High-purity chiral compound separation and collection system

Abstract

The invention belongs to the technical field of chiral compound separation, and particularly relates to a high-purity chiral compound separation and collection system which comprises a sample injection system, a separation system, a collection system and an electronic pressure control module which are connected, the electronic pressure control module is communicated with a detector; the separation system comprises at least one chromatographic column and at least one chiral chromatographic column, and the electronic pressure control module is used for controlling communication between the chromatographic column and the detector, communication between the chromatographic column and the chiral chromatographic column, communication between the chiral chromatographic column and the detector and communication between the chiral chromatographic column and the collection system. The invention aims to solve the problem that a system for separating and collecting high-purity chiral compounds is lacked in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of chiral compound separation, and in particular relates to a high-purity chiral compound separation and collection system. Background Art

[0002] Chiral compounds are a unique structural phenomenon in small molecule compounds. The presence of chiral centers (chiral atoms) causes small molecule compounds to exhibit different spatial isomerism phenomena. Due to the difference in spatial structure, although they have the same molecular formula or chemical and atomic composition, they exhibit completely different characteristics in many properties or activities.

[0003] Among flavor and fragrance molecules, many natural fragrances are chiral molecules. In fact, due to the difference in fragrance between different chiral isomers, flavors and fragrances with only one chiral isomer are more popular. For example, the S-configuration enantiomer of lemon oil fragrance has a lemon scent, but the R-configuration enantiomer has an orange scent. For example, γ-ionone is a chiral compound. Its (S)-configuration has a pleasant floral scent and a very natural violet tone, and is very active (threshold 0.07ppb), but its (R)-configuration has a fruity pineapple-like taste (threshold 11ppb). For example, the left-handed L-configuration in menthol has a minty aroma and a cooling effect, while the right-handed D-configuration has a spicy and irritating smell. For example, nootkatone has 3 chiral centers and 8 isomers, but only (+)-nootkatone has a fragrance (threshold 0.3ppm), while the remaining 7 isomers have almost no grapefruit fragrance.

[0004] In addition, the metabolic mechanisms and physiological characteristics of different isomers are very different. For example, nicotine has two isomers, namely S-(-)-nicotine and R-(+)-nicotine. Among them, the physiological activity and toxicity of S-(-)-nicotine are stronger than those of R-(+)-nicotine.

[0005] Therefore, for the separation of chiral compounds related to spices and flavors, whether for the selection of fragrance or for human health considerations, it is extremely important to split chiral compounds into enantiomers of a single configuration.

[0006] Chromatography is an effective chiral separation method, which mainly includes gas chromatography, high performance liquid chromatography, high performance capillary electrophoresis, etc. Among them, gas chromatography has the characteristics of high column efficiency, high sensitivity, and fast analysis speed, and is widely used in the separation research of chiral compounds.

[0007] In the prior art, the chiral separation system for chiral compounds related to spices and flavors has a low extraction yield and low product purity, and there is a lack of a system for separating and collecting high-purity chiral compounds. Summary of the invention

[0008] The purpose of the present invention is to provide a high-purity chiral compound separation and collection system to solve the problem that the prior art lacks a high-purity chiral compound separation and collection system.

[0009] To achieve the above technical objectives, the technical solution adopted by the present invention is as follows: a high-purity chiral compound separation and collection system, comprising a connected sample injection system, a separation system, a collection system and an electronic pressure control module; the electronic pressure control module is connected to a detector;

[0010] The separation system includes at least one chromatographic column and at least one chiral chromatographic column. The electronic pressure control module is used to control the connection between the chromatographic column and the detector, the chromatographic column and the chiral chromatographic column, the chiral chromatographic column and the detector, and the chiral chromatographic column and the collection system.

[0011] Optionally, the electronic pressure control module includes a multi-way valve 1 and a multi-way valve 2, and the chromatographic column is connected to the detector through the multi-way valve 1, or the chromatographic column is connected to the chiral chromatographic column through the multi-way valve 1; the chiral chromatographic column is connected to the detector through the multi-way valve 2, or the chiral chromatographic column is connected to the collection system through the multi-way valve 2. The electronic pressure control module controls the switching of the multi-way valve, the chromatographic column is connected to the detector and the chiral chromatographic column, and the chromatographic column and the chiral chromatographic column are connected to the mass spectrometer detector, and the switching response speed is fast.

[0012] Optionally, the collection system comprises at least two condensers connected in parallel to the outlet of the separation system for collecting different enantiomers. The condensers are arranged to collect different enantiomers.

[0013] Optionally, the condenser is an electronic condenser provided with a condensation collection bottle, the condensation collection bottle includes a condensation section bottle body and a collection section bottle body arranged in two sections from top to bottom, the condensation section bottle body and the collection section bottle body are detachably connected and connected, and the inner diameter of the condensation section bottle body is larger than the collection section bottle body. The use of an electronic condenser does not require an additional external cold source, and at the same time, it can also reduce the loss of components in the carrier gas.

[0014] Optionally, when there are multiple chromatographic columns, the chromatographic columns are connected in parallel; when there are multiple chiral chromatographic columns, the chiral chromatographic columns are connected in parallel. Since the separation time of the chromatographic column is very long, while the separation time of the chiral column is relatively short, the chromatographic columns arranged in parallel can achieve alternating injection and improve the separation efficiency; the parallel chiral chromatographic columns enable the separation system of the present invention to simultaneously process samples containing multiple chiral isomers.

[0015] Optionally, the separation system further includes at least two temperature control boxes, and the chromatographic column and the chiral chromatographic column are respectively arranged in corresponding temperature control boxes. The temperature control boxes are arranged to ensure the working temperature of the chromatographic column and the chiral chromatographic column, and the gradient change of the carrier gas pressure is adjusted by the electronic pressure control module, or the temperature is adjusted in the temperature control box, so as to achieve effective separation of the sample in the chromatographic column or the chiral chromatographic column.

[0016] Optionally, the outlet end of the chiral chromatographic column is connected to the collection system via a capillary empty column, and the inner diameter of the capillary empty column is larger than that of the chiral chromatographic column. By changing the diameter of the capillary empty column, the flow rate of the carrier gas entering the collection system is reduced to achieve preliminary cooling.

[0017] Optionally, the injection system is a continuous automatic injection system, including an automatic injector, and the single injection volume range of the automatic injector is 0.1mL-1mL, so as to realize continuous injection of samples along with carrier gas.

[0018] Beneficial effects of the present invention:

[0019] 1. The present invention separates chiral compounds by setting a chromatographic column and a chiral chromatographic column, wherein the chromatographic column is used to separate chiral substances and achiral substances in a sample, and an electronic pressure control module introduces the chiral substances separated by the chromatographic column into the chiral chromatographic column, and the chiral chromatographic column is used to chirally separate different enantiomers of the chiral compound to obtain different isomers; different chiral isomers are then introduced into different condensers for collection under the control of the electronic pressure control module. The separation and collection system of the present invention improves the use efficiency of the chiral chromatographic column and prolongs the service life of the chiral chromatographic column by designing the separation system into two stages and only introducing the chiral substance into the chiral chromatographic column. At the same time, there are only samples and carrier gas in the chiral body collection process, and no solvent, so the chiral isomer obtained after condensation has a higher purity.

[0020] 2. The present invention realizes alternating injection and processing of complex samples by setting parallel chromatographic columns and parallel chiral chromatographic columns, and can simultaneously obtain isomers of multiple chiral compounds. In addition, the present invention adopts an electronic condenser, cooperates with a large-caliber capillary, reduces the carrier gas flow rate, does not require an external cold source, has a good condensation effect, has little component loss, and has a high collection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0022] Figure 1 This is a system schematic diagram of Embodiment 1 of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the condensation collection bottle of the present invention;

[0024] Figure 3This is a system schematic diagram of Example 2 of the present invention.

[0025] Wherein: 1-injection system, 11-automatic sampler, 2-separation system, 21-chromatographic column, 22-chiral chromatographic column, 23-temperature control box, 3-collection system, 31-condenser, 311-condensation collection bottle, 3111-condensation section bottle, 3112-collection section bottle, 4-electronic pressure control module, 41-detector, 42-multi-way valve 1, 43-multi-way valve 2. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that in the drawings or descriptions of the specification, similar or identical parts use the same figure numbers, and the implementation methods not shown or described in the drawings are forms known to ordinary technicians in the relevant technical field. In addition, the directional terms mentioned in the embodiments, such as "upper", "lower", "top", "bottom", "left", "right", "front", "back", etc., are only referenced to the directions of the drawings and are not used to limit the scope of protection of the present invention.

[0027] Example 1

[0028] like Figure 1-Figure 2 As shown, a high-purity chiral compound separation and collection system of the present invention comprises a connected sample injection system 1, a separation system 2, a collection system 3 and an electronic pressure control module 4; the electronic pressure control module 4 is connected to a detector 41;

[0029] In the present invention, chiral compounds refer to small molecule compounds having one or more chiral centers or chiral atoms, such as ionone and nootkatone, which are commonly found in flavors and fragrances.

[0030] In this embodiment, the separation system 2 includes a chromatographic column 21 and a chiral chromatographic column 22, and the electronic pressure control module 4 is used to control the connection between the chromatographic column 21 and the detector 41, the chromatographic column 21 and the chiral chromatographic column 22, the chiral chromatographic column 22 and the detector 41, and the chiral chromatographic column 22 and the collection system 3. The chromatographic column 21 is used as a one-dimensional chromatogram to separate the desired chiral compounds, and the chiral chromatographic column 22 is used as a two-dimensional chromatogram to perform chiral separation on the chiral compounds, which is different from the common two-dimensional gas chromatography.

[0031] In this embodiment, the electronic pressure control module 4 (EPC module for short) includes a multi-way valve 1 42 and a multi-way valve 2 43. The chromatographic column 21 is connected to the detector 41 through the multi-way valve 1 42, or the chromatographic column 21 is connected to the chiral chromatographic column 22 through the multi-way valve 1 42; the chiral chromatographic column 22 is connected to the detector 41 through the multi-way valve 2 43, or the chiral chromatographic column 22 is connected to the collection system 3 through the multi-way valve 2 43. The existing EPC module is used to accurately control the pressure of gas or liquid, and mainly includes a pressure sensor and a feedback control system. The feedback control system controls the passage switching and opening of the multi-way valve in real time according to the data monitored by the pressure sensor, and its specific structure and principle are not described in detail.

[0032] In this embodiment, the multi-way valve adopts a three-way valve or a four-way valve, one inlet and two outlets or one inlet and three outlets. Other multi-way valves can also be selected according to specific circumstances. While ensuring the working passage, an empty outlet is reserved; the detector 41 adopts a mass spectrometer detector, which can usually detect the separation of sample substances based on the chromatogram, perform qualitative identification based on the retention time and the mass spectrum, and perform quantitative detection based on the chromatographic peak response value. In this embodiment, the mass spectrometer detector can also be set to only display or respond to the characteristic peak signal of the target compound (chiral compound) to simplify the system control logic.

[0033] The passage switching of the multi-way valve is controlled by the electronic pressure control module 4. When the chromatographic column 21 is connected to the detector 41, when the characteristic peak detection signal corresponding to the target compound appears in the mass spectrometer detector, the chromatographic column 21 is connected to the chiral chromatographic column 22, and the eluate in the chromatographic column 21 is introduced into the chiral chromatographic column 22; when the chiral chromatographic column 22 is connected to the detector 41, when the mass spectrometer detector displays separated chromatographic peaks at different retention times, the chiral chromatographic column is connected to the separation system 2, and the separation system 2 can collect different isomers that have completed chiral separation.

[0034] In this embodiment, the collection system includes at least two condensers 31 for collecting different enantiomers connected in parallel to the outlet of the separation system 2. The condenser 31 is an electronic condenser.

[0035] Specifically, the electronic condenser, i.e., semiconductor refrigerator, includes semiconductor cooling elements, condensation collection bottles, heat sinks, and control systems, and uses the thermoelectric effect (thermoelectric second effect, or Peltier effect) of semiconductor materials for refrigeration. Specifically, when the electronic condenser passes current through the contact points of different semiconductor materials, the semiconductor cooling elements can absorb heat and refrigerate, so that the condensation collection bottle 311 is kept at a low temperature, thereby condensing the specific isomers carried by the carrier gas entering the condensation collection bottle 311 to obtain high-purity chiral compounds, and the carrier gas can be directly discharged.

[0036] Among them, the condensation collection bottle 311 is usually made of a material with high thermal conductivity, including a condensation section bottle body 3111 and a collection section bottle body 3112 arranged in two sections from top to bottom. The condensation section bottle body 3111 and the collection section bottle body 3112 are detachably connected and connected. The inner diameter of the condensation section bottle body 3111 is larger than the collection section bottle body 3112. The airflow entering the condensation section bottle body 3111 has a reduced speed. The airflow flows downward in a spiral shape along the side wall from the top of the condensation section bottle body 3111. The separated sample carried gradually condenses and slides to the collection section bottle body 3112 at the bottom. After reaching the lower end of the condensation section bottle body 3111, the carrier gas rises from the middle of the bottle body to the top and is discharged to ensure that the carrier gas carrying the specific isomer can be quickly cooled, thereby condensing the chiral compound.

[0037] Specifically, the heat sink is arranged outside the condensation collection bottle 311. The heat sink can increase the heat exchange area, accelerate the heat dissipation, and thus improve the condensation effect. The heat sink is made of materials with good thermal conductivity such as aluminum or copper. The electronic condenser uses the existing control system to adjust parameters such as refrigeration power and temperature to improve the application range of the collection system.

[0038] In this embodiment, the separation system 2 further includes at least two temperature control boxes 23, and the chromatographic column 21 and the chiral chromatographic column 22 are respectively arranged in the corresponding temperature control boxes 23 and are independently controlled. The temperature control box 23 is set to keep the temperature of the chromatographic column 21 constant, and the separation of the target compound and other substances is achieved by changing the flow rate of the mobile phase (i.e., carrier gas, in this embodiment, high-purity helium / nitrogen) of the chromatographic column 21; for the chiral chromatographic column 22, the temperature condition of the chiral chromatographic column 22 can be changed by the temperature control box 23 to achieve the separation of different isomers (i.e., chiral separation).

[0039] In this embodiment, the outlet end of the chiral chromatographic column 22 is connected to the collection system 3 via a capillary column, and the caliber of the capillary column is larger than that of the chiral chromatographic column 22. By changing the tube diameter, the flow rate of the carrier gas entering the collection system 3 is reduced to achieve preliminary cooling.

[0040] In this embodiment, the injection system 1 is a continuous automatic injection system, including an existing automatic sampler 11. The automatic sampler 11 uses a large-volume injection port, the number of injection ports corresponds to the number of chromatographic columns 21, and the single injection volume range of the automatic sampler 11 is 0.1mL-1mL.

[0041] It should be noted that in order to ensure the accuracy and stability of system separation, the connecting pipes or connectors between the systems, such as empty capillary columns, are all covered with insulation sleeves. At the same time, the multi-way valve used in this embodiment is a constant temperature control valve to ensure that the temperature of the sample medium is always stable near the set value (the same as the corresponding connected temperature control box) to ensure that the sample will not condense in the pipes or valves.

[0042] The working principle of the present invention is as follows:

[0043] like Figure 1 As shown, the (+)-nootkatone isomer of nootkatone separated and collected using an embodiment of the system of the present invention is used as an example for explanation:

[0044] In this embodiment, first, a raw material containing nootkatone (such as citrus) is extracted, purified, and concentrated to obtain a sample to be separated. The obtained sample is introduced into a chromatographic column 21 through a carrier gas (high-purity helium / nitrogen) via an injection port of an automatic sampler 11. The chromatographic column 21 is used in conjunction with a mass spectrometer detector 41 for GC / MS detection, and the chromatographic conditions are optimized to obtain a better separation degree. The retention time of nootkatone is determined by mass spectrometry retrieval (related to the specific separation conditions). It should be noted that only the separation of nootkatone and non-nootkatone components can be achieved in the chromatographic column 21, and the separation of different chiral isomers of nootkatone cannot be achieved.

[0045] Subsequently, the chromatographic column 21 is connected to the electronic pressure control module 4, and the electronic pressure control module 4 is used to switch the dissolution with the same retention time in the chromatographic column 21 to the chiral chromatographic column 22 for further separation, and the separation conditions are optimized. The mass spectrometer detector 41 analyzes the different retention times of the chiral isomers of nootkatone, and correspondingly, the column outlet of the chiral chromatographic column 22 is finally connected to a different electronic condenser, and the electronic condenser is used to collect (+)-nootkatone, and the other isomers are all introduced into another electronic condenser.

[0046] During this process, the automatic sampler 11 can continuously inject 100-200 samples, each with 1 mL, and cut the retention time extract of the chromatographic column 21 into the chiral chromatographic column 22 through the electronic pressure control module 4, and the chiral compounds with different retention times in the chiral chromatographic column 22 into their respective condensers 31, and cut the rest of the time into waste liquid.

[0047] It should be noted that it is possible to set the sample that cuts into the waste liquid in the chromatographic column 21 to be cut back to the detector 41 every dozens of sample injections, or to cut the waste liquid after the chiral chromatographic column 22 back to the detector 41, to monitor the stability of the method and the column efficiency. If the method is stable, the detector 41 should have no chromatographic peaks during the cut-off period, which is convenient for timely optimization of the method or replacement of a new column. At the same time, since the chromatographic column 21 and the chiral chromatographic column 22 are arranged in parallel, replacing one of the new columns will not affect the operation of the entire system.

[0048] The condenser 31 (ie, semiconductor cooler) maintains low temperature capture, performs continuous collection, and cools the chiral compounds carried by the carrier gas. Depending on the number of injection needles, high-purity chiral compounds in the microgram to gram range can be obtained.

[0049] Example 2

[0050] like Figure 3 As shown, another embodiment of the system of the present invention is used to separate and collect different isomers of solanone as an example for illustration, and the difference from Example 1 is that:

[0051] In this embodiment, two one-dimensional chromatograms are used to separate solanone, and two or more parallel chromatographic columns 21 are used to reduce the idle time of the chiral chromatographic column 22 of the two-dimensional chromatogram. At the same time, the two-dimensional chromatogram used to further separate the chiral compound uses two or more parallel chiral chromatographic columns 22, so that the system of the present invention can process samples with complex compound components and obtain enantiomers of multiple compounds at the same time, including solanone (S-configuration solanone, R-configuration solanone), norsolanadione (degradation product of solanone), etc.

[0052] like Figure 2 As shown, there are two chromatographic columns 21, and the connection mode of the chromatographic columns 21 is parallel. The parallel chromatographic columns 21 are convenient for alternating injection, ensuring that the chiral substances entering the chiral chromatographic column 22 are uninterrupted, and saving the total separation time of the system. Compared with the common series chromatographic columns, the series connection method has limited effect on improving the separation resolution, but will make the chromatographic peaks widen and tail, which is not conducive to collection. There are two chiral chromatographic columns 22, and the connection mode of the chiral chromatographic columns 22 is parallel. The parallel chiral chromatographic columns 22 enable the separation system 2 of the present invention to process multiple chiral isomer substances at the same time. The number of chromatographic columns 21 and chiral chromatographic columns 22 can be increased or decreased according to actual needs or system separation conditions.

[0053] Correspondingly, in this embodiment, the number of multi-way valves controlled by the electronic pressure control module 4 is 4, which are used to switch the connection between the parallel chromatographic columns 21, the connection between the chromatographic column 21 and the detector 41, the connection between the chromatographic column 21 and the parallel chiral chromatographic column 22, the connection between the chiral chromatographic column 22 and the corresponding condenser 31, and the discharge of waste liquid.

[0054] Compared with the existing artificial synthesis method of solanone, the synthesis route is long and the cost is high, and there is a difference in the configuration of synthetic solanone and natural solanone in tobacco, which lacks obvious naturalness and coordination in the flavoring of tobacco products; while the method of extracting the above components from tobacco resources (or other raw materials enriched with components) using the separation and collection system of the present invention has a shorter extraction route and a high purity of the extracted chiral compound, thereby being able to maximize the advantages of natural solanone. At the same time, the system of the present invention can be applied to the separation and purification of a variety of spices and flavors, and has high applicability.

[0055] The above is a detailed introduction to a high-purity chiral compound separation and collection system provided by the present invention. The description of the specific embodiment is only used to help understand the method of the present invention and its core concept. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A high-purity chiral compound separation and collection system, characterized in that: It comprises a connected sample injection system, a separation system, a collection system and an electronic pressure control module; the electronic pressure control module is connected to a detector (41); The separation system comprises at least one chromatographic column (21) and at least one chiral chromatographic column (22), and the electronic pressure control module is used to control the connection between the chromatographic column (21) and the detector (41), the chromatographic column (21) and the chiral chromatographic column (22), the chiral chromatographic column (22) and the detector (41), and the chiral chromatographic column (22) and the collection system.

2. The high-purity chiral compound separation and collection system according to claim 1, characterized in that: The electronic pressure control module comprises a multi-way valve 1 (42) and a multi-way valve 2 (43); the chromatographic column (21) is connected to the detector (41) via the multi-way valve 1 (42), or the chromatographic column (21) is connected to the chiral chromatographic column (22) via the multi-way valve 1 (42); the chiral chromatographic column (22) is connected to the detector (41) via the multi-way valve 2 (43), or the chiral chromatographic column (22) is connected to the collection system via the multi-way valve 2 (43).

3. The high-purity chiral compound separation and collection system according to claim 1, characterized in that: The collection system comprises at least two condensers (31) connected in parallel to the outlet end of the separation system for collecting different enantiomers.

4. The high-purity chiral compound separation and collection system according to claim 3, characterized in that: The condenser (31) is an electronic condenser provided with a condensation collection bottle (311), wherein the condensation collection bottle (311) comprises a condensation section bottle body (3111) and a collection section bottle body (3112) arranged in two sections from top to bottom, wherein the condensation section bottle body (3111) and the collection section bottle body (3112) are detachably connected and communicated, and the inner diameter of the condensation section bottle body (3111) is larger than that of the collection section bottle body (3112).

5. The high-purity chiral compound separation and collection system according to claim 1, characterized in that: When the number of the chromatographic columns (21) is multiple, the chromatographic columns (21) are connected in parallel; when the number of the chiral chromatographic columns (22) is multiple, the chiral chromatographic columns (22) are connected in parallel.

6. The high-purity chiral compound separation and collection system according to claim 1, characterized in that: The separation system further comprises at least two temperature control boxes (23), and the chromatographic column (21) and the chiral chromatographic column (22) are respectively arranged in corresponding temperature control boxes (23).

7. The high-purity chiral compound separation and collection system according to claim 1, characterized in that: The outlet end of the chiral chromatographic column (22) is connected to the collection system via a capillary empty column, and the inner diameter of the capillary empty column is larger than that of the chiral chromatographic column (22).

8. The high-purity chiral compound separation and collection system according to claim 1, characterized in that: The injection system is a continuous automatic injection system, comprising an automatic injector (11), and the single injection volume range of the automatic injector (11) is 0.1 mL-1 mL.

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