Simple and novel method for measuring nicotine content in smoke based on density

Abstract

The invention belongs to the technical field of smoke nicotine content measurement, and discloses a method for measuring the nicotine content in smoke based on density. According to the method, by applying the characteristic that the density linearly changes along with the change of the nicotine content, the density of nicotine solutions with different concentrations is tested in advance, and a standard linear equation that the density changes along with the nicotine content at different temperatures is established at a time; and then measuring the density value of a sample with the nicotine content to be measured, and substituting the density value into the linear equation at the corresponding temperature to obtain the nicotine content in the sample to be measured. The method has the characteristics of accurate test result, simplicity in operation, short measurement time and low cost, and can be used for measuring the nicotine content in tobacco products and smoke. The problems of tedious operation process, long time consumption, high measurement cost and the like in the existing chromatographic detection technology are effectively solved.

Description

Technical Field

[0001] The present invention relates to a method for measuring the nicotine content in flue gas by density, a method for measuring the nicotine content in flue gas based on density. Background Art

[0002] Nicotine accounts for more than 90% of the total tobacco alkaloids and is the most important alkaloid in tobacco. The nicotine in the mainstream cigarette smoke exists in the particulate matter of the flue gas. Therefore, accurately measuring the nicotine in the total particulate matter of the mainstream cigarette smoke is an important index for cigarette quality control. At present, the determination of nicotine in the total particulate matter of cigarette smoke mainly uses gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS).

[0003] Since the signal response of the instrument is greatly affected by the operating conditions, internal standard method is generally used for quantification in GC or GC-MS determination. Anethole, n-heptadecane, quinoline and other are commonly used internal standard reagents. In addition, when using GC-MS or GC determination with capillary column for separation, the test solution needs to be dehydrated with reagents such as anhydrous sodium sulfate before being injected into the instrument for analysis. Although the above methods can accurately measure the concentrations of nicotine and water, there are also problems such as cumbersome operation and time-consuming, and the calibration substances of this method are expensive, which seriously affect the measurement efficiency and increase the measurement cost. Summary of the Invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a method for measuring the nicotine content in flue gas based on density, a relatively simple method for detecting the nicotine content in the mainstream cigarette smoke and its application. By establishing the standard linear equation through the correlation between density and concentration to analyze the nicotine content in the flue gas. Solve the problems of cumbersome operation process and high detection cost in the prior art, and provide an effective way for controlling the nicotine content in cigarette formula design.

[0005] The technical solution of the present invention is: a method for measuring the nicotine content in flue gas based on density, comprising the following steps:

[0006] Step (1), dissolving nicotine standard solution in an organic solvent respectively to prepare a series of nicotine solutions with different concentrations;

[0007] Step (2), using a densitometer to measure the densities of the above nicotine solutions with different concentrations at different temperatures;

[0008] Step (3): Respectively take the concentration value and density value of the nicotine solution at different temperatures as the horizontal and vertical coordinates for linear fitting, and establish a standard straight-line equation for the linear change of nicotine content with density at different temperatures: ρ = a1m + b1, where m is the concentration value of the nicotine solution, with the unit of mg / mL; ρ is the corresponding density value of the nicotine solution at a certain concentration, with the unit of g / cm 3 ; where a1 and b1 are constants, and a1 and b1 change with the change of temperature;

[0009] Step (4): Extract the nicotine-containing filter disc of the smoking machine with isopropyl alcohol to obtain extraction liquid A. The nicotine content of extraction liquid A is unknown. Use a densitometer to measure its density value ρ1, with the unit of g / cm 3 , and substitute the measured density value ρ1 of the nicotine solution into the standard straight-line equation at the corresponding temperature to calculate that the nicotine content in the sample to be measured is m1, with the unit of mg / mL.

[0010] Further, the standard straight-line equations at different temperatures of 22°C, 24°C, 26°C, and 28°C are respectively: ρ = 1.8494×10 -4 m + 0.78355; ρ = 1.8489×10 -4 m + 0.78187; ρ = 1.8476×10 -4 m + 0.78017; ρ = 1.8476×10 -4 m + 0.77847.

[0011] Further, the organic solvent in step (1) is one or more of alcohol, ether, and chloroform.

[0012] Further, the organic solvent is selected as isopropyl alcohol.

[0013] Further, in step (1), the nicotine standard solution is dissolved in the organic solvent by shaking. The shaking time is 20 min - 30 min, and the standing time after shaking is 10 min.

[0014] Further, in step (1), the nicotine standard solution is dissolved in the organic solvent at room temperature.

[0015] Further, the concentration of the nicotine solution is 0.01 - 1.5 mg / mL.

[0016] Further, in step (2), the temperature range is 20 - 30°C, and measurements are taken at intervals of 2°C.

[0017] Further, the extraction in step (4) is carried out by shaking extraction at room temperature; the shaking time is 20 min - 30 min, and the standing time is 10 min.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The method for measuring the nicotine content in flue gas by density provided by the present invention is simple to operate, fast in measurement speed, and accurate and reliable in analysis results.

[0020] 2. It does not require special instruments and internal standards, has a relatively low test cost, can be used for the determination of nicotine content in the flue gas of cigarettes, provides an effective way for controlling the nicotine content in cigarette formulations, and can be applied to the quantitative detection of the content of a certain component in multi-component samples. Specific embodiments

[0021] Establishment of the standard linear equation:

[0022] A series of nicotine solutions with different concentrations are prepared by dissolving different amounts of nicotine standard solution in the solvent isopropanol. They are detected according to the method in the invention content, that is: first, weigh 1.0 g of nicotine standard solution and add isopropanol solution to make up to 100 mL volumetric flask, and place it on a magnetic stirrer for 10 min to obtain a nicotine primary solution with a concentration of 10 mg / mL; then take 10 μL, 20 μL, 50 μL, 100 μL, 0.3 mL, 0.7 mL, and 1.5 mL of the primary solution respectively and add isopropanol solution to make up to 10 mL volumetric flask to obtain nicotine solutions with concentrations of 0.01 mg / mL, 0.02 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.3 mg / mL, 0.7 mg / mL, and 1.5 mg / mL. Use a densitometer to measure the density of the above nicotine solutions with different contents at different temperatures. Respectively take the concentration values and density values of the nicotine solutions at different temperatures as the abscissa and ordinate for linear fitting, and establish a standard linear equation for the linear change of nicotine content with density at different temperatures: ρ = a1m + b1, where m is the concentration value of the nicotine solution (mg / mL); ρ is the corresponding density value of the nicotine solution at a certain concentration (g / cm 3 ); where a1 and b1 are constants, and a1 and b1 will change with the change of temperature.

[0023] Four groups of nicotine solutions with unknown concentrations are prepared in the laboratory, numbered 1, 2, 3, and 4 respectively. At 22 °C, 24 °C, 26 °C, and 28 °C, for the accuracy of the experiment, three different concentrations of nicotine solutions are prepared for each group and then averaged.

[0024] Example 1

[0025] Predicted value:

[0026] (1) The density of the No. 1 nicotine solution is measured with a densitometer, and the density measurement results of the three groups of solutions are 0.783633 g / cm 3, 0.783632 g / cm 3 , 0.783633 g / cm 3 , Then substitute the density value of the solution into the standard linear equation ρ = 1.8494×10 -4 m + 0.78355, and calculate the corresponding concentration values: 0.4488 mg / mL, 0.4434 mg / mL, 0.4488 mg / mL. Take the average of the three concentration measurement results, and the final result is: 0.4470 mg / mL.

[0027] Measured value:

[0028] (2) The nicotine content in the No. 1 nicotine solution was determined by gas chromatography (GC), and the internal standard was n - heptadecane. The three - group solution concentration measurement results were: 0.4412 mg / mL, 0.4481 mg / mL, 0.4484 mg / mL. Take the average of the three measurement results, and the final result is: 0.4459 mg / mL. It meets the existing measurement requirements.

[0029] Example 2

[0030] Predicted value:

[0031] (1) The density of the No. 2 nicotine solution was measured with a densitometer. The three - group solution density measurement results were 0.781898 g / cm 3 , 0.781898 g / cm 3 , 0.781899 g / cm 3 , Then substitute the density value of the solution into the standard linear equation ρ = 1.8489×10 -4 m + 0.78187, and calculate the corresponding concentration values: 0.1514 mg / mL, 0.1514 mg / mL, 0.1569 mg / mL. Take the average of the three concentration measurement results, and the final result is: 0.1532 mg / mL.

[0032] Measured value:

[0033] (2) The nicotine content in the No. 2 nicotine solution was determined by gas chromatography (GC), and the internal standard was n - heptadecane. The three - group solution concentration measurement results were: 0.1535 mg / mL, 0.1557 mg / mL, 0.1573 mg / mL. Take the average of the three measurement results, and the final result is: 0.1561 mg / mL. It meets the existing measurement requirements.

[0034] Example 3

[0035] Predicted value:

[0036] (1) The density of the No. 3 nicotine solution was measured with a densitometer. The density measurement results of the three groups of solutions were 0.780219 g / cm 3 , 0.780220 g / cm 3 , 0.780219 g / cm 3 . Then, the density value of the solution was substituted into the standard linear equation ρ = 1.8476×10 -4 m + 0.78017 at 26°C to calculate the corresponding concentration values: 0.2652 mg / mL, 0.2706 mg / mL, 0.2652 mg / mL. The average value of the three concentration measurement results was taken, and the final result was: 0.2670 mg / mL.

[0037] Measured value:

[0038] (2) The nicotine content in the No. 3 nicotine solution was determined by gas chromatography (GC), and the internal standard was n - heptadecane. The concentration measurement results of the three groups of nicotine solutions were: 0.2671 mg / mL, 0.2668 mg / mL, 0.2679 mg / mL. The average value of the three measurement results was taken, and the final result was: 0.2672 mg / mL. It meets the existing measurement requirements.

[0039] Example 4

[0040] Predicted value:

[0041] (1) The density of the No. 4 nicotine solution was measured with a densitometer. The density measurement results of the three groups of nicotine solutions were 0.778531 g / cm 3 , 0.778533 g / cm 3 , 0.778532 g / cm 3 . Then, the density value of the solution was substituted into the standard linear equation ρ = 1.8476×10 -4 m + 0.77847 at 28°C to calculate the corresponding concentration values: 0.3302 mg / mL, 0.3410 mg / mL, 0.3356 mg / mL. The average value of the three concentration measurement results was taken, and the final result was: 0.3356 mg / mL.

[0042] Measured value:

[0043] (2) The nicotine content in the No. 4 nicotine solution was determined by gas chromatography (GC), and the internal standard was n - heptadecane. The concentration measurement results of the three groups of nicotine solutions were: 0.3325 mg / mL, 0.3398 mg / mL, 0.3394 mg / mL. The average value of the three measurement results was taken, and the final result was: 0.3372 mg / mL. It meets the existing measurement requirements.

[0044]

[0045]

[0046] Method reliability test:

[0047] The accuracy of the prediction model was evaluated by three indicators of mean absolute error, root mean square error RMSE and mean relative error used in this study. The calculation formulas are as follows:

[0048] In the above formula, Z i - Actual measured value, n - Number of verification samples; - Predicted value. The smaller the value of RMSE, the more accurate the prediction result and the higher the accuracy. Through calculation, The values of RMSE were: 0.006625, 0.00145 mg / mL, 0.00175 mg / mL. There was no significant difference between the predicted value and the measured value in terms of statistical significance, which proved that this method had high accuracy.

Claims

1. A method for measuring nicotine content in smoke based on density, characterized in that: The following steps are involved: Step (1), dissolving the nicotine standard solution in organic solvents to prepare a series of nicotine solutions with different concentrations; Step (2), using a densitometer to measure the density of the nicotine solutions of different concentrations at different temperatures; Step (3), using the concentration value and density value of the nicotine solution at different temperatures as the horizontal and vertical coordinates for linear fitting, and establishing a standard linear equation for the linear change of nicotine content with density at different temperatures: ρ = a1m + b1, m is the concentration value of the nicotine solution, the unit is mg / mL; ρ is the corresponding density value of the nicotine solution at a certain concentration, the unit is g / cm 3 ; Where a1 and b1 are constants, and a1 and b1 change with temperature; Step (4), extracting the nicotine-containing filter of the smoking machine with isopropanol to obtain an extract A. The nicotine content of the extract A is unknown. The density value ρ1 is measured by a densitometer in g / cm 3 , substitute the measured density value ρ1 of the nicotine solution into the standard linear equation at the corresponding temperature, and calculate the nicotine content in the sample to be tested as m1, in mg / mL.

2. The method for measuring nicotine content in smoke based on density according to claim 1, characterized in that: The standard linear equations at different temperatures of 22°C, 24°C, 26°C, and 28°C are: ρ = 1.8494 × 10 -4 m+0.78355、ρ=1.8489×10 -4 m+0.78187、ρ=1.8476×10 -4 m+0.78017、ρ=1.8476×10 -4 m+0.77847.

3. The method for measuring nicotine content in smoke based on density according to claim 1, characterized in that: The organic solvent in step (1) is one or more of alcohol, ether and chloroform.

4. The method for measuring nicotine content in smoke based on density according to claim 3, characterized in that: The organic solvent is isopropanol.

5. The method for measuring nicotine content in smoke based on density according to claim 1, characterized in that: In the step (1), the nicotine standard solution is dissolved in the organic solvent by shaking, the shaking time is 20 min-30 min, and the standing time after shaking is 10 min.

6. The method for measuring nicotine content in smoke based on density according to claim 1, characterized in that: The nicotine standard solution described in step (1) is dissolved in an organic solvent at room temperature.

7. The method for measuring nicotine content in smoke based on density according to claim 1, characterized in that: The concentration of the nicotine solution is 0.01-1.5 mg / mL.

8. The method for measuring nicotine content based on density according to claim 1, characterized in that: In step (2), the temperature range is 20-30°C, and the measurement is performed at 2°C intervals.

9. The method for measuring nicotine content in smoke based on density according to claim 1, characterized in that: The extraction in step (4) is carried out under shaking at room temperature; the shaking time is 20 min-30 min, and the standing time is 10 min.

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