Method for simulating puff-by-puff smoking of heat-not-burn cigarette

Abstract

The invention discloses a method for simulating puff-by-puff smoking of a heat-not-burn cigarette and a puff-by-puff collected single heat-not-burn cigarette smoke sample prepared on the basis of the method. The method comprises the following steps: heating a core base material of the heat-not-burn cigarette, enabling positive-pressure carrier gas to pass through the core base material for t1 seconds, collecting aerosol carried by the carrier gas by using absorption liquid, then stopping passing of the positive-pressure carrier gas for t2 seconds, and replacing the absorption liquid; and repeating passing and stopping of the positive ballast gas for n times to obtain n + 1 parts of puff-by-puff suction gas absorption liquid. The invention further discloses a method for puff-by-puff analysis of smoke of the heat-not-burn cigarette based on the method for simulating puff-by-puff smoking of the heat-not-burn cigarette. According to the method provided by the invention, puff-by-puff collection and analysis of the smoke of the single heat-not-burn cigarette can be simply, conveniently and quickly realized, and the difference between the heat-not-burn cigarettes can be accurately reflected, so that the quality stability of the heat-not-burn cigarettes is favorably improved.

Description

Technical Field

[0001] The invention belongs to the field of testing technology, and in particular relates to a method for simulating puff-by-puff smoking of a heat-not-burn cigarette based on a new volatile component collection device. Background Art

[0002] Heat-not-burn cigarettes (also known as "new cigarettes") heat the filler (commonly known as the core substrate) through the temperature control technology of the heating device and emit smoke to achieve the purpose of satisfying consumers' smoking experience. New cigarettes do not involve the burning behavior of tobacco in traditional cigarettes. The aerosol generation process is low-temperature heating, that is, the distillation or preliminary thermal decomposition reaction of the core substrate under the condition of not more than 350°C. Since the new cigarettes heat the entire core substrate at the same time when heated, the core substrate volatilizes and releases nicotine and aroma substances evenly and stably under the entire low-temperature heating and non-combustion state, which is crucial to meet the needs of smokers. In order to evaluate the release of volatile substances in the core substrate of heat-not-burn cigarettes under heating conditions, smoke puff analysis is a common method. Smoke puff analysis can detect the relevant components and their content in each puff of smoke from heat-not-burn cigarettes. It is an important tool for evaluating the quality of heat-not-burn cigarettes and also provides data support for the development of new core substrates. In order to achieve puff-by-puff analysis with smoke, it must be based on simulating cigarette puff-by-puff and puff-by-puff capture.

[0003] At present, all the simulations of puff-by-puff smoking of heat-not-burn cigarettes are based on the method of traditional cigarettes, that is, they are completed with the help of a smoking machine with a smoking function. These methods are to capture the aerosols of multiple cigarettes with the same puff number on the same glass fiber filter, then elute the glass fiber filter, detect the eluate, and then divide the quantitative detection results by the number of cigarettes to obtain the puff-by-puff data of a single cigarette. For example, the Chinese invention patent application with publication number CN113562409A discloses a heat-not-burn cigarette puff-by-puff capture type turntable smoking machine and its use method. Due to the physical and chemical properties of the glass fiber filter itself, it is impossible to capture the particulate phase and gas phase of the smoke aerosol together at the same time. Secondly, and most urgently to be solved, the capture of aerosols of the same puff number of multiple cigarettes on the same glass fiber filter will to a certain extent cover up the differences between the cigarettes, which is not a true single new cigarette puff-by-puff analysis. Therefore, it is necessary to develop a new method for simulating the puff-by-puff smoking of heat-not-burn cigarettes and realizing the puff-by-puff capture of smoke from a single cigarette. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a novel method for simulating puff-by-puff puffing of a heat-not-burn cigarette and a method for puff-by-puff analysis of smoke from a heat-not-burn cigarette based on the method. The present invention does not require equipment with a negative pressure suction function (such as a smoking machine) to complete the simulated puff-by-puff puffing, and the particulate matter and gaseous matter of the smoke aerosol are collected at the same time, and no solvent elution is required. The capture efficiency is high and the operation is simple, and the puff-by-puff capture and analysis of smoke from a single heat-not-burn cigarette is truly realized.

[0005] To this end, the present invention adopts the following technical solution:

[0006] A method for simulating puff-by-puff smoking of a heat-not-burn cigarette comprises heating a core substrate of the heat-not-burn cigarette, passing a positive-pressure carrier gas through the core substrate for t1 second, collecting aerosols carried by the carrier gas with an absorption liquid, then stopping the passage of the positive-pressure carrier gas for t2 seconds, and replacing the absorption liquid; repeating the passage and stopping of the positive-pressure carrier gas n times to obtain n+1 portions of puff-by-puff smoking gas absorption liquid.

[0007] Preferably, the carrier gas is selected from one of nitrogen, helium, argon and compressed air.

[0008] Also preferably, the carrier gas passes through the core substrate at a flow rate of 0.5 to 5 ml / min.

[0009] Preferably, the core substrate heating temperature is 350°C±5°C.

[0010] The duration of t1 and t2 can be arbitrary. Generally, t1 < t2. For analysis convenience, t1 + t2 = 30 seconds or 60 seconds. As an exemplary embodiment, t1 = 5 seconds, t2 = 55 seconds. As another exemplary embodiment, t1 = 2 seconds, t2 = 58 seconds. As another exemplary embodiment, t1 = 2 seconds, t2 = 28 seconds.

[0011] Preferably, t1 = 5 seconds, t2 = 55 seconds.

[0012] Preferably, n is a positive integer of 4-11.

[0013] More preferably, n=5, 6, 7, 8 or 9.

[0014] Preferably, the absorption liquid is selected from one or more of cyclohexane, ethyl acetate, methanol, ethanol, dichloromethane and acetonitrile in any proportion.

[0015] More preferably, the absorption liquid is ethanol.

[0016] Optionally, the absorption liquid may or may not contain an internal standard.

[0017] Preferably, the absorption liquid is cooled to 0°C±5°C when collecting the aerosol carried by the carrier gas; more preferably 0°C±2°C.

[0018] As the carrier gas passes through the heated core substrate each time, the smoke aerosol volatilized by the heat is carried away by the carrier gas and then captured and absorbed by the absorption liquid. By allowing the carrier gas to pass through the core substrate intermittently, the simulation of the cigarette puff by puff is achieved.

[0019] Preferably, the method is based on a volatile component collecting device; the volatile component collecting device includes a carrier gas pipeline, a gas flow meter, a heating device, a material storage cavity, a first gas circuit valve, a collecting device and a controller; wherein the gas flow meter is connected and installed on the carrier gas pipeline; a storage cavity for placing the core substrate to be tested is provided in the material storage cavity, the storage cavity is connected to the carrier gas pipeline, and the storage cavity is provided with a carrier gas inlet and a carrier gas outlet on two opposite surfaces; the heating device is used to heat the storage cavity; the first gas circuit valve is connected and arranged on the carrier gas pipeline after the material storage cavity; the collecting device includes a collecting bottle with absorption liquid placed therein, the collecting bottle is placed at the end of the carrier gas pipeline, and the end opening of the carrier gas pipeline is immersed in the absorption liquid; the controller is communicatively connected with the gas flow meter, the heating device and the first gas circuit valve.

[0020] Preferably, the heating device comprises a heating layer, a temperature sensor and a heater for heating the heating layer, the heating layer is wrapped on the outer wall of the material storage cavity, and the temperature sensor is arranged in the storage cavity; the heater, temperature sensor and controller are all communicatively connected.

[0021] Preferably, the volatile component collecting device further comprises a cooling device for cooling the absorption liquid in the collecting bottle; the collecting bottle is placed in the cooling device.

[0022] Preferably, the cooling device is communicatively connected to the controller.

[0023] Preferably, the cooling device is selected from a cold trap or an ice bath, more preferably a cold trap.

[0024] Preferably, the cold trap is a condensation trap.

[0025] It is also preferred that the volatile component collection equipment also includes a cleaning device, a second gas circuit valve and a three-way pipe joint, the carrier gas pipeline includes a conveying section, a cleaning section and a collecting section that are connected; the three-way pipe joint includes a first end, a second end and a third end, the first end is connected and installed in the conveying section, the second end is connected and installed in the collecting section, and the third end is connected and installed in the cleaning section; the gas flow meter, the material storage cavity and the first gas circuit valve are connected and arranged on the conveying section; the second gas circuit valve is connected and arranged on the cleaning section, and the collecting bottle is placed at the end of the collecting section; the cleaning device includes an infusion pump and a cleaning bottle with cleaning liquid, the suction port of the infusion pump is placed in the cleaning bottle, and the suction port is immersed in the cleaning liquid, and the output port of the infusion pump is connected to the collecting section; the controller is communicatively connected with the second gas circuit valve and the infusion pump.

[0026] When the first gas circuit valve is closed, the second gas circuit valve is opened, and the infusion pump is started, the cleaning section and the collection section of the pipeline can be cleaned, thereby preventing the residual gas in the pipeline from contaminating the next collection of volatile components.

[0027] As a preferred embodiment, the present invention provides a method for simulating puff-by-puff smoking of a heat-not-burn cigarette based on the above-mentioned volatile component collection device, and the specific operations include:

[0028] Place the core substrate of a heat-not-burn cigarette in the storage cavity of the material storage cavity of the volatile component collection equipment, and set the temperature of the cooling device to 0℃±5℃; accurately aspirate n+1 portions of 1mL absorption liquid, and transfer them into n+1 collection bottles respectively, and then place all the collection bottles in the cooling device, place one of the collection bottles under the end opening of the carrier gas pipeline collection section and immerse the end opening in the absorption liquid; set the heating layer temperature to 350℃±5℃; close the second gas circuit valve; open the first gas circuit valve for t1 second, adjust the gas flow meter to set the carrier gas flow rate to 0.5-5mL / min, then close the first gas circuit valve for t2 seconds, and replace the collection bottle; repeatedly open and close the first gas circuit valve n times; collect the smoke when the first gas circuit valve is in the open state into a collection bottle each time, and collect a total of n+1 portions of puff-by-puff smoke absorption liquid.

[0029] Preferably, the absorption liquid is selected from one or more of cyclohexane, ethyl acetate, methanol, ethanol, dichloromethane and acetonitrile in any proportion.

[0030] More preferably, the absorption liquid is ethanol.

[0031] Optionally, the absorption liquid may or may not contain an internal standard.

[0032] Preferably, the carrier gas is selected from one of nitrogen, helium, argon and compressed air; more preferably nitrogen.

[0033] Also preferably, the carrier gas flow rate is 0.5 ml / min.

[0034] Preferably, t1 = 5 seconds, t2 = 55 seconds.

[0035] Preferably, n=5, 6, 7, 8 or 9.

[0036] Therefore, a second object of the present invention is to provide a single heat-not-burn cigarette smoke sample collected puff by puff, which is prepared by the above-mentioned method of simulating puff by puff of a heat-not-burn cigarette.

[0037] Another object of the present invention is to provide a method for puff-by-puff analysis of heat-not-burn cigarette smoke, based on the method of simulating puff-by-puff smoking of a heat-not-burn cigarette of the present invention, comprising the following steps:

[0038] S1. Collect heat-not-burn cigarette smoke puff by puff

[0039] The method for simulating puff-by-puff smoking of a heat-not-burn cigarette of the present invention is adopted to obtain n+1 portions of puff-by-puff smoke absorption liquid as samples to be tested;

[0040] S2. Testing of samples to be tested;

[0041] S3. Data processing and analysis.

[0042] Preferably, in step S2, the sample to be tested obtained in step S1 is directly tested without being processed.

[0043] In step S2, the separation method can be selected from any appropriate method; for example, including but not limited to gas chromatography and high performance liquid chromatography. The detector can also be selected from any appropriate method, for example, including but not limited to ultraviolet detector (UVD), fluorescence detector (FLD), differential refractive index detector (RID), evaporative light scattering detector (ELSD), chemiluminescence detector (CD), electrochemical detector (ED), thermal conductivity detector, hydrogen flame ionization detector, photoionization detector, mass spectrometer.

[0044] Optionally, step S2 may include preparation of a standard solution; the standard solution includes but is not limited to one or more of nicotine, propylene glycol, glycerol, menthol and triacetin.

[0045] As an exemplary embodiment, the step S2 uses gas chromatography-hydrogen flame ionization detection; the chromatographic conditions are:

[0046] Chromatographic column: fused silica capillary column DB-ALC1, 30m×0.25mm×1.80μm;

[0047] Heating program: initial temperature 100°C, hold for 1 min, increase to 150°C at a rate of 10°C / min, hold for 3 min, increase to 250°C at a rate of 30°C / min, hold for 5 min;

[0048] Injection volume: 1 μL;

[0049] Injection mode: split injection, split ratio is 40:1;

[0050] Inlet temperature: 250°C;

[0051] Carrier gas: helium, purity ≥ 99.999%;

[0052] Constant flow rate: 0.8mL / min;

[0053] Detector temperature: 250°C.

[0054] Optionally, step S3 includes qualitative detection and / or quantitative determination.

[0055] The qualitative detection includes determining the retention time of each standard substance. If a chromatographic peak appears in the chromatogram of the sample to be tested at the same retention time, the sample to be tested contains the corresponding target compound.

[0056] The quantitative determination includes drawing a working curve, and obtaining the content of the target compound in the sample to be tested based on the working curve and the chromatographic peak area of ​​the target compound in the chromatogram of the sample to be tested.

[0057] As an exemplary embodiment, the present invention provides a method for puff-by-puff analysis of heat-not-burn cigarette smoke, based on the method of simulating puff-by-puff smoking of a heat-not-burn cigarette according to the present invention, comprising the following steps:

[0058] S1. Collect heat-not-burn cigarette smoke puff by puff

[0059] The method for simulating puff-by-puff smoking of a heat-not-burn cigarette of the present invention is adopted to obtain n+1 portions of puff-by-puff smoke absorption liquid as the sample to be tested; wherein the absorption liquid is ethanol, and an internal standard compound n-heptadecane is added to make the concentration of n-heptadecane be 100 μg / mL;

[0060] S2. Testing of samples to be tested

[0061] S2-1. Preparation of series of mixed standard solutions

[0062] Using nicotine, propylene glycol, glycerol, and menthol as standard substances, n-heptadecane as an internal standard, and isopropanol as a solvent, a series of mixed standard solutions containing internal standards of different concentrations are prepared; wherein the concentration gradient of nicotine in the mixed standard solution is 0.002, 0.005, 0.025, 0.05, 0.075, 0.10, 0.15, and 0.20 mg / mL, the concentration gradient of propylene glycol, glycerol, and menthol in the mixed standard solution is independently 0.02, 0.05, 0.25, 0.50, 0.75, 1.00, 1.50, and 2.00 mg / mL, and the concentration of n-heptadecane in the series of standard solutions is 100 μg / mL;

[0063] S2-2. Establishment of chromatographic conditions

[0064] Chromatographic column: fused silica capillary column DB-ALC1, 30m×0.25mm×1.80μm;

[0065] Heating program: initial temperature 100°C, hold for 1 min, increase to 150°C at a rate of 10°C / min, hold for 3 min, increase to 250°C at a rate of 30°C / min, hold for 5 min;

[0066] Injection volume: 1 μL;

[0067] Injection mode: split injection, split ratio is 40:1;

[0068] Inlet temperature: 250°C;

[0069] Carrier gas: helium, purity ≥ 99.999%;

[0070] Constant flow rate: 0.8mL / min;

[0071] Detector: Hydrogen flame ionization detector;

[0072] Detector temperature: 250°C;

[0073] S2-3. Measurement

[0074] 1 μL of the series of mixed standard solutions and the sample to be tested were respectively aspirated, injected into the gas chromatograph, and the chromatogram was recorded.

[0075] S3. Data processing and analysis

[0076] S3-1 Qualitative testing

[0077] Compare with the chromatogram of the mixed standard solution, and judge whether the corresponding target compound exists in the sample to be tested by the retention time of nicotine, propylene glycol, glycerol and menthol;

[0078] S3-2. Quantitative determination

[0079] The working curve is drawn with the ratio of the peak area of ​​the four standards in the series of mixed standard solutions to the peak area of ​​the internal standard as the ordinate, and the concentration of the four standards in the series of mixed standard solutions as the abscissa to obtain the slope a and intercept b of the working curve; the content of each target compound in the sample to be tested is calculated according to formula I;

[0080]

[0081] Where m is the content of the target compound in each puff of smoke, mg / puff,

[0082] x is the ratio of the chromatographic peak area of ​​the target compound to that of the internal standard,

[0083] a is the slope of the working curve,

[0084] b is the intercept of the working curve,

[0085] V is the volume of the sample to be tested, mL,

[0086] n is the number of puffs, unit: puff; n=1.

[0087] It can be understood that in step S1, the internal standard compound n-heptadecane can be added to the absorption liquid before the flue gas is captured, and can also be added to the absorption liquid after the flue gas is captured.

[0088] In the present disclosure, unless otherwise specified, all solvents (including the absorption liquid, solvents for preparing a series of standard solutions, etc.) are chromatographically pure.

[0089] The method provided by the present invention can simply and quickly collect and analyze the smoke of a single heat-not-burn cigarette puff by puff. Compared with the traditional method, the method of the present invention takes less time, consumes less solvent, and does not require operations such as elution and desorption. The method of the present invention can accurately reflect the differences between heat-not-burn cigarettes, thereby helping to improve the stability of the quality of heat-not-burn cigarettes, especially heat-not-burn cigarettes with various flavors. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The present invention will be further described below in conjunction with the accompanying drawings.

[0091] Figure 1 The figure is a schematic diagram of the structure of the volatile component collection device. The reference numerals in the figure are explained as follows:

[0092] 1: carrier gas pipeline; 2: gas flow meter; 3: material storage chamber; 4: storage chamber; 5: first gas circuit valve; 6: collecting bottle; 7: heating layer; 8: cooling device; 9: cleaning device; 10: second pneumatic valve; 13: collecting section; 14: cleaning section.

[0093] Figure 2 This is an overlay chromatogram of eight puff-by-puff smoke samples of core substrate A obtained by gas chromatography-hydrogen ion flame detection in Example 3.

[0094] In the figure, the arrows indicate the chromatograms of the smoke samples from the 1st to the 8th puff. In the chromatogram, the retention time of 3.57 min is propylene glycol, the retention time of 6.63 min is glycerol, the retention time of 12.79 min is nicotine, and the retention time of 15.99 min is the internal standard compound.

[0095] Figure 3 3 is an overlay chromatogram of eight puff-by-puff smoke samples of core substrate B obtained by gas chromatography-hydrogen ion flame detection in Example 3.

[0096] In the figure, the arrows indicate the chromatograms of the smoke samples from the 1st to the 8th puff. In the chromatogram, the retention time of 3.57 min is propylene glycol, the retention time of 6.63 min is glycerol, the retention time of 10.04 min is menthol, the retention time of 12.79 min is nicotine, and the retention time of 15.99 min is the internal standard compound.

[0097] Figure 4 This is the puff-by-puff release curve of glycerol from the core substrate A obtained by quantitative detection in Example 3.

[0098] Figure 5 This is the puff-by-puff nicotine release curve of the core substrate A obtained by quantitative detection in Example 3.

[0099] Figure 6 This is the puff-by-puff release curve of glycerol from the core substrate B obtained by quantitative detection in Example 3.

[0100] Figure 7 This is the puff-by-puff release curve of nicotine, propylene glycol and menthol of the core substrate B obtained by quantitative detection in Example 3. DETAILED DESCRIPTION

[0101] The present invention is described below with reference to specific examples. It will be appreciated by those skilled in the art that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0102] The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagents, etc. used in the following examples are commercially available products unless otherwise specified. Among them, some of the instruments used are as follows:

[0103] Gas chromatograph: Agilent 7890A.

[0104] Example 1: A volatile component collection device

[0105] like Figure 1 As shown, a volatile component collection device includes a carrier gas pipeline 1, a gas flow meter 2, a heating device, a material storage chamber 3, a first gas circuit valve 5, a collection device, a cooling device 8, a cleaning device 9, a second gas circuit valve 10, a three-way pipe joint and a controller.

[0106] The carrier gas pipeline 1 is used for gas supply, and includes a conveying section, a cleaning section 14 and a collecting section 13 that are connected. The three-way pipe joint includes a first end, a second end and a third end, the first end is connected and installed in the conveying section of the carrier gas pipeline 1, the second end is connected and installed in the collecting section 13, and the third end is connected and installed in the cleaning section 14. The first gas circuit valve 5 is connected and installed in the conveying section of the carrier gas pipeline 1 after the material storage cavity 3. The second gas circuit valve 10 is connected and installed in the cleaning section 14.

[0107] The gas flow meter 2 is connected and installed on the conveying section of the carrier gas pipeline 1. A storage chamber 4 is provided in the material storage chamber 3, and the storage chamber 4 is used to store solid or liquid samples. The storage chamber 4 is connected to the conveying section of the carrier gas pipeline 1, and a carrier gas inlet and a carrier gas outlet are provided on two opposite surfaces of the storage chamber 4. The heating device includes a heating layer 7, a temperature sensor and a heater; the heater is used to heat the heating layer 7, the heating layer 7 is wrapped on the outer wall of the material storage chamber 3, and the temperature sensor is provided in the storage chamber 4.

[0108] The collecting device includes a collecting bottle 6 containing an absorption liquid, which is placed at the end of the collecting section 13 of the carrier gas pipeline 1, and the solvent used for absorption in the collecting bottle covers the end opening of the collecting section 13. The collecting bottle 6 is also placed in a cooling device 8, which is used to cool the absorption liquid in the collecting bottle 6.

[0109] The cleaning device 9 comprises an infusion pump and a cleaning bottle containing cleaning liquid. The suction port of the infusion pump is placed in the cleaning bottle, and the output port of the infusion pump is connected to the collecting section 13.

[0110] The controller is communicatively connected with the gas flow meter 2 , the heater, the temperature sensor, the first gas circuit valve 5 , the second gas circuit valve 10 and the cooling device 8 .

[0111] When using the volatile component collection device of this embodiment to collect volatile components, first, move an appropriate amount of absorption liquid (solvent) into the collection bottle 6, place the collection bottle 6 in the cooling device 8 and place it below the end opening of the collection section 13 of the carrier gas pipeline 1, the opening of the collection section 13 is immersed in the absorption liquid, and start the cooling device; then, place the solid or liquid sample in the storage chamber 4 of the material storage chamber 3; open the first gas circuit valve 5, and close the second gas circuit valve 10; finally, the controller turns on the heater, and the heater heats the solid or liquid sample in the storage chamber 4 through the heating layer 7, and the gas in the carrier gas pipeline 1 at a specific flow rate will carry the volatile components in the storage chamber 4 to the collection bottle 6 through the collection section 13, and be absorbed by the absorption liquid. Thereby, the volatile components can be collected at a specific temperature.

[0112] After a heating program is completed, the first gas circuit valve 5 is closed, the inlet of the infusion pump is immersed in the cleaning liquid, the second gas circuit valve 10 is opened, and the infusion pump is started, so that the pipelines of the cleaning section 14 and the collection section 13 can be cleaned, thereby avoiding the residual gas in the pipe from contaminating the next collection of volatile components.

[0113] Example 2 Puff-by-Puff Collection of Heat-Not-Burn Cigarette Smoke

[0114] Take two core substrates of heat-not-burn cigarettes: A (original flavor, without menthol) and B (mint flavor, with menthol). Collect smoke puff by puff as follows:

[0115] Place a core substrate in the storage chamber of the volatile component collection device of Example 1, and set the temperature of the cooling device to -2°C; take 8 collection bottles, transfer 1 mL of ethanol containing n-heptadecane (internal standard compound, 100 μg / mL) accurately aspirated into each collection bottle, and then place all the collection bottles in the cooling device; set the temperature of the heating layer to 350°C; close the second gas circuit valve; open the first gas circuit valve for 5 seconds, adjust the gas flow meter to set the nitrogen flow rate to 0.5 mL / min, then close the first gas circuit valve for 55 seconds, and replace the collection bottle; repeatedly open and close the first gas circuit valve 7 times to achieve 8 puffs of simulated heat-not-burn cigarettes, and collect the smoke in a collection bottle each time when the first gas circuit valve is in the open state, and a total of 8 bottles of samples to be tested are obtained.

[0116] Example 3 Puff-by-puff smoke analysis and data analysis and processing of heat-not-burn cigarettes

[0117] The sample to be tested obtained in Example 2 was measured and data analyzed by the following steps:

[0118] 1. Preparation of a series of mixed standard solutions

[0119] Using nicotine, propylene glycol, glycerol, and menthol as standard substances, n-heptadecane as an internal standard, and isopropanol as a solvent, a series of mixed standard solutions containing internal standards of different concentrations are prepared; wherein the concentration gradient of nicotine in the mixed standard solution is 0.002, 0.005, 0.025, 0.05, 0.075, 0.10, 0.15, and 0.20 mg / mL, the concentration gradient of propylene glycol, glycerol, and menthol in the mixed standard solution is independently 0.02, 0.05, 0.25, 0.50, 0.75, 1.00, 1.50, and 2.00 mg / mL, and the concentration of n-heptadecane in the series of standard solutions is 100 μg / mL;

[0120] 2. Establishment of Chromatographic Conditions

[0121] Chromatographic column: fused silica capillary column DB-ALC1, 30m×0.25mm×1.80μm;

[0122] Heating program: initial temperature 100°C, hold for 1 min, increase to 150°C at a rate of 10°C / min, hold for 3 min, increase to 250°C at a rate of 30°C / min, hold for 5 min;

[0123] Injection volume: 1 μL;

[0124] Injection mode: split injection, split ratio is 40:1;

[0125] Inlet temperature: 250°C;

[0126] Carrier gas: helium, purity ≥ 99.999%;

[0127] Constant flow rate: 0.8mL / min;

[0128] Detector: Hydrogen flame ionization detector;

[0129] Detector temperature: 250°C;

[0130] 3. Determination

[0131] Pipette 1 μL of the series of mixed standard solutions and the sample to be tested respectively, inject them into the gas chromatograph, and record the chromatograms. Figure 2 and Figure 3 .

[0132] 4. Qualitative testing

[0133] By comparing the chromatogram of the mixed standard solution, the retention times of nicotine, propylene glycol, glycerol and menthol are used to determine whether the corresponding target compounds exist in the sample to be tested.

[0134] The qualitative test results are shown in Tables 1 and 2.

[0135] Table 1 Qualitative test results of smoke from core substrate A

[0136] No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 No.7 No. 8 Nicotine have have have have none none none none Propylene glycol have none none none none none none none Glycerol have have have have none have have none Menthol none none none none none none none none

[0137] Table 2 Qualitative test results of smoke from core substrate B

[0138] No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 No.7 No. 8 Nicotine have have have none none none none none Propylene glycol have have none none none none none none Glycerol have none have have have none none none Menthol have have have have none have none have

[0139] S3-2. Quantitative determination

[0140] The working curves were drawn with the ratio of the peak area of ​​the four standards in the series of mixed standard solutions to the peak area of ​​the internal standard as the ordinate and the concentration of the four compounds in the series of mixed standard solutions as the abscissa to obtain the slope a and intercept b of the working curve; the content of each target compound in the sample to be tested was calculated according to formula I;

[0141]

[0142] Where m is the content of the target compound in each puff of smoke, mg / puff,

[0143] x is the ratio of the chromatographic peak area of ​​the target compound to that of the internal standard,

[0144] a is the slope of the working curve,

[0145] b is the intercept of the working curve,

[0146] V is the volume of the sample to be tested, mL,

[0147] n is the number of puffs, unit: puff; n=1.

[0148] The calculated target compound content in each puff of smoke is used as the ordinate and the number of puffs is used as the abscissa to draw a puff-by-puff release curve of the target compound. The puff-by-puff release curves of glycerol and nicotine of core substrate A are shown in Figures 1 and 2, respectively. Figure 4 and Figure 5 The puff-by-puff release profile of glycerol from core substrate B is shown in Figure 6 The puff-by-puff release profiles of nicotine, propylene glycol, and menthol are shown in Figure 7 .

[0149] from Figure 4 It can be seen that the glycerol in the aerosol of core substrate A (original heat-not-burn cigarette core substrate) has the highest release amount in the second puff, and finally drops sharply with the increase in the number of puffs, and is basically completely released in 4-8 puffs. Figure 5 It shows that the nicotine release in the core substrate A aerosol is high in the first two puffs, then drops sharply, and is basically completely released in 4-8 puffs. Figure 6The puff-by-puff release of glycerol in the smoke aerosol of core substrate B (mint-flavored heat-not-burn cigarette core substrate) is shown. Similar to core substrate A, glycerol also has a maximum release at puffs, followed by a sharp drop. The difference is that its maximum release is at the 3rd puff, and is basically completely released at 6-8 puffs. Figure 7 The puff-by-puff release of nicotine, propylene glycol, and menthol in the aerosol of core substrate B is shown. It can be found that menthol and nicotine have similar puff-by-puff release patterns: both are low in the first puff, the second puff releases the largest amount, and then the release drops sharply, and is basically completely released in 4-8 puffs; the release of propylene glycol is mainly concentrated in the first two puffs, and continues to drop with the increasing number of puffs, and is basically completely released in 3-8 puffs.

[0150] In summary, the method provided by the present invention can simply and quickly realize the puff-by-puff collection and analysis of smoke from a single heat-not-burn cigarette, and can accurately reflect the differences between heat-not-burn cigarettes, thereby helping to improve the quality stability of heat-not-burn cigarettes.

Claims

1. A method for simulating puff-by-puff smoking of a heat-not-burn cigarette, comprising heating a core substrate of the heat-not-burn cigarette, passing a positive-pressure carrier gas through the core substrate for t1 second, collecting aerosols carried by the carrier gas with an absorption liquid, then stopping the passage of the positive-pressure carrier gas for t2 seconds, and replacing the absorption liquid; repeating the passage and stopping of the positive-pressure carrier gas n times to obtain n+1 portions of puff-by-puff smoking smoke absorption liquid.

2. The method according to claim 1, characterized in that The carrier gas is selected from one of nitrogen, helium, argon and compressed air; Also preferably, the carrier gas passes through the core substrate at a flow rate of 0.5 to 5 ml / min; Preferably, the core substrate heating temperature is 350°C±5°C.

3. The method according to claim 1, characterized in that: The duration of t1 and t2 can be arbitrary; Preferably, t1<t2; Preferably, t1+t2=30 seconds or 60 seconds; Preferably, t1=5 seconds, t2=55 seconds; or t1=2 seconds, t2=58 seconds; or t1=2 seconds, t2=28 seconds; More preferably, t1=5 seconds, t2=55 seconds.

4. The method according to claim 1, characterized in that n is a positive integer from 4 to 11; Preferably, n=5, 6, 7, 8 or 9.

5. The method according to claim 1, characterized in that The absorption liquid is selected from one or more of cyclohexane, ethyl acetate, methanol, ethanol, dichloromethane and acetonitrile in any proportion; Preferably, the absorption liquid is ethanol; Optionally, the absorption liquid may or may not contain an internal standard.

6. The method according to claim 1 or 5, characterized in that: When the absorption liquid collects the aerosol carried by the carrier gas, it is cooled to 0°C±5°C; more preferably 0°C±2°C.

7. The method according to claim 1, characterized in that The method is based on a volatile component collecting device; the volatile component collecting device comprises a carrier gas pipeline, a gas flow meter, a heating device, a material storage cavity, a first gas circuit valve, a collecting device and a controller; wherein the gas flow meter is connected and installed on the carrier gas pipeline; a storage cavity for placing a core substrate to be tested is arranged in the material storage cavity, the storage cavity is connected to the carrier gas pipeline, and a carrier gas inlet and a carrier gas outlet are arranged on two opposite surfaces of the storage cavity; the heating device is used to heat the storage cavity; the first gas circuit valve is connected and arranged on the carrier gas pipeline after the material storage cavity; the collecting device comprises a collecting bottle with an absorption liquid placed therein, the collecting bottle is placed at the end of the carrier gas pipeline, and the end opening of the carrier gas pipeline is immersed in the absorption liquid; the controller is communicatively connected with the gas flow meter, the heating device and the first gas circuit valve.

8. The method according to claim 7, characterized in that The heating device includes a heating layer, a temperature sensor and a heater for heating the heating layer, the heating layer is wrapped on the outer wall of the material storage cavity, and the temperature sensor is arranged in the storage cavity; the heater, temperature sensor and controller are all communicatively connected.

9. The method according to claim 7, characterized in that: The volatile component collecting device further comprises a cooling device for cooling the absorption liquid in the collecting bottle; the collecting bottle is placed in the cooling device; Preferably, the cooling device is communicatively connected to the controller; Preferably, the cooling device is selected from a cold trap or an ice bath, more preferably a cold trap; Preferably, the cold trap is a condensation trap.

10. The method according to claim 7, characterized in that The volatile component collection equipment also includes a cleaning device, a second gas circuit valve and a three-way pipe joint, the carrier gas pipeline includes a conveying section, a cleaning section and a collecting section that are connected; the three-way pipe joint includes a first end, a second end and a third end, the first end is connected and installed in the conveying section, the second end is connected and installed in the collecting section, and the third end is connected and installed in the cleaning section; the gas flow meter, the material storage cavity and the first gas circuit valve are connected and arranged on the conveying section; the second gas circuit valve is connected and arranged on the cleaning section, and the collecting bottle is placed at the end of the collecting section; the cleaning device includes an infusion pump and a cleaning bottle with cleaning liquid, the suction port of the infusion pump is placed in the cleaning bottle, and the suction port is immersed in the cleaning liquid, and the output port of the infusion pump is connected to the collecting section; the controller is communicatively connected with the second gas circuit valve and the infusion pump.

11. The method according to claims 8 to 10, characterized in that The specific operations of the method include: Place the core substrate of a heat-not-burn cigarette in the storage cavity of the material storage cavity of the volatile component collection device, and set the temperature of the cooling device to 0℃±5℃; accurately aspirate n+1 portions of 1mL absorption liquid, and transfer them into n+1 collection bottles respectively, and then place all the collection bottles in the cooling device, and place one of the collection bottles under the end opening of the carrier gas pipeline collection section so that the end opening is immersed in the absorption liquid; set the temperature of the heating layer to 350℃±5℃; close the second gas circuit valve; open the first gas circuit valve for t1 second, adjust the gas flow meter to set the carrier gas flow rate to 0.5-5mL / min, then close the first gas circuit valve for t2 seconds, and replace the collection bottle; repeatedly open and close the first gas circuit valve n times; collect the smoke when the first gas circuit valve is in the open state into a collection bottle each time, and collect a total of n+1 portions of smoke absorption liquid for each puff; Preferably, the absorption liquid is selected from one or more of cyclohexane, ethyl acetate, methanol, ethanol, dichloromethane and acetonitrile in any proportion; More preferably, the absorption liquid is ethanol; Optionally, the absorption liquid is added with or without an internal standard; Preferably, the carrier gas is selected from one of nitrogen, helium, argon and compressed air; more preferably nitrogen; Also preferably, the carrier gas flow rate is 0.5 ml / min; Preferably, t1=5 seconds, t2=55 seconds; Preferably, n=5, 6, 7, 8 or 9.

12. A smoke sample of a single heat-not-burn cigarette collected puff by puff, prepared by the method for simulating puff by puff of a heat-not-burn cigarette according to any one of claims 1 to 11.

13. A method for puff-by-puff analysis of heat-not-burn cigarette smoke, based on the method for simulating puff-by-puff smoking of a heat-not-burn cigarette according to any one of claims 1 to 11, comprising the following steps: S1. Collect heat-not-burn cigarette smoke puff by puff The method for simulating puff-by-puff smoking of a heat-not-burn cigarette according to any one of claims 1 to 11 is used to obtain n+1 portions of puff-by-puff smoke absorption liquid as samples to be tested; S2. Testing of samples to be tested; S3. Data processing and analysis.

14. The method according to claim 13, characterized in that In step S2, the sample to be tested obtained in step S1 is directly tested without being processed; Preferably, in step S2, the separation method is selected from gas chromatography or high performance liquid chromatography; the detector is selected from ultraviolet detector (UVD), fluorescence detector (FLD), differential refractive index detector (RID), evaporative light scattering detector (ELSD), chemiluminescence detector (CD), electrochemical detector (ED), thermal conductivity detector, hydrogen flame ionization detector, photoionization detector or mass spectrometer; Preferably, step S2 may include preparation of a standard solution; the standard solution includes but is not limited to one or more of nicotine, propylene glycol, glycerol, menthol and triacetin.

15. The method according to claim 13 or 14, characterized in that The step S2 adopts gas chromatography-hydrogen flame ionization detection; the chromatographic conditions are: Chromatographic column: fused silica capillary column DB-ALC1, 30m×0.25mm×1.80μm; Heating program: initial temperature 100°C, hold for 1 min, increase to 150°C at a rate of 10°C / min, hold for 3 min, increase to 250°C at a rate of 30°C / min, hold for 5 min; Injection volume: 1 μL; Injection mode: split injection, split ratio is 40:1; Inlet temperature: 250°C; Carrier gas: helium, purity ≥ 99.999%; Constant flow rate: 0.8mL / min; Detector temperature: 250°C.

16. The method according to claim 13, characterized in that The step S3 includes qualitative detection and / or quantitative determination; Preferably, the qualitative detection includes, according to the retention time of each standard, if the chromatogram of the sample to be tested shows a chromatographic peak at the same retention time, then the sample to be tested contains the corresponding target compound; Preferably, the quantitative determination includes drawing a working curve, and obtaining the content of the target compound in the sample to be tested based on the working curve and the chromatographic peak area of ​​the target compound in the chromatogram of the sample to be tested.

17. A method for puff-by-puff analysis of heat-not-burn cigarette smoke, based on the method for simulating puff-by-puff smoking of a heat-not-burn cigarette according to any one of claims 1 to 11, comprising the following steps: S1. Collect heat-not-burn cigarette smoke puff by puff The method for simulating puff-by-puff smoking of a heat-not-burn cigarette according to any one of claims 1 to 11 is used to obtain n+1 portions of puff-by-puff smoke absorption liquid as the sample to be tested; wherein the absorption liquid is ethanol, and an internal standard compound n-heptadecane is added to make the concentration of n-heptadecane 100 μg / mL; S2. Testing of samples to be tested S2-1. Preparation of series of mixed standard solutions Nicotine, propylene glycol, glycerol and menthol were used as standard substances, n-heptadecane was used as an internal standard, and isopropanol was used as a solvent to prepare a series of mixed standard solutions containing internal standards of different concentrations; The concentration gradient of nicotine in the mixed standard solution is 0.002, 0.005, 0.025, 0.05, 0.075, 0.10, 0.15 and 0.20 mg / mL, the concentration gradient of propylene glycol, glycerol and menthol in the mixed standard solution is independently 0.02, 0.05, 0.25, 0.50, 0.75, 1.00, 1.50 and 2.00 mg / mL, and the concentration of n-heptadecane in the series of standard solutions is 100 μg / mL; S2-2. Establishment of chromatographic conditions Chromatographic column: fused silica capillary column DB-ALC1, 30m×0.25mm×1.80μm; Heating program: initial temperature 100°C, hold for 1 min, increase to 150°C at a rate of 10°C / min, hold for 3 min, increase to 250°C at a rate of 30°C / min, hold for 5 min; Injection volume: 1 μL; Injection mode: split injection, split ratio is 40:1; Inlet temperature: 250°C; Carrier gas: helium, purity ≥ 99.999%; Constant flow rate: 0.8mL / min; Detector: Hydrogen flame ionization detector; Detector temperature: 250°C; S2-3. Measurement Pipette 1 μL of the series of mixed standard solutions and the sample to be tested respectively, inject into the gas chromatograph, and record the chromatogram; S3. Data processing and analysis S3-1 Qualitative testing Compare with the chromatogram of the mixed standard solution, and judge whether the corresponding target compound exists in the sample to be tested by the retention time of nicotine, propylene glycol, glycerol and menthol; S3-2. Quantitative determination The working curve is drawn with the ratio of the peak area of ​​the four standards in the series of mixed standard solutions to the peak area of ​​the internal standard as the ordinate, and the concentration of the four standards in the series of mixed standard solutions as the abscissa to obtain the slope a and intercept b of the working curve; the content of each target compound in the sample to be tested is calculated according to formula I; Wherein, m is the content of the target compound in each puff of smoke, mg / puff, x is the ratio of the chromatographic peak area of ​​the target compound to that of the internal standard, a is the slope of the working curve, b is the intercept of the working curve, V is the volume of the sample to be tested, mL, n is the number of puffs, unit: puff; n=1.

18. The method according to claim 17, characterized in that In the step S1, the internal standard compound n-heptadecane can be added to the absorption liquid before the flue gas is captured, or can be added to the absorption liquid after the flue gas is captured.

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