JPH07232056A - Trace reactor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an apparatus for efficiently reacting in a minute area so as not to dilute a minute amount of sample. [Structure] Power supply units 1 and 2 for applying a high voltage in a flow path arranged on the same plane, flow paths 7a-f in which electroosmotic flow is generated by high voltage application of the power supply units 1 and 2, a reaction reagent tank 3, waste liquid tanks 4, 5, sample tank 6, flow path switching devices 9, 10, 11, 12 for switching the introduction of reaction reagents and samples,
13 and 14, and a controller unit 20 that controls the operation of the flow path switching device.

Description

Detailed Description of the Invention

[0001]

[Industrial application] The present invention relates to a microreactor using a microsample.

[0002]

2. Description of the Related Art As a method of reacting a sample and a reaction reagent in a flow system, there is a flow injection analysis method in which a sample and a reaction reagent are introduced into a solution and reacted to measure the concentration by an optical detection method such as absorbance. It is common. Further, in high performance liquid chromatography, a reaction liquid chromatography such as a post-column method in which a sample is separated with a separation column and then the separated sample is reacted with a reaction reagent is well known, and particularly an amino acid analyzer is widely used. ing. In any of these methods, as a method of feeding a sample and a reaction reagent, a mechanical drive type liquid feeding pump is used, in which a solution is sucked into a pump, a cylinder is extruded through a plunger, and continuously pressurized to feed the solution. The flow injection analysis method is described in, for example, Bunseki 11
Page (785) pages 785-791, or Banseki 7-box (1984) pages 513-522.
For the page and the reaction liquid chromatography of the post-column method, for example,
High Performance Liquid Chromatographic Analysis, Japan Society for Analytical Chemistry, Kanto Chapter, Industrial Books, pp. 230-254 (1985)
Page.

[0003]

FIG. 2 shows the flow in the flow path when the mechanical drive type liquid feed pump used for the reaction liquid chromatography such as the flow injection analysis method and the post column method is used. It is a laminar flow having a flow pattern 21. At that time, the velocity becomes 0 at both ends due to the resistance of the walls 22 and 23, and the velocity distribution becomes the maximum velocity at the central portion. Therefore, the injected sample does not flow as it is due to the difference in the flow velocity in the channel,
There was a problem that the mixture gradually spreads when mixed with the solution before and after, causing a decrease in the concentration of the sample and an increase in the volume. Furthermore, unlike the batch method, the flow-type analysis method measures a transient reaction rather than a reaction at which chemical equilibrium has been reached, so strict control of the flow rate is required, but a mechanically-driven transfer method is required. It was very difficult to improve the quantitativeness in a minute flow rate range of 10 μl / min or less using a liquid pump.

Further, the pressure drop Δp at that time is Hagen ·
It is expressed as Poiseuille's formula as follows.

Δp = 8 μlQ / πr^Four  Where: μ: viscosity of liquid: l: length of flow channel Q: flow rate r: radius of flow channel That is, the pressure drop is large in inverse proportion to the fourth power of the radius of the flow channel.
I hear Therefore, a nanoliter level trace amount of sample
Uses a channel with an inner diameter of 100 μm or less to handle the pull
Pressure drop in the equipment, the pressure
Problems, that is, the pressure resistance of the flow path material and the joint between the flow paths
There is a problem that requires special measures to have pressure resistance.
It was In addition, the conventional device has a complicated device configuration and is a large device.
It was.

[0006]

In order to solve the above problems, in the present invention, an electroosmotic flow is used as a liquid feeding method of a sample and a reaction reagent, and further reaction is performed on a flat substrate having fine grooves. The channels were formed on the same plane.

[0007]

The electroosmotic flow is generated by applying a voltage to both ends of the capillary tube as shown in FIG. 3, whereby the electric double layers 31 and 32 generated on the inner surface of the tube move in the same direction as the direction of the electric field. . The flow pattern 33 at that time is a plug flow as shown in FIG. Therefore, the diffusion of the sample is about several tenths of that in the case of the laminar flow. Also,
The flow velocity u _{osm of the} electroosmotic flow is expressed by the following equation.

U _osm = keE / z η√c where k; constant e; amount of charge per unit surface of the capillary tube E; applied voltage z; number of charges of electrolyte η; viscosity of solution c; concentration of electrolyte Since the electroosmotic flow depends on the applied voltage, the concentration of the electrolyte in the solution, the positive / negative of the surface charge of the capillary tube, and the amount thereof, it is easy to control the liquid delivery amount. Further, there is almost no pressure drop due to the liquid transfer.

Further, since the flow path is formed on the same plane, the switching valve and the like can be installed on the same plane as the flow path, and the device can be downsized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the block diagram of FIG.

The microreactor according to this embodiment comprises a power source section 1 and 2, a reaction reagent tank 3, a waste liquid tank 4 and 5, a sample tank 6,
Flow paths 7a-f, flow path switching devices 8, 9, 10, 11,
12, 13, 14, measurement unit 15, light source unit 16, detection unit 1
7 and the controller unit 18. Power supply 1
Can use a high voltage power source with an output voltage of 0-30 kV and can apply a high voltage between the reaction reagent tank 3 and the waste liquid tank 4. Further, the power supply unit 2 can apply a high voltage between the sample tank 6 and the waste liquid tank 5. The reaction reagent solution in the reaction reagent tank 3 is flowed by the electroosmotic flow generated by applying a high voltage between the reaction reagent tank 3 and the waste liquid tank 4 to the flow path 7a,
It flows sequentially between 7b and 7c. Similarly, the sample in the sample tank 6 has a flow path 7 due to an electroosmotic flow generated by applying a high voltage between the sample tank 6 and the waste liquid tank 5.
Flows sequentially between d, 7e, 7b, and 7f. The flow of the reaction reagent solution and the sample is the flow path switching devices 8, 9, 1
It can be controlled by using 0 and 11. The flow rate can be easily set by controlling the applied voltage.

The reaction using the trace amount reactor of this example is as follows.
Perform in the following order. First of all, the channels 7a, 7b, 7
The reaction reagent is introduced into c. At that time, the flow path switching devices 10 and 11 are used to close the flow path and stop the flow of the sample. Next, the reaction reagent in the reaction reagent tank 3 is sequentially introduced between the flow paths 7a, 7b, 7c by an electroosmotic flow generated by applying a high voltage between the reaction reagent tank 3 and the waste liquid tank 4. After that, the flow passages are closed using the flow passage switching devices 8 and 9 to stop the flow of the reaction reagent. Next, the sample is introduced into the flow path 7b which also serves as the sample measuring section by applying a high voltage between the sample tank 6 and the waste liquid tank 5 by using the power source section 2 for sample injection. First, the flow passage is opened using the flow passage switching devices 10 and 11. After that, the sample in the sample tank 6 sequentially flows between the flow paths 7d, 7e, 7b, and 7f by the electroosmotic flow generated by applying a high voltage between the sample tank 6 and the waste liquid tank 5. The amount of sample introduced at that time can be set by the capacity of the flow path 7b which also serves as a sample measuring unit. The introduced sample and the reaction reagent stop the flow of the sample by closing the flow path by using the flow path switching devices 10 and 11.
Next, the flow path through which the reaction reagent flows is opened using the flow path switching devices 8 and 9, and the flow path 7 is generated by the electroosmotic flow generated by applying a high voltage between the reaction reagent tank 3 and the waste liquid tank 4.
It reacts while flowing in b and 7c. That is, the flow path 7b
There is a reaction reagent before and after the sample introduced into the, and the sample is sandwiched between the reaction reagents.

After that, by liquid transfer using an electroosmotic flow,
While flowing, the sample and the reaction reagent are reacted.
At that time, since the sample is sandwiched between the reaction reagents, the sample is efficiently mixed with the reaction reagents before and after the diffusion, and the reaction is efficiently performed. When the optimum reaction temperature of the reaction is high, there is no problem if the reaction is carried out by setting the flow paths 7b and 7c to arbitrary temperatures. afterwards,
In the measuring unit 15, light is incident on the reacted sample from the light source unit 16. The amount of sample is measured by detecting the amount of light changed by the reacted sample with the detector 17.

The change in the amount of light is the absorbance, the amount of fluorescence or the like. Therefore, the measuring unit 15 has a good light transmittance, and particularly has a light reflecting layer on the surface of the flow path in order to increase the optical path length when measuring the change in the absorbance. Moreover, when a large number of samples are measured, it can be easily performed by sequentially using the flow path switching devices 11, 12, 13, and 14 in the same procedure as described above.

The above operation is controlled by the controller unit 18, and can be performed by a single switch by programming the applied voltage and time, the flow passage switching timing and the like.

Another embodiment showing the flow path structure of the micro-reactor will be described with reference to FIG.

FIG. 4 (a) shows the flow channel structure of the trace amount reactor. First of all, the flow path of the microreactor was manufactured.
Fine grooves and through holes are formed in a flat substrate such as glass or silicon, and another flat substrate is superposed on the surface and joined by fusion or the like. As a result, the fine grooves and the through holes are formed in the flow channels 41a-h, the reaction reagent tank 42, and the waste liquid tank 4, respectively.
3, 44 and the sample tanks 45a-d are formed. The fine grooves and the through holes can be produced by machining such as a drill or etching. Further, the flow path switching device 46a-g controls the opening / closing of the electroosmotic flow by a method of opening / closing a through hole formed for flow path switching or by freezing / thawing a part of the flow path 41a-h. You can

FIG. 4 (b) is a side sectional view of the flow path of the trace amount reaction device as seen in the direction of the arrow at the position AA in FIG. 4 (a). In the figure, 46a 'and 46c' show stoppers for switching the flow paths, which are used for opening and closing the through holes by a device (not shown) (for example, a device in the form of an electromagnet and a plunger). Reaction reagent tank 42, waste liquid tank 4
Since 3, 44 and the sample tanks 45a-d are formed on the same plane substrate, it is not necessary to connect the reaction reagent tank, the waste liquid tank, and the sample tank to the flow path through a connector as in the conventional case, and it is very small. There are no coupling or leakage problems in the area. further,
The external device is a high-voltage power supply and a photodetector, and it is easy to downsize the entire device. Further, since the reaction reagent tank 42, the waste liquid tanks 43 and 44, and the sample tanks 45a to 45d face the outside, the reaction reagent and the sample can be introduced, exchange cleaning and the waste liquid treatment can be easily performed. The amounts of the reaction reagent and sample used at that time depend on the sizes of the reaction reagent tank and the sample tank. Therefore, by setting the through thin holes for the reaction reagent tank and the sample tank to be 500 μm or less, it becomes possible to handle a trace amount sample of microliter or less without loss. The measuring section 47 includes a light transmitting section 48 made of quartz glass having a good light transmitting property, and the light reflecting layer 4.
It consists of 9. There is no problem if the light reflecting layer 49 is made of platinum, rhodium, or the like having excellent light reflectance.

Another embodiment showing the structure of the flow path switching device will be described with reference to FIG.

FIG. 5A shows sample flow paths 51a, 5a.
1b, a reaction reagent liquid flow path 52a-c, and a part of a flow path switching device including flow path switching devices 53 and 54. The flow channel 52b also serves as a sample measuring unit. The sample weighing and reaction can be performed by introducing the sample into the channel 52b that also serves as the sample weighing unit by closing the channel switching devices 53 and 54. FIG. 5B shows a side cross-section of a part of the flow path switching device. The flow path switching device is the flow path 5
It is composed of Peltier elements 58, 59, 60, 61 installed on flat substrates 56, 57 facing the substrate 5. To change the flow path, set the Peltier elements 58, 59, 60, 61 to -1.
By cooling to below 5 ° C., the solution in the channel is frozen and the channel 55 is closed. In this example, frozen,
Since the channels are opened and closed by thawing, it is possible to easily switch the channels in a minute area with a simple configuration.

[0021]

According to the present invention, since the electroosmotic flow is used as a method for feeding the sample and the reaction reagent, the diffusion of the sample and the reaction reagent is about several tenths as compared with the laminar flow. small. Further, there is almost no pressure drop due to the liquid feeding, and it is possible to efficiently react a small amount of sample with a reaction reagent in a channel having an inner diameter of 100 μm or less. Also,
Since the flow paths are formed on the same plane, the device can be easily downsized.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a trace amount reactor.

FIG. 2 is a diagram showing a laminar flow pattern.

FIG. 3 is a diagram showing a flow pattern of electroosmotic flow.

FIG. 4 is a block diagram showing a flow path configuration of a trace amount reaction device.

FIG. 5 is a diagram showing a configuration of a flow path switching device.

[Explanation of symbols]

1, 2: Power supply section, 3, 42: Reaction reagent tanks, 4, 5, 4
3, 44: waste liquid tank, 6, 45a-d: sample tank, 7a
-F, 41a-h, 51a, b, 52a-c, 55: flow path, 8, 9, 10, 11, 12, 13, 14, 46a-
g, 53, 54: flow path switching device, 15, 47: measurement unit, 16: light source unit, 17: detection unit, 18: controller unit, 21: laminar flow pattern, 22, 23: wall, 3
1, 32: electric double layer, 33: flow pattern of electroosmotic flow, 48: light transmitting portion, 49: light reflecting layer 49, 56, 5
7: flat substrate, 58, 59, 60, 61: Peltier element.

Claims (4)

[Claims] 1. An electroosmosis device, which has microgrooves having an inner diameter of 100 μm or less on the same plane and which reacts a sample with a reaction reagent, by applying a voltage to a part of the microgrooves as a liquid feeding means. A microreactor characterized in that a sample or a reaction reagent is sent using a flow. 2. A microreaction according to claim 1, wherein the fine groove is formed by a flat substrate having a fine groove of 100 μm or less formed on at least one surface and another flat substrate covering the surface. apparatus. 3. At least two fine grooves, a power source for applying a voltage to a part of the fine groove, a power source changeover switch for switching the power source, and a voltage applied to a part of the fine groove. The trace amount reaction device according to claim 1, comprising a flow path switching device that switches a flow path of the electroosmotic flow, and a controller that controls the flow path switching device. 4. The microreactor according to claim 1, wherein the flow path switching device controls opening / closing of the electroosmotic flow by freezing a part or one of the fine grooves and thawing the other.