CN112213415A - Device and method for extracting and enriching volatile components from sample - Google Patents

Abstract

The invention discloses a device for extracting and enriching volatile components from a sample, which is mainly composed of an interconnected reaction unit, a separation unit and a power unit; the reaction unit includes a constant temperature reaction pool and its super constant temperature system; the separation unit Including the cold trap and its insulation system; the power unit includes the oil backing pump and the secondary pump. Based on this, a corresponding use method and a method for analyzing food aroma components are also established. Through the diffusion and transfer phenomenon of flavor substances in high vacuum, flavor substances can be separated at low temperature, which greatly reduces the decomposition of compounds caused by excessive extraction temperature and For the problems caused by new compounds, flavor substances with different boiling points can be obtained by adjusting the vacuum degree of the vacuum system and the extraction temperature of the sample, which can overcome the problems of long extraction time and a large number of high-boiling point compounds affecting the detection results. The flavor substances collected by ultra-low temperature cold hydrazine are: Provide convenience for later product testing and product production.

Description

A device and method for extracting and enriching volatile components from a sample

technical field

The invention belongs to the technical field of separation and extraction of volatile substances, and particularly relates to a device and method for extracting and enriching volatile components from a sample.

Background technique

As shown in Figure 1, the process of extracting and analyzing the flavor substances contained or adsorbed from the sample is the key to the whole process, which determines the integrity of the flavor substances in the sample before analysis. And directly determines the quality of the later products and the accuracy of the test results. The extraction techniques of flavor substances in samples are mainly divided into headspace method and solvent method. The headspace method has strong adaptability to the detection equipment, but due to the small amount of samples entering the detection, some compounds with higher boiling points are difficult to detect, and they are not suitable for detection. The extraction temperature and humidity and other environmental requirements are relatively high, and the reproducibility is poor. Solvent method is currently the main method for extraction and analysis of flavorable substances in samples, which has high reproducibility and can detect compounds with higher boiling points.

The Chinese patent "A Simultaneous Distillation and Extraction Device and Simultaneous Distillation and Extraction Method" (Patent Application No. 201811063293.2) adopts the simultaneous distillation and extraction technology to effectively extract the flavor substances in the sample, but due to the long extraction time and high extraction temperature, for Heat-sensitive volatile substances are difficult to detect, and high temperature for a long time can easily cause substances in the sample to react with each other to generate flavor substances that were not in the original sample.

Chinese patent "a temperature-controlled Soxhlet extraction" (patent application No. 201010279671.8 published) can be used to separate flavor substances from samples using Soxhlet extraction technology, but for fluids such as oils and fats, it is easy to dissolve some compounds with extremely high boiling points in Organic solvents have a negative impact on the separation performance of the detection equipment.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a device and method for extracting and enriching volatile components from a sample, which is especially suitable for separating and collecting flavor substances with low heat resistance and low stability from food.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

The device for extracting and enriching volatile components from samples is mainly composed of interconnected reaction units, separation units, and power units; the reaction unit includes a constant temperature reaction cell and its super constant temperature system, and the inlet of the constant temperature reaction cell is connected to add liquid The liquid inlet pipe of the funnel, and the liquid inlet pipe branch is provided with a high vacuum valve; the separation unit includes a cold trap and its heat preservation system, and the air inlet of the cold trap is connected to the outlet of the constant temperature reaction pool through a constant temperature migration pipe; the power unit includes an oil backing pump and a secondary pump. The first stage pump, the intake end of the fore-stage pump is connected to the air outlet end of the secondary pump, and the intake end of the secondary pump is connected to the air outlet of the cold trap.

The cold trap includes three end-to-end dry ice cold traps, liquid nitrogen cold traps and liquid helium cold traps or other refrigeration equipment that can obtain ultra-low temperature. It is placed in a Dewar flask, and the air inlet pipe connected to the air inlet of the cold trap is inserted into the liquid storage bottle; the front pump is a two-stage rotary vane vacuum pump or other dry pump or oil pump that can obtain low vacuum, and the secondary pump is an oil diffusion pump, Molecular pump or other dry pump or oil pump capable of obtaining high vacuum.

The liquid inlet pipe of the liquid addition funnel extends to the bottom of the constant temperature reaction tank through the extension pipe; the constant temperature migration pipe is equipped with a constant temperature system.

The method of extracting and enriching volatile components from the sample using the above-mentioned device, using the power unit to pump the internal pressure of the device to a high vacuum, using the super constant temperature system to control the temperature in the constant temperature reaction cell and the transfer pipeline within a reasonable range, Add the liquid funnel with the high vacuum valve to add the sample into the vacuum system, and collect the target components in the cold trap after the high vacuum transfer.

A method for analyzing food aroma components (volatile flavor substances), comprising the following steps:

(1) adding liquid nitrogen to the solid food and grinding it into powder, or the liquid food will initially extract the flavor substances in the food by solvent extraction;

(2) use the device of claim 1 to carry out fine extraction to the primary extract;

(3) Qualitative and quantitative analysis of refined extracts (volatile flavor substances) using GC-MS.

In the fine extraction of step (2), the system is first pumped into a rough vacuum of 10-0.1Pa by the front pump, and then the system is pumped into a high vacuum of 1.333× ^10-1-1.333 × ^10-6Pa by the secondary pump ; The extraction temperature is 20-65°C.

In step (3), the analysis of volatile flavor substances is done in DB-WAX, 30m×0.25mm×0.25μm elastic capillary column to complete separation; carrier gas (high-purity inert gas) flow rate 0.8-10mL/min; injection volume 0.1-2μL; The split volume ratio is splitless or split; the inlet temperature is 230°C-300°C; chromatographic temperature programming conditions: the initial column temperature is 20-40°C, maintained for 5min, and then heated to 70-120°C at a rate of 2-10°C/min ℃, hold for 2min, then increase to 200-240℃ at a heating rate of 3-15℃/min, hold for 10-30min. MS parameters are mass spectrometry conditions: ionization mode EI; emission current 80μA; ionization voltage 70eV; scanning range 25-500m/z; ion source temperature 230-300℃, interface temperature 230-300℃; 450; the scan mode is full scan mode, and the solvent delay is 5min; the tuning file is standard tuning; the carrier gas is high-purity inert gas, and the flow rate is 0.6-2mL/min.

Aiming at the problems of high extraction temperature, long extraction time, and low boiling point compounds in the existing flavor extraction methods, the high boiling point compounds are difficult to separate and affect the detection results. The device for enriching volatile components is mainly composed of an interconnected reaction unit, a separation unit and a power unit; the reaction unit includes a constant temperature reaction pool and its super constant temperature system, and the inlet of the constant temperature reaction pool is connected to the liquid inlet pipe of the liquid addition funnel , the branch of the liquid inlet pipe is equipped with a high vacuum valve; the separation unit includes a cold trap and its heat preservation system, and the air inlet of the cold trap is connected to the outlet of the constant temperature reaction pool through a constant temperature migration pipe; the power unit includes an oil backing pump and a secondary pump. The air inlet end of the pump is connected to the air outlet end of the secondary pump, and the air inlet end of the secondary pump is connected to the air outlet of the cold trap. Based on this, a corresponding application method and a method for analyzing food aroma components are also established. The principle is to use the principle of gas molecular migration under high vacuum to reduce the saturated vapor pressure of the gas through an ultra-low temperature cold trap to liquefy or sublime to collect volatile substances. . Through the diffusion and transfer phenomenon of flavor substances in high vacuum, the flavor substances can be separated at low temperature, which greatly reduces the decomposition of compounds and the generation of new compounds caused by excessive extraction temperature. By adjusting the vacuum degree of the vacuum system and the extraction of samples The temperature can obtain flavor substances with different boiling points, which can overcome the problems of long extraction time and a large number of high-boiling point compounds affecting the detection results. The collection of flavor substances by ultra-low temperature cold hydrazine provides convenience for later product testing and product production.

Compared with the prior art, the outstanding advantages of the present invention are:

(1) The principle of the core device of the method is simple in structure and low in maintenance cost.

(2) Flavor substances can be separated and collected at a lower temperature to avoid pyrolysis or denaturation of compounds.

(3) The distance between gas molecules under high vacuum is very long to avoid intermolecular collision and reaction to generate new products, and the combination of lower temperature can ensure the authenticity of the extracted flavor substances.

(4) Shorter extraction and separation time and less solvent-sample usage can significantly improve extraction and collection efficiency, and can save a lot of time and raw material costs.

(5) The expansion is very strong, and multi-stage cold traps can be set up to realize the separation of compounds with different boiling points.

(6) It can extract and detect flavor substances in food, and provide a basis for in-depth research on food flavor substances.

Description of drawings

Figure 1 is a flow chart for extracting flavor substances from a sample.

FIG. 2 is a schematic structural diagram of the apparatus for extracting and enriching volatile components from a sample according to the present invention.

FIG. 3 is a total ion current diagram of application example 1. FIG.

FIG. 4 is a total ion current diagram of application example 2. FIG.

FIG. 5 is a total ion current diagram of application example 3. FIG.

FIG. 6 is a total ion current diagram of application example 4. FIG.

In the picture: 1 addition funnel, 2 high vacuum valve, 3 constant temperature reaction cell, 4 super constant temperature system, 5 constant temperature migration tube, 6 dry ice cold trap, 7 liquid nitrogen cold trap, 8 liquid helium cold trap, 9 Dewar flask, 10 oil diffusion pump, 11 two-stage rotary vane vacuum pump.

Detailed ways

1. Basic structure

As shown in Figure 1, the device of the present invention for extracting and enriching volatile components from a sample is mainly composed of a reaction unit, a separation unit and a power unit that are connected to each other. Ground ball or KF quick flange connection. in,

The reaction unit includes a constant temperature reaction pool and its super constant temperature system. The inlet of the constant temperature reaction pool is connected to the liquid inlet pipe of the liquid addition funnel, and the liquid inlet pipe is branched with a high vacuum valve; the liquid inlet pipe of the liquid addition funnel extends to the constant temperature reaction tank through the extension pipe bottom so that liquid can be added to the bottom of the reaction tank. The constant temperature reaction cell can be equipped with a sandwich layer and two water nozzles to pass constant temperature liquid into the outer layer to maintain constant temperature.

The separation unit includes a cold trap and its heat preservation system. The air inlet of the cold trap is connected to the outlet of the constant temperature reaction pool through a constant temperature migration tube. The constant temperature migration tube can be equipped with a sandwich layer and two water nozzles to pass the equipped constant temperature system (water bath) , oil bath or heating tube) into the constant temperature liquid to maintain the constant temperature. According to needs, the cold trap can be designed with multiple cold traps connected end-to-end to separate volatile compounds with different boiling points. As shown in Figure 1, there are three cold traps connected in series. The refrigerant can be selected from dry ice, liquid nitrogen or liquid helium. Dewar flask can be used for its insulation system. The liquid storage bottle of the cold trap is placed in the Dewar flask, and the air inlet pipe connected to the air inlet of the cold trap is inserted into the liquid storage bottle.

The power unit includes an oil backing pump and a secondary pump for the system to obtain a predetermined high vacuum. The air inlet end of the fore pump is connected to the air outlet end of the secondary pump, and the air inlet end of the secondary pump is connected to the air outlet of the cold trap. The front pump is a two-stage rotary vane vacuum pump or other dry pump or oil pump that can obtain low vacuum, and the secondary pump is an oil diffusion pump, molecular pump or other dry pump or oil pump that can obtain high vacuum.

Second, the principle function

2.1 Working principle

The internal air pressure of the device is pumped into a high vacuum through the power unit, and the temperature in the constant temperature reaction cell and transfer pipeline is controlled within a reasonable range by using the super constant temperature system. The target components are then collected in a cold trap. Due to the large mean free path of gas molecules in the system in the high vacuum state, the gas exists in the form of molecular flow, and its flow can be regarded as the free movement of molecules, which can exclude the collision and interference of other molecules in the system. Therefore, in such an environment It can basically eliminate the possibility of the gas reacting with each other to form new components.

2.2 Component function

The addition funnel adds the sample into the high vacuum system, and the addition speed can be controlled by the high vacuum valve. After closing the vacuum valve, the addition funnel can be separated from the atmosphere. After the vacuum is obtained, the sample-solvent mixture is added to the addition funnel, the vacuum valve is opened, and the sample-solvent mixture is added to the device through the vacuum valve. The opening adjusts the rate at which the sample-solvent mixture enters the sample cell. As the temperature remains unchanged or increases and the air pressure in the system becomes lower, the volatile substances will rapidly vaporize into the vacuum system and diffuse in the vacuum system.

When the constant temperature system controls the temperature in the reaction tank and the gas diffusion and migration pipeline to a relatively high constant temperature, the flavor substances can be in a gaseous state before encountering ultra-low temperature liquefaction.

The cold hydrazine controls the ambient temperature to a very low temperature through the ultra-low temperature refrigerant. When the migrated gas enters the ultra-low temperature cold hydrazine, the temperature decreases rapidly, its saturated vapor pressure decreases and the phenomenon of liquefaction or desublimation occurs, forming droplets or solids. The cold hydrazine bottom can realize the collection of flavor substances, which can effectively avoid the decomposition and denaturation of flavor substances caused by high temperature. Since the movement of gas molecules is diffused from the place with high density to the place with low density, when new sample-solvent mixture is continuously added in the reaction cell, the volatile matter is rapidly vaporized, resulting in a higher gas density in the sample cell, while The gas in the ultra-low temperature cold hydrazine is continuously condensed and liquefied, so the gas density is low, which promotes the vaporized flavor substances to continuously diffuse into the ultra-low temperature cold hydrazine and be collected.

3. Operation and use

In use, first close the high vacuum valve, and then complete the operation in sequence to open the vacuum pump, control temperature, add ultra-low temperature refrigerant, balance, add sample-solvent mixture, close the pump, open the vacuum valve, collect flavor substances, and clean the equipment.

The process of turning on the vacuum pump: Twist the high vacuum cock to close the high vacuum valve, turn on the front pump to pump the vacuum of the device to a rough vacuum of 10-0.1Pa, and then use the secondary pump (diffusion pump or molecular pump or ion pump and other vacuum pumps ) to draw the system into a high vacuum of 1.333×10 ^-1 -1.333×10 ^-6 Pa.

Temperature control process: Connect the external circulation system of the water bath to the nozzle of the constant temperature migration tube, set the temperature and turn on the constant temperature system to control the temperature of the migration tube and the reaction tank at 20-65°C.

The process of adding cryogenic refrigerant and equilibration: add dry ice, liquid nitrogen, liquid helium or other refrigerants to the Dewar flask or other thermal insulation equipment outside the cold trap, when the liquid level reaches two-thirds of the height of the thermal insulation equipment , and replenish the refrigerant in time to maintain the liquid level. After adding the refrigerant, the system is kept for 10 minutes to make the temperature of each part reach equilibrium.

The process of adding the sample-solvent mixture: Introduce the homogenized sample-solvent mixture into the addition funnel, slowly rotate the vacuum valve to slowly add the mixture into the reaction tank through the vacuum valve, and observe the vacuum gauge reading at any time. It is appropriate that the system pressure is not higher than 0.01Pa in the process of sample addition. When the mixed solution in the addition hopper is completely added to the reaction tank, the high vacuum valve is closed in time to prevent air from entering, and the extraction is completed after the reading of the vacuum gauge is stable and unchanged.

The process of turning off the pump and opening the vacuum valve: when the extraction is completed, turn off the secondary pump, keep the mechanical pump (pre-pump) working until the diffusion pump cools to room temperature, turn off the mechanical pump, and open the high vacuum valve to balance the air pressure inside and outside the system.

The process of collecting flavor substances: When the migrating gas enters the ultra-low temperature cold hydrazine, the temperature rapidly decreases and its saturated vapor pressure decreases and the phenomenon of liquefaction or desublimation occurs, forming droplets or solids that settle at the bottom of the cold hydrazine. First disassemble the Dewar flask, then disassemble the cold trap, wait for the solids in the cold trap to liquefy, and then introduce all the liquid into the conical flask, rinse the cold trap with a small amount of solvent, and add the rinse liquid to the conical flask. bottle.

The process of equipment cleaning: (1) Load the cold trap into the device, and disconnect the pump from the equipment; (2) Add 50 mL of saturated potassium dichromate and 1 L of concentrated sulfuric acid from the liquid addition hopper in turn and wash the ears with ear washing on the top of the funnel. Pressurize the ball or other pressurized equipment to make the cleaning agent flow out from the end of the last cold trap connected to the pump; (3) Use tap water from the addition funnel to rinse the entire equipment until the cleaning liquid is neutral; (4) Use 1% caustic soda (5) Rinse the entire device with tap water until the lotion is neutral; (6) Rinse the entire device with 1M dilute hydrochloric acid; (7) Rinse the entire device with distilled water until the lotion is neutral; (8) The device was placed in an oven at 150°C for 2 hours.

4. Application Examples

Application example 1

(1) The food is ground into powder, and the flavor substances in the food are initially extracted by rapid solvent extraction;

(2) using a high vacuum extraction device to perform fine extraction on the primary extract;

(3) Qualitative and quantitative analysis using GC-MS.

The solvent method in step (1) is an accelerated solvent extraction method. It is characterized in that 40 g of fried tilapia minced meat is weighed, 10 g of diatomaceous earth and 10 g of anhydrous sodium sulfate are added to it, and the mixture is fully mixed. A 40 mL pressure vessel was filled with 10 g of quartz sand, and the previously homogeneous mixture was added to 4 pressure vessels and compacted. Each pressure vessel was extracted with 20 mL for 5 min under the condition of 50° C. pressure of 1000 Pis, extracted three times, and washed with 10 mL of dichloromethane for 2 min after each extraction, and a total of 360 mL of extract was obtained.

The extracted extract was concentrated for 35 minutes using a 500mm Webster column at a column temperature of 40°C and a heating temperature of 50°C, and the extract was concentrated to about 150 mL, and then the heat source was removed for cooling for 10 minutes.

(2) Use a high-vacuum extraction device to perform precise extraction on the primary extract, characterized in that the extraction concentrate is transferred to the liquid addition funnel of the present invention, and the heating temperature of the device is set at 40°C, at a temperature of 5.8×10 ^-3 Pa Extracted under high vacuum for 4.3h, and kept for 20min after adding the sample.

(3) Qualitative and quantitative analysis by GC-MS is characterized in that the volatile flavor substances in the GC-MS analysis are separated on DB-WAX, 30m×0.25mm×0.25μm elastic capillary column. The flow rate of carrier gas (He) was 10 mL/min; the injection volume was 1 μL; the split volume ratio was 5:1; the injection port temperature was 250 °C; The temperature was increased to 90 °C at a rate of 2 min, and then increased to 240 °C at a heating rate of 5 °C/min and held for 10 min. MS parameters are mass spectrometry conditions: ionization mode EI; emission current 80 μA; ionization voltage 70 eV; scanning range 30-500 m/z; ion source temperature 280 °C, interface temperature 250 °C; It is full scan mode, the solvent delay time is 5min; the tuning file is standard tuning; the carrier gas is helium, the flow rate is 0.90mL/min; the detector voltage is 1000V.

Table 1 Flavor substances extracted from application example 1 and their relative contents

Application example 2

(1) The food is ground into powder, and the flavor substances in the food are initially extracted by solid-liquid extraction;

(2) using a high vacuum extraction device to perform fine extraction on the primary extract;

(3) Qualitative and quantitative analysis using GC-MS.

The solvent method in step (1) is a solid-liquid extraction method. It is characterized in that 40g of fried tilapia minced meat is weighed, placed in a 500mL round-bottom flask, 200mL of dichloromethane is added, extracted at 50°C for 30min, the solvent is poured into a 500mL round-bottom flask with a stopper, and then Add 100 mL of dichloromethane to the remaining solid and extract at 45°C for 30 min. Repeat twice to obtain a total of 400 mL of extract.

Concentrate the extracted solution using a 500mm Webster column at a column temperature of 40°C and a heating temperature of 50°C for 45min. The extract was concentrated to about 150mL, and the heat source was removed for cooling for 10min.

The feature of the refined extraction method in step (2) is that the extraction concentrate is transferred to the device adding funnel of the present invention, the device heating temperature is set to 40° C., and the extraction is performed under a high vacuum of 5.8×10 ^-3 Pa for 4.3 hours. After adding the sample, keep it for 20min.

The concentrated liquid extracted from the device of the present invention is concentrated for 3.5 hours at a column temperature of 40 °C and a heating temperature of 50 °C, and then cooled for 20 minutes to obtain about 10 mL of concentrated liquid, and the liquid is concentrated using a nitrogen blower. After reaching 1mL, transfer it to a 2mL liquid phase vial and place it in a -80°C refrigerator for inspection.

(3) Qualitative and quantitative analysis by GC-MS is characterized in that the volatile flavor substances in the GC-MS analysis are separated on DB-WAX, 30m×0.25mm×0.25μm elastic capillary column. The flow rate of carrier gas (He) was 10 mL/min; the injection volume was 1 μL; the split volume ratio was 5:1; the injection port temperature was 250 °C; The temperature was increased to 90°C at a rate of 2 min, and then increased to 240°C at a heating rate of 5°C/min and maintained for 10 min. MS parameters are mass spectrometry conditions: ionization mode EI; emission current 80 μA; ionization voltage 70 eV; scanning range 30-500 m/z; ion source temperature 280 °C, interface temperature 250 °C; It is full scan mode, the solvent delay time is 5min; the tuning file is standard tuning; the carrier gas is helium, the flow rate is 0.90mL/min; the detector voltage is 1000V.

Table 2 Flavor substances extracted by application example 2 and their relative contents

Application example 3

(1) The food is ground into powder, and the flavor substances in the food are initially extracted by Soxhlet extraction;

(2) using a high vacuum extraction device to perform fine extraction on the primary extract;

(3) Qualitative and quantitative analysis using GC-MS.

The solvent method in step (1) is a solid-liquid extraction method. It is characterized in that 40g of fried tilapia minced meat is weighed, 10g of anhydrous sodium sulfate is added and mixed well, the mixture is transferred to a 200ml Soxhlet extraction sleeve, and the sleeve is put into a 500ml Soxhlet extraction device. Add 300 mL of dichloromethane solution to the 500 mL volumetric flask and connect to the device. Turn on the condensate water and set the condensing temperature to 8°C. The round-bottomed flask was placed in a 45°C water bath, heated and waited until there was liquid dripping from the condenser to start timing, and the extraction was performed for 5 hours (about 5 siphons were completed).

The extracted extract was concentrated for 30 minutes using a 500mm Webster column at a column temperature of 40°C and a heating temperature of 50°C, and the extract was concentrated to about 150 mL, and the heat source was removed for cooling for 10 minutes.

The feature of the refined extraction method in step (2) is that the extraction concentrate is transferred to the device adding funnel described in the present invention, the device heating temperature is set to 40°C, and the extraction is performed under a high vacuum of 5.8×10 ^-3 Pa for 4.3 hours. , and keep it for 20min after adding the sample.

The concentrated solution of the present invention is extracted and concentrated using a Webster column at a column temperature of 40 °C and a heating temperature of 50 °C for 3.5 hours, and then cooled for 20 minutes to obtain about 10 mL of extraction and concentrated liquid. The liquid is concentrated to 1 mL using a nitrogen blower. Transfer to a 2mL liquid phase vial and place it in a -80°C refrigerator for testing.

(3) Qualitative and quantitative analysis by GC-MS is characterized in that the volatile flavor substances in the GC-MS analysis are separated on DB-WAX, 30m×0.25mm×0.25μm elastic capillary column. The flow rate of carrier gas (He) was 10 mL/min; the injection volume was 1 μL; the split volume ratio was 5:1; the injection port temperature was 250 °C; The temperature was increased to 90°C at a rate of 2 min, and then increased to 240°C at a heating rate of 5°C/min and maintained for 10 min. MS parameters are mass spectrometry conditions: ionization mode EI; emission current 80 μA; ionization voltage 70 eV; scanning range 30-500 m/z; ion source temperature 280 °C, interface temperature 250 °C; It is full scan mode, the solvent delay time is 5min; the tuning file is standard tuning; the carrier gas is helium, the flow rate is 0.90mL/min; the detector voltage is 1000V.

Table 3 Flavor substances extracted by application example 3 and their relative contents

Application example 4

(1) after the residue in the food soup is filtered, the flavor substances in the food are initially extracted by the solvent method;

(2) using a high vacuum extraction device to perform fine extraction on the primary extract;

(3) Qualitative and quantitative analysis using GC-MS.

The solvent method in step (1) is a liquid-liquid extraction method. It is characterized by measuring 100mL of the filtered food soup, placing it in a 500mL round-bottomed flask, adding 100mL dichloromethane, extracting at 40°C for 60min, pouring it into a separating funnel and letting it stand for stratification, collecting the organic phase and pouring it into 500mL in a stoppered round bottom flask. The remaining mixture was then poured into a round-bottomed flask, and 100 mL of dichloromethane was added for extraction at 40° C. for 60 min. Repeat three times to obtain a total of 350 mL of extract. After adding 100g of anhydrous sodium sulfate to remove excess water, the extract was concentrated using a 500mm Webster column at a column temperature of 40°C and a heating temperature of 50°C for 45min, the extract was concentrated to about 150mL, and the heat source was removed for cooling for 10min.

The feature of the refined extraction method in step (2) is that the extraction concentrate is transferred to the device adding funnel described in the present invention, the device heating temperature is set to 40°C, and the extraction is performed under a high vacuum of 5.8×10 ^-3 Pa for 4.3 hours. , and keep it for 20min after adding the sample.

The concentrated liquid of the present invention is extracted and concentrated using vacuum rotary evaporation at a vacuum degree of 800 mBar and a water temperature of 40 ° C for 30 min to obtain about 10 mL of extraction concentrated liquid, and the liquid is concentrated to 1 mL using a nitrogen blower and then transferred to 2 mL of liquid. The phase vials were placed in a -80°C refrigerator for inspection.

The qualitative and quantitative analysis by GC-MS in step (3) is characterized in that the volatile flavor substances in the GC-MS analysis are separated on DB-WAX, 30m×0.25mm×0.25μm elastic capillary column. The flow rate of carrier gas (He) was 10 mL/min; the injection volume was 1 μL; the split volume ratio was 5:1; the inlet temperature was 250 °C; The temperature was increased to 90°C at a rate of 2 min, and then increased to 240°C at a heating rate of 5°C/min and maintained for 10 min. MS parameters are mass spectrometry conditions: ionization mode EI; emission current 80 μA; ionization voltage 70 eV; scanning range 30-500 m/z; ion source temperature 280 °C, interface temperature 250 °C; It is full scan mode, the solvent delay time is 5min; the tuning file is standard tuning; the carrier gas is helium, the flow rate is 0.90mL/min; the detector voltage is 1000V.

Table 4 Flavor substances extracted by application example 4 and their relative contents

Claims (7)

1. a device for extracting and enriching volatile components from a sample is characterized in that it is mainly composed of an interconnected reaction unit, a separation unit and a power unit; the reaction unit comprises a constant temperature reaction tank and a super constant temperature system thereof , the inlet of the constant temperature reaction tank is connected to the liquid inlet pipe of the liquid addition funnel, and the liquid inlet pipe is branched with a high vacuum valve; the separation unit includes a cold trap and its heat preservation system, and the cold trap air inlet is connected to the constant temperature reaction tank through a constant temperature migration pipe. outlet; the power unit includes an oil backing pump and a secondary pump, the air inlet end of the backing pump is connected to the air outlet end of the secondary pump, and the air inlet end of the secondary pump is connected to the air outlet of the cold trap. 2 . The device for extracting and enriching volatile components from a sample according to claim 1 , wherein the cold trap comprises three end-to-end dry ice cold traps, liquid nitrogen cold traps and liquid helium cold traps. 3 . The heat preservation system is a Dewar flask, the liquid storage bottle of the cold trap is placed in the Dewar flask, and the air inlet pipe connected to the air inlet of the cold trap is inserted into the liquid storage bottle; The stage pump is an oil diffusion pump and a molecular pump. 3. The device for extracting and enriching volatile components from a sample according to claim 2, wherein the liquid inlet pipe of the liquid addition funnel extends to the bottom of the constant temperature reaction tank through an extension pipe; the constant temperature The migration tube is equipped with a constant temperature system. 4. The method for extracting and enriching volatile components from the sample using the device according to claim 1 is characterized in that: the internal pressure of the device is evacuated into a high vacuum by the power unit, and the constant temperature reaction tank and the transfer chamber are transferred by a super constant temperature system. The temperature in the pipeline is controlled within a reasonable range, the sample is added to the vacuum system through the addition funnel and the high vacuum valve, and the target components are collected in the cold trap after high vacuum transfer. 5. a method for analyzing food aroma components, is characterized in that comprising the following steps: (1) adding liquid nitrogen to the solid food and grinding it into powder, or the liquid food will initially extract the flavor substances in the food by solvent extraction; (2) use the device described in claim 1 to carry out fine extraction to the primary extract; (3) Qualitative and quantitative analysis of refined extracts by GC-MS. 6. the method for analyzing food aroma components according to claim 5, is characterized in that in the fine extraction of step (2), the system is first pumped into the rough vacuum of 10-0.1Pa by the fore-stage pump, and then the secondary pump is used The system is evacuated to a high vacuum of 1.333×10 ^-1 -1.333×10 ^-6 Pa; the extraction temperature is 20-65°C. 7. The method for analyzing food aroma components according to claim 5, characterized in that in step (3), analyzing volatile flavor substances in DB-WAX, 30m × 0.25mm × 0.25μm elastic capillary column completes separation; carrier gas flow rate 0.8-10mL/min; injection volume 0.1-2μL; split volume ratio is splitless or split; inlet temperature 230°C-300°C; chromatographic temperature programming conditions: column initial temperature 20-40°C, maintained for 5min, and then with The temperature was raised to 70-120°C at a rate of 2-10°C/min, held for 2 minutes, and then raised to 200-240°C at a heating rate of 3-15°C/min and held for 10-30 minutes. MS parameters are mass spectrometry conditions: ionization mode EI; emission current 80μA; ionization voltage 70eV; scanning range 25-500m/z; ion source temperature 230-300℃, interface temperature 230-300℃; 450; the scan mode is full scan mode, the solvent delay is 5min; the tuning file is standard tuning; the carrier gas is high-purity inert gas, and the flow rate is 0.6-2mL/min.

Images