Microchromatographic column and preparation method

Abstract

The present invention provides a micro-chromatographic column and a preparation method thereof. The micro-chromatographic column comprises a substrate, a microchannel and an elliptical micro-column array, and can greatly reduce the area of ​​a "quasi-zero flow rate zone" behind the micro-columns; the minor axis length q of the elliptical micro-columns can be adjusted while increasing the number of elliptical micro-columns, so as to effectively increase the column inner surface area under the premise of keeping the width w of the microchannel and the effective width d of the microchannel unchanged, and can effectively solve the problem of increased pressure before the column caused by the increase in the number of micro-columns; by designing different spacings between n columns of elliptical micro-columns and between the elliptical micro-columns and the side walls of the microchannel in the width direction of the microchannel, the problem of uneven carrier gas flow rate can be further alleviated, so as to further make the flow rate distribution in the column uniform; the micro-chromatographic column of the present invention has a simple structure and a preparation process, can improve the efficacy of the micro-chromatographic column, reduce the burden of the gas supply system, is conducive to portable application, and has a wide application prospect for the micro-chromatographic column.

Description

Technical Field

[0001] The invention belongs to the field of micro-electromechanical systems and relates to a micro-chromatographic column and a preparation method thereof. Background Art

[0002] The chromatographic column is one of the important components of the gas chromatograph. It plays a role in separating mixed gases in the entire system. The quality of its performance directly affects the analytical effect of the entire analytical instrument. The separation effect of the chromatographic column mainly depends on the stationary phase coated on the inner surface of the channel. The stationary phase has different adsorption and desorption capabilities for different gases, resulting in different flow rates of different gas components to be measured in the channel. Ultimately, different gas components reach the outlet of the chromatographic column at different times, achieving the separation of the mixed gas.

[0003] Traditional gas chromatography columns include capillary columns, packed columns, etc. Due to their large size, they require a special column oven for heating, and their power consumption is as high as several kilowatts. Therefore, in order to achieve the miniaturization of gas chromatographs, the miniaturization of gas chromatography columns is crucial.

[0004] With the improvement of microelectronics technology, the technology of preparing micro-chromatographic columns on silicon wafers has been realized, which solves the problems of large volume and high power consumption of traditional chromatographic columns. Due to the small volume of micro-chromatographic columns, the surface area that can be coated with the stationary phase is also small, and the separation performance has declined. Therefore, a new type of micro-chromatographic column structure named semi-filled column was proposed. The so-called semi-filled column is to implant a regularly arranged micro-column structure in the channel of the micro-chromatographic column. This design can greatly increase the internal surface area of ​​the micro-chromatographic column. However, in order to further increase the internal surface area of ​​the semi-filled column, researchers usually increase the number of micro-columns. However, this method will increase the number of micro-columns, which will cause the pre-column pressure of the semi-filled column to increase significantly. Therefore, it is necessary to increase the pre-column pressure to allow the gas to pass through the channel of the micro-chromatographic column well, which undoubtedly increases the demand for carrier gas, and in portable applications, the demand for carrier gas needs to be reduced as much as possible.

[0005] Therefore, it is necessary to provide a micro-chromatographic column and a preparation method thereof. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a micro-chromatographic column and a preparation method for solving the problem that the micro-chromatographic column in the prior art is difficult to coordinate the internal surface area of ​​the column with the pressure before the column.

[0007] In order to achieve the above-mentioned object and other related objects, the present invention provides a micro-chromatographic column, comprising:

[0008] substrate;

[0009] A microchannel, wherein the microchannel is located in the substrate, the width of the microchannel is w, and the effective width of the microchannel is d;

[0010] An elliptical microcolumn is located in the microchannel, and includes n columns of the elliptical microcolumns arranged at intervals along the width direction of the microchannel, and m rows of the elliptical microcolumns arranged at intervals along the extension direction of the microchannel, so as to form an n×m elliptical microcolumn array, and the major axis direction of the elliptical microcolumn is parallel to the extension direction of the microchannel, the minor axis direction of the elliptical microcolumn is parallel to the width direction of the microchannel, and the minor axis length q of the elliptical microcolumn is q=(wd) / n.

[0011] Optionally, in the width direction of the microchannel, adjacent n columns of the elliptical microcolumns are arranged at equal intervals.

[0012] Optionally, along the width direction of the microchannel, the n columns of elliptical microcolumns have different spacings, and the spacings gradually decrease along the extension direction from the center of the microchannel to the sidewall of the microchannel.

[0013] Optionally, along the width direction of the microchannel, the spacing between n adjacent columns of the elliptical microcolumns is smaller than the spacing between the elliptical microcolumns located at the edge and the sidewalls of the microchannel.

[0014] Optionally, the width w of the microchannel is 100 μm to 600 μm, the effective width d of the microchannel is 50 μm to 300 μm, the major axis length p of the elliptical microcolumn is 10 μm to 150 μm, the minor axis length q of the elliptical microcolumn is 5 μm to 75 μm, and the ratio of the major axis length p of the elliptical microcolumn to the minor axis length q of the elliptical microcolumn is 3:2 to 30:1.

[0015] Optionally, the width w of the microchannel is 250 μm, the effective width d of the microchannel is 130 μm, the major axis length p of the elliptical microcolumn is 60 μm, and the minor axis length q of the elliptical microcolumn is 10 μm to 40 μm.

[0016] Optionally, the microchannel extends in a serpentine shape; the substrate includes a silicon substrate, a glass substrate or a ceramic substrate; the microchromatographic column also includes a cover plate, which is bonded to the substrate and covers the microchannel, and the cover plate includes a glass cover plate, a silicon cover plate or a ceramic cover plate.

[0017] The present invention also provides a method for preparing a micro-chromatographic column, comprising the following steps:

[0018] providing a substrate;

[0019] forming a patterned mask layer on the surface of the substrate;

[0020] The substrate is etched based on the patterned mask layer to form a microchannel and an elliptical microcolumn in the substrate, wherein the microchannel is located in the substrate, the width of the microchannel is w, and the effective width of the microchannel is d; the elliptical microcolumn is located in the microchannel, and includes n columns of the elliptical microcolumns arranged at intervals along the width direction of the microchannel, and includes m rows of the elliptical microcolumns arranged at intervals along the extension direction of the microchannel to form an n×m elliptical microcolumn array, and the major axis direction of the elliptical microcolumn is parallel to the extension direction of the microchannel, the minor axis direction of the elliptical microcolumn is parallel to the width direction of the microchannel, and the minor axis length q of the elliptical microcolumn is q=(wd) / n.

[0021] Optionally, in the width direction of the microchannel, the adjacent n columns of elliptical microcolumns are arranged at equal intervals; or the n columns of elliptical microcolumns have different intervals, and the interval gradually decreases in the extension direction from the center of the microchannel to the sidewall of the microchannel.

[0022] Optionally, the method further includes the following steps:

[0023] Provide cover plate;

[0024] Bonding the cover plate to the surface of the substrate, with the cover plate covering the microchannel;

[0025] The bonded structure is diced.

[0026] As described above, the micro-chromatographic column and preparation method of the present invention have the following beneficial effects:

[0027] The micro-chromatographic column and preparation method of the present invention can greatly reduce the area of ​​the "quasi-zero flow rate zone" formed behind the micro-columns through the n×m elliptical micro-column array located in the micro-channel, so that the flow rate distribution in the column is uniform;

[0028] The micro-chromatographic column and preparation method of the present invention can adjust the minor axis length q of the elliptical micro-columns while increasing the number of elliptical micro-columns in an n×m elliptical micro-column array through the relationship q=(wd) / n, so as to effectively increase the column inner surface area under the premise of keeping the width w of the micro-channel and the effective width d of the micro-channel unchanged, thereby improving the separation performance of the micro-chromatographic column, and effectively solving the problem of increased pre-column pressure caused by the increase in the number of micro-columns, so that the micro-chromatographic column can maintain a low pre-column pressure while effectively increasing the surface area;

[0029] The micro-chromatographic column and preparation method of the present invention can further alleviate the problem of uneven flow rate of carrier gas by designing n rows of elliptical micro-columns to have different spacings along the width direction of the micro-channel, and the spacing gradually decreases in the extension direction from the center of the micro-channel to the side wall of the micro-channel, and the spacing between the elliptical micro-columns located at the edge and the side wall of the micro-channel is designed to be larger than the spacing between the elliptical micro-columns, so as to further make the flow rate distribution in the column uniform;

[0030] The micro-chromatographic column of the present invention has a simple structure and a preparation process, and can effectively improve the detection performance of the micro-chromatographic column. It can maintain a low pre-column pressure while increasing the surface area, and make the flow rate distribution in the column uniform, thereby improving the efficacy of the micro-chromatographic column and reducing the burden on the gas supply system, which is conducive to portable applications, and makes the micro-chromatographic column have a wide range of application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Shown is a flow chart of the method for preparing a micro-chromatographic column provided in Example 1 of the present invention.

[0032] Figure 2 to Figure 6 It is a schematic structural diagram showing the structure obtained in each step of the preparation method of the micro-chromatographic column provided in Example 1 of the present invention.

[0033] Figure 7 Shown is a schematic diagram of the three-dimensional structure of the micro-chromatographic column provided in Example 1 of the present invention.

[0034] Figure 8 Display as Figure 7 Schematic diagram of the enlarged structure of area A in the middle, viewed from above.

[0035] Figure 9a to Figure 9c Shown is a schematic diagram of a partially enlarged top view of the structure of three micro-chromatographic columns provided in Example 1.

[0036] Fig.10 Shown is a schematic diagram of a partially enlarged top view of the structure of the micro-chromatographic column provided in the second embodiment of the present invention.

[0037] Component number description

[0038] 100 Substrate

[0039] 110, 120 Sidewalls of microchannels

[0040] 200 Mask layer

[0041] 201 Silicon oxide mask layer

[0042] 202 photoresist mask layer

[0043] 300, 310 Microchannel

[0044] 400, 410 Elliptical Microcolumns

[0045] 500 Cover

[0046] 610 Carrier gas carrying the gas component to be measured DETAILED DESCRIPTION

[0047] 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.

[0048] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0049] For ease of description, spatial relational 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 spatial relational terms are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can be one or more intervening layers. As used herein, "between..." means including the end point values.

[0050] 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 formed 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.

[0051] It should be noted that the illustrations provided in this embodiment 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.

[0052] As described in the background technology, in order to further increase the column internal surface area of ​​the semi-filled column of the microchromatographic column, when researchers only increase the number of microcolumns in the microchannel, it will produce a side effect: the pre-column pressure of the semi-filled column needs to be increased. This is mainly because simply increasing the number of microcolumns will lead to a decrease in the effective width of the microchannel, that is, it will reduce the minimum gas flow path width on the channel cross section perpendicular to the gas flow rate. Therefore, in order to achieve the test effect, a greater pre-column pressure needs to be provided to allow the gas to effectively pass through the microchannel of the microchromatographic column, which undoubtedly increases the demand for carrier gas, and in portable applications, the demand for carrier gas needs to be reduced as much as possible.

[0053] Therefore, in order to solve the coordination problem between the surface area in the column and the pressure before the column, it is necessary to provide a new type of micro-chromatographic column and a preparation method. The concept of the present invention is specifically introduced below in conjunction with the drawings and embodiments.

[0054] Embodiment 1

[0055] like Figure 1 As shown, this embodiment provides a method for preparing a micro-chromatographic column, comprising the following steps:

[0056] providing a substrate;

[0057] forming a patterned mask layer on the surface of the substrate;

[0058] The substrate is etched based on the patterned mask layer to form a microchannel and an elliptical microcolumn in the substrate, wherein the microchannel is located in the substrate, the width of the microchannel is w, and the effective width of the microchannel is d; the elliptical microcolumn is located in the microchannel, and includes n columns of the elliptical microcolumns arranged at intervals along the width direction of the microchannel, and includes m rows of the elliptical microcolumns arranged at intervals along the extension direction of the microchannel to form an n×m elliptical microcolumn array, and the major axis direction of the elliptical microcolumn is parallel to the extension direction of the microchannel, the minor axis direction of the elliptical microcolumn is parallel to the width direction of the microchannel, and the minor axis length q of the elliptical microcolumn is q=(wd) / n.

[0059] The preparation method of the micro-chromatographic column of the present embodiment can greatly reduce the area of ​​the "quasi-zero flow rate zone" formed behind the micro-columns by forming the n×m elliptical micro-column array located in the micro-channel, so that the flow rate distribution in the column is uniform; further, through the relationship q=(wd) / n, in the n×m elliptical micro-column array, the short axis length q of the elliptical micro-columns can be adjusted while increasing the number of the elliptical micro-columns, so as to effectively increase the surface area in the column while keeping the width w of the micro-channel and the effective width d of the micro-channel unchanged, so as to improve the separation performance of the micro-chromatographic column, and at the same time effectively solve the problem of increased pressure before the column caused by the increase in the number of micro-columns, so that the micro-chromatographic column can maintain a low pressure before the column while effectively increasing the surface area, so that the flow rate distribution in the column is uniform, the efficacy of the micro-chromatographic column is improved, the burden of the gas supply system is reduced, and it is conducive to portable applications, so that the micro-chromatographic column has a wide application prospect.

[0060] For details, see Figure 2 to Figure 6 The preparation of the micro-chromatographic column described in this embodiment is described below in conjunction with the accompanying drawings. Figure 7 FIG. 1 is a schematic diagram of the three-dimensional structure of the micro-chromatographic column formed in this embodiment. Figure 8 Indicated as Figure 7 The enlarged top view of the structure of area A in the middle, Figure 2 to Figure 5 It can be understood as Figure 7 Schematic diagram of the partially enlarged cross-sectional structure obtained along C-C'. Figure 6 FIG. 4 is a schematic diagram of the structure of a micro-chromatographic column with a cover plate.

[0061] First, see Figure 2 , providing a substrate 100 and forming a patterned mask layer 200 on the surface of the substrate 100 .

[0062] As an example, the substrate 100 may include a silicon substrate, a glass substrate or a ceramic substrate; the mask layer 200 may include one or a combination of a silicon oxide mask layer, a silicon nitride mask layer and a photoresist mask layer.

[0063] Specifically, the types of the substrate 100 and the mask layer 200 are not limited thereto and can be selected as needed. In this embodiment, the substrate 100 adopts a silicon substrate, and the mask layer 200 adopts a stack of a silicon oxide mask layer 201 and a photoresist mask layer 202 covering the substrate 100, but is not limited thereto.

[0064] As an example, forming the patterned mask layer 200 on the surface of the substrate 100 may include the following steps:

[0065] Forming a mask stack including the silicon oxide mask layer 201 and the photoresist mask layer 202 on the surface of the substrate 100;

[0066] The photoresist mask layer 202 is first patterned by photolithography and etching processes to obtain a photoresist etching window;

[0067] Based on the patterned photoresist mask layer 202, etching is performed to pattern the silicon oxide mask layer 201 to obtain a silicon oxide etching window.

[0068] In this embodiment, the patterned silicon oxide mask layer 201 is obtained by photolithography and BOE etching. The formation process of the silicon oxide mask layer 201 is not limited thereto. Figure 3 and Figure 4 The shape and position of the microchannel 300 and the elliptical microcolumn 400 to be formed subsequently can be defined through the silicon oxide etching window.

[0069] Next, see Figure 4 , Figure 7 and Figure 8 , etching the substrate 100 based on the patterned mask layer 200 to form a microchannel 300 and an elliptical microcolumn 400 in the substrate 100, wherein the microchannel 300 is located in the substrate 100, the width of the microchannel 300 is w, and the effective width of the microchannel 300 is d; the elliptical microcolumn 400 is located in the microchannel 300, and includes n columns of the elliptical microcolumns 400 arranged at intervals along the width direction of the microchannel 300, and includes m rows of the elliptical microcolumns 400 arranged at intervals along the extension direction of the microchannel 300 to form an n×m elliptical microcolumn array, and the major axis direction of the elliptical microcolumn 400 is parallel to the extension direction of the microchannel 300, the minor axis direction of the elliptical microcolumn 400 is parallel to the width direction of the microchannel 300, and the minor axis length q of the elliptical microcolumn 400 is (wd) / n.

[0070] Specifically, in this embodiment, the exposed substrate 100 is etched based on deep reactive ion etching (DRIE) technology to form the microchannels 300 and elliptical microcolumns 400 in the substrate 100, but the etching method is not limited thereto and can be adaptively selected according to needs.

[0071] In this embodiment, the n×m elliptical microcolumn array located in the microchannel 300 can greatly reduce the area of ​​the "quasi-zero flow rate zone" formed behind the microcolumns, so that the flow rate distribution in the column is uniform; and through the relationship q=(wd) / n, the minor axis length q of the elliptical microcolumns 400 can be adjusted while increasing the number of the elliptical microcolumns 400, so as to effectively increase the surface area in the column while keeping the width w of the microchannel 300 and the effective width d of the microchannel 300 unchanged, so as to improve the separation performance of the microchromatographic column 400, and at the same time effectively solve the problem of increased pressure before the column caused by the increase in the number of microcolumns, so that the microchromatographic column 400 can maintain a low pressure before the column while effectively increasing the surface area, thereby improving the efficacy of the microchromatographic column 400 and reducing the burden on the gas supply system, which is conducive to portable applications and has a wide application prospect.

[0072] As an example, along the width direction of the microchannel 300 , the adjacent n columns of elliptical microcolumns 400 are arranged at equal intervals.

[0073] Specifically, in order to reduce the complexity of the process, when patterning the mask plate 200, patterned etching windows arranged at equal intervals can be formed along the width direction of the microchannel 300 as needed, but it is not limited to this. In another embodiment, patterned etching windows arranged at non-equal intervals can also be formed along the width direction of the microchannel 300 as needed, which will not be introduced here.

[0074] See also Figure 8 In this embodiment, in the width direction of the microchannel 300, the adjacent n columns of the elliptical microcolumns 400 have an equal spacing s, and in the extension direction of the microchannel 300, the adjacent m rows of the elliptical microcolumns 400 have an equal spacing t. The values ​​of the spacing s and the spacing t are not overly limited here.

[0075] As an example, along the width direction of the microchannel 300 , the spacing s between the n adjacent columns of elliptical microcolumns 400 is smaller than the spacing S between the elliptical microcolumns 400 at the edge and the sidewall 110 of the microchannel 300 , that is, S>s, to provide a uniform flow rate in the microchannel 300 .

[0076] As an example, the width w of the microchannel 300 is 100 μm to 600 μm, the effective width d of the microchannel 300 is 50 μm to 300 μm, the major axis length p of the elliptical microcolumn 400 is 10 μm to 150 μm, the minor axis length q of the elliptical microcolumn 400 is 5 μm to 75 μm, and the ratio of the major axis length p of the elliptical microcolumn 400 to the minor axis length q of the elliptical microcolumn 400 is 3:2 to 30:1.

[0077] Specifically, the width w of the microchannel 300 can be 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, etc. as required, the effective width d of the microchannel 300 can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, etc., and the major axis length p of the elliptical microcolumn 400 can be 10 μm, 50 μm, 10 0μm, 120μm, 150μm, etc., the short axis length q of the elliptical microcolumn 400 may be 5μm, 10μm, 30μm, 60μm, 75μm, etc., and the ratio of the major axis length p of the elliptical microcolumn 400 to the short axis length q of the elliptical microcolumn 400 may be 3:2 to 30:1, such as 3:2, 2:1, 3:1, 4:1, 10:1, 20:1, 25:1, 30:1, etc.

[0078] As an example, the width w of the microchannel 300 may be 250 μm, the effective width d of the microchannel 300 may be 130 μm, the major axis length p of the elliptical microcolumn 400 may be 60 μm, and the minor axis length q of the elliptical microcolumn 400 may be 10 μm to 40 μm.

[0079] Specifically, in this embodiment, refer to Figure 7 , a 6×12 elliptical micro-column array is contained in a microchannel 300 of the micro-chromatographic column, and the elliptical micro-columns 400 are regularly distributed periodically. It is worth noting that Figure 7 Where n is 6 and m is 12, five sub-microchannels with a width of s and two sub-microchannels with a width of S are formed in the microchannel 300, that is, d=5s+2S. Figure 8 As shown, in fact, the number of columns, the number of rows and the size of the elliptical micro-columns 400 can be selected according to actual needs. Figure 9a to Figure 9c As shown, three types of micro-chromatographic columns with a channel width w of 250 μm, an effective width d of 130 μm, and n of 6, 4, and 8 are illustrated, and their short axes are 20 μm, 30 μm, and 15 μm, respectively. The length ratios of the column center distance to the short axis of two adjacent elliptical micro-columns are 37:20, 9:5, and 29:15, respectively. The length ratio of the column center distance to the short axis of two adjacent elliptical micro-columns is generally less than 2.5, but the structure of the micro-chromatographic column is not limited to this.

[0080] The micro-chromatographic column of this embodiment, through the relationship q=(wd) / n, in the n×m elliptical micro-column array, the minor axis length q of the elliptical micro-columns 400 can be adjusted while increasing the number of the elliptical micro-columns 400, so as to effectively increase the surface area inside the column while keeping the width w of the micro-channel 300 and the effective width d of the micro-channel 300 unchanged, so as to improve the separation performance of the micro-chromatographic column, and at the same time effectively solve the problem of increased pre-column pressure caused by the increase in the number of micro-columns, so that the micro-chromatographic column can maintain a low pre-column pressure while effectively increasing the surface area, and make the flow velocity distribution in the column uniform, thereby improving the efficacy of the micro-chromatographic column, reducing the burden on the gas supply system, facilitating portable applications, and making the micro-chromatographic column have a wide range of application prospects.

[0081] As an example, the formed microchannel 300 may extend in a serpentine shape. Of course, in other examples, the formed microchannel 300 may extend in any extension manner in the substrate 100, such as a zigzag extension, a U-shaped extension, a spiral extension, etc., without excessive limitation here.

[0082] As an example, the following steps are also included:

[0083] Providing a cover plate 500;

[0084] Bonding the cover plate 500 to the surface of the substrate 100 , with the cover plate 500 covering the microchannel 300 ;

[0085] The bonded structure is diced.

[0086] As an example, the cover plate 500 may include a glass cover plate, a silicon cover plate or a ceramic cover plate. Preferably, in this embodiment, the cover plate 500 is a double-sided polished glass cover plate.

[0087] For details, see Figure 6 The cover plate 500 can be bonded to the surface of the substrate 100 by an anodic bonding process, wherein the bonding process conditions can be selected as needed and are not overly limited here. If a plurality of independent micro-chromatographic columns are formed in the substrate 100, after the cover plate 500 is bonded to the surface of the substrate 100, the bonded structure can also be diced to obtain a plurality of micro-chromatographic columns to improve production efficiency.

[0088] Then, capillaries (not shown) may be installed at the inlet and outlet ends of the prepared micro-chromatographic column, respectively, and relevant tests may be performed, which will not be described in detail here.

[0089] See also Figure 7 to Figure 9c This embodiment also provides a micro-chromatographic column, the micro-chromatographic column comprising:

[0090] Substrate 100;

[0091] A microchannel 300, wherein the microchannel 300 is located in the substrate 100, the width of the microchannel 300 is w, and the effective width of the microchannel 300 is d;

[0092] The elliptical microcolumn 400 is located in the microchannel 300, and includes n columns of the elliptical microcolumns 400 arranged at intervals along the width direction of the microchannel 300, and includes m rows of the elliptical microcolumns 400 arranged at intervals along the extension direction of the microchannel 300, so as to form an n×m elliptical microcolumn array, and the major axis direction of the elliptical microcolumn 400 is parallel to the extension direction of the microchannel 300, the minor axis direction of the elliptical microcolumn 400 is parallel to the width direction of the microchannel 300, and the minor axis length q of the elliptical microcolumn 400 is q=(wd) / n.

[0093] The micro-chromatographic column of this embodiment can greatly reduce the area of ​​the "quasi-zero flow rate zone" formed behind the micro-column through the n×m elliptical micro-column array located in the micro-channel 300, so that the flow rate distribution in the column is uniform; further, through the relationship q=(wd) / n, in the n×m elliptical micro-column array, the minor axis length q of the elliptical micro-column 400 can be adjusted while increasing the number of the elliptical micro-columns 400, so as to effectively increase the surface area in the column while keeping the width w of the micro-channel 300 and the effective width d of the micro-channel 300 unchanged, so as to improve the separation performance of the micro-chromatographic column, and at the same time effectively solve the problem of increased pressure before the column caused by the increase in the number of micro-columns, so that the micro-chromatographic column can maintain a low pressure before the column while effectively increasing the surface area, so that the flow rate distribution in the column is uniform, the efficacy of the micro-chromatographic column is improved, the burden of the gas supply system is reduced, and it is conducive to portable applications, so that the micro-chromatographic column has a wide application prospect.

[0094] The micro-chromatographic column can be prepared by the above-mentioned preparation method, but is not limited thereto.

[0095] As an example, along the width direction of the microchannel 300, the adjacent n columns of the elliptical microcolumns 400 are arranged at equal intervals to reduce the complexity of the process.

[0096] As an example, along the width direction of the microchannel 300 , the spacing between n adjacent columns of the elliptical microcolumns 400 is smaller than the spacing between the elliptical microcolumns 400 at the edge and the sidewall 110 of the microchannel 300 , that is, S>s, to provide a uniform flow rate in the microchannel 300 .

[0097] As an example, the width w of the microchannel 300 is 100 μm to 600 μm, such as 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, etc.; the effective width d of the microchannel 300 is 50 μm to 300 μm, such as 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, etc.; the major axis length p of the elliptical microcolumn 400 is 10 μm to 150 μm, such as 10 μm, 50μm, 100μm, 120μm, 150μm, etc.; the short axis length q of the elliptical microcolumn 400 is 5μm~75μm, such as 5μm, 10μm, 30μm, 60μm, 75μm, etc.; the ratio of the major axis length p of the elliptical microcolumn 400 to the short axis length q of the elliptical microcolumn 400 is 3:2~30:1, such as 3:2, 2:1, 3:1, 4:1, 10:1, 20:1, 25:1, 30:1, etc., but is not limited to this.

[0098] As an example, the width w of the microchannel 300 is 250 μm, the effective width d of the microchannel 300 is 130 μm, the major axis length p of the elliptical microcolumn 400 is 60 μm, and the minor axis length q of the elliptical microcolumn 400 is 10 μm to 40 μm. Figure 9a to Figure 9c , but is not limited to this.

[0099] As an example, the microchannel 300 extends in a serpentine shape. Of course, in other examples, the formed microchannel 300 can also extend in any extension manner in the substrate 100, such as zigzag extension, U-shaped extension, spiral extension, etc., which is not excessively limited here.

[0100] As an example, the substrate 100 may include a silicon substrate, a glass substrate or a ceramic substrate; the micro-chromatographic column may also include a cover plate 500, which is bonded to the substrate 100 and covers the micro-channel 300. The cover plate 500 may include a glass cover plate, a silicon cover plate or a ceramic cover plate, but the types of the substrate 100 and the cover plate 500 are not limited thereto.

[0101] Embodiment 2

[0102] See also Fig.10 This embodiment also provides a micro-chromatographic column and a preparation method. The difference between this embodiment and the first embodiment is that: along the width direction of the microchannel 310, the n columns of elliptical microcolumns 410 have different spacings, and the spacing gradually decreases along the center of the microchannel 310 toward the extension direction of the sidewall 120 of the microchannel 310, that is, s'3<s'2<s'1.

[0103] Specifically, when the carrier gas 610 carrying the gas to be tested enters the micro-chromatographic column, the gas in the central area has a greater gas velocity than the gas in the edge area, so it is difficult to provide the micro-chromatographic column with a uniform flow rate of gas. In this embodiment, the n rows of elliptical micro-columns 410 are designed to have different spacings along the width direction of the micro-channel 310, and the spacing gradually decreases along the extension direction from the center of the micro-channel 310 to the side wall 120 of the micro-channel 310, so as to further alleviate the problem of uneven flow rate of the carrier gas 610, so as to further make the flow rate distribution in the column uniform, thereby improving the efficacy of the micro-chromatographic column, reducing the burden on the gas supply system, and being conducive to portable applications, so that the micro-chromatographic column has a wide range of application prospects.

[0104] Among them, the width of the microchannel 310 is w', and the effective width of the microchannel 310 is d', d'=s'1+2(S'+s'2+s'3); the number of columns n' and the number of rows m' of the elliptical microcolumns 410 located in the microchannel 310, the short axis length q' and the long axis length p' of the elliptical microcolumns 410, the spacing S', s'1, s'2, s'3 and t', as well as the material and preparation method of the microchromatographic column, etc. can all be referred to Example 1 and will not be repeated here.

[0105] In summary, the micro-chromatographic column and preparation method of the present invention can greatly reduce the area of ​​the "quasi-zero flow rate zone" formed behind the micro-columns through the n×m elliptical micro-column array located in the micro-channel, so that the flow rate distribution in the column is uniform; through the relationship q=(wd) / n, in the n×m elliptical micro-column array, the minor axis length q of the elliptical micro-columns can be adjusted while increasing the number of elliptical micro-columns, so as to effectively increase the surface area in the column while keeping the width w of the micro-channel and the effective width d of the micro-channel unchanged, so as to improve the separation performance of the micro-chromatographic column, and at the same time effectively solve the problem of increased pressure before the column caused by the increase in the number of micro-columns, so that the micro-chromatographic column can maintain a low pressure before the column while effectively increasing the surface area. pressure; by designing n rows of elliptical microcolumns to have different spacings along the width direction of the microchannel, and the spacing gradually decreases in the extension direction from the center of the microchannel to the side wall of the microchannel, and designing the spacing between the elliptical microcolumns located at the edge and the side wall of the microchannel to be larger than the spacing between the elliptical microcolumns, the problem of uneven flow rate of the carrier gas can be further alleviated, so as to further make the flow rate distribution in the column uniform; the detection performance of the microchromatographic column can be effectively improved, and a lower pre-column pressure can be maintained while increasing the surface area, and the flow rate distribution in the column can be uniform, thereby improving the efficacy of the microchromatographic column, reducing the burden on the gas supply system, being conducive to portable applications, and making the microchromatographic column have a wide range of application prospects.

[0106] 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 ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A micro-chromatographic column, characterized in that: The micro-chromatographic column comprises: substrate; A microchannel, wherein the microchannel is located in the substrate, the width of the microchannel is w, and the effective width of the microchannel is d; An elliptical microcolumn, wherein the elliptical microcolumn is located in the microchannel, and includes n columns of the elliptical microcolumns arranged at intervals along the width direction of the microchannel, and includes m rows of the elliptical microcolumns arranged at intervals along the extension direction of the microchannel to form an n×m elliptical microcolumn array, and the major axis direction of the elliptical microcolumn is parallel to the extension direction of the microchannel, the minor axis direction of the elliptical microcolumn is parallel to the width direction of the microchannel, and the minor axis length of the elliptical microcolumn is q=(wd) / n, and along the width direction of the microchannel, the n columns of the elliptical microcolumns have different spacings, and the spacing gradually decreases along the extension direction from the center of the microchannel to the side wall of the microchannel, and along the width direction of the microchannel, the spacing between the n adjacent columns of the elliptical microcolumns is smaller than the spacing between the elliptical microcolumns located at the edge and the side wall of the microchannel.

2. The micro-chromatographic column according to claim 1, characterized in that: The width w of the microchannel is 100 μm~600 μm, the effective width d of the microchannel is 50 μm~300 μm, the major axis length p of the elliptical microcolumn is 10 μm~150 μm, the minor axis length q of the elliptical microcolumn is 5 μm~75 μm, and the ratio of the major axis length p of the elliptical microcolumn to the minor axis length q of the elliptical microcolumn is 3:2~30:

1.

3. The micro-chromatographic column according to claim 1, characterized in that: The width w of the microchannel is 250 μm, the effective width d of the microchannel is 130 μm, the major axis length p of the elliptical microcolumn is 60 μm, and the minor axis length q of the elliptical microcolumn is 10 μm to 40 μm.

4. The micro-chromatographic column according to claim 1, characterized in that: The microchannel extends in a serpentine shape; the substrate includes a silicon substrate, a glass substrate or a ceramic substrate; the microchromatographic column also includes a cover plate, which is bonded to the substrate and covers the microchannel, and the cover plate includes a glass cover plate, a silicon cover plate or a ceramic cover plate.

5. A method for preparing a microchromatographic column, characterized in that: The following steps are involved: providing a substrate; forming a patterned mask layer on the surface of the substrate; The substrate is etched based on the patterned mask layer to form a microchannel and an elliptical microcolumn in the substrate, wherein the microchannel is located in the substrate, the width of the microchannel is w, and the effective width of the microchannel is d; the elliptical microcolumn is located in the microchannel, and includes n columns of the elliptical microcolumns arranged at intervals along the width direction of the microchannel, and includes m rows of the elliptical microcolumns arranged at intervals along the extension direction of the microchannel to form an n×m elliptical microcolumn array, and the long axis direction of the elliptical microcolumn is parallel to the long axis direction of the microchannel. The extension direction of the microchannel is parallel, the short axis direction of the elliptical microcolumn is parallel to the width direction of the microchannel, the short axis length of the elliptical microcolumn is q=(wd) / n, and along the width direction of the microchannel, the n columns of the elliptical microcolumns have different spacings, and the spacing gradually decreases along the extension direction from the center of the microchannel to the side wall of the microchannel, and along the width direction of the microchannel, the spacing between adjacent n columns of the elliptical microcolumns is smaller than the spacing between the elliptical microcolumns located at the edge and the side wall of the microchannel.

6. The method for preparing a micro-chromatographic column according to claim 5, characterized in that: The following steps are also included: Provide cover plate; Bonding the cover plate to the surface of the substrate, with the cover plate covering the microchannel; The bonded structure is diced.

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