Method for segmentally determining escapes in tobacco heating process

Abstract

The invention discloses a method for segmentally determining escapes in a tobacco sample heating process. The method comprises the following steps: (1) determining a segmental heating program; (2) collecting escapes of a to-be-detected tobacco sample at different temperature segments; and (3) detecting the escapes. Wherein the step (2) is based on a volatile component collection device; the volatile component collecting equipment comprises a carrier gas pipeline, a gas flowmeter, a heating device, a material storage cavity, a first gas circuit valve, a collecting device and a cooling device. The method solves the problem that the traditional method can only analyze the escapes at a temperature lower than a certain temperature T (< = T), and can collect, analyze and compare the escapes of a tobacco sample in a plurality of heating temperature intervals. The method provided by the invention only needs a small amount of organic solvent, is short in time consumption and simple and convenient to operate, and efficiently, simply and conveniently realizes the purpose of staged research on the escapes in the heating process of the tobacco sample by combining with a proper analytical instrument.

Description

Technical Field

[0001] The invention belongs to the field of testing technology, and in particular relates to a method for segmentally collecting and measuring exudates during tobacco heating based on a novel volatile component collecting device. Background Art

[0002] Heat-not-burn cigarettes are new tobacco products that use special heat sources to heat tobacco (below 500°C or even lower), and the tobacco is only heated but not burned; the characteristics are low release of harmful components and provide consumers with a certain tobacco characteristic experience. At present, international research on heat-not-burn cigarettes focuses on the smoke generated by heating (including smoke components, toxicological evaluation, etc.) and thermal analysis of heat-not-burn cigarettes themselves. For example, Yang Ji et al. used a thermogravimetric / differential thermal integrated thermal analyzer combined with a gas chromatography / mass spectrometer to study the thermal cracking behavior of tobacco materials in the temperature range of 50-350°C (Yang Ji, et al. Thermal Analysis of Tobacco Materials for Heat-Not-Burn Cigarettes [J]. Journal of Chinese Tobacco Society. Issue 06, 2015: 7-13). Among them, silica glass wool filled in a stainless steel tube was used to collect the volatile components of the tobacco material.

[0003] The existing pyrolysis-gas chromatography / mass spectrometry (Py-GC / MS) technology realizes the analysis (qualitative and semi-quantitative) of emissions from solid samples or materials under heating. However, Py-GC / MS also has some problems in practical applications: 1) The adsorption capacity of solid adsorption materials is limited, resulting in a small sample load, usually only a few milligrams, which makes it impossible to detect low-content components (or trace components); at the same time, for samples with poor uniformity, the results of batch measurements vary greatly. 2) Only volatile components below a certain temperature can be analyzed at one time, and volatile components of the same sample under multiple heating temperature intervals cannot be collected in segments. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for segmented determination of exudates during the heating process of tobacco samples. The method can achieve segmented capture of volatile components in a specific heating temperature range, and then combine with gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry to achieve the purpose of segmented study of exudates during the heating process of tobacco. The method of the present invention requires only a small amount of organic solvent, is short in time, and is easy to operate.

[0005] The present invention adopts the following technical solution:

[0006] A method for segmented determination of exudates during heating of a tobacco sample comprises: (1) determining a segmented heating program, (2) collecting exudate samples of the tobacco sample to be tested at different temperature segments, and (3) detecting the exudate samples; wherein step (2) is based on a volatile component collection device;

[0007] The volatile component collection equipment 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 cooling device; wherein the gas flow meter is connected and installed on the carrier gas pipeline; a storage cavity for placing the tobacco sample to be tested is arranged 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 absorption liquid in the collecting bottle submerges the end opening of the carrier gas pipeline; the collecting bottle is placed in the cooling device.

[0008] 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.

[0009] Preferably, the cooling device is selected from a cold trap or an ice bath, more preferably a cold trap.

[0010] Preferably, the cold trap is a condensation trap.

[0011] Preferably, the volatile component collection device further comprises a controller, and the controller is communicatively connected with the gas flow meter, the heater, the temperature sensor, and the first gas path valve.

[0012] Preferably, the controller is connected to the gas flow meter, the heater, the temperature sensor, the first gas path valve and the cooling device.

[0013] 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 fluid placed therein, 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.

[0014] In the above preferred embodiment including the cleaning device, the volatile component collection device also includes a controller, and the controller is communicatively connected with the gas flow meter, the heater, the temperature sensor, the first gas circuit valve, the cooling device and the second gas circuit valve.

[0015] When the first gas circuit valve is closed, the second gas circuit valve is opened, and the infusion pump is started, the pipelines of the cleaning section and the collection section can be cleaned, avoiding the residual gas in the pipe from contaminating the next collection of volatile components, thereby improving the collection purity of the volatile component collection equipment.

[0016] Preferably, in step (1), the segmented heating procedure includes the heating stage number n and the end temperature T of each heating stage. n , where n is a positive integer greater than or equal to 1, T n-1 <T n .

[0017] Preferably, n is selected from any positive integer between 1 and 10.

[0018] More preferably, n is selected from any positive integer between 1 and 5.

[0019] Most preferably, n is any positive integer selected from 2, 3, 4 and 5.

[0020] The step (1) is performed on a thermogravimetric analyzer, and the heating stage n and the end point temperature T of each heating stage are determined according to the thermal weight loss of the tobacco sample in the heating temperature range. n .

[0021] More preferably, in step (1), the heating temperature range is from room temperature to 380° C., and the heating rate is 2 to 40° C. / min.

[0022] Further preferably, in the step (1), the heating temperature range is from room temperature to 360°C.

[0023] Also preferably, in step (1), the heating rate is 5 to 10° C. / min.

[0024] Preferably, in step (1), nitrogen is used as the purge gas at a flow rate of 10 to 100 ml / min, more preferably 60 ml / min. 。

[0025] Preferably, in step (1), nitrogen is used as the protective gas with a flow rate of 5 to 50 ml / min, more preferably 20 mL / min.

[0026] As a preferred embodiment, the specific operation of step (1) of the present invention is:

[0027] Take 50-500 mg of the tobacco sample to be tested and place it in a thermogravimetric platinum crucible of a thermogravimetric analyzer. Use nitrogen as the purge gas and protective gas, with flow rates of 10-100 mL / min and 5-50 mL / min, respectively. Heat from room temperature to 380°C at a rate of 2-40°C / min. Record the thermogravimetric curve (TG curve) and differential thermogravimetric curve (DTG curve) of the sample in the entire heating temperature range. Determine the segmented heating stage n and the end point temperature T of each stage of heating according to the thermal weight loss of the tobacco sample. n , where n is a positive integer greater than or equal to 1, T n-1 <T n .

[0028] As a more preferred embodiment, the specific operation of step (1) of the present invention is:

[0029] Take 100-300 mg of the tobacco sample to be tested and place it in the thermogravimetric platinum crucible of the thermogravimetric analyzer. Use nitrogen as the purge gas and protective gas with flow rates of 60 mL / min and 20 mL / min respectively. Heat from room temperature to 360 °C at a rate of 5-10 °C / min. Record the thermogravimetric curve (TG curve) and differential thermogravimetric curve (DTG curve) of the sample in the entire heating temperature range. Determine the segmented heating stage n and the end temperature T of each stage of heating according to the thermal weight loss of the tobacco sample. n , where n is a positive integer greater than or equal to 1, T n-1 <T n .

[0030] Preferably, n is selected from any positive integer between 1 and 5.

[0031] More preferably, n is any positive integer selected from 2, 3, 4 and 5.

[0032] Preferably, in step (2), the sampling amount of the tobacco sample to be tested is 50-500 mg; more preferably 250 mg.

[0033] Preferably, in step (2), a corresponding number of collecting bottles are prepared according to the stage number n of segmented heating determined in step (1), and the same volume of absorption liquid is transferred into each collecting bottle.

[0034] Preferably, in step (2), the absorption liquid is selected from one or more of cyclohexane, acetonitrile, ethyl acetate, methanol, ethanol and dichlorohexane in any proportion; more preferably, ethanol.

[0035] Also preferably, in step (2), the volume of the absorption liquid is 0.5 to 1.5 mL; more preferably 1 mL.

[0036] Preferably, in step (2), the temperature is raised according to the segmented heating program determined in step (1), with a heating rate of 160°C / min in each segment and insulation for 0.5 to 8 min; after the insulation is completed, the collection bottle is immediately replaced with a collection bottle containing blank absorption liquid.

[0037] More preferably, in step (2), the holding time of each stage of programmed temperature increase is 3 to 5 minutes.

[0038] Also preferably, in step (2), the carrier gas is selected from one or more of nitrogen, helium and air in any proportion, preferably nitrogen or helium.

[0039] Preferably, in step (2), the carrier gas flow rate is 0.5 to 5 mL / min, more preferably 5 mL / min.

[0040] Preferably, in step (2), the cooling device is a cold trap, and the temperature is set to -5 to 5°C, more preferably -2°C.

[0041] As a preferred embodiment, the specific operation of step (2) of the present invention is:

[0042] Accurately weigh 50-500 mg of the tobacco sample to be tested, place it in the storage chamber of the volatile component collection device, and set the temperature of the cooling device to -5-5°C; according to the segmented heating program determined in step (1), prepare n collection bottles, accurately draw 1 mL of ethanol respectively, and transfer it to each collection bottle respectively, then place all the collection bottles filled with ethanol in the cooling device, place one of them under the terminal outlet of the carrier gas pipeline collection section and immerse the terminal outlet in ethanol; if there is a second gas circuit valve, close the second gas circuit valve; open the first gas circuit valve, adjust the gas flow meter to set the carrier gas flow rate to 0.5-5 mL / min; according to the segmented heating program determined in step (1), start the programmed heating at a rate of 160°C / min, and keep the temperature for 0.5-8 min at each stage; after each stage of keeping the temperature is completed, immediately replace the collection bottle under the terminal outlet of the carrier gas pipeline until the segmented heating program is completed, and obtain n heated effluent samples of the tobacco sample to be tested.

[0043] As a more preferred embodiment, the specific operation of step (2) of the present invention is:

[0044] Accurately weigh 250 mg of the tobacco sample to be tested and place it in the material storage chamber of the volatile component collection device, and set the temperature of the cooling device to -2°C; according to the segmented heating program determined in step (1), prepare n collection bottles, accurately draw 1 mL of ethanol respectively, and transfer it to each collection bottle respectively, then place all the collection bottles filled with ethanol in the cooling device, and place one of them under the terminal outlet of the carrier gas pipeline collection section so that the terminal outlet is immersed in ethanol; if there is a second gas circuit valve, close the second gas circuit valve; open the first gas circuit valve, adjust the gas flow meter to set the nitrogen flow rate to 5 mL / min; according to the segmented heating program determined in step (1), start the program heating at a rate of 160°C / min, and keep each stage for 3 to 5 minutes; after each stage of keeping warm is completed, immediately replace the collection bottle under the terminal outlet of the carrier gas pipeline until the segmented heating program is completed, and obtain n heated effluent samples of the tobacco sample to be tested.

[0045] The step (2) may also include closing the first gas circuit valve, immersing the inlet of the infusion pump in the cleaning liquid, opening the second gas circuit valve, starting the infusion pump, cleaning the pipelines of the cleaning section and the collection section, and discarding the cleaning liquid.

[0046] Preferably, in step (1) and step (2), the tobacco sample is a core substrate of a heat-not-burn cigarette.

[0047] Preferably, in step (3), the heating effluent sample obtained in step (2) is directly detected without being processed.

[0048] In the step (3), 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 detector, 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.

[0049] As an exemplary embodiment, the step (3) uses gas chromatography-mass spectrometry, preferably gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry, to detect the effluent sample obtained in step (2).

[0050] As a preferred exemplary embodiment, in the step (3), the effluent sample obtained in step (2) is detected by gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry; wherein the chromatographic conditions are:

[0051] The chromatographic column was a DB-5 elastic capillary column, 60 m × 0.25 mm × 0.25 μm, with the inner wall coated with 5% phenyl / 95% methyl polysiloxane;

[0052] Carrier gas: Helium with purity >99.999%, constant flow rate 1.0mL / min;

[0053] Inlet temperature: 280°C;

[0054] Injection volume: 1 μL;

[0055] Injection method: split mode injection, split ratio is 15:1;

[0056] Column oven temperature program: 50°C, hold for 2 min; 6°C / min to 104°C, hold for 5 min; 6°C / min to 164°C, hold for 4 min; 6°C / min to 280°C, hold for 2 min;

[0057] The mass spectrometry conditions were:

[0058] Ionization mode: EI ionization source;

[0059] Ionization energy: 70 eV;

[0060] Ion source temperature: 280°C;

[0061] Transmission line temperature: 280°C;

[0062] Acquisition mode: Full scan;

[0063] Scanning range: 33-495Da;

[0064] Mass resolution: 60000FWHM (200m / z);

[0065] Lock mass (m / z): 73.04680, 133.0356, 207.03235, 281.05114, 355.06993.

[0066] As an optional embodiment, the method of the present invention may further include, after step (3): (4) processing and analyzing data.

[0067] The step (4) includes analyzing the test results obtained in step (3) with the aid of computer software and a database to identify the compounds therein; and may also include determining the content of the compounds therein.

[0068] In the present disclosure, unless otherwise specified, all solvents (such as the absorption liquid) are chromatographically pure.

[0069] The method of the present invention can continuously collect exudates in multiple heating temperature intervals for a heat-not-burn cigarette sample (e.g., core substrate), thereby solving the problem that the traditional method can only collect all exudates of the heat-not-burn cigarette below a certain temperature, but cannot collect exudates in a certain or several temperature intervals. The method of the present invention requires only a small amount of organic solvent, is time-saving, and is easy to operate; by being used in conjunction with appropriate separation and detection instruments, the purpose of segmented determination of exudates in the heating process of the heat-not-burn cigarette is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The present invention will be further described below in conjunction with the accompanying drawings.

[0071] 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:

[0072] 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.

[0073] Figure 2 Shown are thermogravimetric curves (TG curves) of two tobacco samples obtained in Example 2.

[0074] Figure 3 Shown are differential thermogravimetric curves (DTG curves) of two tobacco samples obtained in Example 2.

[0075] Figure 4 The photo shows segmented exudate samples (two groups) of two tobacco samples obtained in Example 3. The three collection bottles with lids next to each other in the figure are three exudate samples (one group) of one tobacco sample, and each group is exudate samples in the temperature ranges of room temperature → 120°C, 120°C → 240°C and 240°C → 360°C from left to right.

[0076] Figure 5 Shown is the total ion current chromatogram of a group of segmented effluent samples obtained in Example 3.

[0077] Figure 6 Shown is the total ion current chromatogram of another group of segmented effluent samples obtained in Example 3.

[0078] Figure 5 and Figure 6 In the figure, "1st" is the total ion current chromatogram of the escape from room temperature → 120℃; "2nd" is the total ion current chromatogram of the escape from 120℃ → 240℃; "3rd" is the total ion current chromatogram of the escape from 240℃ → 360℃. DETAILED DESCRIPTION

[0079] 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.

[0080] 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:

[0081] Thermogravimetric analyzer: STA 449F3 NETZSCH, Germany;

[0082] Gas chromatography-quadrupole / electrostatic field orbitrap high-resolution mass spectrometer: TRACE1610-OrbitrapExploris GC, equipped with TriPlus RSH smart autosampler, Thermo Scientific, USA;

[0083] DB-5 elastic capillary column, inner wall coating is 5% phenyl / 95% methyl polysiloxane, 60m×0.25mm×0.25μm, Agilent, USA.

[0084] Example 1: A volatile component collection device

[0085] like Figure 1As shown, a volatile component collection device includes a carrier gas pipeline 1, a gas flow meter 2, a heating device, a material storage cavity 3, a first gas circuit valve 5, a collecting device, a cooling device 8, a cleaning device 9, a second gas circuit valve 10, a three-way pipe joint and a controller. 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 second gas circuit valves 10 are connected and installed on the cleaning section 14. The gas flow meter 2 is connected and installed on the conveying section of the carrier gas pipeline 1. A storage chamber 4 is arranged in the material storage cavity 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 arranged 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 cavity 3, and the temperature sensor is arranged in the storage cavity 4. The first gas circuit valve 5 is connected to the conveying section of the carrier gas pipeline 1 after the material storage cavity 3. The collecting device includes a collecting bottle 6 with an absorption liquid placed therein, the collecting bottle 6 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 submerges the end opening of the collecting section 13. The cooling device 8 is used to cool the solvent in the collecting bottle 6, so the collecting bottle 6 is placed in the cooling device 8. The cleaning device 9 includes an infusion pump and a cleaning bottle with a cleaning liquid placed therein. 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. The controller is connected in communication with the gas flow meter 2, the heater, the temperature sensor, the first gas circuit valve 5 and the second gas circuit valve 10. The controller can also be connected in communication with the cooling device.

[0086] The cooling device 8 may be a cold trap or an ice bath, preferably a cold trap, and more preferably a condensation trap.

[0087] 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 the cooling device is started; then, the solid or liquid sample is placed in the storage chamber 4 of the material storage chamber 3; the first gas circuit valve 5 is opened, and the second gas circuit valve 10 is closed; finally, the controller turns on the heater, and the heater heats the solid or liquid sample in the storage chamber 4. The gas in the carrier gas pipeline 1 at a specific flow rate will carry the volatile components in the storage chamber 4 through the collection section 13 to the collection bottle 6, and be absorbed by the absorption liquid. By setting a segmented heating program and replacing the collection bottle, the collection of volatile components in each specific temperature range can be achieved.

[0088] After the 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 and improving the collection purity of the volatile component collection equipment.

[0089] Example 2 Thermal Analysis of Heat-Not-Burn Cigarette Core Substrates A and B and Determination of Segmented Heating Program

[0090] The changes of the core substrates A and B of two heat-not-burn cigarettes during the heating process were investigated using a thermogravimetric analyzer. The specific operation was as follows:

[0091] 250 mg of core substrate was taken and placed in a platinum crucible of a thermogravimetric analyzer. Nitrogen was used as the purge gas and protective gas, with flow rates of 60 mL / min and 20 mL / min, respectively. The temperature was raised from room temperature to 360 °C at 10 °C / min, and the thermogravimetric curve (TG curve) and differential thermogravimetric curve (DTG curve) of the core substrate were recorded in the entire heating temperature range.

[0092] Figure 2 Thermogravimetric curves (TG curves) of core substrates A and B are shown. Figure 3 The differential thermogravimetric curves (DTG curves) of core substrates A and B are shown. Figure 2 and Figure 3 It is shown that the two core substrates have similar thermal weight loss behaviors: the first stage, room temperature → 120°C, is mainly the volatilization and escape of water and small molecular compounds; the second stage, 120°C → 240°C, is mainly the release of nicotine, humectants (propylene glycol and glycerol) and volatile components; the third stage, 240°C → 360°C, is mainly the degradation of cellulose, hemicellulose and non-volatile components. Based on this, three heating temperature sections were determined: room temperature → 120°C, 120°C → 240°C and 240°C → 360°C; that is, the segmented heating procedures of core substrates A and B are:

[0093] n=3, T1=120℃, T2=240℃, T3=360℃.

[0094] Example 3 Segmented collection of emissions from two core substrates A and B during heating

[0095] The volatile component collection device of Example 1 is used, and the three-stage effluent of the core substrates A and B in the temperature range of room temperature to 360° C. is collected in stages according to the staged heating program determined in Example 2. The specific operation is:

[0096] 250 mg of core substrate was placed in the storage chamber 4 of the volatile component collection device of Example 1, and the temperature of the cooling device 8 was set to -2°C. 1 mL of ethanol was accurately drawn and transferred to the collection bottle 6 as the absorption liquid; three collection bottles with absorption liquid were prepared in the same way. Then all three collection bottles were placed in the cooling device 8, and one of the collection bottles was placed below the end outlet of the collection section 13 of the carrier gas pipeline and the outlet was immersed in the absorption liquid. Close the second gas circuit valve; open the first gas circuit valve, adjust the gas flow meter to set the nitrogen flow rate to 5 mL / min. The heating layer heating program was set according to the segmented heating program determined in Example 2 to achieve the heating of the tobacco sample at different temperature sections. The segmented heating program was set as follows: the room temperature was raised to 120°C and maintained for 4 minutes; then raised to 240°C and maintained for 4 minutes; finally raised to 360°C and maintained for 4 minutes; the heating rate for each section was 160°C / min. The exudates from the temperature rise to the insulation period in each temperature section were collected in the same collection bottle to obtain the exudate samples in the corresponding temperature section. Finally, stop heating the heating layer and close the first gas path valve.

[0097] Immerse the inlet of the infusion pump in the cleaning liquid (ethanol), open the second gas circuit valve, start the infusion pump, clean the pipelines of the cleaning section and the collection section, and discard the cleaning liquid.

[0098] Through the above operations, three samples of exudates were obtained from the core substrates A and B, corresponding to the exudates in three temperature ranges respectively. Figure 4 The photographs show the effluent samples of core substrates A and B. Figure 4 As shown in the figure, as the heating temperature continues to rise, the color of the absorption liquid gradually becomes darker, indicating that more components escape at higher temperatures. The intuitive difference in the color of the absorption liquid at different temperature ranges also shows that the method of the present invention can be used to study the changes in the escaped substances of a material (such as the core substrate of this embodiment) in different temperature ranges.

[0099] Example 4 Detection of the effluent sample obtained in Example 3

[0100] The effluent sample obtained in Example 3 was detected by gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry.

[0101] The chromatographic conditions are:

[0102] The chromatographic column was a DB-5 elastic capillary column, 5% phenyl / 95% methylpolysiloxane (60 m × 0.25 mm × 0.25 μm, Agilent, USA);

[0103] Carrier gas: helium (purity>99.999%), constant flow rate of 1.0 mL / min;

[0104] Inlet temperature: 280°C;

[0105] Injection volume: 1 μL;

[0106] Injection method: split mode injection, split ratio is 15:1;

[0107] The column oven temperature program conditions were as follows: 50°C, hold for 2 min, increase to 104°C at 6°C / min, hold for 5 min, increase to 164°C at 6°C / min, hold for 4 min, increase to 280°C at 6°C / min, hold for 2 min.

[0108] Mass spectrometry conditions:

[0109] Ionization mode: EI ionization source;

[0110] Ionization energy: 70 eV;

[0111] Ion source temperature: 280°C;

[0112] Transmission line temperature: 280°C;

[0113] Acquisition mode: Full scan;

[0114] Scanning range: 33-495Da;

[0115] Mass resolution: 60000FWHM (200m / z);

[0116] Lock mass (m / z): 73.04680, 133.0356, 207.03235, 281.05114, 355.06993.

[0117] Under the above conditions, the total ion current chromatograms of the three effluent samples obtained from each core substrate are shown in Figure 5 and Figure 6 .observe Figure 5 and Figure 6 It can be found that the total ion flow chromatograms of the three exudate samples obtained from the two tobacco samples have the same pattern, showing that the chromatographic peak intensity in the first stage is the weakest and the number of chromatographic peaks is the least ("1st" in the figure), and the chromatographic peak intensity in the next two stages is stronger and the number of chromatographic peaks is larger ("2nd" and "3rd" in the figure). The second temperature interval ("2nd") shows the strongest chromatographic peak intensity at a retention time of around 11.5 minutes (nicotine), and the first temperature interval also shows the strongest chromatographic peak intensity at a retention time of around 11.5 minutes, which provides a method for studying nicotine release behavior. Excluding the chromatographic peak of nicotine, the chromatographic peak intensity in the third stage is the highest and the number of chromatographic peaks is the largest, which corresponds to the color depth of the exudate samples. In addition, Figure 5 and Figure 6It is also shown that there are differences in the total ion current chromatograms of the two core substrates at the same heating stage. The above shows that the method of the present invention can be used to study the emission of tobacco samples in the heating process in stages.

[0118] Example 5 Analysis and processing of data obtained by gas chromatography-mass spectrometry detection

[0119] Thermo Scientific TM The chromatographic and mass spectrometric data obtained in Example 4 were processed by TraceFinder and Compound Discoverer 3.3 software, and the data were processed through the steps of data import, peak extraction, deconvolution, database search, compound identification and subsequent statistical analysis. Among them, the peak analysis (deconvolution) was automatically performed by TraceFinder, and the compound identification was performed in combination with commercial mass spectrometric databases (NIST, Wiley, etc.). The parameters in the data processing method were set as follows: mass deviation: 5ppm; signal-to-noise ratio (S / N) threshold: 3; total ion current (TIC) threshold: 1.0×10 6 Since the amount of effluent collected during the period from room temperature to 120°C is relatively small, only the search results of the two tobacco samples obtained by the above-mentioned treatment method during this period are shown below. The results are shown in Tables 1 and 2.

[0120] The present invention provides a method for using a volatile component collection device to collect and then detect exudates from tobacco products (such as the core substrate of heat-not-burn cigarettes) during heating. The device of the present invention heats the same tobacco sample in sections, and the exudates from the sample in different heating sections are absorbed by a cooled absorption liquid, and then detected and analyzed (such as using gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry). The present invention solves the problem that traditional methods can only analyze exudates below a certain temperature T (≤T), and can collect, analyze and compare the exudates of a sample in multiple heating temperature intervals. The method only requires a small amount of organic solvent, is short in time, and is easy to operate. By combining it with an appropriate analytical instrument (such as a gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry), the purpose of studying the exudates from tobacco samples during heating in a segmented manner is achieved efficiently and conveniently.

[0121] The above embodiments are only preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

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[0127]

Claims

1. A method for segmentally determining the emission of a tobacco sample during heating, comprising: (1) determining a segmented heating procedure, (2) collecting samples of exudates from the tobacco sample to be tested at different temperature segments, and (3) detecting the samples of exudates; wherein said step (2) is based on a volatile component collection device; The volatile component collection equipment 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 cooling device; wherein the gas flow meter is connected and installed on the carrier gas pipeline; a storage cavity for placing the tobacco sample to be tested is arranged 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 absorption liquid in the collecting bottle submerges the end opening of the carrier gas pipeline; the collecting bottle is placed in the cooling device.

2. The method according to claim 1, characterized in that 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; 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.

3. The method according to claim 1 or 2, characterized in that: The volatile component collection device further includes a controller, which is communicatively connected with the gas flow meter, the heater, the temperature sensor, and the first gas path valve; Preferably, the controller is communicatively connected with the gas flow meter, the heater, the temperature sensor, the first gas path valve and the cooling device.

4. The method according to claim 1, 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 placed therein, 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.

5. The method according to claim 4, characterized in that The volatile component collection device further comprises a controller, which is communicatively connected with the gas flow meter, the heater, the temperature sensor, the first gas path valve, the cooling device and the second gas path valve.

6. The method according to claim 1, characterized in that In step (1), the segmented heating procedure includes the heating stage number n and the end temperature T of each heating stage. n , where n is a positive integer greater than or equal to 1, T n-1 <T n ; Preferably, n is selected from any positive integer between 1 and 10; More preferably, n is selected from any positive integer between 1 and 5; Most preferably, n is any positive integer selected from 2, 3, 4 and 5.

7. The method according to claim 6, characterized in that The step (1) is performed on a thermogravimetric analyzer, and the heating stage n and the end point temperature T of each heating stage are determined according to the thermal weight loss of the tobacco sample in the heating temperature range. n ; Preferably, in step (1), the heating temperature range is room temperature to 380°C, and the heating rate is 2 to 40°C / min; Further preferably, in step (1), the heating temperature range is room temperature to 360°C; Also preferably, in step (1), the heating rate is 5 to 10°C / min; Also preferably, in the step (1), nitrogen is used as the purge gas, with a flow rate of 10 to 100 ml / min, more preferably 60 ml / min; Preferably, in step (1), nitrogen is used as the protective gas with a flow rate of 5 to 50 ml / min, more preferably 20 mL / min.

8. The method according to claim 1, 6 or 7, characterized in that: The specific operation of step (1) is: Take 50-500 mg of the tobacco sample to be tested and place it in a thermogravimetric platinum crucible of a thermogravimetric analyzer. Use nitrogen as the purge gas and protective gas, with flow rates of 10-100 mL / min and 5-50 mL / min, respectively. Heat from room temperature to 380°C at a rate of 2-40°C / min. Record the thermogravimetric curve (TG curve) and differential thermogravimetric curve (DTG curve) of the sample in the entire heating temperature range. Determine the segmented heating stage n and the end point temperature T of each stage of heating according to the thermal weight loss of the tobacco sample. n , where n is a positive integer greater than or equal to 1, T n-1 <T n ; Preferably, the specific operation of step (1) is: Take 100-300 mg of the tobacco sample to be tested and place it in the thermogravimetric platinum crucible of the thermogravimetric analyzer. Use nitrogen as the purge gas and protective gas with flow rates of 60 mL / min and 20 mL / min respectively. Heat from room temperature to 360 °C at a rate of 5-10 °C / min. Record the thermogravimetric curve (TG curve) and differential thermogravimetric curve (DTG curve) of the sample in the entire heating temperature range. Determine the segmented heating stage n and the end temperature T of each stage of heating according to the thermal weight loss of the tobacco sample. n , where n is a positive integer greater than or equal to 1, T n-1 <T n ; Preferably, n is selected from any positive integer between 1 and 5; More preferably, n is any positive integer selected from 2, 3, 4 and 5.

9. The method according to claim 1, 6, 7 or 8, characterized in that: In the step (2), the sampling amount of the tobacco sample to be tested is 50 to 500 mg, more preferably 250 mg; Preferably, in step (2), a corresponding number of collecting bottles are prepared according to the stage number n of segmented heating determined in step (1), and the same volume of absorption liquid is transferred into each collecting bottle; Preferably, in step (2), the absorption liquid is selected from one or more of cyclohexane, acetonitrile, ethyl acetate, methanol, ethanol and dichlorohexane in any proportion; more preferably, ethanol; Also preferably, in step (2), the volume of the absorption liquid is 0.5 to 1.5 mL; more preferably 1 mL; Preferably, in step (2), the temperature is programmed to rise according to the segmented heating program determined in step (1), with a heating rate of 160° C. / min in each segment and insulation for 0.5 to 8 min; after the insulation is completed, the collection bottle is immediately replaced with a collection bottle containing a blank absorption solution; More preferably, in step (2), the holding time of each stage of the programmed temperature increase is 3 to 5 minutes; Also preferably, in step (2), the carrier gas is selected from one or more of nitrogen, helium and air in any proportion, preferably nitrogen or helium; Preferably, in step (2), the carrier gas flow rate is 0.5 to 5 mL / min, more preferably 5 mL / min; Preferably, in step (2), the cooling device is a cold trap, and the temperature is set to -5 to 5°C, more preferably -2°C.

10. The method according to claim 9, characterized in that The specific operation of step (2) is: Accurately weigh 50-500 mg of the tobacco sample to be tested, place it in the storage chamber of the volatile component collection device, and set the temperature of the cooling device to -5-5°C; according to the segmented heating program determined in step (1), prepare n collection bottles, accurately draw 1 mL of ethanol respectively, and transfer it to each collection bottle respectively, then place all the collection bottles filled with ethanol in the cooling device, place one of them below the terminal outlet of the carrier gas pipeline collection section and immerse the terminal outlet in ethanol; if there is a second gas circuit valve, close the second gas circuit valve; open the first gas circuit valve, adjust the gas flow meter to set the carrier gas flow rate to 0.5-5 mL / min; according to the segmented heating program determined in step (1), start the programmed heating at a rate of 160°C / min, and keep the temperature for 0.5-8 min per stage; after each stage of keeping the temperature, immediately replace the collection bottle under the terminal outlet of the carrier gas pipeline until the segmented heating program is completed, and obtain n heated effluent samples of the tobacco sample to be tested; Preferably, the specific operation of step (2) is: Accurately weigh 250 mg of the tobacco sample to be tested and place it in the material storage chamber of the volatile component collection device, and set the temperature of the cooling device to -2°C; according to the segmented heating program determined in step (1), prepare n collection bottles, accurately draw 1 mL of ethanol respectively, and transfer it to each collection bottle respectively, then place all the collection bottles filled with ethanol in the cooling device, and place one of them under the terminal outlet of the carrier gas pipeline collection section so that the terminal outlet is immersed in ethanol; if there is a second gas circuit valve, close the second gas circuit valve; open the first gas circuit valve, adjust the gas flow meter to set the nitrogen flow rate to 5 mL / min; according to the segmented heating program determined in step (1), start the program heating at a rate of 160°C / min, and keep each stage for 3 to 5 minutes; after each stage of keeping warm is completed, immediately replace the collection bottle under the terminal outlet of the carrier gas pipeline until the segmented heating program is completed, and obtain n heated effluent samples of the tobacco sample to be tested.

11. The method according to any one of claims 1 to 10, characterized in that In the steps (1) and (2), the tobacco sample is a core substrate of a heat-not-burn cigarette.

12. The method according to claim 1, characterized in that In the step (3), the heating effluent sample obtained in the step (2) is directly tested without being processed.

13. The method according to claim 1 or 12, characterized in that: In the step (3), the separation method can be selected from gas chromatography or high performance liquid chromatography; the detector can be 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.

14. The method according to claim 13, characterized in that The step (3) uses gas chromatography-mass spectrometry, preferably gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry, to detect the effluent sample obtained in step (2).

15. The method according to claim 14, characterized in that In the step (3), the effluent sample obtained in step (2) is detected by gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry; wherein the chromatographic conditions are: The chromatographic column was a DB-5 elastic capillary column, 60 m × 0.25 mm × 0.25 μm, with the inner wall coated with 5% phenyl / 95% methyl polysiloxane; Carrier gas: Helium with purity >99.999%, constant flow rate 1.0mL / min; Inlet temperature: 280°C; Injection volume: 1 μL; Injection method: split mode injection, split ratio is 15:1; Column oven temperature program: 50°C, hold for 2 min; 6°C / min to 104°C, hold for 5 min; 6°C / min to 164°C, hold for 4 min; 6°C / min to 280°C, hold for 2 min; The mass spectrometry conditions were: Ionization mode: EI ionization source; Ionization energy: 70 eV; Ion source temperature: 280°C; Transmission line temperature: 280°C; Acquisition mode: Full scan; Scanning range: 33-495Da; Mass resolution: 60000FWHM (200m / z); Lock mass (m / z): 73.04680, 133.0356, 207.03235, 281.05114, 355.06993.

16. The method according to any one of claims 1 to 15, characterized in that After step (3), the following may also be included: (4) processing and analyzing the data; Preferably, the step (4) includes analyzing the test results obtained in step (3) with the aid of computer software and a database to identify the compounds therein; it may also include determining the content of the compounds therein.

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