: 73, 147, 207, 221, 267, 271, 295, 341, 255, 429.

[0079] 1.2 Reagent preparation

[0080] Take 500 mL of ultrapure water, add 180 g of sodium chloride, dissolve and mix well to prepare a saturated sodium chloride solution with a mass fraction of 36%.

[0081] 1.3 Sample pretreatment

[0082] Take a certain amount of atomizing liquid and divide it into two parts. One part is put into the electronic cigarette cartridge (referred to as atomizing liquid W1), and the other part is not in contact with the silica gel (referred to as atomizing liquid W2). They are placed in the same environment for 30 days.

[0083] 1.4 Standard curve drawing

[0084] Mixed standard solution: measure 100 μL, 200 μL, 500 μL, 800 μL, and 1000 μL of the mixed standard intermediate solution into a 10 mL volumetric flask, dilute to volume with methanol, and obtain mixed standard solutions with single standard (D4 / D5 / D6) concentrations of 5.0 mg / L, 10.0 mg / L, 25.0 mg / L, 40.0 mg / L, and 50.0 mg / L, respectively. Record them as S1, S2, S3, S4, and S5, respectively.

[0085] Accurately weigh 1.000g of atomized liquid W2 into 5 dedicated headspace bottles, add 10mL of saturated sodium chloride solution and 10.0μL of mixed standard solutions S1, S2, S3, S4, S5, and prepare mixed standard series solutions with single target compound (D4 / D5 / D6) contents of 50ng, 100ng, 250ng, 400ng, and 500ng. According to the set detection conditions, the mixed standard series solutions of different concentrations were injected and analyzed in sequence to obtain the chromatograms of the mixed standard series solutions, see Figure 1 (The content of D4, D5 and D6 are all 250ng) Figure 1 The upper figure is in full ion scanning mode, and the lower figure is in SIM mode). Draw a standard curve of peak area relative to the mass content of the target compound. The standard curves of D4, D5, and D6 are as follows: Figure 2-Figure 4 It can be seen that D4, D5, and D6 have a good linear relationship in the range of 50.0ng-500ng, and the linear correlation coefficient is greater than 0.999.

[0086] 1.5 Determination of cyclosiloxane content in the atomized liquid to be tested

[0087] Accurately weigh 1.000g of atomized liquid W1 (atomized liquid to be tested) into a dedicated headspace bottle, add 10mL of saturated sodium chloride solution and 10.0μL of methanol. Inject and analyze under the same detection conditions as the mixed standard series solution to obtain the chromatogram of the atomized liquid to be tested, see Figure 5 ( Figure 5 The upper figure is in full ion scan mode, and the lower figure is in SIM mode).

[0088] According to the peak area of ​​each target compound in the atomized liquid to be tested and the corresponding standard curve, the mass m0 of the corresponding target compound is obtained.

[0089] The cyclosiloxane content in the atomized liquid to be tested is calculated according to the following formula:

[0090] X=m0 / m

[0091] Where: X represents the content of cyclosiloxane in the atomized liquid to be tested, in μg / Kg;

[0092] m0, unit is ng;

[0093] m represents the mass of the atomized liquid to be tested, in g.

[0094] The test results are as follows: the contents of three cyclosiloxanes D4, D5 and D6 in the tested atomized liquid are 203 μg / Kg, 263 μg / Kg and 238 μg / Kg respectively.

[0095] 1.6 Specificity determination

[0096] Accurately weigh 1.000g of nebulized liquid W2 (blank nebulized liquid) into a dedicated headspace bottle, add 10mL of saturated sodium chloride solution and 10.0μL of methanol. Inject and analyze under the same detection conditions as the mixed standard series solutions to obtain the chromatogram of the blank nebulized liquid, see Figure 6 ( Figure 6 (The upper figure is the full ion scan mode, and the lower figure is the SIM mode). It can be seen that the blank nebulized liquid has no interference with the chromatographic peak of the target compound.

[0097] 1.7 Detection limit determination

[0098] Take 1.00mL of the mixed standard intermediate solution into a 10mL volumetric flask, dilute to volume with methanol, and prepare a mixed standard stock solution with a single standard (D4 / D5 / D6) concentration of 50mg / L. Take 50μL, 100μL, 150μL, 200μL, 250μL, 300μL, 350μL, and 400μL of the mixed standard stock solution into a 10mL volumetric flask, dilute to volume with methanol, and obtain mixed standard solutions with single standard concentrations of 0.25mg / L, 0.50mg / L, 0.75mg / L, 1.00mg / L, 1.25mg / L, 1.50mg / L, 1.75mg / L, and 2.00mg / L, respectively, and record them as N1, N2, N3, N4, N5, N6, N7, and N8.

[0099] Accurately weigh 1.000g of atomized liquid W2 into 8 dedicated headspace bottles, add 10mL of saturated sodium chloride solution and 10.0μL of mixed standard solutions N1, N2, N3, N4, N5, N6, N7, N8, and prepare a series of low-concentration samples with single target compound (D4 / D5 / D6) content of 2.5ng, 5.0ng, 7.5ng, 10.0ng, 12.5ng, 15.0ng, 17.5ng, 20.0ng. Inject and analyze under the same detection conditions as the mixed standard series solution. When the signal-to-noise ratio of the target chromatographic peak is 3:1, this concentration is the method detection limit.

[0100] In this embodiment, the detection limits of D4, D5 and D6 are 5.00 μg / Kg, 10 μg / Kg and 12.5 μg / Kg respectively, which have high sensitivity and can well meet the detection requirements of trace cyclosiloxanes in the atomized liquid.

[0101] 1.8 Recovery and repeatability test

[0102] 1.000 g of blank atomized liquid W2 was accurately weighed, and the spiked recovery experiment of 3 factors and 3 levels of low, medium and high was carried out according to the spiked amount in Table 1. The results are shown in Table 1. It can be seen that in this embodiment, the recovery rates of D4, D5 and D6 are between 87.5% and 110%, and the recovery rate RSD of the repeatability experiment is between 1.05% and 5.60%, which has the advantages of good accuracy and good reproducibility.

[0103] Table 1 Recovery and repeatability test results of Example 1

[0104]

[0105]

[0106] Example 2

[0107] This embodiment provides a method for detecting the content of cyclosiloxane in atomized liquid. Compared with Embodiment 1, the difference is that:

[0108] In the reagent preparation stage in Section 1.2, replace sodium chloride with an equal amount of sodium sulfate to prepare a saturated sodium sulfate solution with a mass fraction of 36%; and replace the saturated sodium chloride solution in the subsequent steps with an equal amount of saturated sodium sulfate solution; the rest remains unchanged.

[0109] The test results are as follows: the contents of three cyclosiloxanes D4, D5 and D6 in the tested atomized liquid are 199 μg / Kg, 265 μg / Kg and 229 μg / Kg respectively.

[0110] Example 3

[0111] This embodiment provides a method for detecting the content of cyclosiloxane in atomized liquid. Compared with Embodiment 1, the difference is that:

[0112] In the test conditions in section 1.1, change the heating equilibrium temperature to 90°C; the rest remain unchanged.

[0113] The test results are as follows: the contents of three cyclosiloxanes D4, D5 and D6 in the tested atomized liquid are 205 μg / Kg, 261 μg / Kg and 241 μg / Kg respectively.

[0114] Comparative Example 1 (without adding inorganic salt)

[0115] This embodiment provides a method for detecting the content of cyclosiloxane in an atomized liquid. Compared with Embodiment 1, the difference is that in Sections 1.4, 1.5, 1.6, and 1.7, 10 mL of saturated sodium chloride solution is replaced with ultrapure water, and the other conditions remain unchanged.

[0116] In this embodiment, the detection limits of D4, D5 and D6 are 7.50 μg / Kg, 12.5 μg / Kg and 15.0 μg / Kg respectively.

[0117] The test results are as follows: the contents of three cyclosiloxanes D4, D5 and D6 in the tested atomized liquid are 202 μg / Kg, 261 μg / Kg and 239 μg / Kg respectively.

Claims

1. A method for detecting the content of cyclosiloxane in atomized liquid, characterized in that: Includes steps: preparing an aqueous solution containing an atomized liquid and a water-soluble inorganic salt; The aqueous solution is detected by using a headspace gas chromatography-mass spectrometer, wherein the heating equilibrium temperature of the headspace gas chromatography is 70-90°C.

2. The method for detecting the content of cyclosiloxane in the atomized liquid according to claim 1, characterized in that: The water-soluble inorganic salt is selected from water-soluble sulfate or chloride salt.

3. The method for detecting the content of cyclosiloxane in the atomized liquid according to claim 1 or 2, characterized in that: In the aqueous solution, the concentration of the water-soluble inorganic salt is the saturated solubility of the water-soluble inorganic salt in water.

4. The method for detecting the content of cyclosiloxane in the atomized liquid according to claim 1, characterized in that: The atomized liquid is an electronic cigarette atomized liquid.

5. The method for detecting the content of cyclosiloxane in the atomized liquid according to claim 1, characterized in that: The heating equilibrium temperature of the headspace gas chromatography is 80-90°C.

6. The method for detecting the content of cyclosiloxane in the atomized liquid according to claim 1 or 5, characterized in that: The heating equilibrium time of the headspace gas chromatography is not less than 20 minutes.

7. The method for detecting the content of cyclosiloxane in atomized liquid according to claim 1, characterized in that: The chromatographic column of the headspace gas chromatography is selected from HP-5MS, HP-5, DB-5, DB-5MS, OV-5, BP-5, SE-52, SE-54 or Rtx-5.

8. The method for detecting the content of cyclosiloxane in atomized liquid according to claim 1, characterized in that: The split ratio of the headspace gas chromatography is (10-50):

1.

9. The method for detecting the content of cyclosiloxane in atomized liquid according to claim 1, characterized in that: The heating conditions of the headspace gas chromatography are: The initial column temperature was 40-60°C and maintained for 0-5 min; Raise the temperature to 150-220°C at a rate of 5-20°C / min and maintain for 0-5min; Raise the temperature to 280-300°C at a rate of 10-25°C / min and maintain for 0-5min.

10. The method for detecting the content of cyclosiloxane in atomized liquid according to claim 1, characterized in that: The scanning mode of the mass spectrometer is SIM, and the charge-to-mass ratios of the monitored ions are: 73, 147, 207, 221, 267, 271, 295, 341, 255, and 429.

11. Use of the method for detecting the content of cyclosiloxane in atomized liquid according to any one of claims 1 to 10 in detecting the migration amount of cyclosiloxane in atomized liquid of electronic cigarettes or in quality detection of electronic cigarettes.

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