Micro valve, chromatographic sample injector, preparation method of chromatographic sample injector, chromatographic system and application method of chromatographic system

Abstract

The invention provides a micro valve, a chromatographic sample injector, a preparation method of the chromatographic sample injector, a chromatographic system and an application method of the chromatographic system. The micro valve sequentially comprises a first sealing substrate, a silicon substrate, SOI top layer silicon, an SOI buried oxide layer, SOI bottom layer silicon and a second sealing substrate, the SOI top layer silicon is bonded with the first surface, with the groove, of the silicon substrate, the second surface of the silicon substrate is provided with a first groove and a second groove, the first channel is communicated with the groove and the first groove, the second channel is communicated with the groove and the second groove, the first sealing substrate is bonded with the second surface of the silicon substrate, and the second sealing substrate is bonded with the SOI bottom layer silicon; and the control gas groove is obtained by etching the SOI bottom layer silicon and the SOI buried oxide layer. According to the invention, the single crystal deformation film in the SOI top layer silicon is used as a micro valve switch piece, and the micro valve and the chromatographic sample injector are obtained by utilizing the characteristics that the single crystal silicon film has better elasticity, wear resistance and high temperature resistance and can be prepared in batches by an MEMS (Micro Electro Mechanical System) process, so that the integration of the chromatographic sample injector and other chromatographic components is improved, and the microminiaturization of a chromatographic system is facilitated.

Description

Technical Field

[0001] The invention belongs to the field of micro-electromechanical systems, and in particular relates to a micro-valve, a chromatographic injector and a preparation method thereof, a chromatographic system and an application method thereof. Background Art

[0002] Chromatography is a widely used method for separation and analysis of mixed samples. Among them, the six-way valve is the core component of the chromatograph. Sample injection can be achieved through the sampling-injection switching of the six-way valve, which is one of the main injection methods of the chromatographic system. However, the traditional automatic injection six-way valve is large in size and high in power consumption, which is not conducive to the miniaturization of the chromatographic system. Therefore, the development of a microvalve-based chromatographic injector based on MEMS technology is conducive to the miniaturization of the chromatographic system.

[0003] At present, micro-chromatographic injectors based on MEMS technology are mainly divided into two types: pressure-driven and electromagnetic-driven. However, in the prior art, pressure-driven micro-injectors need to use polymer films as switch components. The valve-controlled switches prepared by polymer films are incompatible with silicon-based MEMS processes, and reliable bonding of polymer films to silicon substrates is also a challenge; while electromagnetic-driven micro-injectors in the prior art require multi-layer MEMS processes to realize the preparation of electrodes and movable units. The process is highly complex, difficult and costly, and it is difficult to integrate with other components of the chromatography system.

[0004] Therefore, there is an urgent need to develop a micro-chromatographic injector that can improve process compatibility and reduce process difficulty.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology part of the present application. Summary of the invention

[0006] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a microvalve, a chromatographic injector and a preparation method thereof, a chromatographic system and an application method thereof, so as to solve the problems of poor compatibility and high process difficulty of micro chromatographic injectors in the prior art.

[0007] To achieve the above object, the present invention provides a microvalve, the microvalve comprising: a first sealing substrate, a silicon substrate, an SOI substrate and a second sealing substrate;

[0008] The SOI substrate comprises SOI top silicon, SOI buried oxide layer and SOI bottom silicon in sequence, the SOI top silicon is a single crystal silicon film, and the deformation film is prepared in the SOI top silicon; the silicon substrate comprises a first surface and a second surface arranged oppositely, and the SOI top silicon is bonded to the first surface of the silicon substrate;

[0009] The first surface of the silicon substrate comprises a groove, the second surface of the silicon substrate comprises a first groove and a second groove, the silicon substrate further comprises a first channel and a second channel, the first channel connects the groove and the first groove, the second channel connects the groove and the second groove, and the first groove and the second groove are connected in sequence through the first channel, the groove and the second channel;

[0010] The SOI buried oxide layer and the SOI bottom silicon are provided with control gas grooves at positions corresponding to the grooves, and the deformable film is the portion of the SOI top silicon located between the control gas grooves and the grooves; the gas introduced from the inlet of the control gas grooves can apply pressure to the deformable film on the SOI top silicon, so that the deformable film is deformed and contacts the bottom of the groove, so as to block the connection between the first groove and the second groove;

[0011] The second surface of the silicon substrate is bonded to the first sealing substrate, and the second sealing substrate is bonded to the side of the SOI bottom silicon away from the SOI buried oxide layer. The first sealing substrate and the second sealing substrate enable the first groove, the second groove, and the control gas groove to form closed channels respectively.

[0012] The present invention also provides a method for preparing a microvalve, the method for preparing the microvalve is used to prepare the above-mentioned microvalve, the method comprising:

[0013] Providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged opposite to each other; providing a first channel and a second channel on the first surface of the silicon substrate; providing a groove on the first surface of the silicon substrate, the projection of the groove on the first surface covers the projection of the first channel and the second channel on the first surface;

[0014] A first groove and a second groove are provided on the second surface of the silicon substrate, wherein the first channel is connected to the first groove and the groove, and the second channel is connected to the second groove and the groove;

[0015] Providing an SOI substrate, wherein the SOI substrate sequentially comprises an SOI top silicon layer, an SOI buried oxide layer and an SOI bottom silicon layer, wherein the SOI top silicon layer is a single crystal silicon thin film; bonding the SOI top silicon layer of the SOI substrate to the first surface of the silicon substrate;

[0016] The SOI bottom silicon and the SOI buried oxide layer of the SOI substrate are etched at positions corresponding to the grooves to obtain control gas grooves, and a portion of the SOI top silicon located between the control gas grooves and the grooves constitutes a deformable film;

[0017] The second surface of the silicon substrate is bonded to a first sealing substrate, and the surface of the SOI bottom silicon away from the SOI buried oxide layer is bonded to a second sealing substrate to form closed channels for the first trench, the second trench, and the control gas trench.

[0018] Optionally, the preparation method further comprises: after forming the groove, growing an oxidation protection layer on the surface exposed by the groove.

[0019] The present invention also provides a chromatographic injector, which comprises at least one of the above-mentioned microvalve.

[0020] Optionally, the chromatographic injector comprises at least 6 of the above-mentioned microvalves, and the 6 microvalves are respectively a first microvalve A, a second microvalve B, a third microvalve C, a fourth microvalve D, a fifth microvalve E and a sixth microvalve F; the chromatographic injector further comprises: a sample inlet, a mobile phase inlet, a sample outlet, a mobile phase outlet, a quantitative loop, a microchannel structure and at least two control gas inlets;

[0021] The microfluidic channel structure comprises a first flow channel, a second flow channel, a third flow channel, a fourth flow channel and a fifth flow channel, wherein the first flow channel, the second flow channel, the third flow channel, the fourth flow channel and the fifth flow channel are all flow channels; a first flow channel is arranged between the sample inlet and the mobile phase inlet, a second flow channel is arranged between the sample outlet and the mobile phase outlet, and both ends of the third flow channel, the fourth flow channel and the fifth flow channel are respectively connected with the first flow channel and the second flow channel; the third flow channel is located at one end close to the sample inlet and the sample outlet, the fifth flow channel is located at one end close to the mobile phase inlet and the mobile phase outlet, and the fourth flow channel is located between the third flow channel and the fifth flow channel;

[0022] The quantitative ring is located in the fourth flow channel; the first microvalve A is located in the third flow channel to control the connection state of the third flow channel, and the sixth microvalve F is located in the fifth flow channel to control the connection state of the fifth flow channel; the second microvalve B is located between the third flow channel and the fourth flow channel on the first flow channel to control the connection state of the quantitative ring and the sample inlet, the third microvalve C is located between the third flow channel and the fourth flow channel on the second flow channel to control the connection state of the quantitative ring and the sample outlet, the fourth microvalve D is located between the fourth flow channel and the fifth flow channel on the first flow channel to control the connection state of the quantitative ring and the mobile phase inlet, and the fifth microvalve E is located between the fourth flow channel and the fifth flow channel on the second flow channel to control the connection state of the quantitative ring and the mobile phase outlet;

[0023] The inlet of the control gas groove of each microvalve is connected to the corresponding control gas inlet to allow gas to enter to control the switch state of the corresponding microvalve;

[0024] The first groove and the second groove of each microvalve are respectively connected to the corresponding flow channels at both ends to control the connectivity state of the corresponding flow channels; each of the microvalves shares the first sealing substrate, the silicon substrate, the SOI substrate and the second sealing substrate, and each of the microvalves has its own groove, the first groove, the second groove, the first channel, the second channel and the control gas groove; the sample inlet, the mobile phase inlet, the sample outlet, the mobile phase outlet, the quantitative ring and the microfluidic channel structure are all located on the silicon substrate of the microvalve.

[0025] Optionally, the inlets of the control gas grooves of the first microvalve A, the fourth microvalve D and the fifth microvalve E are interconnected through one control gas inlet; the inlets of the control gas grooves of the second microvalve B, the third microvalve C and the sixth microvalve F are interconnected through another control gas inlet.

[0026] The present invention also provides a method for preparing a chromatographic injector, wherein the method for preparing the chromatographic injector adopts any one of the above-mentioned methods for preparing microvalve to prepare six microvalves on the same first sealing substrate, the silicon substrate, the SOI substrate and the second sealing substrate, wherein the six microvalves are respectively a first microvalve A, a second microvalve B, a third microvalve C, a fourth microvalve D, a fifth microvalve E and a sixth microvalve F, and the method for preparing the chromatographic injector further comprises:

[0027] When the first grooves and the second grooves of the six microvalves are arranged on the second surface of the silicon substrate, a sample inlet, a mobile phase inlet, a sample outlet, a mobile phase outlet, a quantitative loop and a microfluidic structure are also arranged on the second surface of the silicon substrate to obtain any one of the above-mentioned chromatographic injectors;

[0028] After bonding the first sealing substrate and the second sealing substrate, a slicing process is performed to expose the sample inlet, mobile phase inlet, sample outlet, mobile phase outlet and control gas inlet of each of the chromatographic injectors; a capillary structure is set at each sample inlet, mobile phase inlet, sample outlet, mobile phase outlet and control gas inlet.

[0029] Optionally, the first channel, the second channel, the first groove, the second groove and the control gas groove of the microvalve and the quantitative loop and the microfluidic channel structure in the chromatographic injector are arranged by deep reactive ion etching.

[0030] The present invention also provides a chromatography system, which comprises any one of the above-mentioned chromatography injectors, and further comprises a chromatography column, wherein the chromatography column is connected to the mobile phase outlet of the chromatography injector.

[0031] The present invention also provides an application method of a chromatography system, and the application method of the chromatography system is performed using the above-mentioned chromatography system;

[0032] Close the first microvalve A, the fourth microvalve D and the fifth microvalve E, open the second microvalve B, the third microvalve C and the sixth microvalve F, inject the sample to be detected from the sample inlet, so that the sample to be detected is injected from the sample inlet through the second microvalve B and fills the quantitative ring, and then is discharged from the sample outlet through the third microvalve C;

[0033] Close the second microvalve B, the third microvalve C structure and the sixth microvalve F, open the first microvalve A, the fourth microvalve D and the fifth microvalve E, inject mobile phase from the mobile phase inlet, allow the mobile phase to enter the quantitative loop from the mobile phase inlet through the fourth microvalve D, and the sample to be detected in the quantitative loop is injected into the chromatographic column from the mobile phase outlet through the fifth microvalve E under the push of the mobile phase for chromatographic separation. After chromatographic separation, use a detector to perform chromatographic detection on the sample flowing out of the chromatographic column.

[0034] As described above, the microvalve, chromatographic injector and preparation method thereof, chromatographic system and application method thereof of the present invention have the following beneficial effects:

[0035] The present invention uses a single crystal deformable film in the top silicon layer of the SOI substrate as a microvalve switch element, and utilizes the characteristics of batch preparation by the MEMS process to obtain a microvalve and a chromatographic injector, thereby improving the integrability of the structures of various chromatographic components and facilitating the miniaturization of the chromatographic system. On the one hand, the method avoids the process problem of incompatibility between the polymer film and the MEMS process, and can use the MEMS process to manufacture related structures, with a simple process and low cost. More importantly, compared with the polymer film, the single crystal silicon film has better elasticity, wear resistance, and high temperature resistance, and therefore has higher reliability. On the other hand, a control gas groove, a control gas inlet, and a deformable film are designed and prepared on the SOI substrate, and structures related to each flow channel are designed and prepared on the silicon substrate, that is, the control gas path and the working flow channel are designed and prepared separately, the structural design is more flexible, the process preparation flow is simpler, and the process difficulty and production cost are reduced.

[0036] The present invention also uses the top silicon of SOI to bond with the silicon substrate. On the one hand, the silicon-silicon bonding temperature is high, and the subsequent silicon-glass bonding temperature is low, and the subsequent bonding will not destroy the silicon-silicon bonding structure. On the other hand, compared with other bonding methods, the silicon-silicon bonding strength is high and the cost is low. At the same time, the sealing substrate adopts a transparent glass substrate, which is convenient for observing whether the microvalve structure is complete and whether it works normally. In terms of preparing deformable films, the reliability of silicon-silicon bonding is higher than that of organic film bonding with silicon substrate, and it is more compatible with MEMS processes, which can reduce process difficulty and cost, and has the technical advantage of high cost performance, which is conducive to the batch application of microvalves and chromatographic injectors based on microvalves in chromatographic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It shows a schematic diagram of the three-dimensional structure of the microvalve in Example 1 of the present invention.

[0038] Figure 2 It is a cross-sectional view along AA' of the microvalve in Embodiment 1 of the present invention.

[0039] Figure 3 It is a schematic diagram of a structural cross-sectional view of the arrangement of the first channel, the second channel and the groove in step 1 of the method for preparing a microvalve in Example 1 of the present invention.

[0040] Figure 4 It is a schematic diagram of a cross-sectional view of the structure presented by setting the first groove and the second groove in step 2 of the method for preparing a microvalve in Example 1 of the present invention.

[0041] Figure 5 It is a schematic diagram of a cross-sectional view of the structure presented by bonding the SOI top silicon layer and the silicon substrate in step 3 of the method for preparing a microvalve in Example 1 of the present invention.

[0042] Figure 6 It is a schematic diagram of a cross-sectional view of the structure presented by setting a control gas groove in step 4 of the method for preparing a microvalve in Example 1 of the present invention.

[0043] Figure 7 It is a schematic diagram of a cross-sectional view of the structure presented by bonding the first sealing substrate and the second sealing substrate in step 5 of the method for preparing a microvalve in Example 1 of the present invention.

[0044] Figure 8 Shown is a schematic diagram of the structural connection relationship of the chromatographic injector in the example of Example 2 of the present invention.

[0045] Fig. 9 The structure diagram shows a perspective view of the SOI bottom silicon of the chromatographic injector in the example of embodiment 2 of the present invention, with the view facing upward.

[0046] Fig.10It is a schematic diagram of the partially enlarged structure of the M part in the perspective view of the SOI bottom silicon upward of the chromatographic injector in the example of embodiment 2 of the present invention.

[0047] Fig.11 The structure diagram shows a perspective view of the chromatographic injector with the silicon substrate facing upward in the example of Embodiment 2 of the present invention.

[0048] Component number description

[0049] 101, SOI bottom silicon; 102, SOI buried oxide layer; 103, SOI top silicon; 1031, deformation film; 104, control gas groove; 105, control gas inlet; A, first microvalve; B, second microvalve; C, third microvalve; D, fourth microvalve; E, fifth microvalve; F, sixth microvalve;

[0050] 200, silicon substrate; 211, groove; 212, first groove; 213, second groove; 214, first channel; 215, second channel; 221, quantitative ring; 231, first flow channel; 232, second flow channel; 233, third flow channel; 234, fourth flow channel; 235, fifth flow channel; 241, sample inlet; 242, sample outlet; 243, mobile phase inlet; 244, mobile phase outlet;

[0051] 301, a first sealing substrate; 302, a second sealing substrate. DETAILED DESCRIPTION

[0052] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0053] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the schematic diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0054] For convenience of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0055] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0056] It should be noted that the illustrations provided in the present invention are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0057] It is worth noting that the mobile phase of the microvalve and chromatographic injector mentioned in the present invention can be gas or liquid, that is, the microvalve and chromatographic injector of the present invention are suitable for both gas chromatography system and liquid chromatography system.

[0058] Embodiment 1:

[0059] This embodiment provides a micro valve, such as Figure 1-Figure 3 As shown, Figure 1 This is a top perspective view of the microvalve. Figure 2 is a bottom perspective view of a microvalve, the microvalve comprising: a first sealing substrate 301, a silicon substrate 200, an SOI substrate, and a second sealing substrate 302;

[0060] The SOI substrate includes SOI top silicon 103, SOI buried oxide layer 102, SOI bottom silicon 101 in sequence, the SOI top silicon 103 is a single crystal silicon film, and the deformation film 1031 is prepared in the SOI top silicon 103; the silicon substrate 200 includes a first surface and a second surface arranged oppositely, and the SOI top silicon 103 is bonded to the first surface of the silicon substrate 200;

[0061] The first surface of the silicon substrate 200 includes a groove 211, the second surface of the silicon substrate 200 includes a first groove 212 and a second groove 213, and the silicon substrate 200 further includes a first channel 214 and a second channel 215, the first channel 214 connects the groove 211 and the first groove 212, the second channel 215 connects the groove 211 and the second groove 213, and the first groove 212 and the second groove 213 are connected in sequence through the first channel 214, the groove 211 and the second channel 215;

[0062] The SOI buried oxide layer 102 and the SOI bottom silicon 101 are provided with a control gas groove 104 at positions corresponding to the groove 211, and the deformable film is the portion of the SOI top silicon 103 located between the control gas groove 104 and the groove 211; the gas introduced from the inlet of the control gas groove 104 can apply pressure to the deformable film 1031 on the SOI top silicon 103, so that the deformable film 1031 is deformed and contacts the bottom of the groove 211, so as to block the communication between the first groove 212 and the second groove 213;

[0063] The second surface of the silicon substrate 200 is bonded to the first sealing substrate 301, and the second sealing substrate 302 is bonded to the side of the SOI bottom silicon 101 away from the SOI buried oxide layer 102. The first sealing substrate 301 and the second sealing substrate 302 enable the first groove 212, the second groove 213, and the control gas groove 104 to form closed channels respectively.

[0064] The present invention arranges a deformable film 1031 using a single crystal silicon film in an SOI substrate as a switch element of a microvalve switch, and utilizes the good elasticity, wear resistance, high temperature resistance and batch preparation characteristics of the single crystal silicon film using a MEMS process to obtain a microvalve, thereby improving the integrability of the microvalve and facilitating the miniaturization of a chromatography system using the microvalve; at the same time, since the SOI top silicon 103 containing the deformable film 1031 switch structure has a stronger bonding reliability with the silicon substrate 200 and is more compatible with the MEMS process, the process difficulty and cost can be reduced.

[0065] Specifically, Figure 1 A-A' in Figure 3-Figure 7 The section line of the sectional view, the upper part of the sectional view is sectioned along the section line direction corresponding to A'O', and the lower part is sectioned along the section line direction corresponding to AO.

[0066] Specifically, the closed channel formed by the first sealing substrate 301 and the second sealing substrate 302 does not refer to a completely closed channel, but refers to a channel similar to Figure 8 The four walls at positions 242 and 244 are closed, and only the inlet and outlet are connected to the outside.

[0067] In one embodiment, Figure 1 As shown, the projection of the position of the control gas groove 104 corresponding to the first channel 214 and the second channel 215 on the first surface is a circle, and the projection of the position of the control gas groove 104 corresponding to the first channel 214 and the second channel 215 on the first surface covers the first channel 214 and the second channel 215.

[0068] The present invention sets the projection of the position corresponding to the control gas groove 104 and the first channel 214 and the second channel 215 on the first surface to be circular, thereby facilitating the deformation of the deformable film 1031 and reducing the stress generated by the deformation of the deformable film 1031 during the deformation process, thereby improving the service life of the microvalve. Personnel in the art can also select a suitable projection shape of the control gas groove 104 on the first surface according to needs.

[0069] This embodiment also provides a method for preparing a microvalve, the method for preparing the above-mentioned microvalve comprising:

[0070] Step 1: providing a silicon substrate 200, wherein the silicon substrate 200 comprises a first surface and a second surface arranged opposite to each other; providing a first channel 214 and a second channel 215 on the first surface of the silicon substrate 200; providing a groove 211 on the first surface of the silicon substrate 200, wherein a projection of the groove 211 on the first surface covers a projection of the first channel 214 and the second channel 215 on the first surface;

[0071] Step 2: a first groove 212 and a second groove 213 are provided on the second surface of the silicon substrate 200 , wherein the first channel 214 is connected to the first groove 212 and the groove 211 , and the second channel 215 is connected to the second groove 213 and the groove 211 ;

[0072] Step 3: providing an SOI substrate, wherein the SOI substrate sequentially comprises an SOI top silicon layer 103, an SOI buried oxide layer 102 and an SOI bottom silicon layer 101, wherein the SOI top silicon layer 103 is a single crystal silicon thin film; bonding the SOI top silicon layer 103 of the SOI substrate to the first surface of the silicon substrate 200;

[0073] Step 4: etching the SOI bottom silicon 101 and the SOI buried oxide layer 102 of the SOI substrate at positions corresponding to the groove 211 to obtain a control gas groove 104, and the portion of the SOI top silicon 103 between the control gas groove 104 and the groove 211 constitutes a deformable film 1031;

[0074] Step 5: Bond the second surface of the silicon substrate 200 to the first sealing substrate 301 , and bond the surface of the SOI bottom silicon 101 away from the SOI buried oxide layer 102 to the second sealing substrate 302 to form closed channels for the first groove 212 , the second groove 213 , and the control gas groove 104 .

[0075] The preparation method of the microvalve of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the above sequence does not strictly represent the sequence of the preparation method of the microvalve protected by the present invention, and those skilled in the art may change it according to the actual preparation steps. Figure 3-Figure 7 The middle is a sectional view, and the section line is Figure 1 A-A' in.

[0076] First, if Figure 3 As shown, step 1 is performed to provide a silicon substrate 200, wherein the silicon substrate 200 includes a first surface and a second surface arranged opposite to each other; a first channel 214 and a second channel 215 are arranged on the first surface of the silicon substrate 200; a groove 211 is arranged on the first surface of the silicon substrate 200, and the projection of the groove 211 on the first surface covers the projection of the first channel 214 and the second channel 215 on the first surface.

[0077] In one embodiment, the distance between the groove 211 and the first surface is smaller than the distance between the first channel 214 and the second channel 215 and the first surface.

[0078] In one embodiment, the silicon substrate 200 is made of single crystal silicon, and a silicon-silicon bonding process is used to bond the first surface of the silicon substrate 200 and the SOI top silicon 103 of the SOI substrate.

[0079] In one embodiment, the preparation method further includes: after forming the groove 211 , growing an oxidation protection layer on the surface of the groove 211 .

[0080] The present invention grows an oxide protection layer on the surface of the groove 211, thereby protecting the groove 211 from being etched by the etching gas entering from the second surface when the first groove 212 and the second groove 213 are set in the subsequent preparation process, thereby avoiding the etched surface affecting the contact between the deformable film 1031 and the groove 211 to achieve the switching effect, thereby improving the reliability of the microvalve.

[0081] In one embodiment, Figure 3 As shown, the first channel 214 and the second channel 215 provided before the groove 211 are provided may not penetrate the silicon substrate 200, but may be etched only to a preset depth, and when the first groove 212 and the second groove 213 are provided, the depths of the first groove 212 and the second groove 213 are controlled so that the first channel 214 connects the first groove 212 and the groove 211, and the second channel 215 connects the second groove 213 and the groove 211. This method can reduce the process time required when the first channel 214 and the second channel 215 are provided, and reduce the aspect ratio when the first channel 214 and the second channel 215 are provided, thereby reducing the process difficulty.

[0082] In one embodiment, the first channel 214 and the second channel 215 provided before the groove 211 can directly penetrate the silicon substrate 200, and the depth of the first groove 212 and the second groove 213 can be set according to specific channel requirements. This method can improve the flexibility of setting the depth of the first groove 212 and the second groove 213. Those skilled in the art can select a suitable method for setting the first channel 214 and the second channel 215 according to specific requirements.

[0083] Then, if Figure 4 As shown, step 2 is performed to set a first groove 212 and a second groove 213 on the second surface of the silicon substrate 200 , the first channel 214 connects the first groove 212 and the groove 211 , and the second channel 215 connects the second groove 213 and the groove 211 .

[0084] Then, if Figure 5 As shown, step 3 is performed to provide an SOI substrate, wherein the SOI substrate sequentially includes an SOI top silicon layer 103, an SOI buried oxide layer 102 and an SOI bottom silicon layer 101, and the SOI top silicon layer 103 is a single crystal silicon film; the SOI top silicon layer 103 of the SOI substrate is bonded to the first surface of the silicon substrate 200.

[0085] Then, if Figure 6 As shown, step 4 is performed to etch the SOI bottom silicon 101 and the SOI buried oxide layer 102 of the SOI substrate at positions corresponding to the groove 211 to obtain a control gas groove 104, and the portion of the SOI top silicon 103 located between the control gas groove 104 and the groove 211 constitutes a deformable film 1031.

[0086] Finally, if Figure 7 As shown, step 5 is performed to bond the second surface of the silicon substrate 200 to the first sealing substrate 301, and to bond the surface of the SOI bottom silicon 101 away from the SOI buried oxide layer 102 to the second sealing substrate 302 to form the first groove 212, the second groove 213, and the control gas groove 104, respectively.

[0087] The present invention designs the structure of the SOI substrate and the silicon substrate 200, so that the MEMS process can be directly used to prepare a microvalve using the SOI top silicon 103 as the deformable film 1031. On the one hand, the process problem of incompatibility between the polymer film and the MEMS process is avoided, and the structure can be manufactured using the MEMS process. The process is simple and the cost is low. More importantly, compared with the polymer film, the single crystal silicon film has better elasticity, wear resistance, and high temperature resistance, and therefore has higher reliability. On the other hand, the control gas groove 104, the control gas inlet 105, and the deformable film 1031 are designed and prepared on the SOI substrate, and the related structures of each flow channel are designed and prepared on the silicon substrate, that is, the control gas path and the working flow channel are designed and prepared separately, the structural design is more flexible, the process preparation flow is simpler, and the process difficulty and production cost are reduced.

[0088] In one embodiment, the first surface of the silicon substrate 200 and the SOI top silicon 103 are bonded to each other. On the one hand, the silicon-silicon bonding temperature is high, and the subsequent silicon-glass bonding temperature is low, and the subsequent bonding will not damage the silicon-silicon bonding structure. On the other hand, compared with other bonding methods, the silicon-silicon bonding strength is high and the cost is low. The first sealing substrate 301 and the second sealing substrate 302 are glass substrates. The glass substrate is placed on the cathode of the bonding machine, and the SOI substrate and the silicon substrate 200 are placed on the anode of the bonding machine to perform silicon-glass anode bonding to achieve bonding with the first sealing substrate 301 and the second sealing substrate 302. At the same time, the first sealing substrate 301 and the second sealing substrate 302 use transparent glass substrates, which is convenient for observing whether the microvalve structure is complete and whether it works normally.

[0089] Embodiment 2:

[0090] This embodiment provides a chromatographic injector, which includes at least one microvalve described in Embodiment 1.

[0091] The present invention uses at least one microvalve as the microvalve in Example 1 to obtain a chromatographic injector capable of automatic injection, so as to improve the process compatibility and structural reliability of the chromatographic injector and reduce the process difficulty and process cost.

[0092] In one embodiment, Figure 8-Figure 11 As shown, Figure 8 The schematic diagram of the structural connection relationship of the chromatographic injector is shown in FIG. Fig. 9 This is a perspective view of the chromatographic injector with the top facing up. Fig.10 This is a schematic diagram of the partially enlarged structure of the M part in the perspective view of the top surface of the chromatographic injector. Fig.11The bottom side of the chromatographic injector is a perspective view upward, wherein the chromatographic injector comprises at least 6 microvalves described in Example 1, wherein the 6 microvalves are respectively a first microvalve A, a second microvalve B, a third microvalve C, a fourth microvalve D, a fifth microvalve E and a sixth microvalve F; the chromatographic injector further comprises: a sample inlet 241, a mobile phase inlet 243, a sample outlet 242, a mobile phase outlet 244, a quantitative ring 221, a microchannel structure and at least two control gas inlets 105;

[0093] The microchannel structure includes a first channel 231, a second channel 232, a third channel 233, a fourth channel 234 and a fifth channel 235, wherein the first channel 231, the second channel 232, the third channel 233, the fourth channel 234 and the fifth channel 235 are all channels; the first channel 231 is arranged between the sample inlet 241 and the mobile phase inlet 243, and the second channel 231 is arranged between the sample outlet 242 and the mobile phase outlet 244. 2, both ends of the third flow channel 233, the fourth flow channel 234 and the fifth flow channel 235 are respectively connected to the first flow channel 231 and the second flow channel 232; the third flow channel 233 is located at one end close to the sample inlet 241 and the sample outlet 242, the fifth flow channel 235 is located at one end close to the mobile phase inlet 243 and the mobile phase outlet 244, and the fourth flow channel 234 is located between the third flow channel 233 and the fifth flow channel 235;

[0094] The quantitative ring 221 is located in the fourth flow channel 234; the first microvalve A is located in the third flow channel 233 to control the connection state of the third flow channel 233, and the sixth microvalve F is located in the fifth flow channel 235 to control the connection state of the fifth flow channel 235; the second microvalve B is located between the third flow channel 233 and the fourth flow channel 234 on the first flow channel 231 to control the connection between the quantitative ring 221 and the sample inlet 241, and the third microvalve C is located on the second flow channel 232 The position between the third flow channel 233 and the fourth flow channel 234 is used to control the communication between the quantitative ring 221 and the sample inlet 242. The fourth microvalve D is located between the fourth flow channel 234 and the fifth flow channel 235 on the first flow channel 231 to control the communication between the quantitative ring 221 and the mobile phase inlet 243. The fifth microvalve E is located between the fourth flow channel 234 and the fifth flow channel 235 on the second flow channel 232 to control the communication between the quantitative ring 221 and the mobile phase outlet 244.

[0095] The inlet of the control gas groove 104 of each microvalve is connected to the corresponding control gas inlet 105 to allow gas to enter to control the switch state of the corresponding microvalve;

[0096] The first groove 212 and the second groove 213 of each microvalve are respectively connected to the corresponding flow channels at both ends to control the connectivity state of the corresponding flow channels; each of the microvalves shares the first sealing substrate 301, the silicon substrate 200, the SOI substrate and the second sealing substrate 302, and each of the microvalves has its own groove 211 and control gas groove 104; the sample inlet 241, the mobile phase inlet 243, the sample outlet 242, the mobile phase outlet 244, the quantitative ring 221 and the microchannel structure are all located on the silicon substrate 200 of the microvalve.

[0097] The present invention adopts the microvalve described in Example 1 as the switching valve of the connecting channel connecting the sample inlet 241, the mobile phase inlet 243, the sample outlet 242, the mobile phase outlet 244, and the quantitative ring 221, so as to control the state switching of the chromatographic injector for automatic sampling and injection; since the switching valves for the overall state switching all adopt the aforementioned microvalves, the overall structure can be made more compatible, can be directly prepared using MEMS technology, have stronger process reliability, and can further reduce the process difficulty and process cost.

[0098] In one embodiment, the inlet of the control gas groove 104 of each microvalve is connected to a corresponding control gas inlet 105, and the gas for controlling the deformation of the deformable film 1031 is introduced through the control gas inlet 105. Specifically, less than 6 control gas inlets 105 may be provided, and some microvalves with the same switch state may realize switch control by sharing one control gas inlet 105.

[0099] Specifically, Figure 8 Only the connection relationship between the structures in the chromatographic injector is shown to illustrate the logical connection relationship between the microchannel structure of the silicon substrate 200 and each microvalve, the quantitative ring 221 and each outlet and inlet, and does not represent the actual structural position.

[0100] In one embodiment, Fig. 9 As shown, the inlets of the control gas groove 104 of the first microvalve A, the fourth microvalve D and the fifth microvalve E are interconnected through one control gas inlet 105; the inlets of the control gas groove 104 of the second microvalve B, the third microvalve C and the sixth microvalve F are interconnected through another control gas inlet 105. Specifically, in this structure, only two control gas inlets 105 need to be provided to realize the switch control of the microvalve to achieve the switch state required by the chromatographic injector.

[0101] The present invention divides the six microvalves into two groups by designing the control gas groove 104. The six microvalves can be controlled by two control gas inlets 105, thereby further improving the control efficiency.

[0102] This embodiment also provides a method for preparing a chromatographic injector. The method for preparing the chromatographic injector adopts any one of the microvalve preparation methods in Example 1 to prepare six microvalves on the same first sealing substrate 301, the silicon substrate 200, the SOI substrate and the second sealing substrate 302. The six microvalves are respectively a first microvalve A, a second microvalve B, a third microvalve C, a fourth microvalve D, a fifth microvalve E and a sixth microvalve F. The method for preparing the chromatographic injector also includes:

[0103] When the six first grooves 212 and the second grooves 213 of the microvalves are arranged on the second surface of the silicon substrate 200, a sample inlet 241, a mobile phase inlet 243, a sample outlet 242, a mobile phase outlet 244, a quantitative ring 221 and a microfluidic structure are also arranged on the second surface of the silicon substrate 200, so as to obtain the structure of any one of the above-mentioned chromatographic injectors;

[0104] After bonding the first sealing substrate 301 and the second sealing substrate 302, a slicing process is performed to expose the sample inlet 241, mobile phase inlet 243, sample outlet 242, mobile phase outlet 244 and control gas inlet 105 of each of the chromatographic injectors; a capillary structure is set at each sample inlet 241, mobile phase inlet 243, sample outlet 242, mobile phase outlet 244 and control gas inlet 105.

[0105] The present invention can improve process efficiency by using etching process to set other structures of the chromatography injector while setting the first groove 212 and the second groove 213; and at the same time, capillary structures are set at each outlet and inlet for connection with other chromatography components.

[0106] In one embodiment, the first channel 214, the second channel 215, the first groove 212, the second groove 213 and the control gas groove 104 of the microvalve and the quantitative ring 221 and the microchannel structure in the chromatographic injector are arranged by deep reactive ion etching.

[0107] The present invention prepares a chromatographic injector by deep reactive ion etching, thereby meeting the demand for miniaturization of the chromatographic injector.

[0108] In one embodiment, deep reactive ion etching is performed using the patterned oxide layer and the photoresist mask layer on the oxide layer as masks.

[0109] The present invention designs the structure of the SOI substrate and the silicon substrate 200, so that the MEMS process can be directly used to prepare a microvalve using the SOI top silicon 103 as the deformable film 1031. On the one hand, the process problem of the incompatibility of the polymer film and the MEMS process is avoided, and the structure can be manufactured using the MEMS process, which has a simple process and low cost. More importantly, compared with the polymer film, the single crystal silicon film has better elasticity, wear resistance, and high temperature resistance, and therefore has higher reliability; on the other hand, the control gas groove 104, the control gas inlet 105, and the deformable film 1031 are designed and prepared on the SOI substrate, and the flow channel related structures are designed and prepared on the silicon substrate, that is, the control gas path and the working flow channel are designed and prepared separately, the structural design is more flexible, the process preparation process is simpler, and the process difficulty and production cost are reduced; and by using the patterned oxide layer and the photoresist mask layer on the oxide layer as a mask for deep reactive ion etching, the number of photolithography times can be reduced, the graphic accuracy can be improved, thereby further reducing the number of processes and reducing the process difficulty.

[0110] In one embodiment, the first surface of the silicon substrate 200 and the SOI top silicon 103 are silicon-silicon bonded. On the one hand, the silicon-silicon bonding temperature is high, and the subsequent silicon-glass bonding temperature is low, and the subsequent bonding will not damage the silicon-silicon bonding structure. On the other hand, compared with other bonding methods, the silicon-silicon bonding strength is high and the cost is low. The first sealing substrate 301 and the second sealing substrate 302 are glass substrates. The glass substrate is placed on the cathode of the bonding machine, and the SOI substrate and the silicon substrate 200 are placed on the anode of the bonding machine to perform silicon-glass anode bonding to achieve bonding with the first sealing substrate 301 and the second sealing substrate 302. At the same time, the first sealing substrate 301 and the second sealing substrate 302 use transparent glass substrates, which are convenient for observing whether the microvalve and chromatographic injector structures are complete and whether they work normally.

[0111] Embodiment 3:

[0112] This embodiment provides a chromatography system, which includes the chromatography injector described in any one of Embodiment 2, and further includes a chromatography column, which is connected to the mobile phase outlet of the chromatography injector.

[0113] Embodiment 4:

[0114] This embodiment provides an application method of a chromatography system, and the application method of the chromatography system is performed using the chromatography system described in Example 3;

[0115] Close the first microvalve A, the fourth microvalve D and the fifth microvalve E, open the second microvalve B, the third microvalve C and the sixth microvalve F, inject the sample to be detected from the sample inlet, so that the sample to be detected is injected from the sample inlet through the second microvalve B and fills the quantitative ring, and then is discharged from the sample outlet through the third microvalve C;

[0116] Close the second microvalve B, the third microvalve C and the sixth microvalve F, open the first microvalve A, the fourth microvalve D and the fifth microvalve E, inject mobile phase from the mobile phase inlet, allow the mobile phase to enter the quantitative loop from the mobile phase inlet through the fourth microvalve D, and the sample to be detected in the quantitative loop is injected into the chromatographic column from the mobile phase outlet through the fifth microvalve E under the push of the mobile phase for chromatographic separation. After chromatographic separation, use a detector to perform chromatographic detection on the sample flowing out of the chromatographic column.

[0117] The present invention switches the state of the chromatographic system for quantitative loop injection and chromatographic column sampling by controlling the switches of various microvalves, and utilizes the MEMS process compatibility of the entire chromatographic system to improve the reliability of the overall state switching and the quality of injection-sampling.

[0118] Specifically, when the second microvalve B and the third microvalve C are opened, the sixth microvalve F can be in an open or closed state, which has no significant impact on the overall sampling effect; when the fourth microvalve D and the fifth microvalve E are opened, the first microvalve A can be in an open or closed state, which has no significant impact on the overall sampling effect; those skilled in the art can select the switching states of the sixth microvalve F and the first microvalve A under the corresponding states according to needs.

[0119] In summary, the microvalve, chromatographic injector and preparation method thereof, chromatographic system and application method thereof of the present invention can be obtained by using the single crystal deformation film in the top silicon of SOI as the microvalve switch element, and utilizing the good elasticity, wear resistance, high temperature resistance and batch preparation characteristics of the single crystal silicon film by MEMS process to obtain the microvalve and chromatographic automatic injector, thereby improving the structural integrability and facilitating the miniaturization of the chromatographic system; at the same time, the reliability of the bonding between the top silicon of SOI and the silicon substrate is higher than that between the bonding between the organic film and the silicon substrate, and the compatibility with the MEMS process is stronger, which can reduce the process difficulty and cost, and realize the batch production and application of the chromatographic system with high cost performance.

[0120] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0121] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A micro valve, characterized in that: The microvalve comprises: a first sealing substrate, a silicon substrate, an SOI substrate, and a second sealing substrate; The SOI substrate comprises SOI top silicon, SOI buried oxide layer and SOI bottom silicon in sequence, the SOI top silicon is a single crystal silicon film, and the deformation film is prepared in the SOI top silicon; the silicon substrate comprises a first surface and a second surface arranged oppositely, and the SOI top silicon is bonded to the first surface of the silicon substrate; The first surface of the silicon substrate comprises a groove, the second surface of the silicon substrate comprises a first groove and a second groove, the silicon substrate further comprises a first channel and a second channel, the first channel connects the groove and the first groove, the second channel connects the groove and the second groove, and the first groove and the second groove are connected in sequence through the first channel, the groove and the second channel; The SOI buried oxide layer and the SOI bottom silicon are provided with control gas grooves at positions corresponding to the grooves, and the deformable film is the portion of the SOI top silicon located between the control gas grooves and the grooves; the gas introduced from the inlet of the control gas grooves can apply pressure to the deformable film on the SOI top silicon, so that the deformable film is deformed and contacts the bottom of the groove, so as to block the connection between the first groove and the second groove; The second surface of the silicon substrate is bonded to the first sealing substrate, and the second sealing substrate is bonded to the side of the SOI bottom silicon away from the SOI buried oxide layer. The first sealing substrate and the second sealing substrate enable the first groove, the second groove, and the control gas groove to form closed channels respectively.

2. A method for preparing a microvalve, characterized in that: The preparation method is used to prepare the microvalve described in claim 1, and the preparation method comprises: Providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged opposite to each other; providing a first channel and a second channel on the first surface of the silicon substrate; providing a groove on the first surface of the silicon substrate, the projection of the groove on the first surface covers the projection of the first channel and the second channel on the first surface; A first groove and a second groove are provided on the second surface of the silicon substrate, wherein the first channel is connected to the first groove and the groove, and the second channel is connected to the second groove and the groove; Providing an SOI substrate, wherein the SOI substrate sequentially comprises an SOI top silicon layer, an SOI buried oxide layer and an SOI bottom silicon layer, wherein the SOI top silicon layer is a single crystal silicon thin film; bonding the SOI top silicon layer of the SOI substrate to the first surface of the silicon substrate; The SOI bottom silicon and the SOI buried oxide layer of the SOI substrate are etched at positions corresponding to the grooves to obtain control gas grooves, and a portion of the SOI top silicon located between the control gas grooves and the grooves constitutes a deformable film; The second surface of the silicon substrate is bonded to a first sealing substrate, and the surface of the SOI bottom silicon away from the SOI buried oxide layer is bonded to a second sealing substrate to form closed channels for the first trench, the second trench, and the control gas trench.

3. The method for preparing a microvalve according to claim 2, characterized in that: The preparation method further comprises: after forming the groove, growing an oxidation protection layer on the surface exposed by the groove.

4. A chromatographic injector, characterized in that: The chromatography injector comprises at least one microvalve as claimed in claim 1.

5. The chromatographic injector according to claim 4, characterized in that: The chromatographic injector comprises at least 6 microvalves as claimed in claim 1, wherein the 6 microvalves are respectively a first microvalve (A), a second microvalve (B), a third microvalve (C), a fourth microvalve (D), a fifth microvalve (E) and a sixth microvalve (F); the chromatographic injector further comprises: a sample inlet, a mobile phase inlet, a sample outlet, a mobile phase outlet, a quantitative loop, a microfluidic channel structure and at least two control gas inlets; The microfluidic channel structure comprises a first flow channel, a second flow channel, a third flow channel, a fourth flow channel and a fifth flow channel, wherein the first flow channel, the second flow channel, the third flow channel, the fourth flow channel and the fifth flow channel are all flow channels; a first flow channel is arranged between the sample inlet and the mobile phase inlet, a second flow channel is arranged between the sample outlet and the mobile phase outlet, and both ends of the third flow channel, the fourth flow channel and the fifth flow channel are respectively connected with the first flow channel and the second flow channel; the third flow channel is located at one end close to the sample inlet and the sample outlet, the fifth flow channel is located at one end close to the mobile phase inlet and the mobile phase outlet, and the fourth flow channel is located between the third flow channel and the fifth flow channel; The quantitative loop is located in the fourth flow channel; the first microvalve (A) is located in the third flow channel to control the communication state of the third flow channel, and the sixth microvalve (F) is located in the fifth flow channel to control the communication state of the fifth flow channel; the second microvalve (B) is located between the third flow channel and the fourth flow channel on the first flow channel to control the communication state of the quantitative loop and the sample inlet, the third microvalve (C) is located between the third flow channel and the fourth flow channel on the second flow channel to control the communication state of the quantitative loop and the sample outlet, the fourth microvalve (D) is located between the fourth flow channel and the fifth flow channel on the first flow channel to control the communication state of the quantitative loop and the mobile phase inlet, and the fifth microvalve (E) is located between the fourth flow channel and the fifth flow channel on the second flow channel to control the communication state of the quantitative loop and the mobile phase outlet; The inlet of the control gas groove of each microvalve is connected to the corresponding control gas inlet to allow gas to enter to control the switch state of the corresponding microvalve; The first groove and the second groove of each microvalve are respectively connected to the corresponding flow channels at both ends to control the connectivity state of the corresponding flow channels; each of the microvalves shares the first sealing substrate, the silicon substrate, the SOI substrate and the second sealing substrate, and each of the microvalves has its own groove, the first groove, the second groove, the first channel, the second channel and the control gas groove; the sample inlet, the mobile phase inlet, the sample outlet, the mobile phase outlet, the quantitative ring and the microfluidic channel structure are all located on the silicon substrate of the microvalve.

6. The chromatographic injector according to claim 5, characterized in that: The inlets of the control gas grooves of the first microvalve (A), the fourth microvalve (D) and the fifth microvalve (E) are interconnected through one control gas inlet; the inlets of the control gas grooves of the second microvalve (B), the third microvalve (C) and the sixth microvalve (F) are interconnected through another control gas inlet.

7. A method for preparing a chromatographic injector, characterized in that: The method for preparing the chromatographic injector adopts the method for preparing the microvalve according to any one of claims 2 to 3 to prepare six microvalves on the same first sealing substrate, the silicon substrate, the SOI substrate and the second sealing substrate, and the six microvalves are respectively a first microvalve (A), a second microvalve (B), a third microvalve (C), a fourth microvalve (D), a fifth microvalve (E) and a sixth microvalve (F), and the method for preparing the chromatographic injector further comprises: When the first grooves and the second grooves of the six microvalves are arranged on the second surface of the silicon substrate, a sample inlet, a mobile phase inlet, a sample outlet, a mobile phase outlet, a quantitative loop and a microfluidic structure are also arranged on the second surface of the silicon substrate to obtain the chromatographic injector according to any one of claims 5 to 6; After bonding the first sealing substrate and the second sealing substrate, a slicing process is performed to expose the sample inlet, mobile phase inlet, sample outlet, mobile phase outlet and control gas inlet of each of the chromatographic injectors; a capillary structure is set at each sample inlet, mobile phase inlet, sample outlet, mobile phase outlet and control gas inlet.

8. The method for preparing a chromatographic injector according to claim 7, characterized in that: The first channel, the second channel, the first groove, the second groove and the control gas groove of the microvalve and the quantitative ring and the microchannel structure in the chromatographic injector are arranged by deep reactive ion etching.

9. A chromatography system, characterized in that: The chromatography system comprises the chromatography injector according to any one of claims 5 to 6, and the chromatography system further comprises a chromatography column, wherein the chromatography column is connected to the mobile phase outlet of the chromatography injector.

10. An application method of a chromatography system, characterized in that: The application method of the chromatography system is carried out using the chromatography system described in claim 9; The first microvalve (A), the fourth microvalve (D) and the fifth microvalve (E) are closed, and the second microvalve (B), the third microvalve (C) and the sixth microvalve (F) are opened, and the sample to be detected is injected from the sample inlet, so that the sample to be detected is injected from the sample inlet through the second microvalve (B) and fills the quantitative ring, and then is discharged from the sample outlet through the third microvalve (C); The second microvalve (B), the third microvalve (C) and the sixth microvalve (F) are closed, and the first microvalve (A), the fourth microvalve (D) and the fifth microvalve (E) are opened, and the mobile phase is injected from the mobile phase inlet, so that the mobile phase enters the quantitative loop from the mobile phase inlet through the fourth microvalve (D), and the sample to be detected in the quantitative loop is injected into the chromatographic column from the mobile phase outlet through the fifth microvalve E under the push of the mobile phase for chromatographic separation. After the chromatographic separation, a detector is used to perform chromatographic detection on the sample flowing out of the chromatographic column.

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