JP2004097978A - Chemical microdevice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical microdevice which is used for measuring the quantity of harmful gas such as NO<SB>X</SB>, SO<SB>X</SB>, CO<SB>X</SB>, and O<SB>3</SB>and which is easily manufactured and attains the cost reduction. <P>SOLUTION: In the chemical microdevice, closed flow passages 11, 13, 14 for supplying test liquid are disposed on substrates 10, 20, and an opened reaction part 12 is disposed in the midst of the flow passage. In addition, a membrane filter 30 made of a resin is disposed so as to cover the opened reaction part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
This invention is a microchip used to perform analysis or reaction, such as a minute amount in the fine reactor relates to a chemical microdevices such microreactor, particularly, NOx in air, SOx, COx, O _3, etc. The characteristic feature is that a chemical microdevice suitable for measuring the amount of the gas can be obtained at low cost.
[0002]
[Prior art]
In recent years, chemical microdevices such as microchips and microreactors have been used to increase the efficiency of reactions and perform rapid and highly sensitive analyses. Attempts to perform analysis, reactions, etc. have been made.
[0003]
Further, in recent years, NOx in air, SOx, COx, to measure the amount of harmful gases O ₃ or the like, was to be considered to use chemical microdevice as described above.
[0004]
Here, in such a chemical microdevice, for example, as shown in FIG. 1, a microchannel necessary for a reaction of a substance is constructed on one surface of a lower substrate 1 made of quartz glass or the like, as described above. Channel 1a for guiding a collecting solution for collecting a gas, and a reaction section 1b having an increased area for contacting the gas with the collecting solution and collecting the gas in the middle of the first channel 1a. And a second flow path 1c that guides a fluorescent reagent solution that generates a fluorescent substance or a color reagent solution that generates a color-forming substance by reacting with the above-described collecting solution that has collected the gas, is connected to the reaction section 1b. A merging flow path 1d is provided on the downstream side so as to merge with the first flow path 1a, and further guides the collected solution thus merged with the fluorescent reagent solution or the coloring reagent solution while reacting them. are doing
[0005]
Then, as shown in FIG. 2, a glass porous plate 3 through which the gas passes is disposed on the reaction section 1b, and an opening 2a is provided so as to correspond to the reaction section 1b. An upper substrate 2 made of quartz glass or the like is placed on the lower substrate 1 so that the gas does not come into contact with a collecting solution, a fluorescent reagent solution, or a coloring reagent solution in a portion other than the reaction section 1b. I have to.
[0006]
Here, in the above-mentioned chemical microdevice, the glass porous plate 3 to be mounted on the reaction part 1b is difficult to manufacture, the cost is high, and the glass porous plate 3 is mounted on the reaction part 1b. When assembled by assembling, there is a problem that the yield is poor, and it is very difficult to perform the above-mentioned processing on one surface of the lower substrate 1 made of quartz glass or the like.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems in a chemical microdevice used for performing a reaction or analysis in a minute amount such as a microchip or a microreactor.
[0008]
That is, in this invention, NOx in air, SOx, COx, production of chemical micro device suitable for measuring the amount of harmful gases O ₃ or the like is easily performed, so that the cost is reduced It is a subject.
[0009]
[Means for Solving the Problems]
In the chemical microdevice according to the present invention, in order to solve the above-described problems, a closed channel for allowing the test solution to pass through the base material is provided, and a reaction portion opened in the middle of the channel is provided. In such a chemical microdevice, a resin-made membrane filter is provided so as to cover the above-mentioned opened reaction part.
[0010]
And, as in the case of the chemical microdevice of the present invention, when a resin-made membrane filter is used to cover the opened reaction part, its manufacture becomes easier as compared with a case where a glass-made porous plate is used. Cost is reduced.
[0011]
Further, as such a chemical microdevice, the above-described base material is composed of an upper substrate and a lower substrate, and the lower substrate is provided with the above-described flow path and reaction section, while the upper substrate corresponds to the above-described reaction section. An opening may be formed so that a resin-made membrane filter is sandwiched between the upper substrate and the lower substrate so as to cover the reaction section.
[0012]
Further, in the chemical microdevice of the present invention, as the above-mentioned membrane filter, it is preferable to use a resin having a water repellency having a contact angle with water of 70 ° or more, preferably 80 ° or more, and particularly, a fluorine-based resin is used. In addition to the water repellency, the chemical resistance of the membrane filter is increased, and various tests can be performed using various test liquids.
[0013]
Here, as the above-mentioned fluororesin, a resin in which fluorine is bonded to an olefin main chain or a side chain can be generally used. For example, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, Ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and the like can be used.
[0014]
In addition, when the pore size of the membrane filter is large, the test solution may flow out through the membrane filter.On the other hand, when the pore size is too small, the production cost is extremely high, and the absorption capacity of the measurement gas is significantly reduced. Therefore, it is preferable to use a membrane filter having an average pore size of 0.001 to 0.3 μm.
[0015]
Further, in the chemical microdevice according to the present invention, when the above-mentioned substrate is made of resin, the cost is reduced as compared with the case where quartz glass or the like is used, and polystyrene, polymethyl methacrylate, polycarbonate, poly (4-methylpentene-1) are used. ) And a thermoplastic resin such as a cyclic polyolefin, a flow path and a reaction section can be formed in the lower substrate by injection molding, and the same shape can be easily mass-produced, thereby reducing costs. Is done. In addition, the thermoplastic resin used here is not limited to the above-mentioned ones, and may be any resin that has the properties of a thermoplastic resin and can be injection-molded.
[0016]
Furthermore, in the chemical microdevice according to the present invention, when a silicone resin is used as the resin constituting the base material, light transmittance in an ultraviolet region or the like also increases, and it is possible to measure the absorbance by irradiating light over a wide range. Will be able to do it. The silicone resin used here is not particularly limited, but may be a commonly used one, for example, a resin obtained by heating and polymerizing an alkyl siloxane, and a typical one is polydimethyl siloxane. Is mentioned.
[0017]
【Example】
Hereinafter, a chemical microdevice according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. However, the chemical microdevice according to the present invention is not particularly limited to those shown in the following examples, but can be appropriately modified and implemented without changing the gist thereof.
[0018]
In this example, a chemical microdevice used to measure the amount of NO ₂ will be described.
[0019]
In the chemical microdevice A of this example, a lower substrate 10 as shown in FIG. 3 and an upper substrate 20 as shown in FIG. 4 were produced by injection molding using polymethyl methacrylate.
[0020]
Here, in the lower substrate 10, a first flow path 11 for guiding a trapping solution containing triethanolamine for trapping NO ₂ gas is provided on one surface thereof, and in the middle of the first flow path 11. In the above, the reaction section 12 having an increased area for collecting the NO ₂ gas in the above-mentioned collecting solution was provided. A second flow path 13 for guiding a fluorescent reagent solution containing 2,3-diaminonaphthalene, which reacts with the above-mentioned trapping solution that has trapped NO ₂ gas to produce a fluorescent substance, is provided from the reaction section 12 to the second flow path 13. Is also provided on the downstream side so as to merge with the above-mentioned first flow path 11, and furthermore, a merging flow path 14 for guiding the collected solution and the fluorescent reagent solution which have collected the NO ₂ gas while reacting with each other. Was formed.
[0021]
On the other hand, in the upper substrate 20, a first hole 21 a for supplying the trapping solution to the first channel 11 in the lower substrate 10, and the fluorescent reagent in the second channel 13. A second hole 21b for supplying a solution and a third hole 21c for collecting a collecting solution and a fluorescent reagent solution guided through the merging flow path 14 are provided. Openings 22 were provided correspondingly.
[0022]
In the chemical microdevice A of this embodiment, a polytetrafluorocarbon having an average pore diameter of 0.1 μm was used as the resin-made membrane filter 30 placed so as to cover the reaction section 12 of the lower substrate 10. The membrane filter 30 made of ethylene was used.
[0023]
Then, as shown in FIG. 5, the membrane filter 30 is placed on the lower substrate 10 so as to cover the reaction section 12 provided on the lower substrate 10, and the reaction section 12 The upper substrate 20 provided with the opening 22 in a corresponding manner is placed on the lower substrate 10, and the membrane filter 30 is sandwiched between the upper substrate 20 and the lower substrate 10. Then, the upper substrate 20 and the lower substrate 10 were thermally fused so that the NO ₂ gas was brought into contact with the collection solution only through the membrane filter 30 in the reaction section 12.
[0024]
In the case where the chemical microdevice A of this embodiment manufactured in this way is used, the amount of NO ₂ gas can be properly detected as in the case where the conventional chemical microdevice is used, and the manufacturing cost is reduced. Has been significantly reduced compared to conventional chemical microdevices.
[0025]
In the chemical microdevice A in this example, NO ₂ has been so used to detect the amount of gas, SOx, COx, detection of O ₃ or the like of the gas, the other of any state substance detection and reaction Etc. can also be used.
[0026]
Next, a specific experiment for detecting the amount of NO ₂ gas using the chemical microdevice according to the present invention will be described.
[0027]
In this experiment, as shown in FIGS. 6A and 6B, the lower substrate was 35 mm long, 12.3 mm wide and 1 mm thick by injection molding using polymethyl methacrylate, respectively. 10 and an upper substrate 20 were produced.
[0028]
The first substrate 11 having a length of 25 mm, a width of 1 mm, and a depth of 0.1 mm is provided on the lower substrate 10, while the first substrate 11 provided on the lower substrate 10 is provided on the upper substrate 20. And a supply port 21d for supplying a trapping solution for trapping NO ₂ gas to the first flow path 11 and collecting the trapping solution for trapping NO ₂ gas. And an opening 22 having a length of 20 mm and a width of 1.2 mm is provided between the supply port 21d and the collecting port 21e. The part of one flow path 11 was made to be the reaction part 12.
[0029]
On the other hand, as the membrane filter 30, a filter made of polytetrafluoroethylene having a thickness of 0.07 mm and an average pore diameter of 0.1 μm was used.
[0030]
Then, as shown in FIG. 7, the membrane filter 30 is placed on the lower substrate 10 so as to be located at a position corresponding to the opening 22 provided in the upper substrate 20, and the lower substrate 10 The upper substrate 20 is placed on the substrate, and the membrane filter 30 is sandwiched between the upper substrate 20 and the lower substrate 10. In this state, the upper substrate 20 and the lower substrate 10 are thermally fused. To obtain an experimental chemical microdevice A1.
[0031]
Next, as shown in FIG. 8, the above-mentioned chemical microdevice A1 is set in a measurement container 40, and a 0.3% (w / v) aqueous solution of triethanolamine is used as a trapping solution for trapping NO ₂ gas. At a flow rate of 1 μl / min from the collection liquid supply device 41 to the first flow path 11 through the supply port 21d of the chemical microdevice A1 installed in the measurement container 40.
[0032]
Then, while the collected solution is guided to the recovery port 21 e through the first flow path 11, the collected solution is brought into contact with the NO ₂ gas in the measurement container 40 through the membrane filter 30 provided in the opening 22, and NO ₂ gas is collected in the above-mentioned collecting solution, the collecting solution in which NO ₂ gas is collected in this way is collected through the above-mentioned collecting port 21e, and the collected solution thus collected is collected by the fluorescence intensity measuring device 42. And 1 μl of a fluorescent reagent solution adjusted to a concentration of 2,3-diaminonaphthalene of 5 × 10 ⁻⁴ mol / l in a 0.19 mol / l sulfuric acid solution with respect to the collected solution. / Min at a flow rate from the fluorescent reagent supply device 43, and a pH adjustment comprising a mixed solution of sodium hydroxide and sodium tetraborate at a concentration of 0.26 mol / l each. It was supplied from a pH adjusting solution supply device 44 at 2 [mu] l / min flow rate, and to measure the fluorescence intensity by the fluorescence intensity measuring device 42 described above.
[0033]
Here, in this experiment, as shown by a solid line in FIG. 9, after the NO ₂ gas concentration in the above-mentioned measurement container 40 was stabilized at about 50 ppb for a certain period of time, the NO ₂ gas was supplied into this measurement container 40. Then, the NO ₂ gas concentration was increased to about 100 ppb and stabilized for a certain period of time, and then the NO ₂ gas concentration in the measurement container 40 was gradually reduced. Under such conditions, the fluorescence intensity was increased as described above. Was measured, and the result is shown by a dashed line in FIG.
[0034]
As is apparent from the result, the fluorescence intensity changed following the change in the NO ₂ gas concentration in the measurement container 40.
[0035]
【The invention's effect】
As described in detail above, in the present invention, in the chemical microdevice provided with a closed channel through which the test solution passes through the base material, and a reaction portion opened in the middle of the channel, Since a resin-made membrane filter was used to cover the reaction part with the opening, the production was easier and the cost was significantly reduced as compared with the case where a conventional glass porous plate was used.
[0036]
Further, in the chemical microdevice according to the present invention, if the base material is made of resin, the cost is reduced as compared with the case where quartz glass or the like is used, and in particular, polystyrene, polymethyl methacrylate, polycarbonate, poly (4-methylpentene) are used. Using a thermoplastic resin such as -1) and a cyclic polyolefin, injection molding can be performed, and the cost has been further reduced.
[0037]
Further, in the chemical microdevice according to the present invention, when a silicone resin such as polydimethylsiloxane is used as a resin constituting the base material, light transmittance in an ultraviolet region or the like is increased, and the absorbance is measured by irradiating light. Can be done in a wide range.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing an example of a lower substrate used in a conventional chemical microdevice.
FIG. 2 is a schematic plan view of a conventional chemical microdevice using the lower substrate shown in FIG.
FIG. 3 is a schematic plan view of a lower substrate used in the chemical microdevice according to one embodiment of the present invention.
FIG. 4 is a schematic plan view of an upper substrate used in the chemical microdevice according to the example.
FIG. 5 is a schematic plan view of the chemical microdevice according to the embodiment using the lower substrate shown in FIG. 3 and the upper substrate shown in FIG. 4;
FIG. 6 is a schematic plan view of a lower substrate and an upper substrate used for a chemical microdevice in an experiment of the present invention.
FIG. 7 is a schematic plan view of a chemical microdevice used in an experiment of the present invention.
8 is a schematic explanatory view of a measuring apparatus using the micro device shown in FIG. 7 in an experiment of the present invention.
9 is a diagram showing the relationship between the concentration of NO ₂ gas in a measurement container and the fluorescence intensity measured using the measurement device shown in FIG.
[Explanation of symbols]
A, A1 Chemical microdevice 10 Lower substrate 11 First flow path 12 Reaction section 13 Second flow path 14 Merging flow path 20 Upper substrate 22 Opening 30 Resin membrane filter

Claims (7)

In a chemical microdevice provided with a closed flow path through which a test solution passes through the base material and a reaction section opened in the middle of this flow path, a resin is formed so as to cover the open reaction section. A chemical microdevice characterized by comprising a membrane filter made of aluminum. 2. The chemical microdevice according to claim 1, wherein the base material is composed of an upper substrate and a lower substrate, and the lower substrate is provided with the flow path and the reaction unit, while the upper substrate is provided with the reaction unit. An opening is formed correspondingly, and a membrane filter made of a resin having water repellency is sandwiched between the upper substrate and the lower substrate so as to cover the reaction section. . 3. The chemical microdevice according to claim 1, wherein the resin-made membrane filter is made of a fluorine-based resin. The chemical microdevice according to any one of claims 1 to 3, wherein an average pore size of the membrane filter is in a range of 0.001 to 0.3 m. The chemical microdevice according to any one of claims 1 to 4, wherein the substrate is made of a resin. The method for using a chemical microdevice according to claim 5, wherein the resin constituting the base material is a transparent thermoplastic resin. The method for using a chemical microdevice according to claim 5, wherein the resin constituting the base material is a silicone resin.

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