Abstract:
Disclosed herewith is an extracting structure for incorporating a substance contained in a first liquid into a second liquid. The extracting structure comprises: a channel for allowing the first liquid and the second liquid to flow therein in a form of a layered flow in which first laminar flows of the first liquid and second laminar flows of the second liquid alternately come in contact with each other, wherein the substance in the first laminar flow of the first liquid moves to the second laminar flow of the second liquid through the boundaries between the first laminar flows and the second laminar flows; and a separating section, connected to a lower stream side of the channel, for separating the second liquid from the first liquid. Further, disclosed also herewith is a separating structure for separating a second liquid from the mixture of a first liquid and the second liquid.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
         [0001]    This application is based on Japanese Patent Application No. 2001-168047 filed in Japan on Jun. 4, 2001, the entire content of which is hereby incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an extracting method, an extracting apparatus, a separating method and a separating apparatus. The invention relates to a technique for selectively extracting an object contained in a liquid.  
           [0004]    2. Description of the Related Art  
           [0005]    In recent years, dioxin or the like generated from garbage incinerators and the like is recognized as serious environmental problem, and it is an important problem to measure and manage a discharge density of the dioxin. Currently, a method of measuring a density of the dioxin or the like is defined by Japanese Industrial Standards (JIS).  
           [0006]    In the case where the dioxin or the like is measured, in order to extract the dioxin contained in water, similarly to a conventional solvent extracting method, water and an organic solvent are put into a separating funnel or the like and are shaken to be mixed, the dioxin in the water is incorporated into the organic solvent and only the organic solvent is extracted so as to be separated from the water.  
           [0007]    However, this method requires a lot of solvent, long time and a lot of costs.  
           [0008]    Recently, an attention is paid to μ-TAS (μ-Total Analysis System) which refines chemical analysis and synthesizing apparatuses and chemical analysis and synthesizing methods using a micromachine technique. The μ-TAS, which is refined more finely as compared with conventional apparatuses, has the merits such that an amount of samples is small, reacting time is short and an amount of refuse is small. In the case where the μ-TAS is adapted to the environment measuring field or the like, it has the merits that usage of reagent and organic solvent is small and reacting time (measuring time) is short, and further since an apparatus is small, the measurement can be made on the ground, so that the immediacy of an inspection is expected to be improved.  
           [0009]    However, conventionally a technique for extracting a solvent using a micro fluid system to which the micromachine technique is applied has not been found.  
           [0010]    For example, in a very narrow channel having a width of several dozen to several hundred μm, the viscosity of a liquid is dominant, and it is difficult to stir and mix liquids. For this reason, in order to incorporate the dioxin contained in the water into the organic solvent, it is inefficient to stir water and organic solvent in a channel.  
           [0011]    In addition, it is desirable that only an organic solvent is extracted from a small amount of mixed water and organic solvent in a microarea and to separate it from the water.  
         SUMMARY OF THE INVENTION  
         [0012]    Therefore, a first technical problem to be solved by the invention is to provide an extracting method, an extracting apparatus and a chip for the extracting apparatus which incorporate a substance contained in a first liquid into a second liquid efficiently in a microarea.  
           [0013]    In addition, a second technical problem to be solved by the present invention suggests a separating method, a separating apparatus and a chip for the separating apparatus which separate a second liquid from mixed first liquid and second liquid in a microarea.  
           [0014]    In order to solve the first technical problem, the present invention provides an extracting method which is basically characterized in that a layered first liquid and a layered second liquid come in contact with each other, and a substance in a first laminar flow of the first liquid is moved into a second laminar flow of the second liquid. More concretely, the following extracting method is provided.  
           [0015]    The extracting method is to incorporate the substance contained in the first liquid into the second liquid so as to extract the substance. This extracting method has the first step and the second step. In the first step, the first liquid and the second liquid are transferred into a channel so as to alternately come in contact with each other respectively in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid is moved to the second laminar flow of the second liquid. In the second step, the second liquid is separated from the first liquid in a lower stream side of the channel.  
           [0016]    In the first step, the first fluid and the second fluid are allowed to flow into the channel with a very small width so as to be in the laminar state. When two or more first laminar flows and the second laminar flows exist, the first laminar flows and the second laminar flows are arranged alternately so as to come in contact with each other.  
           [0017]    Generally the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance) in the medium, and the small matters move irregularly in the medium. Due to this Brownian movement, the small matters diffuse in the medium. A relative interfacial area of the liquid becomes large in the microarea (namely, a surface area becomes wider as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance difficultly return from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is easily incorporated into the second liquid easier than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse it efficiently, it is preferable that a flow velocity of the first laminar flow is equal with a flow velocity of the second laminar flow and the flow velocities do not relatively differ.  
           [0018]    According to the above method, the flow of the laminar flow and the particle diffusion phenomenon in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.  
           [0019]    In the first step, even if the liquids are sequentially transferred, the liquids may be stopped in the middle of the channel.  
           [0020]    In the second step, only the second liquid is collected, so that the substance contained in the first liquid can be extracted.  
           [0021]    Preferably at the first step, a width of one laminar flow is not more than 50 μm. When the width is not more than 50 μm, a Reynolds number becomes small, and the liquid is easily transferred in the channel in the laminar state.  
           [0022]    The second step can collect only the second liquid in the following various forms.  
           [0023]    Preferably, the second step includes a channel branching step. In the channel branching step, in the lower stream side of the channel, the first laminar flow is allowed to flow into a first branch channel, and the second laminar flow is allowed to flow in a second branch channel. In this case, the channels is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily.  
           [0024]    Preferably, the second step includes a charging step. In the charging step, a vicinity of an inlet of the first branch channel or the second branch channel is charged. Polarity is provided to the first liquid or the second liquid and the other liquid has no polarity by the charging step, one liquid having a polarity is activated so as to enter the charged first branch channel or second branch channel, and thus the liquids can be separated more efficiently. For example, nonpolar molecules such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.  
           [0025]    In addition, the present invention provides the following separating method in order to solve the second technical problem.  
           [0026]    The separating method separates a second liquid from mixed first liquid and second liquid. The separating method has the first step and the second step. In the first step, the mixed first liquid and second liquid are allowed to flow into the channel. The channel is composed of a first space and a second space. The first space is provided with a microstructure, and one of the first liquid and the second liquid easily flows relatively. The second space extends along the first space and is connected with the first space. In the second step, the second liquid is collected in a lower stream side of the first space or the second space in which the second liquid flows.  
           [0027]    According to the above method, when the mixed first and second liquids are allowed to flow in the channel, one of the first and second liquids which easily flow relatively into the first space flows in the first space, and the other liquid flows in the second space. For example, the structures undergo a hydrophilic treatment and are provided with a suitable functional group, so that one of the first and second liquids can easily flow relatively in the first space. Since the first liquid and the second liquid separate from each other and the second liquid flows in the first space or the second space, the second liquid can be collected in the lower stream.  
           [0028]    Therefore, the second liquid can be separated from the mixed first and second liquids in the microarea.  
           [0029]    In the above method, the microstructure is constituted suitably, so that one of the first and second liquids can be allowed to easily flow relatively in the first space of the separated channel. For example, the microstructure contains a lot of elements, and a distance (gap) between the adjacent elements is not more than 10 μm. The microstructure may be made of a porous substance in which microholes are opened on all sides, or a fiber block.  
           [0030]    Preferably, the structure is a column-shaped structure which extends from the first space side to the second space side.  
           [0031]    A fluid which difficultly flows relatively in the first space of the first liquid and the second liquid can move easily along the extending direction of the microstructure towards the second space. Therefore, a separating efficiency of the liquid can be heightened.  
           [0032]    More preferably, one of the first liquid and second liquid contains water. The above structure undergoes a water-repellent treatment. In this case, the first or second liquid containing water repels the microstructure which underwent the water-repellent treatment so as to move to the second space, so that the liquid separating efficiency can be heightened. In the case where only one liquid of a mixed liquid composed of three or more liquids has water and affinity, the one liquid can be separated from the other liquids.  
           [0033]    Further, in order to solve the above first technical problem, the present invention provides an extracting apparatus which is basically characterized in that a first liquid space in which a first liquid is to flow in a layered state and a second liquid space in which a second liquid is to flow in a layered state are arranged so as to come in contact with each other in the layer direction. More concretely, the extracting apparatus is constituted in the following manner.  
           [0034]    The extracting apparatus incorporates a substance contained in the first liquid into the second liquid and extract the substance. The extracting apparatus has a channel and a separating section. The first liquid and the second liquid flow in the channel with them contacting alternately in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid moves to the second laminar flow of the second liquid. The separating section is connected to a lower stream side of the channel and separates the second liquid from the first liquid.  
           [0035]    According to the above constitution, the first fluid and the second fluid are allowed to flow in a very small width of the channel so as to be capable of being in a laminar state. In the case of two or more first and second laminar flows, the first laminar flows and the second laminar flows are arranged alternately so as to come in contact with each other.  
           [0036]    Generally, the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance), and the small matters move in the medium irregularly. Due to this Brownian movement, the small matters diffuse in the medium. In the microarea, the relative interfacial area of the liquid becomes large (namely, a surface area becomes larger as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance difficultly return from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is incorporated into the second liquid more easily than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse the substance efficiently, it is preferable that the flow velocity of the first laminar flow is equal with the flow velocity of the second laminar flow and the flow velocities do not vary relatively.  
           [0037]    According to the above constitution, the flow of the laminar flow and the diffusion phenomenon of the particles in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.  
           [0038]    In the separating section, only the second liquid is collected, so that the substance contained in the first liquid can be extracted.  
           [0039]    Preferably, in the channel, a width of one laminar flow is not more than 50 μm. When the width is not more than 50 μm, a Reynolds number becomes small, and the liquid can be easily transferred in the laminar state in the channel.  
           [0040]    The separating section can collect only the second liquid in the following various forms.  
           [0041]    Preferably the separating section includes a first branch channel in which the first laminar flow flows, and a second branch channel in which the second laminar flow flows. In this case, the channel is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily. More preferably, a charging section, which charges a vicinity of an inlet of the first branch channel or the second branch channel is provided.  
           [0042]    According to the above constitution, in the case where the first liquid or the second liquid has polarity and the other one is nonpolar, one liquid having polarity is activated so as to enter the charged first branch channel or second branch channel, so that the liquid can be separated more efficiently. For example, nonpolar molecules such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.  
           [0043]    Further, in order to solve the above second technical problem, the present invention provides a separating apparatus having the following constitution.  
           [0044]    The separating apparatus separates the second liquid from the mixed first liquid and second liquid. The separating apparatus has a first space, a second space and a discharge port. The first space is provided with a microstructure, and one of the first liquid and the second liquid easily flows relatively. The second space extends along the first space and is connected to the first space. The discharge port is connected to a lower stream side of the first space or the second space where the second liquid flows, and the second liquid flows therein.  
           [0045]    According to the above constitution, when the mixed first and second liquids are allowed to flow in the first space and the second space, one of the first liquid and the second liquid which easily flows relatively in the first space flows in the first space, and the other liquid flows in the second space, so that the first liquid and the second liquid are separated from each other. For example, the structures undergo a hydrophilic treatment or a suitable functional group is provided, so that one of the first liquid and the second liquid can be allowed to easily flow in the first space relatively. Since the second liquid flows one of the first space or the second space, the second liquid can be collected from the discharge port. Therefore, the second liquid can be separated from the mixed first liquid and the second liquid in the microarea.  
           [0046]    In the above constitution, the microstructure is suitably constituted, so that one of the first liquid and the second liquid can be allowed to easily flow in the first space of the separated channel relatively. For example, the microstructure includes a lot of elements, and a distance (gap) between the adjacent elements is not more than 10 μm. The microstructure may be composed of a porous substance in which microholes are opened on all sides, or a fiber block.  
           [0047]    Preferably, the structure is a column-shaped structure which extends from the first space side to the second space side.  
           [0048]    A fluid which difficultly flows relatively in the first space of the first liquid and the second liquid can move easily along the extending direction of the microstructure towards the second space. Therefore, a separating efficiency of the liquid can be heightened.  
           [0049]    More preferably, one of the first liquid and second liquid contains water. The above structure undergoes a water-repellent treatment.  
           [0050]    According to the above constitution, the first or second liquid containing water repels the microstructure which has undergone the water-repellent treatment so as to move to the second space, so that the liquid separating efficiency can be heightened. In the case where only one liquid of a mixed liquid composed of three or more liquids has water and affinity, the one liquid can be separated from the other liquids.  
           [0051]    Further, in order to solve the above first technical problem, the present invention provides a chip for the extracting apparatus having the following constitution.  
           [0052]    The chip to be used for the extracting apparatus is used for the extracting apparatus which incorporates the substance contained in the first liquid into the second liquid so as to extracts the substance. The chip has a channel. The first liquid and the second liquid are transferred in the channel so as to come in contact with each other alternately in not less than one or two laminar state, and the substance in the first laminar flow of the first liquid can be moved into the second laminar flow of the second liquid.  
           [0053]    In the above constitution, the first fluid and the second fluid are allowed to flow in a very small width of the channel so as to be capable of being in the laminar state. In the case of two or more first laminar flows and second laminar flows, the first laminar flows and the second laminar flows are arranged alternately so as to be capable of being in contact with each other.  
           [0054]    Generally, the substance in the liquid diffuses voluntarily. Namely, molecules of a medium (liquid) continually collide with small matters (particles of the substance) in the medium, and the small matters move in the medium irregularly. Due to this Brownian movement, the small matters diffuse in the medium. In the microarea, the relative interfacial area of the liquid becomes large (namely, a surface area becomes larger as compared with a volume), and the diffusion speed becomes abruptly high. For this reason, the particles of the substance in the first laminar flow move to the second laminar flow quickly. Namely, the particles are incorporated into the second liquid. In this case, it is preferable that the particles of the substance difficultly returns from the second laminar flow to the first laminar flow, and for example, it is preferable that the substance is incorporated into the second liquid more easily than into the first liquid. When the substance is dioxin or the like, the first fluid can be water and the second fluid can be an organic solvent. Moreover, in order to diffuse the substance efficiently, it is preferable that the flow velocity of the first laminar flow is equal with the flow velocity of the second laminar flow and the flow velocities do not vary relatively.  
           [0055]    According to the above constitution, the flow of the laminar flows and the diffusion phenomenon of the particles in the channel are used, so that the substance contained in the first liquid can be incorporated into the second liquid efficiently in the microarea.  
           [0056]    Only the second liquid is collected, so that the substance contained in the first liquid can be extracted.  
           [0057]    Preferably, in the channel, a width of one laminar flow is not more than 50 μm. When the width is not more than 50 μm, a Reynolds number becomes small, and the liquid can be easily transferred in the laminar state in the channel.  
           [0058]    Preferably, a first branch channel and a second branch channel are provided. The first branch channel is connected to a lower stream side of the channel, and the first laminar flow flows therein. The second branch channel is connected to a lower stream side of the channel, and the second laminar flow flows therein. According to the above constitution, the channel is branched for each liquid in the laminar state, so that the second liquid can be separated from the first liquid easily. More preferably, a charging section, which charges a vicinity of an inlet of the first branch channel or the second branch channel is provided.  
           [0059]    According to the above constitution, in the case where the first liquid or the second liquid has polarity and the other one is nonpolar, one liquid having polarity is activated so as to enter the charged first branch channel or second branch channel, so that the liquid can be separated more efficiently. For example, nonpolar particles such as petroleum ether, carbon tetrachloride, benzene, xylene, nitrobenzene and iodine can be separated from water having polarity. As for a mixed liquid composed of three or more liquids, in the case where only one liquid has polarity or where only one liquid is nonpolar, the one liquid can be separated from the other liquids.  
           [0060]    Further, in order to solve the second technical problem, the present invention provides a chip for the separating apparatus having the following constitution.  
           [0061]    The chip for the separating apparatus is used for the separating apparatus which separates a second liquid from mixed first liquid and second liquid. The chip has a first space, a second space and a discharge port. The first space is provided with a microstructure, and one of the first liquid and the second liquid easily flows relatively. The second space extends along the first space and is connected to the first space. The discharge port is connected to a lower stream side of the first space or the second space where the second liquid flows, and the second liquid flows therein.  
           [0062]    According to the above constitution, when the mixed first and second liquids are allowed to flow in the channel, one of the first liquid and the second liquid which easily flows relatively in the first space flows in the first space, and the other liquid flows in the second space. For example, the structure undergoes a hydrophilic treatment or a suitable functional group is provided, so that one of the first liquid and the second liquid can be allowed to easily flow in the first space relatively. Since the first liquid and the second liquid are separated from each other and the second liquid flows in one of the first space and the second space, the second liquid can be collected on the lower stream side.  
           [0063]    Therefore, the second liquid can be separated from the mixed first liquid and the second liquid in the microarea.  
           [0064]    The microstructure is suitably constituted, so that one of the first liquid and the second liquid can be allowed to easily flow in the first space relatively. For example, the microstructure includes a lot of elements, and a distance (gap) between the adjacent elements is not more than 10 μm. The microstructure may be composed of a porous substance in which microholes are opened on all sides, or a fiber block.  
           [0065]    Preferably, the structure is a column-shaped structure which extends from the first space side to the second space side.  
           [0066]    According to the above constitution, a fluid which difficultly flows relatively in the first space of the first liquid and the second liquid can move easily along the extending direction of the microstructure towards the second space. Therefore, a separating efficiency of the liquids can be heightened.  
           [0067]    More preferably, one of the first liquid and second liquid contains water. The above structure undergoes a water-repellent treatment.  
           [0068]    According to the above constitution, the first or second liquid containing water repels the microstructure which has undergone the water-repellent treatment so as to move to the second space, so that the liquid separating efficiency can be heightened. In the case where only one liquid of a mixed liquid composed of three or more liquids has water and affinity, the one liquid can be separated from the other liquids. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0069]    These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings in which:  
         [0070]    [0070]FIG. 1 is a schematic diagram showing a flow of a microarea;  
         [0071]    [0071]FIG. 2 is a schematic diagram showing movement of particles in the microarea;  
         [0072]    [0072]FIG. 3 is a graph showing a relationship among a channel width, a relative interfacial area and a diffusion speed;  
         [0073]    [0073]FIG. 4 is a main section perspective view of a pretreatment assembly according to a first embodiment of the present invention;  
         [0074]    [0074]FIG. 5 is an exploded perspective view of the pretreatment assembly;  
         [0075]    [0075]FIG. 6 is a top view of the pretreatment assembly;  
         [0076]    [0076]FIG. 7 is a main section exploded perspective view of the pretreatment assembly according to a second embodiment of the present invention;  
         [0077]    [0077]FIG. 8 is a main section enlarged perspective diagram of the pretreatment assembly;  
         [0078]    [0078]FIG. 9 is a structural diagram of divided channels according to a modified example; and  
         [0079]    [0079]FIG. 10 is a flowchart of the pretreatment step in a dioxin measurement. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0080]    There will be explained below embodiments of the present invention with reference to FIGS.  1  to  10 .  
         [0081]    Firs of all, a first embodiment of the present invention will be explained with reference to FIGS.  1  to  6  and FIG. 10.  
         [0082]    [0082]FIG. 1 typically shows a flow of water and solvent in a microarea. Divided channels  10   a  and  10   b , which are divided respectively into plural channels  13   a  to  13   g  and  15   a  to  15   g  by partition walls  12  and  14 , are formed on both ends of one center channel  10  without a partition so as to be opposed to each other. The solvent and the water flow alternately in one divided channel  10   a . For example, the solvent flows in the channels  13   a ,  13   c ,  13   e  and  13   g  and the water flows in the channels  13   b ,  13   d  and  13   f . A width of the respective channels  13   a  to  13   g  is, for example, 20 μm, and since a Reynolds number becomes small in such a microarea, the water and the solvent outflow from the divided channel  10   a  become laminar flows  11   a  and  11   b  respectively in the center channel  10 , and if they are adjacent to each other, they flow without mixing, and interfaces  11   c  are formed respectively between the water and the solvents. The laminar flows  11   a  and  11   b  flow into the channels  15   a  to  15   g  of the other divided channel  10   b . Namely, the solvent flows into the channels  15   a ,  15   c ,  15   e  and  15   g , and the water flows into the channels  15   b ,  15   d  and  15   f.    
         [0083]    [0083]FIG. 2 typically shows movement of particles  16   a  and  16   b  of dioxin or the like in the liquid. In the divided channel  10   a , the particles  16   a  are contained only in the water which flows in the channels  13   b ,  13   d  and  13   f  but are not contained in the solvent which flows in the channels  13   a ,  13   c ,  13   e  and  13   g . Just after outflowing to the center channel  10 , the particles  16   a  are contained in water layers  11   a . The particles  16   a  voluntarily diffuse in the liquid due to Brownian movement. At this time, as shown by arrows  17 , the particles  16   b  which exceed interfaces  11   c  and moves from the water layers  10   d  to solvent layers  10   b  hardly returns to the water layers  10   d  due to a difference of solubility. Since a relative interfacial area of the liquid becomes large in the microarea and a diffusion speed abruptly becomes high, the particles  16   a  in the water layers  11   a  move to the solvent layers  11   b  quickly. Therefore, if only the solvent layers  11   b  are collected by using the divided channel  11   b , the particles  16   b  can be extracted.  
         [0084]    [0084]FIG. 3 is one example of a graph of the channel width, the relative interfacial area S/V and the diffusion speed t. When the channel width becomes smaller than 50 μm, the diffusion time S abruptly becomes short and the diffusion speed becomes high. Therefore, when the channel width is not more than 50 μm, preferably not more than 20 μm, the mixing and extracting time can be shortened greatly. For example, this embodiment can be used in a blood clotting test which requires that a reagent should be mixed fast (within 1 second).  
         [0085]    FIGS.  4  to  6  show an embodiment in which the present invention is applied to a pretreatment assembly  50  for measuring dioxin.  
         [0086]    As shown in FIG. 4( a ), in order to allow a condensed dioxin solution and an organic solvent to flow into a layer form, channels  20  and  30  which cross three dimensionally are formed.  
         [0087]    The organic solvent flows in the channel  20  arranged in an upper section to a direction shown by an arrow  28 . As for the channel  20 , one main channel  21  branches into three branch channels  22  on a lower stream side, and drum-shaped down channels  24  are formed to face downward respectively from bottom faces of end sections  23  of the branch channels  22 .  
         [0088]    The condensed dioxin solution flows in an upper stream channel  31  of the channel  30  arranged in a lower section to a direction shown by an arrow  38 . Divided channels  32  are formed in the middle way of the channel  30 , and the organic solvent and the dioxin solution respectively flow in channels  34  and  35  which are formed alternately. Namely, plural pairs of partition walls  33   a  are arranged with an interval. The respective paired partition walls  33   a  extend to the channel direction and have a thickness of a several μm. Upper stream sides of the paired partition walls  33   a  are combined by connecting walls  33   b . The organic solvent flows from the down channels  24  to the channels  34  between the paired partition walls  33   a , and the condensed dioxin solution flows from the upper stream channel  31  to the channels  35  between the paired adjacent partition walls  33   a.    
         [0089]    One laminar flow mixing channel  36  is formed on the lower stream side of the divided channels  32 , and the dioxin solution and the organic solvent flow in the laminar state in the laminar flow mixing channel  36  so that the dioxin dissolves in and is incorporated into the organic solvent layer. A width of the laminar flow mixing channel  36  is about 200 μm, and its height (up-and-down direction in the diagram) is about 100 μm.  
         [0090]    Meanwhile, as shown in FIG. 4( b ), divided channels  40  are formed on the lower stream side of the laminar flow mixing channel  36  so as to be opposite to the divided channels  32 , and the water and the organic solvent respectively flow in channels  44  and  45  formed alternately.  
         [0091]    Namely, plural pairs of partition walls  41   a  are arranged with an interval. The respective paired partition walls  41  a extend to the channel direction, and their lower stream sides are combined by connecting walls  41   b . The organic solvent containing dioxin flows into the channels  44  between the paired partition walls  41   a , and the water from which the dioxin is removed flows in the channels  45  between the paired adjacent partition walls  41   a.    
         [0092]    Discharge channels  42  are formed on the lower stream side of the paired partition walls  41   a , and as shown by arrows  43 , the organic solvent containing the dioxin is sucked downward and treated at the next step.  
         [0093]    Meanwhile, after the water from which the dioxin is removed passes through the divided channel  40 , it flows in a channel  46  and, as shown by an arrow  48 , is sucked upward from an end section  47  of the channel.  
         [0094]    The channels  20  and  30  are formed in the pretreatment assembly  50  in a manner that a plurality of chips  51  to  60 , shown in FIG. 5, are laminated. In this specification, the pretreatment assembly  50  may be mentioned as a chip.  
         [0095]    The respective chips  51  to  60  can be created accurately, for example, by dry-etching silicon or glass using ICP (Inductively Coupled Plasma). Direct coupling is used for silicon-to-silicon coupling, and anode coupling is used for silicon-to-glass coupling, but the bonding may be carried out by epoxy adhesive. Moreover, a mold of the chip is formed by galvanoplasty using silicon or nickel, and a resin such as PMMA (polymethyl methacrylate) or PDMS (polydimethyl siloxane) is molded so that a lot of chips can be created at a low rate. In this case, it is necessary to coat the resin so that the resin does not react with the organic solvent. Moreover, not only the dry etching but also wet etching may be used as the etching of silicon and glass.  
         [0096]    The first layer chip  51  is formed with an inlet  51   a  for supplying an exhaust gas sample containing dioxin or the like, an inlet  51   b  for supplying the water, an inlet  51   c  and a channel  20  for supplying the organic solvent, a through hole  51   f , a discharge port  51   d  for discharging unnecessary water and a discharge port  51   e  for discharging refined dioxin.  
         [0097]    The second layer chip  52  is formed with channels  52   s  and  52   t  in which the exhaust gas sample and the water supplied from the inlet  51   a  and  51   b  flow and interflow, a porous glass  52   f  for collecting and condensing dioxin, and the channel  30  in which the collected and condensed dioxin solution flows.  
         [0098]    The third layer to tenth layer chips  53  to  60  are provided with a suitable reagent based on, for instance, Japanese Industrial Standards (JIS) in order to refine the dioxin using multi-layer silica chromatography. Namely, pursuant to the JIS, 53 g of sodium sulfate is contained in the third layer chip  53 , 54 g of 10 weight % silver nitrate is contained in the fourth layer chip  54 , 55 g of silica gel is contained in the fifth layer chip  55 , 56 g of 22 weight % silica gel sulfate is contained in the sixth layer chip  56 , 57 g of 44% by weight silica gel sulfate is contained in the seventh layer chip  57 , 58 g of silica gel is contained in the eighth layer chip  58 , 59 g of 2% by weight silica gel potassium hydroxide is contained in the ninth layer chip  59 , and 60 g of silica gel is contained in the tenth layer chip  60 . Of course, the reagents may be altered in accordance with the other standards.  
         [0099]    As shown in FIGS. 6 and 10, the exhaust gas sample and the water which have passed cylindrical filter paper are supplied to the inlets  51   a  and  51   b  of the pretreatment assembly  50  and pass through the channels  52   s  and  52   t  so as to be mixed (#1). The cylindrical filter paper is broken and the dioxin may be collected (#8) by soxhlet extraction using a solvent instead of water.  
         [0100]    The mixed solution of the dioxin and water passes through the porous glass  52   f , so that the dioxin is collected and condensed (#2). Namely, water vapor, carbon dioxide and nitrogen dioxide pass from the porous glass  52   f  through the through hole  51   f  of the chip  51  so as to be discharged.  
         [0101]    The water which contains the condensed dioxin or the like flows in the channel  30 . The organic solvent is supplied from the inlet  51   c  so as to flow in the channel  20 . The organic solvent contains hexane, toluene, acetone, dichloromethane and HCL in at the suitable rate. The water containing the dioxin or the like and the organic solvent pass through the divided channel  32  so as to meet in the laminar flow mixing section  36 , and as mentioned above, the dioxin or the like is incorporated into the organic solvent (#3 in FIG. 10), so that the water and the organic solvent are separated in the divided channel  40  (#4 in FIG. 10).  
         [0102]    The unnecessary water is discharged from the upper discharge port  51   d.    
         [0103]    The organic solvent flows in the lower section and passes sequentially through the chips  53  to  60  provided with  53   g  to  60   g  of reagents and slightly mixed water is removed so that the dioxin is refined (#5 in FIG. 10). The refined dioxin is discharged from the upper outlet  51   e  and is measured by GC/MS (gas chromatography/mass spectrograph).  
         [0104]    A second embodiment of the present invention will be explained below with reference to FIGS. 7, 8 and  10 .  
         [0105]    In the second embodiment, as shown by a reference numeral  90  in FIG. 10, instead that after the water and the organic solvent are mixed by the laminar flow, they are separated (#3 and #4), as shown by a reference numeral  92 , turbulence occurs so that the water and the organic solvent are mixed and thereafter separated (#6 and #7).  
         [0106]    The pretreatment assembly  70  to which the present invention is applied uses chips  71 ,  72  and  73  shown in FIG. 7 instead of the chips  51  and  52  shown in FIG. 5. The chips  71 ,  72  and  73  can be processed by the similar method to the chips  51  and  52 .  
         [0107]    Similarly to the chip  51  of the first embodiment, the first layer chip  71  is formed with an inlet  71   a  for supplying an exhaust gas sample, an inlet  71   b  for supplying water, an inlet  71   c  for supplying an organic solvent, a through hole  71   f  and a discharge port  71   d  for discharging unnecessary water.  
         [0108]    Similarly to the chip  52  of the first embodiment, the third layer chip  73  is provided with channels  73   s  and  73   t  in which the exhaust gas sample and the water flow and interflow, and a porous glass  73   f  for collecting and condensing the dioxin.  
         [0109]    Differently from the first embodiment, mixing spaces  74  for mixing the water containing the dioxin or the like and the organic solvent using turbulence are formed respectively between the first to third layer chips  71  to  73 . Moreover, a PZT layer  71   e  is formed in an area opposed to the mixing spaces  74  on the upper surface of the first layer chip  71 . The PZT layer  71   e  is divided into four sections, for example, and a voltage of suitable waveform is applied to the respective sections in a suitable order so that an ultrasonic is generated. As a result, eddy is generated in the mixing spaces  74 , so that the water containing the dioxin or the like and the organic solvent can be agitated and mixed.  
         [0110]    The mixed water and organic solvent passes from the mixing spaces  74  through a channel  75  formed on the third layer chip  73 , so that the water and the organic solvent are separated.  
         [0111]    As shown in FIG. 8, microstructure  76  is formed in the lower section of the channel  75  (namely, a first space). The microstructure  76  has a plurality of columns having a diameter of several μm to several dozen μm, and they extend from a bottom section  75   a  of the channel  75  to the middle of the height direction of the channel  75 , and there is no obstruction in the upper section of the channel  75  (namely, a second space). A distance (gap) between the columns is, for example, not more than 10 μm. The microstructure  76  are not limited to in the form of the columns, and may be, for example, prisms or cones. Furthermore, the microstructure  76  may be made of a porous substance or a fiber block.  
         [0112]    The surfaces of the microstructures  76  undergo a water-repellent treatment. In the case where the microstructures  76  are formed by an ICP apparatus, since the working process uses C 4 F 8  gas, their surfaces undergo water-repellent process without special additional treatment. The surfaces may undergo the water-repellent treatment by adhering fluorine macromolecules to the surfaces by eutectoid plating or the like.  
         [0113]    The water of the mixed solution which has entered the microstructures  76  moves to the upper section of the channel  75  due to the water-repellent treatment of the microstructures  76 . Meanwhile, the organic solvent just flows in the lower section of the channel  75 . Moreover, the water and the organic solvent are separated to the upper section and the lower section of the channel  75  with the assistance of a difference in specific gravity. The microstructures  76  may be formed in the upper section of the channel  75  according to a difference in specific gravity.  
         [0114]    Thereafter, unnecessary water is sucked from a lower stream end section  75   b  of the channel  75  to the upper section as shown by an arrow  77 . Meanwhile, the organic solvent is sucked from a discharge port  75   c  formed on the bottom face of the lower stream end section  75   b  to the lower section as shown by an arrow  78  so as to flow into a refining section, not shown, (for example, it is composed similarly to the chips  53  to  60 ).  
         [0115]    As explained above, the flow of the laminar flow and the diffusion phenomenon of particles in the microarea are used, so that the dioxin can be extracted efficiently using a very small amount of a sample. Moreover, a second liquid can be separated from mixed first liquid and second liquid in the microarea.  
         [0116]    Therefore, since the treatment can be carried out in the microchips having a size of several cm×several cm, portableness is excellent, and the treatment can be executed immediately anywhere, so that the immediacy of the check is improved. Moreover, the reacting time is fast and the treatment time is shortened, so that the cost can be reduced greatly. Further, since an amount of the organic solvent to be used for the extraction is greatly smaller than conventional methods, the method of the present invention is environmental friendly. Since the chip can be mass produced by utilizing a semiconductor process or the like, the unit price is very low. Since the unit price of the chip is low, the chip can be disposable. When the chip is disposable, unlike in the case where the chip is used plural times, the problem of pollution due to waste water does not arise and troublesome cleaning is not required.  
         [0117]    The present invention is not limited to the above embodiments, and the invention can be carried out in another various forms.  
         [0118]    For example as shown in FIG. 9, a partition wall  80  of the divided channel  10   b  is charged positively or negatively, so that the water and the organic solvent can be separated. As for the partition wall  80 , main body sections  82  are formed by an insulating substance, and electrodes  83   a  and  83   b  are provided on side faces of the main body sections  82  opposed to the channels  15   a  to  15   g , so that outermost layers  84  are covered with the insulating substance. For example, SiO 2  or the like is deposited as an insulating film on the surfaces of the electrodes  83   a  and  83   b . The electrodes  83   a  and  83   b  are connected with a power source  85  so as to be charged positively or negatively. At this time, as shown in the diagram, the electrodes  83   a  and  83   b  which are countered to each other via the channels  15   a  to  15   g  have the same potential, so that the channels  15   a  to  15   g  are charged positively or negatively in an alternate manner.  
         [0119]    Since water is polar molecule and is always charged positively, it does not enter an area charged positively. In order that the water is easily influenced by electric charge, the width of the channels  15   a  to  15   g  is not more than 50 μm. Not more than 10 μm is preferable.  
         [0120]    Further, the present invention can be applied not only to the pretreatment for the measurement of dioxin but also to a wide range. If the present invention is applied, in the case where an organic substance which dissolves or flows in water is extracted, a slight amount of a sample solution and an extracting solvent are mixed and the extracting solvent containing the organic substance can be selectively extracted.  
         [0121]    Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.