Disclosure of Invention
The invention aims to solve the problems in the prior art and realize the rapid and accurate analysis of flavor components in tobacco and tobacco products, and provides a purging and trapping method of the flavor components in the tobacco and the tobacco products, in particular to a method combining ultrasonic water bath extraction, purging and trapping, gas chromatography and mass spectrometry, wherein the method adopts a liquid sample introduction mode of a purging and trapping instrument.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for purging and trapping aroma components in tobacco and tobacco products comprises the steps that water is used as an extracting agent, the sample is firstly extracted through ultrasonic water bath, and then purging and trapping are carried out under the salting-out condition; the temperature of the ultrasonic water bath extraction is 72-95 ℃, and the time is 10-120 min.
The method combines ultrasonic water bath extraction and blowing and trapping, can achieve the aim of effectively extracting the flavor components in the tobacco and the tobacco products under the condition of not using an organic reagent, and compared with the method for extracting the tobacco components by relying on the organic reagent in the prior art, the method avoids the loss of the flavor components caused by the organic reagent and reduces the pollution of the organic reagent to the environment.
Preferably, the salting-out condition is that 5-35% by weight of sodium chloride is added into the extraction liquid, and the purging temperature for purging and trapping is 40-95 ℃. Salting out can change the solubility of the sample, facilitating separation of the components from the water. The higher the solubility of the component, the lower its purging efficiency, and for the high water-soluble component, the purging efficiency can only be increased by increasing the purging temperature.
Preferably, the method for purging and trapping the flavor components in the tobacco and the tobacco products comprises the following steps:
(1) processing tobacco and tobacco products into tobacco shreds with area of 1mm × 10 mm;
(2) weighing cut tobacco, and mixing the cut tobacco with water according to a certain weight volume ratio to obtain an aqueous solution;
(3) performing ultrasonic water bath extraction on the aqueous solution to obtain an extract liquid;
(4) sucking the extract, placing the extract in a purge bottle, and adding sodium chloride;
(5) the purge gas passes through the sample in the purge bottle, and the fragrant components are volatilized from the water phase along with the purge gas through bubbling;
(6) the fragrance components are captured when passing through the trap, and then are desorbed to be back blown into a gas chromatography sample inlet, separated by a chromatographic column and then enter a mass spectrum for detection.
Through a large number of experiments, the loss of flavor components caused by mechanical force can be obviously reduced by processing the tobacco and the tobacco products into cut tobacco with the area of 1mm multiplied by 10mm compared with the conventional tobacco powder processed by the tobacco and the tobacco products.
More preferably, the tobacco shreds are mixed with water according to the weight-volume ratio of 1: 16-1: 18.
More preferably, the temperature of the ultrasonic water bath extraction is 80 ℃ and the time is 60 min.
More preferably, the ultrasonic power of the ultrasonic water bath extraction is 1400W.
More preferably, the salting-out condition is to add 25% by weight of sodium chloride to the extract.
More preferably, the purge temperature of the purge trap is 80 ℃.
More preferably, the desorption temperature in step (6) is 200 ℃; the desorption time was 2.0 min. Higher desorption temperatures allow better feeding of the volatiles into the gas chromatography column, giving a narrow chromatographic peak, typically 200 ℃.
The method adopts an internal standard method to carry out quantitative analysis on the fragrance components, takes methyl phenylacetate as an internal standard and water as a solvent to prepare a series of standard solutions of the fragrance components.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention does not use organic reagent in the extraction process of the fragrance components, thereby avoiding the loss of part of the fragrance components and the pollution to the environment.
2. The invention does not need any dehydration and drying treatment before extraction, and can effectively reduce the loss of the flavor components.
3. Compared with an ultrasonic-assisted extraction method, the method does not need to use an organic reagent but uses water as an extracting agent, and is simple to operate and pollution-free.
4. The invention realizes the rapid and accurate extraction of various aroma components, and has the characteristics of high sensitivity, low detection limit, accurate quantification and simple and rapid operation when being used together with gas chromatography/mass spectrometry.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In a preferred embodiment, a method for purging and trapping flavor components in tobacco and tobacco products comprises the following steps:
(1) processing tobacco and tobacco products into tobacco shreds with area of 1mm × 10 mm;
(2) weighing cut tobacco, and mixing the cut tobacco with water according to a certain weight volume ratio to obtain an aqueous solution;
(3) carrying out ultrasonic water bath extraction on the aqueous solution, wherein the ultrasonic power is 1400W, the ultrasonic temperature is 75-95 ℃, and the ultrasonic time is 10-120 min, so as to obtain an extraction liquid;
(4) sucking the extract liquid, placing the extract liquid in a blowing bottle, and adding 5-35 wt% of sodium chloride;
(5) allowing the purge gas to pass through a sample in a purge bottle, and volatilizing a fragrance component from a water phase along with the purge gas through bubbling, wherein the purge temperature is 40-95 ℃, the flow of the purge gas is 20ml/min, and the purge time is 10-30 min;
(6) the fragrance components are captured when passing through the trap, and then are desorbed to be back blown into a gas chromatography sample inlet, separated by a chromatographic column and then enter a mass spectrum for detection.
Preferably, the ultrasonic time in the step (3) is 60 min.
Preferably, 25% by weight of sodium chloride is added in step (4).
Preferably, the purge time in step (5) is 25 min.
Preferably, the desorption temperature in the step (6) is 200 ℃; the desorption time was 2.0 min.
The invention carries out qualitative and quantitative detection on the flavor components extracted from tobacco and tobacco products by gas chromatography/mass spectrometry.
Example 1
A method for sweeping and trapping flavor components in tobacco and tobacco products comprises the following steps:
(1) processing tobacco and tobacco products into tobacco shreds with the diameter of 1mm multiplied by 10 mm;
(2) weighing cut tobacco, and mixing the cut tobacco with water according to the weight-volume ratio of 1:18 to obtain an aqueous solution;
(3) performing ultrasonic water bath extraction on the aqueous solution, wherein the ultrasonic power is 1400W, the ultrasonic temperature is 80 ℃, and the ultrasonic time is 60min to obtain an extraction liquid;
(4) sucking 20ml of extract liquor, placing the extract liquor into a purge bottle, and adding 25 wt% of sodium chloride;
(5) allowing the sweep gas to pass through a sample in a sweep bottle, and evaporating the fragrance component from the water phase along with the sweep gas by bubbling, wherein the sweep temperature is 80 ℃, the sweep gas flow is 20ml/min, and the sweep time is 25 min;
(6) the fragrance components are captured when passing through the trap, and then are desorbed to be back blown into a gas chromatography sample inlet, separated by a chromatographic column and then enter a mass spectrum for detection.
In the step (6), the desorption temperature is 200 ℃; the desorption time was 2.0 min.
Baking the trap after desorption, wherein the baking temperature is 210 ℃; the baking time is 20 min.
Detecting volatile components by using a gas chromatography/mass spectrometer, wherein the detection conditions of the gas chromatography/mass spectrometer are as follows: a chromatographic column: agient DB-17MS capillary column (30m × 250 μm × 0.25 μm); sample introduction amount: 1 uL; sample inlet temperature: 250 ℃; split-flow sample injection (split ratio 20: 1); carrier gas: helium gas; flow rate: 20 ml/min; temperature programming: 50 ℃ (1min) → 3 ℃/min → 185 ℃ (1 min); an ion source: EI; ion source temperature: 230 ℃; transmission line temperature: 260 ℃; the mass spectrometry detection adopts an SCAN mode, and the scanning range is 29-350 amu.
Preparing a series of standard solutions of the fragrance components by taking methyl phenylacetate as an internal standard and water as a solvent, wherein the concentration of the standard solutions is 1 ng/mL-1 ug/mL, quantifying by adopting an internal standard method, and the correlation coefficient R2Is 0.9986.
The names, quantitative ions and contents of the flavor components obtained in this example are shown in table 1, and the total ion flow chromatogram of the flavor components is shown in fig. 1.
Example 2
A method for purging and trapping flavor components in tobacco and tobacco products is characterized in that the purging temperature in the step (5) is 60 ℃. Otherwise, the same procedure as in example 1 was repeated.
The names, quantitative ions and contents of the flavor components obtained in this example are shown in Table 2, and the total ion flow chromatogram of the flavor components is shown in FIG. 2.
Example 3
A method for purging and trapping flavor components in tobacco and tobacco products is characterized in that in the step (3), the ultrasonic temperature is 72 ℃. Otherwise, the same procedure as in example 1 was repeated.
The number of quantifiable flavor components detected in this example was 19, which indicates that the extraction efficiency was low when the ultrasonic temperature was low in a certain temperature range.
Example 4
A method for purging and trapping flavor components in tobacco and tobacco products is characterized in that in the step (3), the ultrasonic temperature is 95 ℃. Otherwise, the same procedure as in example 1 was repeated.
The number of quantifiable flavor components detected in this example was 22, which indicates that when the ultrasound temperature was too high, some flavor components could be destroyed, resulting in the loss of flavor components.
Example 5
A method for purging and trapping flavor components in tobacco and tobacco products is characterized in that the weight-to-volume ratio in the step (2) is 1: 16. Otherwise, the same procedure as in example 1 was repeated.
The number of the quantifiable flavor components detected in the example is 31, which shows that the weight-volume ratio of the sample and the water has a certain influence on the ultrasonic water bath extraction effect of the sample.
Comparative example 1
A method for purging and trapping flavor components in tobacco and tobacco products is characterized in that in the step (3), the ultrasonic temperature is 60 ℃. Otherwise, the same procedure as in example 1 was repeated.
The number of quantifiable flavor components detected in this example was 9, which indicates that the extraction efficiency was low when the ultrasonic temperature was too low.
Comparative example 2
A method for purging and trapping flavor components in tobacco and tobacco products is characterized in that the weight-volume ratio in the step (2) is 1: 20. Otherwise, the same procedure as in example 1 was repeated.
The quantitative number of the aroma components detected in the example is 26, which shows that the weight volume ratio of the sample and the water has a certain influence on the concentration of the aroma components in the extract liquor, and further influences the subsequent detection result.
Comparative example 3
A method for purging and trapping aroma components in tobacco and tobacco products comprises the step (1) of processing the tobacco and the tobacco products into tobacco shreds, specifically tobacco shreds with the size of 1mm multiplied by 1 mm. Otherwise, the same procedure as in example 1 was repeated.
The number of quantifiable flavor components detected in this example was 27, which indicates that the sample processing step may cause loss of flavor components in tobacco, and has a certain effect on flavor component extraction.
Test results
TABLE 1 name, quantitative ion and content of flavor component
As can be seen from Table 1 and FIG. 1, the number of peaks including the internal standard methyl phenylacetate is 33, the quantifiable flavor components separated from the tobacco and tobacco products are 32, and the lowest concentration of the detected content is 35.90ng/g, which indicates that the method has the characteristics of multiple types of flavor components extracted from the tobacco and tobacco products, high sensitivity and low detection limit when being used together with gas chromatography/mass spectrometry.
TABLE 2 name, quantitative ion and content of flavor component
As can be seen from the comparison of Table 1 and FIG. 1 with Table 2 and FIG. 2, the peak was reduced when the purge temperature in step (5) was 60 ℃ as compared with 80 ℃, indicating that the extracted flavor components were reduced.
Table 3 comparative table of test results
As can be seen from table 3, when the ultrasonic temperature of the ultrasonic water bath extraction is low or the purging temperature during purging is low, the extraction efficiency of the flavor components is poor, and when the ultrasonic temperature of the ultrasonic water bath extraction is too high, some flavor components may be damaged, resulting in the loss of flavor components. Therefore, the flavor components in the tobacco and the tobacco products can be effectively extracted only when the temperature of the ultrasonic water bath extraction and the purging temperature in the purging process reach the requirements. In addition, when the sample is tobacco powder, compared with the sample which is cut tobacco, the detected aroma components are reduced, which shows that the sample processing steps have certain influence on the extraction of the aroma components, and meanwhile, the weight-volume ratio of the sample to water has certain influence on the ultrasonic water bath extraction effect of the sample and the concentration of the aroma components in the extraction liquid, thereby influencing the subsequent detection result.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.