阅读说明：本技术 一种电子烟气溶胶中凉味剂含量的测定方法 (Method for measuring content of cooling agent in electronic smoke sol ) 是由 邹军 邹阳 刘梅森 皮胜涛 于 2021-08-30 设计创作，主要内容包括：本申请涉及凉味剂含量测定的技术领域,更具体地说,它涉及一种电子烟气溶胶中凉味剂含量的测定方法。该一种电子烟气溶胶中凉味剂含量的测定方法采用吸烟机和滤片组合的方式捕集电子烟气溶胶中的凉味剂,再通过振荡萃取得到提取溶液,并使用气相色谱以及内标法定量分析提取溶液中待测物的含量,具有较高的灵敏度、精确度和准确度。本申请建立了较为完善的电子烟气溶胶中WS-3、WS-23等新型凉味剂含量的测定方法,填补了该领域的技术空白,对制定电子烟气溶胶中凉味剂含量的行业标准测定方法具有指导意义。(The application relates to the technical field of cooling agent content determination, in particular to a method for determining the content of a cooling agent in electronic smoke sol. According to the method for measuring the content of the cooling agent in the electronic smoke sol, the cooling agent in the electronic smoke sol is captured by adopting a combined mode of a smoking machine and a filter disc, an extraction solution is obtained through oscillation extraction, the content of an object to be measured in the extraction solution is quantitatively analyzed by using a gas chromatography and an internal standard method, and the method has high sensitivity, accuracy and precision. The method for determining the content of the novel cooling agents such as WS-3 and WS-23 in the electronic smoke sol is more complete, fills up the technical blank in the field, and has guiding significance for formulating an industry standard determination method of the content of the cooling agents in the electronic smoke sol.)

1. A method for measuring the content of a cooling agent in electronic smoke sol is characterized by comprising the following steps:

flue gas capture: adding test tobacco tar into the electronic cigarette atomizer, installing a filter disc between the smoking machine and the electronic cigarette atomizer, extracting electronic smoke sol generated by atomizing the tobacco tar by the electronic cigarette atomizer through the smoking machine, and trapping a substance to be tested in the electronic smoke sol by using the filter disc;

preparing an internal standard solution: preparing a quinoline standard solution by using quinoline as an internal standard substance and using an alcohol substance as a solvent;

extraction of a substance to be detected: putting the filter disc which captures the electronic smoke sol in the smoke collection into a quinoline standard solution, oscillating to extract an object to be detected, and filtering the oscillated solution to obtain an extraction solution;

preparing a standard solution: preparing a series of standard solutions containing WS-23 and WS-3, wherein the concentration of quinoline in the series of standard solutions is the same as that of the quinoline standard solution, and the solvent of the series of standard solutions is the alcohol substance;

and (3) analysis and calculation: and detecting the series of standard solutions and the extraction solution by using a gas chromatograph, and analyzing and calculating the content of the substance to be detected in the electronic smoke sol.

2. The method for measuring the content of the cooling agent in the electronic smoke sol as claimed in claim 1, wherein the smoking parameters of the smoking machine are set as follows: the suction capacity of each mouth is 55.0mL +/-0.3 mL, the suction duration of each mouth is 3.0s +/-0.1 s, and the suction interval time is 30.0s +/-0.5 s; the aerosol from each 20 puffs was captured on the same filter sheet.

3. The method for measuring the content of the cooling agent in the electronic cigarette sol according to claim 1, wherein the rough surface of the filter is used as the contact surface of the electronic cigarette sol in the cigarette trapping step.

4. The method for measuring the content of the cooling agent in the electronic smoke sol according to claim 1, wherein the alcohol is selected from any one of methanol, ethanol and isopropanol.

5. The method as claimed in claim 1, wherein the oscillation rate in the step of extracting the analyte is 200-300 r/min.

6. The method for measuring the content of the cooling agent in the electronic smoke sol according to claim 1, wherein the oscillation time in the step of extracting the substance to be measured is more than 30 min.

7. The method for measuring the content of the cooling agent in the electronic smoke sol according to claim 1, wherein the shaken solution is filtered by an organic filter membrane.

8. The method for measuring the content of the cooling agent in the electronic smoke sol as claimed in claim 1, wherein the split ratio of the gas chromatograph to the feed is 10:1-20: 1.

Technical Field

The application relates to the technical field of cooling agent content determination, in particular to a method for determining the content of a cooling agent in electronic smoke sol.

Background

The cooling agent is a general name of all chemical substances which can generate cooling effect and have weak medicinal properties, and is widely applied to foods such as chewing gum and beverage, and daily chemicals such as toothpaste, mouthwash, floral water and the like. The cooling agent is added into the electronic cigarette oil, so that the electronic cigarette has cool mouthfeel when being smoked. The most common cooling agent is menthol, but is not suitable for use in large quantities due to its strong odor and strong irritation to the skin, mucosal tissues and eyes. Therefore, novel cooling agents WS-3 (menthane carboxamide) and WS-23 (2-isopropyl-N, 2, 3-trimethyl butyramide) are frequently added into the electronic cigarette oil, and the WS-3 and the WS-23 can enable smokers to obtain mild, fresh, rich and lasting cool feeling.

However, the content of the cooling agent is too high, which may cause harm to human health, so that the content of the cooling agent in the electronic smoke sol inhaled by a human body needs to be controlled, and the determination of the content of the cooling agent in the electronic smoke sol is also beneficial to quality control and risk assessment. Regarding the measurement of the content of the cooling agent, the content of the cooling agent in food and daily chemicals is mainly measured by gas chromatography-mass spectrometry at home at present. However, the components of the electronic cigarette oil are complex, and new substances may be generated in the heating and atomizing process, which causes great interference to the determination of the content of the cooling agent in the electronic cigarette aerosol, and more accurate test data is difficult to obtain. The determination of the novel cooling agent in the electronic smoke sol is not reported in documents at present, and China has no formal national standard for detecting the cooling agent in the electronic smoke sol and limiting the dosage of the cooling agent, so that the establishment of a proper method for determining the content of the novel cooling agent such as WS-3, WS-23 and the like in the electronic smoke sol becomes a very urgent problem in the research of the cooling agent at present.

Disclosure of Invention

In order to measure the content of the cooling agent in the electronic smoke sol, the application provides a method for measuring the content of the cooling agent in the electronic smoke sol.

The method for measuring the content of the cooling agent in the electronic smoke sol adopts the following technical scheme: a method for measuring the content of a cooling agent in electronic smoke sol is characterized by comprising the following steps:

flue gas capture: adding test tobacco tar into the electronic cigarette atomizer, installing a filter disc between the smoking machine and the electronic cigarette atomizer, extracting electronic smoke sol generated by atomizing the tobacco tar by the electronic cigarette atomizer through the smoking machine, and trapping a substance to be tested in the electronic smoke sol by using the filter disc;

preparing an internal standard solution: preparing a quinoline standard solution by using quinoline as an internal standard substance and using an alcohol substance as a solvent;

extraction of a substance to be detected: putting the filter disc which captures the electronic smoke sol in the smoke collection into a quinoline standard solution, oscillating to extract an object to be detected, and filtering the oscillated solution to obtain an extraction solution;

preparing a standard solution: preparing a series of standard solutions containing WS-23 and WS-3, wherein the concentration of quinoline in the series of standard solutions is the same as that of the quinoline standard solution, and the solvent of the series of standard solutions is the alcohol substance;

and (3) analysis and calculation: and detecting the series of standard solutions and the extraction solution by using a gas chromatograph, and analyzing and calculating the content of the substance to be detected in the electronic smoke sol.

By adopting the technical scheme, the electronic smoke sol enters the smoking machine through the electronic smoke atomizer, the filter disc on the filter is contacted with the electronic smoke sol, the filter disc can fully absorb the cooling agent in the electronic smoke sol, then the cooling agent on the filter disc is extracted by using a quinoline standard solution, an extraction solution is obtained after filtering, finally a gas chromatograph is used for detecting the extraction solution, and the content of the substance to be detected in the extraction solution is analyzed and calculated by using an internal standard method; the signal peak of the internal standard substance quinoline is positioned between the signal peaks of WS-23 and WS-3, the chromatographic behaviors of quinoline and two substances to be measured are similar during detection and analysis, the influence of split discrimination on analysis is small, the signal peak of quinoline is obviously separated from the two substances to be measured, the peak area can be accurately calculated, and the measurement accuracy can be improved; the solubility of quinoline and a substance to be detected in the selected alcohol substance is good, and the separation degree of a solvent peak of the selected alcohol substance, a substance peak to be detected and a quinoline peak is good, so that the influence on an analysis result is small; the ordinate of the standard curve manufactured by the internal standard method is the ratio of peak areas of the object to be measured and the internal standard substance, so that errors caused by changes of operating conditions are eliminated to a certain extent during analysis, and the accuracy of the method is improved; the gas chromatography is used for analysis and detection, so that the method has the advantages of higher sensitivity and accuracy, high separation efficiency, high analysis speed and low cost.

Optionally, the smoking parameters of the smoking machine are set as: the suction capacity of each mouth is 55.0mL +/-0.3 mL, the suction duration of each mouth is 3.0s +/-0.1 s, and the suction interval time is 30.0s +/-0.5 s; the aerosol from each 20 puffs was captured on the same filter sheet.

By adopting the technical scheme, the fact that the smoking capacity is 55.0 mL/mouth, the smoking duration is 3 s/mouth, and the smoking frequency is 30s +/-0.5 s is determined to be more in line with the actual smoking situation, so that the real situation of a smoker smoking the electronic cigarette can be conveniently simulated, the detection and cognitive standards are unified, and the subsequent quality control and risk assessment are facilitated.

Optionally, in the flue gas trapping step, the rough surface of the filter disc is used as an electronic flue gas sol contact surface.

By adopting the technical scheme, the rough surface of the filter disc is contacted with the electronic cigarette aerosol, so that the contact area of the filter disc and the electronic cigarette aerosol is increased, and the filter disc is favorable for trapping an object to be detected.

Optionally, the alcohol is selected from any one of methanol, ethanol and isopropanol.

By adopting the technical scheme, the solubility of the substance to be detected and the quinoline in methanol, ethanol or isopropanol is good, the separation degree of the solvent peak, the substance peak to be detected and the quinoline peak is good, and the influence on the analysis result is small.

Optionally, the oscillation rate in the step of extracting the analyte is 200-300 r/min.

By adopting the technical scheme, the extraction effect is better when the oscillation rate is 200-300r/min, the oscillation rate is too low, and the accuracy of the detection result is influenced because the extraction of the object to be detected is incomplete; the oscillation rate is too high, and the determinand is easy to adsorb on the container inner wall, causes the determinand concentration reduction in the solution, influences the accuracy of testing result.

Optionally, the oscillation time in the step of extracting the substance to be detected is more than 30 min.

By adopting the technical scheme, the short oscillation time can lead to incomplete extraction, and when the oscillation time is 30min, substances on the filter disc can be extracted completely, so that the detection efficiency is improved.

Optionally, the shaken solution is filtered through an organic filter.

By adopting the technical scheme, the substance to be detected and the quinoline can pass through the organic filter membrane, and other small particle impurities can be filtered and removed by the organic filter membrane, so that the chromatographic column can be protected, the cleaning and maintenance difficulty of the instrument can be reduced, and the service life of the instrument can be prolonged.

Optionally, the split ratio of the gas chromatograph to the sample is 10:1-20: 1.

By adopting the technical scheme, the object to be detected can reach the response value of an instrument and is beneficial to protecting a chromatographic column; the split ratio is small, the content of a sample entering a chromatographic column is high, the chromatographic column is easy to overload, the separation efficiency is reduced, the peak trailing is deformed, and the chromatographic column is not easy to clean, so that the service life of the chromatographic column is seriously influenced; the split ratio is large, the content of a sample entering a chromatographic column is low, the response value of an instrument cannot be reached or is small, and the accuracy of a detection result is influenced.

In summary, the present application has the following beneficial effects:

1. the content of the to-be-detected object in the solution is quantitatively analyzed and extracted by adopting the gas chromatography and the internal standard method, the method has higher accuracy and precision, high separation efficiency, high analysis speed and low cost, the error caused by the change of the operation condition is eliminated to a certain extent, and the detection accuracy is improved.

2. According to the method, the cooling agent in the electronic smoke sol is trapped by adopting a combined mode of the smoking machine and the filter disc, so that the electronic smoke sol completely flows through the filter disc in a closed environment, the object to be detected can be fully trapped by the filter disc, the pretreatment condition is optimized, the trapping rate of the object to be detected in the electronic smoke sol is improved, and the accuracy of the detection method is further improved; and this application uses the mode of vibration extraction to extract the determinand on the filter disc, and extraction efficiency is high, extract effectually.

3. The method for determining the content of the novel cooling agents such as WS-3 and WS-23 in the electronic smoke sol is more complete, fills up the technical blank in the field, and has guiding significance for formulating an industry standard determination method of the content of the cooling agents in the electronic smoke sol.

Drawings

FIG. 1 is a gas chromatogram of a standard solution in which WS-23 and WS-3 are both present at a concentration of 2 mg/L.

FIG. 2 is a gas chromatogram of an extraction solution of a tobacco smoke A aerosol.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. The special description is as follows: the following examples, in which the specific conditions are not specified, were conducted according to the conventional conditions or conditions recommended by the manufacturer, and the raw materials used in the following examples were all available from the ordinary market except for the specific conditions, and the volume vessels used in the following examples were cleaned with 10% ethanol and rinsed with deionized water, and then dried for use.

Example 1

The application provides a method for measuring the content of a cooling agent in electronic smoke sol, which comprises the following steps:

flue gas capture: preheat the smoking machine, add test tobacco tar A in the electron smog spinning disk atomiser. And after the tobacco tar A completely wets the atomizing core, loading the filter disc into a filter of a smoking machine, taking the rough surface of the filter disc as a contact smoke surface, connecting the filter with an electronic smoke atomizer, connecting the filter to the smoking machine after the smoking machine is preheated for 20min, and trapping the substances to be detected in the electronic smoke sol.

Setting the smoking parameters of the smoking machine: the suction curve is a square wave, the suction capacity is 55.0 mL/port, the suction duration is 3 s/port, the suction frequency is 30s, the suction is divided into 5 series of suction, the suction frequency is 20 times, namely, aerosol of each suction port is trapped on the same filter sheet, the time interval of each series is 300s, the maximum flow is 18.5mL/s, the pressure difference is 50hPa, and 100 ports of electronic smoke aerosol is trapped totally.

Preparing an internal standard solution: accurately weighing 0.1g of quinoline standard substance in a 10mL volumetric flask, fixing the volume to a scale with isopropanol, and fully and uniformly mixing by adopting a vortex mixer to obtain a quinoline standard solution with the concentration of 10000 mg/L; accurately transferring 10 mu L of quinoline standard solution with the concentration of 10000mg/L into a 10mL volumetric flask, using isopropanol to fix the volume to a scale, and fully shaking to prepare the quinoline standard solution with the concentration of 10 mg/L.

Extraction of a substance to be detected: the filter disc which has trapped the electronic smoke sol is placed into a 100mL conical flask, 20mL of quinoline standard solution with the concentration of 10mg/L is added, and then the 100mL conical flask is placed on a platform oscillator to oscillate for 30min at the speed of 250 r/min. 2mL of the shaken solution was filtered through a 0.45 μm organic filter to obtain an extract solution.

Preparing a standard solution:

(1) accurately weighing 0.1g of WS-23 standard substance in a 10mL volumetric flask, using isopropanol to fix the volume to a scale, fully and uniformly mixing by adopting a vortex mixer, and preparing a WS-23 standard solution with the concentration of 10000 mg/L. Accurately weighing 0.1g of WS-3 standard substance in a 10mL volumetric flask, fixing the volume to a scale with isopropanol, fully and uniformly mixing by adopting a vortex mixer, and preparing a WS-3 standard solution with the concentration of 10000 mg/L.

(2) Accurately transferring 0.1mL of each of the WS-23 standard solution and the WS-3 standard solution with the concentration of 10000mg/L into a 10mL volumetric flask, adding 0.01mL of quinoline standard solution with the concentration of 10000mg/L, fixing the volume to a scale by using isopropanol, and fully and uniformly mixing by using a vortex mixer to obtain the mixed standard solution.

(3) Accurately transferring 0.2mL, 0.5mL, 1.0mL, 2.5mL and 5.0mL of mixed standard solutions into a 10mL volumetric flask, metering the volume to the scale by using a 10mg/L quinoline standard solution, and fully and uniformly mixing by using a vortex mixer to prepare series of standard solutions of which the WS-23 and WS-3 concentrations are 2mg/L, 5mg/L, 10mg/L, 25mg/L and 50 mg/L.

And (3) analysis and calculation:

(1) detection was performed using an Agilent8860 gas chromatograph, which was a hydrogen Flame Ionization Detector (FID).

Chromatographic conditions are as follows:

a chromatographic column: DB-WAXUI, size 30m 0.25mm 0.25 μm;

temperature rising procedure: the initial column temperature is 80 ℃, the mixture is kept for 3min, the temperature is raised to 150 ℃ at the speed of 10 ℃/min, and the mixture is kept for 2 min; heating to 220 deg.C at 20 deg.C/min, and keeping for 5 min;

air flow rate: 400 mL/min;

hydrogen flow rate: 30 mL/min;

tail blow flow (N2): 25 mL/min;

carrier gas flow (N2): 3 mL/min;

sample inlet temperature: 245 ℃;

detector temperature: 250 ℃;

and (3) sample introduction mode: the split ratio is 20: 1;

sample introduction amount: 1 uL.

And performing a blank experiment by using the quinoline standard solution, and detecting the quinoline standard solution and the series of standard solutions to obtain a gas chromatogram. As shown in figure 1, the signal peak of quinoline is positioned between the signal peaks of WS-23 and WS-3, the chromatographic behaviors of quinoline and two cooling agents are similar during analysis, the influence of split discrimination on the analysis is small, and the measurement accuracy is improved. Retention time and peak area data of the analyte and quinoline were read and recorded in table 1. The expected retention time for WS-23 was 11.379min, for WS-3 was 15.454min, and for quinoline was 12.670 min.

TABLE 1

Data processing is carried out by using DataAnalysis software matched with Agilent8860 gas chromatograph, the detection results of the series of standard solutions are drawn into a standard curve, and the obtained regression equation and the correlation coefficient R2 are shown in Table 2. Wherein X is the concentration of the substance to be detected, and the unit is mg/L; y is the ratio of the peak areas of the substance to be detected and quinoline, and is dimensionless. As can be seen from Table 2, the correlation coefficients R2 of the regression equation of the two cooling agents are 0.9998 and 0.9999, respectively, and the concentration X of the analyte and the peak area ratio Y of the analyte to quinoline have excellent linear correlation.

TABLE 2

Name of item	Regression equation	Coefficient of correlation (R)2)
			WS-23	Y＝0.0792X+0.0076	0.9998
WS-3	Y＝0.0887X-0.0044	0.9999

The gas chromatogram obtained by detecting the extraction solution of the tobacco tar A aerosol is shown in FIG. 2. As can be seen from the graph 2, the substance components in the electronic smoke sol are very complex, so that the measurement difficulty of the object to be measured is increased, and the influence of the impurity peak in the electronic smoke sol on the internal standard peak and the object peak to be measured is reduced by optimizing the measurement conditions, so that the measurement accuracy is effectively improved. The same method is adopted to detect the extraction solution of tobacco tar B and tobacco tar C aerosol. Retention time and peak area data for the test article and quinoline were read and recorded in table 3.

(2) Calculating the concentration CS of the substance to be detected in the extraction solution by using a regression equation, and recording the concentration CS in the table 3;

(3) the content X of the analyte in the aerosol was calculated using the following formula, recorded in table 3:

x is the content of the substance to be detected in the aerosol, and the unit is milligram per hundred mouths (mg/100 mouths);

CS is the concentration of the analyte in the extraction solution in milligrams per liter (mg/L);

cblk is the concentration of the analyte in the blank in milligrams per liter (mg/L);

v is the volume of the extraction solution in milliliters (mL);

d is the dilution multiple of the extraction solution;

1000 is the unit scaling factor.

TABLE 3

In the electronic cigarette industry, the material content in the electronic smoke sol is generally described by using the dimensions of mg/50, mg/100 or mg/200, so that in other embodiments, the smoking number can be set to 50 or 200, and correspondingly, mg/50 or mg/200 is used as the unit of the content of the substance to be detected in the aerosol.

Example 2

Methodology evaluation test detection limits: the detection limit of the substance to be detected is determined by the signal-to-noise ratio (S/N) being more than or equal to 3, the detection limit of WS-23 is 0.5mg/L, and the detection limit of WS-3 is 0.3mg/L, which is beneficial to the detection of two cooling agents with lower concentration.

Precision: one spiked sample was sampled 10 times in duplicate and the results of 10 replicates were recorded in table 4 and the Relative Standard Deviation (RSD) was calculated. As can be seen from Table 4, the RSD of WS-23 analyzed quantitatively by the method is 1.20%, and the RSD of WS-3 analyzed is 1.76%, both of which meet the evaluation requirements, so that the method has higher accuracy.

TABLE 4

Accuracy: the results were recorded in Table 5, in which 5mg/L of the standard solution was added to the extract solution of the tobacco tar A aerosol, 10mg/L of the standard solution was added to the extract solution of the tobacco tar B aerosol, and 30mg/L of the standard solution was added to the extract solution of the tobacco tar C aerosol, and the results were measured in parallel twice, respectively.

TABLE 5

As can be seen from Table 5, the average recovery rates of WS-23 and WS-3 are 102.95% and 96.98%, respectively, which both meet the recovery rate requirement, so the method has higher accuracy for the content determination of WS-23 and WS-3.

The average recovery rate of WS-23 in low concentration is 98.60%, which is closest to 100%, while the average recovery rate of WS-23 in medium and high concentration is 105.25% and 105.00%, which are relatively far from 100%, so the method is more suitable for the determination of WS-23 with low concentration. Similarly, the average recovery rate of WS-3 in high concentration is 100.15%, which is closest to 100%, while the average recovery rates of WS-3 in low and medium concentration are 97.55% and 93.24%, respectively, which are relatively far from 100%, so the method is more suitable for the measurement of WS-3 with high concentration.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.