Sample preparation system and method for extracting analytes from a sample by means thereof

Abstract

The present invention provides a method for extracting an analyte from a sample by a sample preparation system, comprising the steps of: supplying a gas and a liquid solvent capable of dissolving the analyte in the sample to the sample cell; receiving the analyte-containing liquid solvent from the extraction module to the evaporation vessel; evaporating the analyte-containing liquid solvent in the evaporation vessel, the evaporation module being in fluid communication with the sample cell; allowing the evaporation step to be performed after at least a portion of the analyte-containing liquid solvent from the extraction module enters the evaporation vessel. By this method, extraction and evaporation are integrated together to allow "on-line evaporation / concentration", whereby the transfer process of the analyte can be avoided, thus saving labor, improving processing speed, and also avoiding the risk of contamination. The present invention also provides a sample preparation system for extracting an analyte from a sample.

Description

Technical Field

[0001] This invention relates to a sample preparation system, such as a solvent extraction technique. The invention also relates to a method for extracting an analyte from a sample using the sample preparation system. Background Technology

[0002] In modern analytical chemistry, there is a need to analyze large numbers of samples, especially in an automated manner. This requires first extracting the target chemical substance (also known as the analyte) from the sample before it can be measured using analytical techniques.

[0003] Extraction methods for samples include Soxhlet extraction, ultrasonic extraction, microwave extraction, and accelerated solvent extraction (CSE). The concept of CSE was proposed in 1995; it is also known as pressurized solvent extraction, pressurized fluid extraction, or enhanced solvent extraction. CSE can replace more conventional methods such as Soxhlet extraction, ultrasonic treatment, boiling, wrist vibrators, and other extraction methods. CSE utilizes the unique physicochemical properties of solvents under specific temperature and pressure conditions to extract solid and colloidal substances. This method is characterized by its speed, low solvent consumption, and good reproducibility. Dionex developed and commercialized this technology and has applied for numerous US patents for its instruments, such as US patents 5,647,976, 5,843,311, and 5,785,856.

[0004] Specifically, for example in solid-liquid extraction techniques, a liquid solvent can be used to treat a solid sample to dissolve the analyte in the solvent. Such solid samples are typically placed in the sample cell of a sample preparation system. Therefore, the liquid solvent needs to be flowed into the sample cell containing the solid sample so that the sample is immersed in the liquid solvent. When the liquid solvent contains the analyte dissolved from the sample, the liquid solvent can be removed from the sample, further concentrated, and then quantified using a suitable analytical technique. Examples of analytical techniques include, for instance, liquid chromatography coupled to detectors such as conductivity detectors, charge detectors, UV-Vis spectrometers, or mass spectrometers.

[0005] During sample preparation, to facilitate subsequent quantitative analysis (e.g., in liquid chromatography), after the analyte is extracted from the sample using a liquid solvent, it is sometimes necessary to concentrate the large amount of liquid solvent containing the analyte. For this purpose, an extraction device may be used to collect the liquid solvent containing the analyte from the sample cell into a container (also called a collection bottle). Then, the liquid solvent in the collection container is transferred manually or automatically to a solvent evaporation device.

[0006] Solvent evaporation equipment is a common laboratory tool used to distill volatile solvents under reduced pressure or heating conditions. This type of evaporation equipment can concentrate large quantities of liquid solvent to the desired amount. In one example, after concentration, the extracted analyte is transferred to a sample vial, for example, only about 2 ml, before liquid chromatography analysis can begin.

[0007] The evaporation and concentration process described above can lead to unnecessary loss of the analyte in the liquid solvent. This loss is generally unavoidable, especially when the analyte is volatile. Additionally, manual rinsing of the collection flask may be necessary to improve the recovery rate of the extract.

[0008] Therefore, there is always a need to improve the concentration efficiency of the extract after extraction (e.g., reduce loss, speed up concentration, etc.).

[0009] In addition, to accelerate (e.g., solid-liquid) extraction processes, it is known in the prior art to increase the solubility of the analyte by heating the liquid solvent itself. However, because the analyte may decompose or react with other chemicals in the solid sample, and high temperatures may cause the liquid solvent to vaporize and significantly weaken its extraction performance, the effectiveness of this method in improving extraction efficiency is limited.

[0010] To improve extraction efficiency, the liquid solvent and gas can be combined to form a mixture before flowing into the sample cell. Once in the sample cell, the diffusion of the gas phase in the mixture can be several orders of magnitude higher than that of the liquid solvent phase. Therefore, even if the gas itself does not dissolve the analyte, its addition can still improve the overall mass transfer properties of the liquid solvent. Overall, gas-assisted solvent extraction not only reduces solvent consumption but also significantly shortens extraction time.

[0011] However, there is still room for improvement in this gas-assisted solvent extraction technology to further enhance its extraction recovery rate and system efficiency. Summary of the Invention

[0012] This invention provides a method for extracting an analyte from a sample using a sample preparation system. The sample preparation system includes a selectively fluid-connected extraction module and an evaporation module. The extraction module includes a sample cell for holding a sample containing the analyte, and the evaporation module includes an evaporation container for evaporating a liquid solvent containing the analyte. The method may include the following steps: a supply step: supplying a gas and a liquid solvent capable of dissolving the analyte in the sample to the sample cell; a receiving step: receiving the liquid solvent containing the analyte from the extraction module into the evaporation container; and an evaporation step: evaporating the liquid solvent containing the analyte in the evaporation container, wherein the evaporation module and the sample cell are fluidly connected; wherein the evaporation step is permitted to begin after at least a portion of the liquid solvent containing the analyte from the extraction module has entered the evaporation container.

[0013] The above method integrates the extraction and evaporation processes, allowing for "in-situ evaporation / concentration" or "online evaporation / concentration" of the liquid solvent containing the analyte. This avoids the need for analyte transfer, saving labor, increasing processing speed, and eliminating the risk of analyte exposure to the atmosphere or other contamination, thus optimizing overall sample preparation efficiency. In this invention, the term "at least a portion" means that the evaporation step can be initiated after a portion or all of the liquid solvent containing the analyte has entered the evaporation vessel. Initiating the evaporation step after only a portion of the liquid solvent has entered the evaporation vessel allows for simultaneous extraction and evaporation, resulting in extremely high sample preparation speeds. Initiating the evaporation step after all the liquid solvent has entered the evaporation vessel enables high energy efficiency of the evaporation equipment and increases system flexibility (e.g., allowing for concentrated evaporation after multiple extractions).

[0014] It is understood that in this invention, the various steps described above may overlap (partially) in time. For example, the liquid solvent may be received into the evaporation vessel simultaneously with the supply step. Alternatively, evaporation may be performed simultaneously with the receiving step. However, it should be noted that "supply," "receive," and "evaporation" do not necessarily occur simultaneously; for example, receiving may be performed after supply is complete, or evaporation may begin after receiving is complete.

[0015] Advantageously, the supply step includes a first supply sub-step: supplying the mixture of gas and liquid solvent to the sample cell.

[0016] By supplying a gas-liquid mixture, the convection between the sample and the liquid solvent, as well as the diffusion gradient of the extraction solvent from the solid sample, can be increased. Therefore, the extraction recovery rate can be improved with the same or reduced amount of liquid solvent used, and extraction can be completed in a shorter time, resulting in a significantly increased throughput per unit time.

[0017] Preferably, the first supply sub-step includes supplying a predetermined flow rate of gas to the liquid solvent during the supply of the mixture using a gas flow control device to mix with the liquid solvent.

[0018] This allows for a continuous and stable gas flow rate to be supplied to the sample cell. Because the gas flow rate remains stable, the gas content in the liquid solvent-gas mixture will also be stable, and the gas-liquid solvent flow ratio can be precisely controlled. This ensures that the mixing of the gas in the mixture, i.e., the incorporation of gas into the liquid solvent, is uniform.

[0019] Furthermore, the sample preparation system may also include an adjustment device disposed between the sample cell and the evaporation container. The adjustment device includes an inlet communicating with the sample cell and an outlet communicating with the evaporation container, allowing fluid to flow from the inlet through a flow path within the adjustment device and out of the outlet. The receiving step of the present invention includes: adjusting the opening of the flow path based on the pressure within the sample cell using the adjustment device, thereby maintaining the pressure within the sample cell within a preset range, and receiving the liquid solvent into the evaporation container via the flow path.

[0020] When the pressure in the sample cell can be stably maintained at a high preset pressure, it not only ensures that the liquid solvent is not vaporized in the sample cell, but also significantly improves the extraction efficiency. Furthermore, adjusting the opening of the flow path based on the pressure within the sample cell provides negative feedback to pressure fluctuations, allowing the pressure to quickly return to its stable level.

[0021] In an embodiment where a gas flow rate is supplied by means of a gas flow control device and the pressure in the sample cell is maintained within a preset range by means of a regulating device, the liquid solvent can be kept in a liquid state at high temperature under stable (high) pressure, while promoting better mixing of gas into the liquid solvent, producing a more uniform gas-liquid mixture, thereby improving the extraction recovery rate.

[0022] In particular, the extraction module may include multiple sample cells, and the evaporation module includes multiple evaporation containers. Each of the multiple sample cells is selectively fluid-connected to a corresponding evaporation container among the multiple evaporation containers. The first supply sub-step may include multiple supply cycles in which the mixture is sequentially (in a predetermined order) supplied to each of the multiple sample cells in each of the multiple supply cycles.

[0023] By sequentially supplying the mixture to each sample cell during each supply cycle, higher extraction recovery can be achieved while maintaining a high throughput.

[0024] In some embodiments, the duration for which the mixture is supplied to each sample cell in the same supply cycle may be equal. In other embodiments, the amount of the mixture supplied to each sample cell in the same supply cycle may be equal.

[0025] In the case of multiple sample cells, more uniform extraction across the sample cells is advantageous in order to shorten the overall extraction time. Therefore, it is desirable to keep the extraction conditions as consistent as possible across the sample cells (e.g., more consistent physical parameters during extraction, such as pressure, temperature, and flow rate). Thus, this invention designs the same supply time or supply volume within the same supply cycle. Furthermore, this also results in more consistent extraction recovery rates from each sample cell.

[0026] Advantageously, in this evaporation step, the liquid solvent containing the analyte located within the evaporation vessel can be evaporated by heating the evaporation vessel and / or by depressurizing its interior. Heating and / or depressurizing allows for rapid evaporation of the liquid solvent within the evaporation vessel, thereby improving sample preparation efficiency.

[0027] Furthermore, the method may also include preheating the evaporation container before the evaporation step. By preheating the evaporation container before the start of the evaporation process, favorable evaporation conditions can be achieved at the beginning of the evaporation process, thereby promoting improved evaporation efficiency.

[0028] Additionally, the method may include heating the sample cell prior to the supply step. Heating the sample cell ensures that the sample is already under suitable extraction conditions when the liquid solvent is supplied to the sample cell, thereby improving extraction efficiency.

[0029] The present invention also provides a sample preparation system for extracting an analyte from a sample, comprising: an extraction module including a sample cell for holding a sample containing the analyte; a first supply module capable of supplying a gas and a liquid solvent capable of dissolving the analyte in the sample to the sample cell; an evaporation module including an evaporation container for evaporating the liquid solvent containing the analyte, wherein the evaporation container is in fluid communication with the sample cell during evaporation; and a controller configured to allow the evaporation container to evaporate the liquid solvent containing the analyte located therein after at least a portion of the liquid solvent containing the analyte from the extraction module has entered the evaporation container.

[0030] Advantageously, the first supply module may include a mixing device for mixing the gas with the liquid solvent to supply the mixture to the sample cell. This mixing device allows for a more homogeneous gas-liquid mixture to be supplied to the sample cell, thereby improving extraction efficiency.

[0031] Preferably, the first supply module may include a first supply pipeline for supplying gas and a gas flow control device in fluid communication with the first supply pipeline. The gas flow control device may be configured to allow a preset flow rate of gas to flow into the mixing device when the first supply module supplies the mixture to the sample cell, so as to mix with the liquid solvent.

[0032] Particularly preferably, the sample preparation system may further include an adjustment device disposed between the sample cell and the evaporation container. The adjustment device includes an inlet communicating with the sample cell and an outlet communicating with the evaporation container. Fluid can flow from the inlet through a flow path inside the adjustment device and out of the outlet. The adjustment device may be configured to adjust the opening of the flow path based on the pressure in the sample cell, thereby maintaining the pressure in the sample cell within a preset range.

[0033] This adjustment device can provide negative feedback for pressure fluctuations in the sample cell, so that they can return to their stable pressure as soon as possible, that is, stabilize the pressure in the sample cell within a small preset range.

[0034] For example, the regulating device may include a first valve body portion, a second valve body portion, and a cavity defined by the two, with the inlet and the outlet disposed on the first valve body portion, the pre-pressurization component of the regulating device supported in the cavity, and movable between a blocking position for blocking the flow path and a non-blocking position for releasing the flow path, the opening being defined by the space between the pre-pressurization component and the first valve body portion.

[0035] With the help of the aforementioned pre-pressurization component of the regulating device, the regulating device can maintain the pressure of the sample cell at a preset stable pressure with a simple construction.

[0036] In some embodiments, the extraction module may include a plurality of sample pools, and the evaporation module may include a plurality of evaporation containers, wherein each of the plurality of sample pools may be in selective fluid communication with a corresponding evaporation container among the plurality of evaporation containers.

[0037] Advantageously, the first supply module may also include a switching valve having multiple different operating configurations, each of which can be used to direct the liquid solvent to a corresponding sample cell among the multiple sample cells during a corresponding time period of each supply cycle.

[0038] By utilizing the multiple different operating configurations of the switching valve, it is easy and stable to sequentially guide the liquid solvent into the corresponding sample cells.

[0039] In addition, the first supply pipeline may include multiple branch pipelines and multiple switching devices. Each of the multiple switching devices is connected to a corresponding branch pipeline among the multiple branch pipelines, so that the branch pipeline can selectively flow into a corresponding sample cell among the multiple sample cells. With the help of the multiple switching devices, the gas can be guided to flow to the corresponding sample cell among the multiple sample cells during the corresponding time period of each supply cycle.

[0040] With the help of multiple switching devices, the fluid flow on each branch of the first supply line can be controlled independently, thereby facilitating the sequential guidance of gas into the corresponding sample cells.

[0041] In particular, the sample preparation system can also include multiple regulating devices, with one regulating device arranged between each sample cell and its corresponding evaporation vessel. By placing a regulating device on each of the multiple paths, it is possible to ensure that the pressure on each path remains stable.

[0042] For example, the evaporation module may include a first heating device to evaporate the liquid solvent containing the analyte located therein by heating the evaporation container. Attached Figure Description

[0043] Figure 1 A schematic diagram of the architecture of an embodiment of a sample preparation system according to the present invention is shown, which relates to a combination of four-channel extraction and four-channel evaporation;

[0044] Figure 2 A schematic diagram of another embodiment of the sample preparation system according to the present invention is shown, which involves a combination of two-channel extraction and two-channel evaporation;

[0045] Figure 3 A schematic diagram of yet another embodiment of the sample preparation system according to the present invention is shown, which relates to a combination of two-channel extraction and two-channel evaporation;

[0046] Figure 4 A general flow diagram is shown for one embodiment of the sample preparation system according to the present invention; and

[0047] Figure 5 A pressure curve is shown in the sample cell when using the adjustment device of the sample preparation system according to the invention.

[0048] List of reference numerals

[0049] 100 Sample Preparation System

[0050] 110 First Supply Module

[0051] 111 First supply pipeline

[0052] 111a-111e (First supply line) First to fifth branch lines

[0053] 112 Second supply pipeline

[0054] 112a-112d (Second or mixed supply lines) First to fourth branch lines

[0055] 113 Solvent Pump

[0056] 114 Gas flow control device

[0057] 115 Diverter Valve

[0058] 116a-116e First to Fifth Switching Devices

[0059] 117 Mixing device

[0060] 118 Pressure Sensor

[0061] 122a-122d First to Fourth Sample Cells

[0062] 124a-124d First to Fourth Preheaters

[0063] 130a-130d First to Fourth Adjustment Devices

[0064] 141a-141d First to Fourth Evaporation Vessels

[0065] 142a-142d First to Fourth Vacuum Tubing

[0066] 144 Vacuum Valve

[0067] 145 Vacuum Sensor

[0068] 152 Gas Source

[0069] 153 Filter

[0070] 154 Solvent Source

[0071] 155 Solvent mixing valve. Detailed Implementation

[0072] In this document, the sample preparation system and the method for extracting analytes from samples using the sample preparation system are described primarily with reference to gas-assisted solvent extraction techniques and equipment. However, it should be understood that the sample preparation system and the method for extracting analytes from samples using the sample preparation system of the present invention are not limited to accelerated solvent extraction techniques, such as solid-phase extraction (SPE), pressurized fluid extraction (PLE), or other extraction techniques known in the art. Furthermore, they are not limited to gas-assisted solvent extraction techniques. Moreover, the sample preparation system of the present invention is not limited to performing extraction and evaporation functions, but can be a system that performs multiple functions including extraction and evaporation, especially an automated sample preparation system.

[0073] In this invention, the term "sample" refers to a substance that contains the chemical substance to be analyzed (or "analyte") before extraction. The sample is suitable for placement within the sample preparation system of this invention, particularly its extraction module. For example, the sample can be loaded into the sample cell of the extraction module when needed, but it can also be pre-integrated into the sample cell of the extraction module, or even placed in the sample cell of the extraction module during extraction (e.g., in the case of multi-channel extraction). The sample is generally in solid form, but semi-solid, colloid, etc., are not excluded. Furthermore, the sample can be ground, mixed with a dispersant, or subjected to other pretreatments before being placed into the extraction module, which will not be elaborated here.

[0074] In this invention, the term "analyte" refers to the substance to be analyzed contained in the sample, such as fatty substances in food or specific chemical agents in pesticides. According to the sample preparation principle of this invention, when the liquid solvent flows through the sample, it can dissolve the analyte contained in the sample, so that the liquid solvent flowing out of the sample cell can contain this analyte, facilitating subsequent quantitative or qualitative analysis of the analyte. The liquid solvent used to dissolve the analyte in this invention can contain various types, such as n-hexane, DCM (dichloromethane), acetone, etc., while the gas involved in this invention is preferably an inert gas such as nitrogen.

[0075] In this invention, the term "between" refers to the positioning of a device or component in the flow path. For example, when referring to the arrangement of a regulating device between a sample cell and an evaporation vessel, it means that, viewed in the direction of fluid flow, the regulating device is located downstream of the sample cell (i.e., after the sample cell) and upstream of the evaporation vessel (i.e., before the evaporation vessel).

[0076] In this invention, the term "extraction recovery rate" refers to the recovery rate compared to a standard sample. For example, it is the ratio of the concentration of the extracted sample obtained by gas chromatography-mass spectrometry (GC-MS) to the nominal concentration. The specific calculation process is as follows: A certain amount of standard sample is mixed with a fixed volume of solvent to obtain a standard solvent. This standard solvent is directly sent to GC-MS for concentration analysis to obtain a baseline for the recovery rate. Assuming no loss of standard sample, the baseline represents a 100% recovery rate. Then, the same amount of standard sample is added to the sample in the sample cell. During the extraction process, the standard sample is extracted by the solvent and collected in the final concentrated sample. Finally, this concentrated sample is sent to GC-MS for concentration analysis. If all the standard sample can be extracted and remain in the final concentrated sample, the analytical result should be consistent with the baseline, that is, the recovery rate can reach 100%. However, due to various reasons, such as insufficient extraction of the standard sample or standard evaporation during concentration, sample loss may occur, resulting in an actual recovery rate lower than 100%. Furthermore, the accuracy of GC-MS can also affect the recovery test results, for example, by introducing a random error of approximately 10% in the recovery measurement. This error can sometimes cause the test results for concentrated samples to be higher than those for standard solvents, meaning the calculated recovery rate may be greater than 100%. In contrast, in this invention, high extraction efficiency refers to achieving the highest possible recovery rate with minimal effort (including solvent, temperature, and time).

[0077] First, the sample preparation system 100 of the present invention includes an extraction module, which may include one or more sample cells in which a sample containing the analyte can be placed. However, it should be understood that the presence of the sample in the sample cell is not a prerequisite for performing the method of extracting the analyte from the sample; that is, the sample may be loaded into the sample cells as needed (one by one or together) during the execution of the method. In some embodiments, when the extraction module includes multiple sample cells, the sample may be loaded into some of the sample cells before extraction begins, and then loaded into another portion of the sample cells during the extraction process.

[0078] It should be noted that the terms "pool," "chamber," and "column" are used interchangeably to describe the portion of the extraction module described herein used for placing the sample, wherein the term "column" (e.g., sample column, packed column, extraction column, etc.) can, for example, be used to describe a sample pool having a cylindrical shape. Alternatively, the sample pool of the present invention can also be in various other suitable configurations and shapes. Figure 1 and Figure 2 As shown, the sample cell may include an inlet and an outlet. Apart from the inlet and outlet for communication with the outside of the sample cell (e.g., a supply line), the sample cell should have a generally closed structure to prevent leakage of the sample within it. Preferably, the inner diameter of the sample cell can be constant.

[0079] Typically, the volume (axial or radial dimension) of a sample cell can vary within a wide range. For chemical analysis applications, for example, sample cell volumes can range from about 1 to 100 mL, such as 1 mL, 10 mL, 33 mL, 66 mL, etc., but are not limited to these examples; volumes greater than 100 mL are also possible. Furthermore, the inner diameter of the sample cell can be, for example, 1 / 16 inch. It is conceivable that the size of the sample cell can be proportional to the sample used. For example, a 30 g soil sample can be used with a 100 mL sample cell.

[0080] Advantageously, the extraction module of the present invention may include one or more extraction channels. In some embodiments, a sample cell may be loaded into the extraction channel (before or during extraction) or pre-formed into the extraction channel. However, in other embodiments, the sample cell may not be located inside the extraction channel, but rather communicated with it. When the extraction channel is upstream of the sample cell and communicates with it, the liquid solvent and gas may flow through the extraction channel first and then into the sample cell. However, it should be noted that, viewed in the direction of fluid flow, the extraction channel may also be located at least partially downstream of the sample cell (i.e., downstream of the sample cell), meaning that fluid flowing out of the sample cell may also flow out of the extraction module via a portion of the extraction channel located downstream of the sample cell. But regardless of whether the sample cell is located inside, before, or after the extraction channel, when the extraction module of the present invention includes an extraction channel, the sample cell is always in fluid communication with the extraction channel.

[0081] To improve extraction efficiency, the sample temperature within the sample cell can be maintained at a suitable extraction temperature, such as around 40-200 degrees Celsius. Advantageously, the invention may include a step of heating the sample cell to raise (or maintain, as needed) the temperature of the sample cell (extraction temperature). However, it is understood that the invention does not exclude extraction without heating, i.e., extraction at room temperature.

[0082] Preferably, the sample preparation system 100 of the present invention, such as the extraction module, may include an extraction heating device or a similar temperature control device. The extraction heating device may include an oven or furnace, into which the sample cell can be loaded, for example, before sample extraction begins. Loading the sample cell into the oven can be done automatically by a robot or gripper, but can also be done manually by an operator. An extraction heating device in the form of an oven, for example, can rapidly raise the temperature of the sample cell to the target temperature in a short time, and provides good temperature control stability. Additionally or alternatively, the extraction heating device may include other forms of heating elements, such as heating wires or heating rods. Preferably, the sample cell can be made of stainless steel, titanium, zirconium, and similar materials. Sample cells made of these materials facilitate heat conduction from an external heat source (via the walls of the sample cell) to the sample cell. Furthermore, a temperature sensor can be located within the extraction heating device to detect and control the temperature it provides.

[0083] Furthermore, it is conceivable that the temperature of the liquid solvent flowing into the sample cell be increased by heating during or preferably before supplying the liquid solvent to the sample cell, which could help improve the solubility of the analyte in the liquid solvent. For example, as... Figure 1 As shown, a preheater 124a-124d is arranged before each sample cell 122a-122d so that the liquid solvent is heated by the preheater before flowing into the sample cell, but this is not necessary. The heating temperature of the preheater can be higher than the heating temperature of the sample cell. Furthermore, it is conceivable that the preheater is not as shown... Figure 1 or Figure 5 Instead of being positioned close to the sample cell as shown in the diagram, it can be placed at any suitable location on the second supply line, or at other locations within the system.

[0084] To extract an analyte from a sample, a liquid solvent required for extraction needs to be supplied to the sample cell of the extraction module so that the analyte in the sample can dissolve in the liquid solvent flowing into the sample cell. As mentioned earlier, although the solvent used for extraction is primarily a liquid solvent, in the case of gas-assisted extraction, a gas-liquid mixture of liquid solvent and gas can flow into the sample cell. That is, the method of the present invention may include a supply step, namely, supplying gas and a liquid solvent capable of dissolving the analyte in the sample to the sample cell. Here, supplying gas and liquid solvent may refer to supplying gas alone, supplying liquid solvent alone, or supplying a gas-liquid mixture. For example, in the case of gas-assisted solvent extraction, this supply step may include a first supply sub-step of supplying a mixture of gas and liquid solvent to the sample cell. It is understood that the various supply steps of the present invention may or may not be performed with the aid of the first supply module, which will be detailed below. In other words, the method steps of the present invention may or may not be associated with the apparatus, device, or element described in detail below.

[0085] When the analyte dissolves in the liquid solvent, the liquid solvent containing the analyte can flow out of the sample cell of the extraction module (e.g., via the sample cell outlet) for subsequent operations (explained further below). However, it is also understood that other fluids, such as gases (if any), may also flow out of the sample cell during this process.

[0086] To supply fluids, such as fluids (liquid solvents, gases, or mixtures thereof) to a sample cell, the sample preparation system 100 according to the invention may include a first supply module 110. Here, the term "first supply module" may encompass any means or components that provide fluids such as liquid solvents or gases. It will be understood that the first supply module 110 of the invention may include, but may not include, a solvent source 154 (e.g., a container containing liquid solvent), a gas source 152 (e.g., a compressed nitrogen cylinder), means or components directly associated with the solvent source 154 and the gas source 152 (e.g., a gas source switch, a filter 153, a pressure sensor 118, a solvent mixing source 155), etc. For example, as Figure 2 and Figure 3 As shown, a solvent mixing valve for mixing different solvents can also be arranged upstream of the solvent pump 113.

[0087] Furthermore, it should be noted that the first supply module 110 of the present invention is not limited to supplying liquid solvents or gases to the extraction module, but can also supply them to other modules or devices of the sample preparation system 100 of the present invention (e.g., the evaporation module, which will be detailed below). In other words, the first supply module 110 of the present invention can utilize at least a portion of its common piping, devices, or elements to supply liquid solvents, gases, or mixtures thereof to other modules or devices besides the sample cell, thereby reducing the overall number of system components and optimizing sample preparation efficiency.

[0088] See Figure 4 The first supply module 110 may include a first supply line 111 for supplying gas. In this invention, the supplied gas may be nitrogen, air, or other suitable inert gas. The first supply module 110 may also include a second supply line 112 for supplying liquid solvent. It is understood that the first supply line 111 and the second supply line 112 are not necessarily physically fixed for supplying gas and liquid solvent, but at different stages or at different times during sample preparation, such as extraction, at least a portion of the line may be used for both supplying gas and supplying liquid solvent, for example, as shown in the diagram. Figure 5The common conduit (which may also be referred to as a mixing supply line, depending on the situation) located between the mixing device 117 (described in detail below) and the sample cell is shown. In other words, for some lines in the first supply module 110, gas flows through at some times and liquid solvent flows through at other times (see further details below). Furthermore, in embodiments of gas-assisted solvent extraction, some lines in the first supply module 110 also supply a mixture of gas and liquid solvent, i.e., both gas and liquid solvent flow through these lines simultaneously (which may be referred to as a mixing supply line). It should also be understood that the first supply module 110 may include other supply lines that are not used to supply liquid solvent or gas.

[0089] Furthermore, to rapidly increase the extraction temperature, the mixture of gaseous and liquid solvents can advantageously be preheated to a target temperature (e.g., 40-200°C) before entering the sample cell. It is understood that the preheated temperature of the liquid solvent may differ from the (extraction) temperature of the sample cell. Apparatus for preheating the liquid solvent is of known construction and will not be described further in this invention.

[0090] The sample preparation system 100 of the present invention further includes an evaporation module. After the liquid solvent flowing through the sample cell dissolves the analyte in the sample, the liquid solvent containing the analyte flows out of the sample cell. The evaporation module may include an evaporation container, such as an evaporation flask, for receiving the liquid solvent flowing out of the sample cell. As mentioned above, the liquid solvent flowing out of the sample cell may contain not only the liquid solvent containing the analyte, but also other fluids such as gases. However, the substance flowing into the evaporation container in any case includes at least the liquid solvent containing the analyte. Therefore, the method according to the present invention includes a receiving step of receiving the liquid solvent containing the analyte from the extraction module into the evaporation container.

[0091] The liquid solvent containing the analyte can be evaporated within the evaporation vessel. Therefore, the method of the present invention further includes an evaporation step of evaporating the liquid solvent containing the analyte within the evaporation vessel. The evaporation process can be controlled by various factors, such as evaporating to a fixed volume (e.g., a few milliliters) or for a predetermined duration (e.g., a predetermined 20 minutes). In some embodiments, a larger volume (e.g., 50 milliliters) of liquid solvent can be concentrated to a desired volume (e.g., only 2 milliliters). This can preferably be achieved using a combination of a large evaporation flask and a small evaporation flask, the small flask being, for example, a sample vial that can be directly inserted into an analyzer such as a gas chromatograph-mass spectrometer (GC-MS). Furthermore, the evaporation module can detect the remaining volume of sample in the evaporation vessel (e.g., large and small evaporation flasks) during the evaporation process. For example, the evaporation module may include one or more level sensors for detecting the current liquid level of the sample. The sensors of the present invention can be communicatively connected to a controller (not shown), which may store an algorithm for executing the method of the present invention.

[0092] According to the present invention, the evaporation module can be allowed to evaporate the liquid solvent containing the analyte in the evaporation container after at least a portion of the liquid solvent containing the analyte from the extraction module has entered the evaporation container. Here, "at least a portion" refers to all the liquid solvent containing the analyte from the extraction module; that is, evaporation can be allowed as long as some liquid solvent containing the analyte has entered the evaporation container. It should be noted in particular that the term "allowed evaporation" means that evaporation (whether continuous or intermittent) can begin as soon as the evaporation container receives liquid solvent containing the analyte from the sample cell. However, it is important to note that this does not mean that evaporation must begin when the evaporation container receives liquid solvent containing the analyte from the sample cell. In other words, the evaporation process can begin as early as the point at which the evaporation container receives liquid solvent containing the analyte from the sample cell, but the evaporation process can obviously begin later than this point, for example, it can begin only after a predetermined amount of liquid solvent containing the analyte has entered the evaporation container. In some embodiments, evaporation may begin only after all the liquid solvent containing the analyte from the extraction module has entered the evaporation vessel (or even after a predetermined period of time has elapsed since the evaporation vessel has received all the liquid solvent containing the analyte).

[0093] In this invention, "all" refers to the liquid solvent containing the analyte, meaning the liquid solvent in which the desired amount of analyte in the sample is dissolved. In other words, "all" does not mean dissolving the theoretically complete amount of analyte originally contained in the sample in the liquid solvent, but only the amount of analyte that can be dissolved or is expected to be dissolved in the liquid solvent during this extraction process. It is understood that, due to issues such as dissolution efficiency, it is practically difficult to dissolve all the analyte contained in the sample in the liquid solvent, thereby allowing it to flow into the evaporation container.

[0094] In this invention, the term "evaporation" refers to the physical process of concentrating the volume of a liquid substance (i.e., a liquid solvent) by vaporizing it. The evaporation process in the evaporation module can be carried out by means including, but not limited to, heating, depressurization (e.g., vacuuming), blowing (e.g., nitrogen blowing), or any combination thereof. It is understood that in this invention, the analyte dissolved in the liquid solvent should generally not, or very little, vaporize through evaporation. Therefore, by evaporating the liquid solvent containing the analyte using the evaporation module, a large amount of the liquid solvent can be evaporated, thereby obtaining a desired volume of liquid solvent containing the analyte (also referred to as "concentration") for subsequent quantitative analysis of the analyte.

[0095] It should be noted that, as emphasized above, evaporation only begins when the evaporation container receives liquid solvent from the extraction module. Actions performed before this point are not considered "evaporation" in the context of this invention. For example, heating, evacuating, or purging the evaporation container before it enters the liquid solvent containing the analyte is not considered the start of the "evaporation" process in the context of this invention, but rather as preheating, pre-depressurization, pre-purification, or purification. It is understood that, considering the potential time difference between supplying liquid solvent or a mixture containing liquid solvent to the sample cell (starting), extracting the analyte from the sample using liquid solvent (starting), and receiving the liquid solvent containing the analyte from the sample cell (starting), this invention specifies that evaporation of the liquid solvent within the evaporation container is only permitted after the evaporation container has received (at least a portion) of the liquid solvent containing the analyte.

[0096] As described above, the above method steps can be controlled by configuring the controller of the present invention. It is understood that the controller of the present invention can also execute other method steps of the present invention, such as controlling various devices and apparatuses to execute predetermined programs.

[0097] According to the present invention, the extraction module may be in selective fluid communication with the evaporation module. Specifically, the sample cell of the extraction module may be in selective fluid communication with the evaporation container of the evaporation module. In some embodiments, the extraction module may include multiple sample cells, and the evaporation module may include multiple evaporation containers. Here, each of the multiple sample cells may be in selective fluid communication with a corresponding evaporation container among the multiple evaporation containers, that is, there is a one-to-one correspondence between the two.

[0098] In this invention, the evaporation container and the sample cell are in fluid communication, at least during the evaporation process. This means that when the liquid solvent in the evaporation container is evaporated, the fluid in the sample cell (not only the liquid solvent, but also other fluids such as gases, if present) can directly enter the evaporation container. That is, the liquid solvent containing the analyte can flow from the sample cell of the extraction module into the evaporation container after the evaporation process has started or during the evaporation process, without interruption due to the start or continuation of the evaporation process. However, it is understood that the sample cell can also be in fluid communication with the evaporation container before or after the evaporation process has started. Thus, the method of this invention can include an evaporation step, i.e., evaporating the liquid solvent containing the analyte in the evaporation container, during which the evaporation module and the sample cell are in fluid communication.

[0099] As described above, during the evaporation process, the evaporation container is in fluid communication with the sample cell. That is, this invention innovatively integrates or combines the extraction module with the evaporation module, thereby allowing the evaporation container to perform "in-situ evaporation / concentration" or "online evaporation / concentration" of the liquid solvent containing the analyte. In other words, in this invention, it is unnecessary to transfer the liquid solvent containing the analyte collected in the evaporation container to the evaporation equipment for the evaporation step. More advantageously, in some embodiments, the evaporation container comprises a combination of a large-volume evaporation flask and a small-volume evaporation flask, thereby allowing the analyte to be directly concentrated into an evaporation vial that can be directly placed into a quantitative analysis instrument (e.g., into an analyzer such as gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS)).

[0100] In existing technologies, the extraction of the analyte from the sample and its collection in a container are performed independently from the evaporation / concentration of the liquid solvent containing the analyte. Typically, the liquid solvent containing the analyte needs to be transferred manually or using additional tools to a subsequent evaporation device. Unlike existing technologies, the sample preparation system 100 of this invention integrates the extraction and evaporation modules, avoiding the analyte transfer process, thereby saving labor, increasing processing speed, and also avoiding the risk of the analyte coming into contact with the atmosphere or other contamination.

[0101] As previously described, in some embodiments of the present invention, the evaporation process may begin after all the liquid solvent containing the analyte has entered the evaporation container of the evaporation module from the sample cell of the extraction module. However, even this embodiment is still quite different from the prior art because the evaporation container remains in fluid communication with the sample cell during the evaporation process. This allows for the possibility of accepting extracts from multiple extraction processes into the evaporation container for evaporation. For example, after all the liquid solvent containing the analyte has been in the evaporation container and is being evaporated, a new sample can be loaded into the sample cell, thereby increasing the flexibility of the system. Even if extraction is no longer planned, this integration retains the possibility of redirecting fluids such as gases through the extraction module to the evaporation module. For example, at least some of the devices, piping, etc., that perform functions such as blowing (e.g., nitrogen blowing), venting, rinsing, and purifying the evaporation container of the evaporation module can be integrated with the devices, piping, etc., in the first supply module 110 of the system (i.e., sharing a portion of the piping and / or devices), thereby significantly reducing the number of components and significantly optimizing the overall efficiency of the system.

[0102] In some preferred embodiments, the liquid solvent in the evaporation vessel evaporates simultaneously with the receipt of the liquid solvent containing the analyte from the sample cell. However, it is understood that the entire evaporation process is not required to completely overlap with the extraction process; rather, the evaporation process can partially overlap with the extraction process. In other embodiments, it is permissible for the evaporation vessel to begin receiving the liquid solvent containing the analyte from the sample cell only after extraction is complete, while the evaporation of the liquid solvent can begin during or after the evaporation vessel has received it.

[0103] In addition to the evaporating container, the evaporation module may also include one or more devices for evaporating liquid solvents, such as an evaporation heating device for promoting heating of the evaporating container to achieve a controlled evaporation process by raising the temperature. If the evaporation module includes multiple evaporating containers, these containers can be arranged in a single temperature control device, or each evaporating container can be provided with an independent evaporation heating device or element, such as a heating wire, heating rod, or heating cylinder.

[0104] For example, the evaporation module may also include a suction (vacuum) device to reduce the pressure inside the evaporation container, thereby increasing the evaporation area or reducing the liquid surface pressure and accelerating the vaporization of the liquid solvent within the evaporation container. In this case, the evaporation module includes suction lines or vacuum lines leading into the evaporation container, which are connected to suction equipment (e.g., a vacuum pump, vacuum generator, etc.) located outside the evaporation container. The evaporation module may also have pressure sensors or vacuum sensors 145 arranged on the suction lines or vacuum lines or inside the evaporation container to monitor the real-time vacuum level inside the evaporation container.

[0105] To accelerate the solvent evaporation process, the evaporation module may also include a blowing or aeration device. The blowing or aeration device is configured to blow or aeration a gas, such as an inert gas, into or aeration the liquid solvent in the evaporation container through a conduit, thereby increasing the surface area of ​​the liquid solvent and significantly increasing the evaporation rate under the same conditions (same temperature, container cross-sectional area, and other factors affecting evaporation). As previously mentioned, in addition to supplying the sample cell, the first supply module 110 of the present invention can also supply gas, such as nitrogen for nitrogen blowing, to the evaporation module, primarily its evaporation container, using at least a portion of its common conduit, device, or element. This saves the need for a separate gas source 152 and some gas conduit for evaporation. When the gas conduit is shared, the gas, such as nitrogen, can first flow into the sample cell through the first supply conduit 111 and then into the evaporation container of the evaporation module via the extraction module, or it can flow into the evaporation container via a portion of the first supply conduit 111 and another portion of the conduit dedicated to the evaporation container, such as... Figure 5 As shown in the diagram (which will be explained further below).

[0106] The first supply module 110 may include a solvent pump 113 for pumping liquid solvent. For example, the solvent pump 113 may provide a pumping flow rate of 0.5-80 mL / min. In some embodiments, the solvent pump 113 may have a first operating configuration and a second operating configuration. In the second operating configuration, the solvent pump 113 is not operational, and therefore no liquid solvent is pumped to the extraction module, while in the first operating configuration, the solvent pump 113 operates, thereby pumping liquid solvent. However, it is understood that in the first operating configuration, there is also a possibility that liquid solvent may not be supplied to the sample cell of the extraction module, because the first supply module 110 also includes a device for selectively switching the flow path between the solvent pump 113 and the extraction module, such as a switching valve 115, or other switching device.

[0107] Typically, solvent pump 113 pumps liquid solvent at a relatively stable flow rate, which can be preset or adjusted online by the user. Furthermore, the first supply module 110 may also have other valves arranged between solvent pump 113 and switching valve 115 (e.g., see...). Figures 1 to 3 This allows for flexible adjustment of the fluid flow on / off in the second supply line 112 or further adjustment of the liquid solvent flow rate.

[0108] It is conceivable that during the switching process between sample cells using the switching valve 115, the solvent pump 113 can be briefly placed in the first operating configuration to avoid high pressure caused by passage blockage during the switching process of the switching valve 115. However, the solvent pump 113 can also be kept in the second operating configuration during this process to ensure that the liquid solvent flowing into the switching valve 115 is uninterrupted.

[0109] To supply the sample cell with a mixture of liquid solvent and gas, the first supply module 110 may further include a mixing device 117 for mixing the gas and liquid solvent. In some embodiments, the mixing device 117 is configured as a fluid connector (see...). Figure 5 This includes separate inlets for allowing the liquid solvent and gas to enter, and an outlet for allowing the mixed mixture to flow out. However, in other embodiments, the mixing device 117 may have other configurations, such as valves, manifolds, or other fluid components. It is understood that the mixing device 117 of the present invention can also be implemented as a broader mixing component; for example, a first gas supply line 111 and a second liquid solvent supply line 112 may be incorporated into one of the mixing lines, rather than necessarily being a dedicated mixing device. For example, Figures 1 to 3 The diagram does not show a dedicated mixing device, but only shows the merging or convergence of the first supply line 111 and the second supply line 112 (i.e., the section of the pipeline at the merging or convergence point can be referred to as a mixing device).

[0110] Extraction efficiency of analytes from a sample cell depends on several factors. Key factors include pressure, temperature, and flow rate. For gas-assisted liquid solvent extraction, this invention maintains a more stable pressure within the sample cell (i.e., pressure stability during extraction), better ensuring that the liquid solvent (e.g., in the mixture) remains liquid at the set extraction temperature, thus avoiding significant evaporation and actual loss of the liquid solvent, thereby further improving extraction efficiency. Furthermore, the mixing ratio between the gas and liquid solvent also needs to consider its impact on extraction performance. This invention provides a more stable mixing ratio of liquid solvent and gas (i.e., more precise control of the mixing ratio) to ensure sufficient mixing of gas and liquid during actual supply, thus positively impacting extraction performance.

[0111] Adjustment device

[0112] During extraction, especially in gas-assisted solvent extraction, it is crucial to maintain the pressure within the sample cell as stable as possible. For example, liquid solvents need to remain in their liquid phase within the sample cell; otherwise, the efficiency of solvent extraction will be significantly reduced. Maintaining a high, preset pressure within the sample cell ensures that the liquid solvent does not vaporize within the sample cell.

[0113] Therefore, the sample preparation system 100 of the present invention may include a regulating device. The regulating device may be arranged between the extraction module and the evaporation module, specifically in the flow path between the sample cell and the evaporation container. More precisely, the regulating device may be in fluid communication with both the sample cell and the evaporation container. Thus, in some embodiments, selective fluid communication between the sample cell and the evaporation container can be achieved by means of the regulating device, but it is also contemplated that such selective fluid communication may be achieved by other devices (if any) between the sample cell and the evaporation container. Advantageously, the regulating device may be driven by an actuating device, such as a stepper motor.

[0114] The regulating device of the present invention has an inlet and an outlet. The inlet is connected to a sample cell, and the outlet is connected to an evaporation vessel. A flow path between the inlet and the outlet is formed inside the regulating device. A fluid (e.g., a liquid solvent, a gas, or a mixture of both) can flow from the inlet through the flow path inside the regulating device to the outlet. In this invention, the cross-sectional size (or expressed as a relative value) of the portion of the flow path from the inlet to the outlet whose cross-section is variable is called the "opening" of the regulating device. For example, when the cross-sectional size is at its maximum variable value, it can be called the maximum opening, and when the cross-sectional size is zero (i.e., the flow path is not open), it can be called the minimum opening. The opening of the regulating device can vary between the maximum opening (100% opening) and the minimum opening (0 opening). When the pressure in the sample cell is relatively stable, the opening of the regulating device stabilizes near a certain equilibrium position, which is between the maximum opening and the minimum opening.

[0115] The regulating device can have operating and non-operating modes. In the non-operating mode, the regulating device is at its maximum opening to ensure constant fluid communication between the sample cell and the evaporation vessel. This mode allows fluid to pass rapidly through the sample cell at maximum flow rate, for example, when purge gas is supplied to the sample cell for purging. In the operating mode, the opening of the regulating device is variable. Specifically, the regulating device can adjust its opening based on the pressure within the sample cell, and this variation in opening can maintain the pressure within the sample cell within a preset range. The preset pressure range is, for example, a preset pressure value within 200-400 psi, particularly 300-350 psi (see [link to relevant documentation]). Figure 5 The pressure range is 1%-5% above or below the center (e.g., 200 psi).

[0116] Furthermore, it can be understood that the "pressure-based" adjustment of the opening degree in this invention means that the pressure within the sample cell is one of the determining factors for adjusting the opening degree of the regulating device, but it does not preclude the possibility of adjusting the opening degree based on other factors besides the pressure within the sample cell. That is, "based on" refers to an open set of influencing factors, and not necessarily the only influencing factor.

[0117] Specifically, when the pressure inside the sample cell is relatively stable, the opening of the regulating device also remains relatively stable at its equilibrium position. When the pressure inside the sample cell fluctuates, for example, when the pressure suddenly increases, the pressure at the inlet of the regulating device also increases due to the interconnectedness of the sample cell. This increased pressure leads to a larger opening of the regulating device, which reduces the resistance to flow through it, thus increasing the flow rate. This reduces the pressure (resistance) in the flow path, thereby lowering the pressure inside the sample cell and balancing the aforementioned sudden pressure fluctuation. Conversely, if the pressure inside the sample cell decreases, the opening of the regulating device will decrease, increasing the pressure (resistance) in the flow path and causing the pressure inside the sample cell to rise again.

[0118] Therefore, the regulating device of the present invention can provide negative feedback for pressure fluctuations within the sample cell, allowing it to return to its stable pressure as quickly as possible. In other words, even if pressure fluctuations exist within the sample cell, this negative feedback mechanism allows the pressure to fluctuate within a small range around a certain pressure value without exceeding this preset range, thereby achieving the desired pressure stability. Thus, in the operating mode of the regulating device, it not only allows the flow path between the sample cell and the evaporation vessel to be opened or closed, but more importantly, it can stabilize the pressure within the sample cell within a small preset range. Particularly advantageously, the regulating device can maintain the pressure within the sample cell within a preset pressure, especially higher pressures (e.g., 200-500 psi, particularly 220-300 psi), within a range of 1%, 2%, 3%, or 5% above or below this preset pressure, particularly higher pressures (e.g., 200-500 psi, especially 220-300 psi).

[0119] The regulating device may include a pre-compression assembly that provides a predefined resistance. In some embodiments, the pre-compression assembly may be configured as a membrane assembly, such as an elastic membrane. Preferably, the resistance provided by the pre-compression assembly is adjustable (e.g., by adjusting the tension of the membrane assembly). When the regulating device is in its operating mode, after the pressure in the sample cell reaches a first preset pressure determined by the pre-compression assembly, the flow path between the inlet and outlet is opened (i.e., the sample cell and the evaporation vessel are fluidly connected), meaning the flow path opening is not zero. In a preferred embodiment, gas may be supplied to the sample cell before the liquid solvent is supplied, allowing the pressure in the sample cell to rapidly rise to a preset back pressure since the regulating device is not open.

[0120] The pre-compression assembly can move between a blocking position for obstructing the flow path and a non-blocking position for releasing the flow path, preferably along the axial direction of the regulating device. Advantageously, the regulating device is arranged so that its axis is perpendicular or substantially perpendicular to the extension direction of the flow path in which the regulating device is located. It should be noted that the blocking position is usually the only position (i.e., the position with zero opening), while the non-blocking positions can be various positions with different openings. Furthermore, as mentioned above, when the pressure in the sample cell is relatively stable, the opening of the regulating device is also substantially stable at its equilibrium position. Therefore, the pre-compression assembly is also in one of its equilibrium positions to provide a stable opening. The aforementioned pressure fluctuations in the sample cell will cause pressure fluctuations at the inlet of the regulating device, and thus, such pressure fluctuations will disrupt the balance between the pressure at the inlet (or the pressure difference between the inlet and outlet) when the pressure is stable and the pre-compression resistance provided by the pre-compression assembly (e.g., the elastic force that can be provided by the diaphragm assembly).

[0121] In some embodiments, the regulating device may include a first valve body portion (e.g., located axially downward), a second valve body portion (e.g., located axially upward), and a cavity defined by both (e.g., an axial cavity). Here, both the inlet and outlet of the regulating device are located on the first valve body portion. The pre-pressurization assembly of the regulating device may be supported within the cavity and is movable between a blocking position for blocking the flow path and a non-blocking position for releasing the flow path. In some embodiments, the two ends of the diaphragm assembly are supported, while the middle portion is suspended within the cavity. According to the invention, the opening degree may be defined by the space between the pre-pressurization assembly and (e.g., the first valve body portion located axially downward) of the pre-pressurization assembly, for example, the axial height of that space. Alternatively, the inlet and outlet of the regulating device may also be located on different valve body portions.

[0122] Furthermore, to facilitate the evaporation container's reception of the liquid solvent containing the analyte from the sample cell, a delivery needle interface or a dispensing needle interface can be used between the regulating device and the evaporation container to conveniently transfer and receive the fluid from the sample cell to the evaporation container. This delivery needle interface or dispensing needle interface provides a sealing function for the evaporation container to prevent contamination and loss of the analyte, and also provides a path for transferring vacuum to the evaporation container.

[0123] Gas flow control device

[0124] In gas-assisted solvent extraction, a mixture of liquid solvent and gas needs to be supplied to the sample cell. Advantageously, the gas-liquid mixing ratio can be controlled (especially continuously). An inappropriate gas-liquid mixing ratio leads to uneven mixing, resulting in an undesirable decrease in extraction efficiency within the sample cell. However, due to pressure pulsations that occur in the supply line during fluid supply, precise control of the gas-liquid mixing ratio in the sample cell is impossible.

[0125] To address this issue, the supply step of the method of the present invention may include supplying a predetermined flow rate of gas to the sample cell for mixing with the liquid solvent during the supply of the gas-liquid solvent mixture. Preferably, the first supply module 110 of the sample preparation system 100 may include a gas flow control device 114, which supplies a predetermined flow rate (e.g., 1-200 ml / min) of gas for mixing with the liquid solvent during the supply of the gas-liquid solvent mixture. Of course, the present invention may also implement the above-described supply step using other devices.

[0126] The gas flow control device 114 can be arranged on or in fluid communication with the first supply line 111. The gas flow control device 114 may include an inlet and an outlet, with the inlet connected to the gas source 152 and the outlet connected to the extraction module. Typically, the inlet pressure of the gas flow control device 114 is higher than the outlet pressure. With the aforementioned regulating device, the outlet pressure of the gas flow control device 114 can also be maintained within a stable preset range (e.g., 220-300 psi). Since the gas source 152 preferably provides pressurized gas, the inlet pressure of the gas flow control device 114 is typically high, for example, 250-400 psi, particularly 300-350 psi.

[0127] The gas flow control device 114 may include a flow control mode in which a continuous and stable gas flow rate is provided to the sample cell. Because the gas flow rate remains stable, the gas will also occupy a stable proportion in the mixture of liquid solvent and gas. This ensures that the mixing of gas in the mixture, i.e., the mixing of gas into the liquid solvent, is uniform. Thus, in the mixture entering the sample cell, the liquid solvent and gas can increase convection and diffusion mass transfer efficiency, thereby shortening the extraction time, further improving the overall mass transfer properties of the liquid solvent, and increasing the extraction rate of the analyte.

[0128] Furthermore, the stable gas flow rate provided by the gas flow control device 114 of the present invention can be preset by the user, thereby adjusting the desired gas-liquid mixing ratio during the gas-assisted solvent extraction process and thus optimizing the extraction performance.

[0129] Furthermore, when the extraction module includes multiple sample cells, if the mixture of liquid solvent and gas is sequentially supplied to each sample cell, uneven or unbalanced distribution of the mixture (flow rate) may occur in each sample cell. By incorporating the gas flow control device 114 of this invention, the uneven flow rate in each sample cell can be effectively resolved, because the gas flow control device 114 can always maintain the supplied gas flow rate at a preset flow rate. Of course, it is understood that the preset flow rate also allows for a very small fluctuation range, for example, 1-5%.

[0130] Furthermore, the gas flow control device 114 may also include a fully open mode. The fully open mode can be applied during the stage of rapidly increasing the pressure within the sample cell before supplying the gas-liquid mixture. As previously mentioned, maintaining a high pressure within the sample cell is a key factor in keeping the liquid solvent in a liquid phase at high temperatures. Rapidly increasing the pressure within the sample cell (e.g., to a pressure value between 200-500 psi) can eliminate liquid solvent loss due to possible vaporization, because such high pressure directly raises the boiling point of most organic solvents, thereby keeping the liquid solvent within the sample cell in the liquid phase.

[0131] It is understood that once the desired high pressure is achieved in the sample cell, the gas flow control device 114 can switch from the fully open mode (automatic or manual) to the flow control mode to facilitate gas-assisted operation. However, this switch can also be performed automatically or manually under other conditions (e.g., preset time). In some embodiments, the switch from the fully open mode to the flow control mode can be performed when the liquid solvent in the sample cell reaches a preset amount (e.g., preset volume).

[0132] To optimize extraction efficiency, the extraction module of the present invention may include multiple sample cells (e.g., two, four, or eight sample cells). Furthermore, to simultaneously improve overall sample preparation efficiency, the evaporation module of the present invention may also include multiple evaporation containers (e.g., two, four, or eight evaporation containers). As previously described, each sample cell may be in selective fluid communication with a corresponding evaporation container. Preferably, the sample preparation apparatus of the present invention may further include multiple adjustment devices, with one adjustment device arranged between each sample cell and its corresponding evaporation container.

[0133] In this invention, whether performed sequentially or simultaneously, supplying liquid solvent, gas, or a mixture of both to multiple sample cells is termed multiple-channel supply; dissolving the analyte in liquid solvent within multiple sample cells is termed multiple-channel extraction; and evaporating the analyte-containing liquid solvent in multiple evaporation containers is termed multiple-channel evaporation. The term "multi-channel" is used to distinguish it from cases where only a single sample cell is supplied, extraction is performed in a single sample cell, or liquid solvent is evaporated in a single evaporation container. By employing a multiple-channel setup, the same device can meet the varying throughput requirements of users.

[0134] Advantageously, the extraction module may include multiple extraction channels, with each sample cell connected to one of the multiple extraction channels. In some embodiments, a sample cell is placed within an extraction channel, and the extraction channel and the sample cell therein are selectively fluidly connected to an evaporation vessel. However, it is worth noting that even if the extraction module does not have multiple extraction channels associated with multiple sample cells, the extraction process can still be referred to as "multi-channel extraction," meaning that multiple sample cells can be extracted (either sequentially or simultaneously). That is, the term "multi-channel" in this invention is close to "multi-path," and does not necessarily imply the existence of physical channels. Similarly, even if the evaporation module does not have evaporation channels corresponding to evaporation vessels, a multi-channel evaporation process involving evaporation of multiple evaporation vessels can still be called multi-channel evaporation. Furthermore, in this invention, the term "sequential" refers to a sequence or according to (e.g., a predetermined) order. Advantageously, this predetermined order (i.e., the order in which gas, liquid solvent, or gas-liquid mixture is supplied to multiple sample cells) remains unchanged between different supply cycles, as this ensures that the extraction conditions of each sample cell are kept as consistent as possible, thereby improving the recovery rate. In this invention, multichannel extraction, multichannel evaporation, or particularly a combination of both can be performed. In some embodiments, for multichannel extraction, the liquid solvent can be supplied sequentially to each sample cell, or the liquid solvent can be supplied to multiple sample cells simultaneously. While simultaneous supply of liquid solvent to each sample cell can achieve a higher throughput, sequentially filling each sample cell with liquid solvent (also known as intermittent supply or filling) can benefit faster solvent equilibration and higher extraction recovery. It will be understood that the method of this invention can be automatically or manually switched between simultaneously supplying liquid solvent or a mixture thereof with gas to each sample cell and sequentially supplying it to each sample cell, thereby improving operational flexibility.

[0135] Specifically, compared to a continuous solvent flow through each extraction channel or sample cell, intermittent delivery of liquid solvent allows for a faster equilibration time to the predetermined extraction temperature and more efficient extraction of the analyte. It can be noted that in the case of sequential supply, a static extraction time exists because when one sample cell is supplied with liquid solvent, other sample cells are not. In this invention, the term "static extraction time" refers to the time during which liquid solvent is not supplied to the sample cells. However, it is understood that static extraction time does not necessarily mean that liquid solvent does not flow through the sample cells or into the evaporation vessel, but only indicates that no liquid solvent is supplied to the sample cells during this static extraction time.

[0136] In this case, at least during the process of supplying the liquid solvent and gas mixture to the sample cells, it is preferable to include multiple supply cycles or multiple supply loops. In each of the multiple supply cycles, the gas-liquid mixture is sequentially supplied to each of the multiple sample cells. In one example, with four extraction channels (i.e., four sample cells), the duration of one supply cycle is 60 seconds, and preferably, the liquid solvent or the liquid solvent and gas mixture is sequentially supplied to each sample cell for 15 seconds. That is, after one sample cell has been supplied with liquid solvent or the gas-liquid mixture for 15 seconds, the system switches to the next sample cell for supply. In this example, each sample cell generates three-quarters of the static extraction time within one supply cycle. It is understood that the supply time to each sample cell may not be the same 15 seconds; for example, one sample cell may be supplied for 10 seconds, while another sample cell may be supplied for 20 seconds, and so on.

[0137] However, it should be noted that, for ease of description, this invention specifies that a supply cycle in which the gas-liquid mixture (or only liquid solvent, or only gas) is not sequentially supplied to each sample cell is not considered one of the aforementioned plurality of supply cycles, and a sample cell in which no gas-liquid mixture is supplied is also not considered one of the aforementioned plurality of sample cells. In other words, this invention does not exclude the possibility that the gas-liquid mixture is not sequentially supplied to each sample cell in other supply cycles, nor does it exclude the existence of sample cells in which no gas-liquid mixture is supplied, but these supply cycles are not considered one of the aforementioned plurality of supply cycles, and these sample cells are not considered one of the aforementioned plurality of sample cells.

[0138] With a constant supply volume, multiple supply cycles better ensure uniformity of extraction conditions across sample cells compared to embodiments with only one supply cycle (i.e., supplying the desired full amount of liquid solvent to one sample cell before switching to the next). Multiple supply cycles allow for a more consistent and shorter static extraction time across sample cells. Furthermore, increasing the frequency of switching between sample cells minimizes temperature variations during extraction between sample cells or extraction channels. It should also be noted that because the liquid solvent or its gas-liquid mixture is supplied intermittently between sample cells (i.e., the aforementioned static extraction time exists), there are conditions for changing the liquid solvent, thereby allowing for adjustments to extraction conditions as needed and providing overall system flexibility.

[0139] Advantageously, the duration of supplying the gas-liquid mixture to each sample cell within the same supply cycle is equal, i.e., the supply duration is evenly distributed across the sample cells. However, the invention is not limited to this; the duration of supplying the gas-liquid mixture to each sample cell may also differ between the sample cells, or at least partially differ, but equal duration is preferred. It is also advantageous that the amount (e.g., mass, volume, or flow rate) of the gas-liquid mixture supplied to each sample cell within the same supply cycle is equal. That is, an equal amount of gas-liquid mixture is supplied to each sample cell in one supply cycle. However, the invention is not limited to this; the amount of gas-liquid mixture supplied to each sample cell may also differ between the sample cells, or at least partially differ, but equal supply is preferred. Of course, when the flow rate of the supplied mixture remains constant, if the supply duration is the same, it means that the supply amount is also the same.

[0140] Furthermore, the amount of mixture supplied to each sample cell or the supply duration may be the same or different in different supply cycles. Preferably, the total duration of each supply cycle, or the supply time or amount of each sample cell in each supply cycle under the condition of equal supply, is kept small (e.g., 10 seconds, 15 seconds, 20 seconds, etc.) to reduce the adverse effect of decreased recovery rate due to uneven increase in extraction temperature.

[0141] In this invention, the amount of liquid solvent supplied to (each) sample cell can be adjusted by the user or preset. For example, a liquid solvent equivalent to 20%-80%, particularly 30%-70%, of the sample cell's volume can be supplied. In some cases, the greater the amount of liquid solvent supplied to the sample cell (e.g., the larger the volume), the better the extraction recovery.

[0142] To sequentially supply liquid solvent or a mixture of liquid solvent and gas to sample cells, the first supply module 110 of the present invention may include a switching valve 115 (e.g., a multi-way rotary valve) connected to a second supply line 112. The switching valve 115 may have multiple different operating configurations, each of which directs the flow of liquid solvent to a corresponding sample cell among the multiple sample cells during a corresponding time period in each supply cycle. It is understood that the time consumed by switching between the multiple different operating configurations is minimal, and the switching time between multiple supply cycles is also extremely short and therefore negligible. Here, the term "corresponding time period" refers to the time period or duration associated with the corresponding sample cell to be directed to within that supply cycle.

[0143] It will be understood that in some embodiments, only the liquid solvent may flow through the switching valve 115, i.e., the gas and liquid solvent are mixed downstream of the switching valve 115 (see, for example, see...). Figure 3 This avoids compromising the durability of the switching valve 115 due to the flow of a gas-liquid mixture. However, in other embodiments, the gas and liquid solvent can be mixed upstream of the switching valve 115 so that the gas-liquid mixture flows into the sample cell via the switching valve 115 (e.g., see...). Figure 2 ).

[0144] In some embodiments, the switching valve 115 may include a first port communicating with a second supply line 112 (upstream of it) or a solvent pump 113, and may also include multiple ports in fluid communication with multiple sample cells respectively. Liquid solvent can flow into the switching valve 115 from the first port and then flow to the sample cell via one of the multiple ports, thereby enabling the switching of the liquid solvent flow path. In this case, the operating configuration may refer to a state where the first port of the switching valve 115 is in fluid communication with one of the multiple ports. Multiple operating configurations may refer to multiple states where the first port of the switching valve 115 is in fluid communication with multiple ports respectively. Of course, the invention is not limited to this, and other states of the switching valve 115 constituting the above operating configurations are also conceivable.

[0145] For example, during the first time period of a supply cycle, switching valve 115 may be in its first operating configuration to supply liquid solvent (or a mixture of liquid solvent and gas) to the first sample cell 122a of the plurality of sample cells. In the immediately following second time period of the supply cycle, switching valve 115 may be in its second operating configuration to supply liquid solvent (or a mixture of liquid solvent and gas) to the second sample cell 122b of the plurality of sample cells. Similarly, in the subsequent third and fourth time periods of the same supply cycle, liquid solvent (or a mixture of liquid solvent and gas) is supplied to the third and fourth sample cells. That is, switching valve 115 may be in the third and fourth operating configurations. If multiple supply cycles exist, after supplying liquid solvent (or a mixture of liquid solvent and gas) to the last sample cell of the plurality of sample cells in the last time period of the aforementioned supply cycle, the first time period of the next supply cycle continues, returning to supplying liquid solvent (or a mixture of liquid solvent and gas) to the first sample cell 122a. This continues until all predetermined supply cycles are completed.

[0146] Compared to setting up a switch or valve for each sample cell, using the switching valve 115 to switch between sample cells can reduce the number of components.

[0147] To sequentially supply gas or a mixture of liquid solvent and gas to the sample cells, the first supply module 110 of the present invention may include switching devices. In the context of the present invention, the switching devices may allow or prevent fluid from passing through them, thereby controlling the flow path. In cases where the extraction module includes multiple sample cells, the first supply module 110 of the present invention has, on the one hand, a first supply line 111 including multiple branch lines, and on the other hand, multiple switching devices corresponding to the multiple branch lines. Advantageously, each of the multiple switching devices is connected to a corresponding branch line of the multiple branch lines (e.g., as shown in the diagram). Figure 3 As shown, each switching device is arranged on a branch pipe, allowing selective fluid communication between that branch pipe and a corresponding sample cell among multiple sample cells. Since the switching device 116, as shown above, can guide gas flow within a segment to a corresponding sample cell among multiple sample cells.

[0148] In some embodiments, during a first time period of a supply cycle, a second switching device 116b on a second branch line 111b in the first supply line 111 allows fluid to flow through it to supply gas (or a mixture thereof with a liquid solvent) to the first sample cell 122a among the plurality of sample cells. During a second time period immediately following the supply cycle, a third switching device 116c on a third branch line 111c in the first supply line 111 allows fluid to flow through it (at which point the first switching device blocks fluid flow) to supply gas (or a mixture thereof with a liquid solvent) to the second sample cell 122b among the plurality of sample cells. Similarly, during subsequent third and fourth time periods of the same supply cycle, gas (or a mixture thereof with a liquid solvent) is supplied to the third sample cell 122c and the fourth sample cell 122d. If multiple supply cycles exist, after supplying gas (or a mixture thereof with a liquid solvent) to the last sample cell among the plurality of sample cells in the last time period of the aforementioned supply cycle, the first time period of the next supply cycle continues, returning to supplying gas (or a mixture thereof with a liquid solvent) to the first sample cell 122a. This process continues until the entire predetermined supply cycle or supply loop is completed.

[0149] Although the switching device can be constructed as a valve, it can also be other known mechanical structures capable of achieving on / off switching. However, it is understood that the switching device is not limited to performing only the function of opening and closing a flow path; for example, it can also be a device with an adjustable opening degree, which will not be elaborated further here. It should be noted that the gas supply step according to the invention can also be performed without the aforementioned switching device.

[0150] Furthermore, the present invention can also envision using a switching valve 115 to achieve sequential purging of the sample cell. In this case, it is necessary to connect the first gas supply line 111 to the switching valve 115 in fluid communication (e.g., Figure 4 The first branch pipe 111a of the first supply pipe 111 shown can be connected to the switching valve 115, so that the gas used as purge gas flows from the first supply pipe 111 through the switching valve 115 to the sample cells, i.e., sequentially to each sample cell. At this time, the gas flow control device 114 can be in the aforementioned fully open mode, and the regulating device is in its non-operating mode (maximum opening) to reduce the flow resistance difference on each branch pipe, thereby promoting almost identical purging of each sample cell. Furthermore, instead of using multiple switching devices (e.g., the first to fourth switching devices) connected to the first supply pipe 111, the present invention can also achieve sequential gas supply to the extraction module and / or evaporation module by means of the combination of the first supply pipe 111 and the switching valve 115 to achieve the desired cleaning, purification, and aeration functions.

[0151] Corresponding to multi-channel or multi-path extraction, multi-path evaporation can be performed online. As mentioned above, "multi-path" does not mean that the evaporation module has multiple evaporation channels, but rather that there are multiple evaporation containers that can be evaporated simultaneously or sequentially. Furthermore, it can be understood that in this invention, multi-path evaporation may not be combined with multi-path extraction. For example, multi-path extraction can be performed, but liquid solvents containing the analyte from multiple sample cells flow into the same evaporation container (i.e., single-path evaporation) or into evaporation containers of varying numbers. Alternatively, extraction can be single-channel, but liquid solvents containing the analyte from the same sample cell can flow into multiple evaporation containers and be evaporated simultaneously or in a predetermined order. However, combining multi-path evaporation with multi-path extraction is a preferred embodiment of this invention.

[0152] In the case of multi-channel evaporation, when evaporation is carried out by depressurization, for example, a vacuum can be provided by an external vacuum pump. The vacuum can be transmitted into the evaporation vessel via a vacuum manifold, which can distribute vacuum paths for the corresponding multiple channels. Each vacuum path in the first to fourth vacuum lines is preferably equipped with a vacuum valve 144 to individually control the evaporation process. These vacuum valves 144 are necessary for evaporating a fixed volume, but may not be necessary for general evaporation.

[0153] In the case of multi-channel evaporation, when evaporation is performed by heating, the heating of the evaporation vessel is heat conduction, microwave heating, or other known forms of heating. The evaporation module includes a first heating device to evaporate the liquid solvent containing the analyte located within the evaporation vessel by heating it. In the case of multi-channel evaporation, the number of first heating devices can be determined by the number of evaporation vessels. Furthermore, the first heating devices can also be individually controlled by each evaporation vessel.

[0154] In the case of multi-channel evaporation, when evaporation is carried out by blowing or purging, the blowing of gas into the multiple evaporation containers can be provided by an external gas source 152. The external gas can be distributed to the corresponding evaporation containers using a distributor. As described above, the gas used for blowing can be the same gas source 152 as the gas supplied to the sample cell, and multiple branch lines of the aforementioned first supply line 111 can also be used. Preferably, regardless of whether it shares a line with the gas supplied to the sample cell, each branch line can be individually controlled by a valve that can switch the gas flow on and off.

[0155] The following example illustrates the integrated process of extraction and evaporation. However, it should be noted that the illustrated process is merely exemplary, and the apparatus, parameters, and even some steps used are exemplary or optional.

[0156] 1) Initialize the equipment so that the controller and various devices of the present invention can enter the working state.

[0157] 2) The sample (e.g., a fixed or semi-solid sample) may be loaded into the sample cell. However, it will be understood that in other embodiments, the sample may be pre-integrated into the sample cell. Alternatively, at least a portion of the sample may be loaded into the sample cell after the extraction process has begun, particularly some of multiple sample cells.

[0158] 3) The sample cell can be heated until a target temperature is reached (e.g., a temperature value within the range of 40-200 degrees Celsius). For example, the sample cell can be loaded into the extraction heating device (e.g., an oven) using an automated pneumatic gantry. Alternatively, the sample cell may already be in the extraction heating device, for example, the extraction heating device can be integrated into the extraction module.

[0159] 4) Position the regulating device in operating mode and the gas flow control device 114 in fully open mode to pre-fill the sample cell with gas. This allows the pressure inside the sample cell to rapidly rise to the preset pressure. The preset pressure can be between 100-500 psi, for example, 220 psi.

[0160] 5) The liquid solvent is supplied to the sample cell, for example by means of solvent pump 113. In embodiments comprising multiple sample cells, the liquid solvent can be filled into each sample cell once, i.e., a specified volume of liquid solvent can be continuously filled at maximum pumping speed. Alternatively, multiple supply cycles can be used to supply liquid solvent to each of the multiple sample cells, and the latter is preferred.

[0161] 6) In gas-assisted solvent extraction, a mixture of liquid solvent and gas can be supplied to the sample cell. The gas and liquid solvent are mixed before entering the sample cell. The gas flow control device 114 can be in gas flow control mode to supply a preset flow rate of gas (in the form of a mixture with liquid solvent) to the sample cell (for example, the preset flow rate of gas can be supplied to the mixing device 117 of the first supply module 110).

[0162] 7) After the liquid solvent containing the analyte flows from the sample cell (e.g., via a regulating device) into the evaporation container, evaporation of the liquid solvent in the evaporation container can begin. Evaporation can be performed, for example, by heating the evaporation container, evacuating (e.g., opening vacuum valve 144), or nitrogen blowing (e.g., introducing nitrogen gas). The collected liquid solvent is thus rapidly vaporized, and the solvent vapor is transferred outside the evaporation container through a conduit. The evaporation container can also be preheated before this evaporation process, for example, before the liquid solvent has flowed into it, so that it reaches its operating temperature more quickly when evaporation begins.

[0163] 8) After a predetermined amount of liquid solvent has been collected in the evaporation container or after a predetermined evaporation time (but also after other predetermined conditions are met), optionally, the sample cell is purged with a purge gas (e.g., high-pressure nitrogen). At this time, the regulating device is in its non-operating state (maximum opening), and the vacuum valve 144 of the evaporation module is closed. Thus, any residual analyte remaining in the sample cell can be collected into the evaporation container.

[0164] 9) After purging, the adjustment device can be returned to operating mode, and the evaporation of the liquid solvent in the evaporation container can continue. In embodiments where a fixed volume is evaporated, the level sensing module continues to record the liquid solvent level in the evaporation container (e.g., evaporation vial).

[0165] 10) After evaporation, the sample cell (e.g., each extraction channel) can be rinsed with a liquid solvent, such as one for the next extraction, an organic solvent, or distilled water, but this is not mandatory. Alternatively, it is conceivable to use a gas, especially a high-pressure gas, to clean the sample cell (e.g., each extraction channel).

[0166] Optionally, in a multi-channel extraction embodiment, the liquid solvent and gas mixture can be supplied to the sample cells in multiple supply cycles (e.g., 1-100 supply cycles). In each of the multiple supply cycles, the mixture is fed into one of the multiple sample cells and supplied for a corresponding time period (e.g., 10-60 seconds), then transferred to the next sample cell (the supply time can vary, but may be the same), until all the multiple sample cells have been supplied, thus completing one supply cycle. Multiple supply cycles are repeated until a predetermined amount of the gas-liquid mixture has been supplied, or until a mixture has been supplied for a predetermined time.

[0167] Alternatively, during the gas supply to the sample cells before extraction begins, the gas can be supplied to each of the multiple sample cells in at least one supply cycle. In each supply cycle, the gas can be supplied sequentially to each sample cell. Particularly advantageously, this gas supply process for the sample cells can be combined with a heating process for the sample cells. For example, when filling the first sample cell 122a of the multiple sample cells with gas, the first sample cell 122a can be heated (only). When switching to filling the second sample cell 122b of the multiple sample cells with gas, the second sample cell can be heated (only), and so on. In a preferred embodiment, for a multi-channel sample cell, the extraction heating device, such as a furnace, can be started first (e.g., heated to the target temperature), and then each sample cell can be loaded into the extraction heating device sequentially at intervals (e.g., 15-20 seconds apart), so that the timing of supplying gas and liquid solvent to each sample cell is close to the temperature rise profile of the sample in that sample cell, thereby obtaining more consistent extraction conditions.

[0168] It can be noted that the above-described method and apparatus of the present invention can be easily extended from a single channel to multiple channels, and from two channels to four or eight channels.

[0169] exist Figure 5 In the specific embodiment shown (containing four sample cells), the pressure is maintained within a stable preset pressure range by an adjusting device during the extraction process (e.g., approximately ten minutes). The adjusting device is then placed in a non-operating mode (the adjusting device opening is maximized) to purge each sample cell. In this embodiment, two high-pressure pulses are applied sequentially to each of the four sample cells for purging, for example, setting a purging time of 60 seconds per sample cell or channel. First, a 15-second high-pressure purge is applied, followed by a 15-second wait, then another 15 seconds of high pressure is applied, and finally another 15-second wait. However, this is merely exemplary. Furthermore, in embodiments containing multiple sample cells, the pressure values ​​of the individual sample cells may be inconsistent due to differences in the sample filling, differences in the distribution of liquid solvent in the sample, differences in the gas resistance of the individual tubing, etc. The system and method according to the invention can minimize the inconsistencies or adverse effects caused by these differences.

[0170] In summary, using the method and equipment of the present invention, an extraction recovery rate of 70%-95% can be achieved for low-boiling-point compounds and an extraction recovery rate of over 95% can be achieved for high-boiling-point compounds (see examples in the table below).

[0171] Table 1: Fat Extraction Recovery Rate (High-Boiling-Point Compounds)

[0172]

[0173] Furthermore, by using the method and apparatus of the present invention, the processing throughput can be increased (by at least 2.5 times) while ensuring the recovery rate, as shown in the comparison table below.

[0174] Table 2: Comparison of Processing Throughput between the Invention and Existing Technologies

[0175]

[0176] Next, using Figure 4 To describe in detail the systems and equipment in some instances, especially their supply paths.

[0177] The gas, particularly an inert gas such as high-pressure nitrogen, can be split into two paths after exiting the gas source 152. The first path serves the first supply line 111 of the first supply module 110, while the second path can be used for other supply modules not described in detail herein. The first gas path flows to the gas flow control device 114 via an optional filter 153. After passing through the gas flow control device 114, the first supply line 111 can be divided into five branch lines 111a-111e via a first manifold, each branch line being equipped with a switching device 116a-116e, such as a valve.

[0178] The liquid solvent can come from multiple different solvent containers, and the liquid solvents in these containers can be mixed (e.g., by means of a mixing valve) before flowing into the second supply line 112 of the first supply module 110. The solvent pump 113 pumps the liquid solvent (whether or not it has been mixed) to the switching valve 115. Figure 4 It can be seen that the gas flowing through the first switching device 116a installed on the first branch pipeline (also known as the main gas path) 111a can be mixed with the liquid solvent that has not flowed through the switching valve 115, or it can flow directly through the switching valve 115 without mixing. The gas flowing through the second to fifth switching devices 116b-116e installed on the second to fifth branch pipelines 111b-111e can be mixed with the liquid solvent flowing through the switching valve 115 inside the mixing device 117.

[0179] More specifically, when only gas is supplied to the sample cell, the first branch line (main gas line) 111a in the first supply line 111 is preferably used. The gas can flow from the first branch line 111a to the switching valve 115, which then splits it into four sub-gas lines, which can then be supplied to the first to fourth sample cells 122a-122d simultaneously or sequentially to rapidly increase the pressure in the sample cells. However, it is understood that when only gas is supplied to the sample cell and / or evaporation vessel, the main gas line can be omitted, and instead, four branch lines 111b-111e can be used, so that the gas does not pass through the switching valve 115 and is already split into four gas lines before the mixing device 117.

[0180] When only liquid solvent is supplied to the sample cell, the liquid solvent can be pumped to the switching valve 115 by the solvent pump 113. The switching valve 115 divides the liquid into four sub-liquid paths, which can then be supplied to the first to fourth sample cells simultaneously or sequentially to quickly wet the sample in the sample cell and prevent the sample from drying out in the sample cell.

[0181] When a mixture of liquid solvent and gas is supplied to the sample cells, the liquid solvent is pumped to a switching valve 115 by a solvent pump 113, which divides the liquid into four sub-liquid paths. The liquid solvent flows into the mixing device 117 through these four sub-paths. Simultaneously, gas also flows into the mixing device 117 via the second to fifth branch lines 111b-111e to mix with the liquid solvent. The mixed gas-liquid mixture flows from the mixing device 117 to the first to fourth sample cells via the first to fourth mixing supply lines 112a-112d, thereby dissolving the analytes in the sample. In other words, the mixture can be supplied to the first to fourth sample cells 122a-122d simultaneously or sequentially. It can be understood that supply lines 112a-112d, when only gas is supplied, can be referred to as part of the first supply line 111, and supply lines 112a-112d, when only liquid solvent is supplied, can be referred to as part of the second supply line 112.

[0182] The liquid solvent containing the analyte can be introduced from the first to the fourth sample cells 122a-122d into the first to the fourth evaporation vessels 141a-141d via their respective regulating devices 130a-130d, and evaporation can be started when evaporation is required to obtain the desired concentrate.

[0183] Depend on Figure 4It is understood that the first to fourth vacuum lines 142a-142d are in fluid communication with the first to fourth evaporation containers 141a-141d, respectively, to enable rapid depressurized evaporation inside the first to fourth evaporation containers 141a-141d. Here, the first to fourth evaporation containers 141a-141d each include a large evaporation flask located above and a small evaporation flask (also referred to as a sample bottle) located below. Advantageously, multiple evaporation containers can be arranged on an automated rotating device for convenient subsequent replacement or monitoring.

[0184] In addition, gas can be supplied to the first to fourth evaporation containers (or a portion thereof) via the first supply module 110 (through the sample cell) for purging or blowing. Alternatively, purge gas can be supplied to the first to fourth sample cells 122a-122d via the first supply module 110 to further collect any residual analytes remaining in the first to fourth sample cells 122a-122d into the first to fourth evaporation containers 141a-141d.

[0185] It is understandable that, despite Figure 4 The boundary of the first supply module 110 is shown in dashed lines, but the actual range of the first supply module of the present invention can vary depending on the devices or components it includes. For example, when the first supply module 110 includes a gas source and / or a solvent source, it can produce a range similar to... Figure 4 The different boundary ranges are shown.

[0186] Although various embodiments of the invention have been described in the accompanying drawings with reference to examples of sample preparation systems incorporating gas-assisted solvent extraction techniques and methods for collecting analytes from samples using such sample preparation systems, it should be understood that embodiments within the scope of the invention can be applied to systems, apparatuses, and methods having similar structures and / or functions.

[0187] The foregoing description has already given many features and advantages, including various alternative implementations, as well as details of the structure and function of the apparatus and methods. This document is intended to be exemplary and is not exhaustive or limiting.

[0188] It will be apparent to those skilled in the art that various modifications can be made within the full scope indicated by the broad superordinate meaning of the terms expressed in the appended claims, particularly in terms of structure, materials, elements, components, shapes, dimensions, and arrangements of components, including combinations of these aspects within the scope of the principles described herein. Such various modifications are intended to be included herein, provided they do not depart from the spirit and scope of the appended claims.

Claims

1. A method of extracting an analyte to be analyzed from a sample by a sample preparation system, the sample preparation system comprising an extraction module and an evaporation module in selective fluid communication, wherein, The extraction module includes a sample cell for placing a sample containing an analyte to be analyzed, and the evaporation module includes an evaporation vessel for evaporating a liquid solvent containing an analyte to be analyzed, The method includes the following steps: a supply step of supplying a gas and a liquid solvent capable of dissolving an analyte to be analyzed in the sample cell; a receiving step of receiving the liquid solvent containing an analyte to be analyzed from the extraction module to the evaporation vessel; an evaporation step of evaporating the liquid solvent containing an analyte to be analyzed in the evaporation vessel, the evaporation module and the sample cell being in fluid communication; wherein the evaporation step is allowed to be performed after at least a portion of the liquid solvent containing an analyte to be analyzed from the extraction module enters the evaporation vessel, wherein a portion of the gas and a portion of the liquid solvent are supplied by a common line, wherein the supply step includes a first supply sub-step of supplying a mixture of the gas and the liquid solvent to the sample cell, wherein the first supply sub-step includes supplying a predetermined flow rate of the gas to the liquid solvent during the supply of the mixture by means of a gas flow control device, and wherein the sample preparation system further includes a regulating device arranged between the sample cell and the evaporation vessel, and the receiving step further includes regulating an opening degree of a flow path based on a pressure in the sample cell by means of the regulating device, and maintaining the pressure in the sample cell within a predetermined range by changing the opening degree, the liquid solvent being received to the evaporation vessel via the flow path.

2. The method of claim 1, wherein, The regulating device includes an inlet in communication with the sample cell and an outlet in communication with the evaporation vessel, and fluid can flow from the inlet to the outlet via a flow path inside the regulating device.

3. The method of claim 1, wherein, The extraction module includes a plurality of sample cells, and the evaporation module includes a plurality of evaporation vessels, each of the plurality of sample cells being selectively in fluid communication with a corresponding one of the plurality of evaporation vessels, wherein the first supply sub-step includes a plurality of supply cycles, and in each of the plurality of supply cycles, the mixture is sequentially supplied to each of the plurality of sample cells.

4. The method of claim 3, wherein, The duration of supplying the mixture to each sample cell in the same supply cycle is equal, or the amount of the mixture supplied to each sample cell in the same supply cycle is equal.

5. The method of claim 1, wherein, In the evaporation step, the liquid solvent containing an analyte to be analyzed in the evaporation vessel is evaporated by heating the evaporation vessel and / or reducing the pressure inside the evaporation vessel.

6. The method of claim 5, wherein, The method further includes pre-heating the evaporation vessel before the evaporation step.

7. The method of claim 1, wherein, The method further includes heating the sample cell before the supply step.

8. A sample preparation system for extracting an analyte to be analyzed from a sample, comprising: an extraction module including a sample cell for placing a sample containing an analyte to be analyzed; a first supply module capable of supplying a gas and a liquid solvent capable of dissolving an analyte to be analyzed in the sample cell, the first supply module including: a mixing device for mixing the gas and the liquid solvent to supply a mixture to the sample cell, a first supply line for supplying gas, and a gas flow control device in fluid communication with the first supply line and configured to cause a preset flow of the gas to flow into the mixing device when the first supply module supplies the mixture to the sample cell, so that the mixing of the gas in the mixture is uniform, wherein at least a portion of the first supply module is used to supply both the gas and the liquid solvent; an evaporation module including an evaporation vessel for evaporating the liquid solvent containing the analyte to be analyzed, wherein the evaporation vessel is in fluid communication with the sample cell when evaporating; a controller configured to allow the evaporation vessel to evaporate the liquid solvent containing the analyte to be analyzed located therein after at least a portion of the liquid solvent containing the analyte to be analyzed from the extraction module enters the evaporation vessel; and a regulating device arranged between the sample cell and the evaporation vessel and configured to regulate the opening degree of a flow path based on the pressure in the sample cell, so that the pressure in the sample cell is maintained within a preset interval by the change of the opening degree.

9. The sample preparation system of claim 8, wherein, The regulating device includes an inlet in communication with the sample cell and an outlet in communication with the evaporation vessel, and fluid can flow from the inlet to the outlet via a flow path inside the regulating device.

10. The sample preparation system of claim 9, wherein, The regulating device includes a first valve body portion, a second valve body portion, and a cavity defined by the two, the inlet and the outlet are provided on the first valve body portion, a pre-pressing assembly of the regulating device is supported in the cavity and can move between a blocking position for blocking the flow path and a non-blocking position for releasing the flow path, and the opening degree is defined by the space between the pre-pressing assembly and the first valve body portion.

11. The sample preparation system of claim 8, wherein, The extraction module includes a plurality of sample cells, and the evaporation module includes a plurality of evaporation vessels, wherein each sample cell in the plurality of sample cells can be selectively in fluid communication with a corresponding evaporation vessel in the plurality of evaporation vessels.

12. The sample preparation system of claim 11, wherein, The first supply module further includes a switching valve having a plurality of different operating configurations, each of the plurality of different operating configurations being used to direct the flow of the liquid solvent to a corresponding one of the plurality of sample cells in a corresponding time period of each supply cycle.

13. The sample preparation system of claim 12, wherein, The first supply line includes a plurality of branch lines and a plurality of switching devices, each of the plurality of switching devices being in communication with a corresponding one of the plurality of branch lines so that the one branch line can be selectively in fluid communication with a corresponding one of the plurality of sample cells, wherein the flow of the gas to the corresponding one of the plurality of sample cells in the corresponding time period of each supply cycle is directed by means of the plurality of switching devices.

14. The sample preparation system of claim 11, wherein, A plurality of regulating devices are further included, one regulating device being arranged between each sample cell and a corresponding evaporation vessel.

15. The sample preparation system of claim 8, wherein, The evaporation module comprises a first heating device to evaporate the liquid solvent containing the analyte to be analyzed located inside the evaporation vessel by heating the evaporation vessel. The evaporation module comprises a first heating device to evaporate the liquid solvent containing the analyte to be analyzed located inside the evaporation vessel by heating the evaporation vessel.

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