JP2007105708A - Deaeration device and total organic carbon measuring apparatus using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deaeration device which removes gas in liquid without using a vacuum pump. <P>SOLUTION: The deaeration device 1 which is made of a cylindrical gas dissolving material, such as PDMS, and in which a through-hole 6 is formed is used. One end of the through-hole 6 is tapered to facilitate connection with a syringe. The deaeration device 1 is sufficiently deaerated beforehand, and an aluminum film 7 is formed on the outer surface so as not to contact with outside air. A sample liquid is supplied into the through-hole 6 by using the syringe, and brought into contact with PDMS in the through-hole to remove gas in the liquid. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deaeration device for deaerating air contained in a liquid, and an analyzer such as a total organic carbon measuring device using the deaeration device.

Conventionally, as a degassing device used to remove air or other gas contained in a liquid, a degassing device in which a vacuum pump is connected to a degassing chamber in which a permeable membrane tube is provided is known. (For example, refer to Patent Document 1).
In this apparatus, the liquid to be deaerated is circulated through the permeable membrane tube, and the gas contained in the liquid is permeated into the deaeration chamber through the wall in the tube to be removed. A gas permeable tube is obtained by, for example, fixing a degassing element in which a fluororesin joining member and a fluororesin tube are joined to each other in a plastic, metal, or glass vacuum chamber using a fixing jig. Manufactured.
On the other hand, polydimethylsiloxane (PDMS) is known to dissolve a large amount of air, and is being researched as a pump that does not require external power (see Non-Patent Document 1).
JP-A-4-203479 K. Hosokawa, K. Sato, N. Ichikawa, M. Maeda; Lab Chip, 2004, 4, 181-185

In the conventional degassing apparatus, it is necessary to continuously distribute the degassed liquid in the permeable membrane tube, so that it has been difficult to handle a small amount of the degassed liquid. Further, since the device structure is complicated, it is difficult to reduce the size of the device. Furthermore, not only an expensive vacuum pump is required for deaeration, but also the degassed gas dissolves in the pump oil, so regular maintenance is inevitable.
An object of this invention is to provide the deaeration device which deaerates the gas in a liquid, without using a vacuum pump, and the total organic carbon measuring apparatus using the same.

  The degassing device of the present invention includes a gas-soluble resin main body that dissolves and degass a gas in a liquid that has been degassed in advance, and the gas-soluble resin main body has a liquid contact portion. Is provided.

  The resin body is made of, for example, PDMS that is known to dissolve a large amount of air.

  In one embodiment of the deaeration device, a through hole for circulating a liquid sample is formed as a contact portion in the resin main body, and the outer surface of the resin main body is covered with a gas impermeable cover.

  In addition, in this deaeration device, for example, the resin main body is deaerated before use, and the openings at both ends of the through hole are sealed with a gas impermeable film.

  The total organic carbon measuring device of the present invention includes an organic oxidative decomposition unit that converts organic carbon in sample water into carbon dioxide, a carbon dioxide extraction unit that extracts carbon dioxide generated in the organic oxidative decomposition unit into pure water, and the carbon dioxide. In order to measure the amount of carbon dioxide extracted by the carbon extraction unit, a detection unit for measuring the conductivity of the pure water is provided. And the inorganic carbon removal part which removes the carbon dioxide in sample water is provided in the channel which supplies sample water to the above-mentioned organic matter decomposition part, and the deaeration device of the present invention is used as this inorganic carbon removal part.

  The carbon dioxide extraction unit includes a base, two flow paths formed in the base, each having an inlet and an outlet, and a plurality of grooves connecting the two flow paths, and the grooves are liquid. It is preferable that at least a part of the inner surface is made hydrophobic and the size of its cross-sectional area is set so that the gas component can move without passing through.

  Conventionally, a vacuum pump was used when degassing a gas from a gas-containing liquid, but the degassing device of the present invention previously degassed the gas-soluble resin in a decompression chamber or the like at the manufacturing site, Since the liquid sample is brought into contact with this, the gas in the liquid sample can be degassed without using a vacuum pump.

If a degassing device made of PDMS is used as the resin body, it can be used as a degassing device instead of a vacuum pump depending on the property of dissolving the gas.
If the resin body of the degassing device has a through hole for sample distribution and its outer surface is covered with a gas impermeable cover, the resin body is degassed and the sample is allowed to flow through the through hole. Even when the sample is degassed, there is no dissolution of gas from the outer surface, so that the sample can be used for a long time.

  In addition, if the resin main body is deaerated before use and both ends of the through hole portion are sealed with a gas impermeable film, it can be used immediately as a deaeration device even in a place where there is no decompression chamber or the like. be able to.

If the degassing device of the present invention is used as the inorganic carbon removing unit of the total organic carbon measuring device, it is not necessary to use a conventionally used vacuum pump, so that the measurement can be performed easily.
Also, use a carbon dioxide extraction part of the total organic carbon measurement device that has a groove in which at least a part of its inner surface is made hydrophobic so that the gas component can move without passing through the liquid. If so, the extraction rate of carbon dioxide can be increased as compared with those using a gas permeable membrane.

Embodiments of the present invention will be described below with reference to the drawings.
[Example 1]
FIG. 1 is a perspective view showing an embodiment of a deaeration device. As the deaeration device 1, for example, a device in which a through hole having an inner diameter of 0.1 mm is formed at the center of a cylinder having a diameter of 10 mm and a length of 50 mm using PDMS as a base material is used. One end (the upper end in the figure) of the through hole is processed into a tapered shape in order to facilitate joining with an instrument such as a syringe when a sample is injected.
Since PDMS dissolves air, the degassing device 1 is vacuum degassed for 30 minutes or more in a vacuum chamber of 1 kPa or less in advance and stored in a portable vacuum container for transport to the measurement site.

Next, an example of a TOC measurement method using the deaeration device 1 will be described.
After collecting the sample in the syringe 2 at the measurement site, the degassing device 1 is taken out from the vacuum container, and one end (upper end) is attached to the syringe 2 as shown in FIG. Connect to the sample inlet 3 of the apparatus 4. FIG. 2 is a perspective view when the deaeration device 1 is connected between the syringe 2 and the sample introduction part 3.

  By slowly pushing the syringe 2, the sample is passed through the deaeration device 1 and injected into the total organic carbon measuring device 4 for analysis. When the sample passes through the degassing device 1, inorganic carbon contained in the sample is removed by re-dissolving into the degassing device 1 as carbon dioxide.

[Example 2]
Another embodiment of the deaeration device will be described with reference to FIG. This deaeration device is obtained by providing an outer air blocking film on the outer surface of the deaeration device of FIG.
The deaeration device 1 of Example 1 has a simple structure and can be manufactured at low cost. However, when the deaeration device 1 is taken out from a storage container such as a vacuum container, re-dissolution of air starts from the outside, and must be used promptly. In order to solve this problem, the outer surface of the deaeration device 1 is covered with a gas impermeable cover (outside air blocking film) 5 made of a plastic such as PET (polyethylene terephthalate) having poor air permeability or a metal such as an aluminum vapor deposition film. By covering, re-dissolution of the outside air into the deaeration device 1 is prevented.

  Furthermore, a thin film-like membrane 7 is used to block the outside air so as to close the central through hole 6 of the deaeration device 1, and the membrane 7 is broken and connected at the sample inlet of the syringe or the total organic carbon measuring device at the time of use. If designed to do so, a vacuum container for transport is not required, and thus a deaeration device that is easy to transport and can be used easily can be obtained.

  When an aluminum vapor deposition film is used as the gas impermeable cover 5, a thin film film 7 such as plastic is formed in advance so as to close the central through hole 6 of the deaeration device 1. Then, after deaeration of the whole deaeration device 1 in a vacuum, an aluminum film is vapor-deposited on the entire outer surface of the deaeration device 1 so that the surface other than the through hole 6 is covered with an aluminum vapor deposition film. Can be obtained.

[Example 3]
Still another embodiment of the present invention will be described with reference to FIGS. In the total organic carbon measuring device configured on the chip, inorganic carbon is removed by preparing a part of the flow path with PDMS and degassing in advance. FIG. 4 is a perspective view of a two-channel gas exchange chip, and FIG. 5 is a plan view of the main part of the total organic carbon measuring device using the gas exchange chip of FIG.
The substrate 41 is, for example, a quartz glass substrate, and a flow path 60 having a width and depth of 1000 μm or less, preferably several hundred μm or less, is formed on the upper surface thereof. The channel 60 includes a sample water channel 62 and a measurement water channel 64.

  The other substrate 42 is also a quartz glass substrate, for example, and the measurement water is introduced into the hole 45 for discharging the sample water from the flow path 62 and the flow path 64 at positions corresponding to the flow path ends of both flow paths 62 and 64. A hole 46 for discharging the measurement water from the flow path 64 is formed. A plurality of grooves 66 having hydrophobicity, which will be described later in detail in FIGS. 6 and 7, are formed on at least one of the substrates 41 and 42 so as to connect the flow paths 62 and 64.

  43 is a PDMS substrate, and a hole 44 for introducing the sample water into the sample water channel 62 is formed at a position corresponding to the inlet of the sample water channel 62. The substrate 42 and the PDMS substrate 43 are joined and integrated with the substrate 41 so that the surface on which the flow paths 62 and 64 are formed and the surface on which the groove 68 is formed are inward. It has become.

  A part of the sample water flow path 62 connected to the sample introduction hole 44 is in contact with the PDMS substrate 43 to form an inorganic carbon removing unit 51, and the inorganic carbon removing unit 51 includes carbon dioxide dissolved in the sample water from the beginning. The gas component is removed. Downstream of the inorganic carbon removing unit 51, there is an organic matter oxidative decomposition unit 52 that oxidizes organic matter in the sample water by the ultraviolet energy from the ultraviolet lamp 54, and further by the addition of an oxidizing agent and the action of a catalyst (for example, titanium oxide). Is provided. Further downstream of the organic oxidative decomposition unit 52, a carbon dioxide extraction unit 53 is provided for extracting carbon dioxide in the sample water to the measurement water side in order to measure the conductivity.

FIG. 6 is a diagram showing in detail an example of the carbon dioxide extraction unit 53 described above, (A) is a plan view showing the arrangement of flow paths and grooves, and (B) is a position along the line AA in (A). FIG.
Flow paths 62 and 64 are formed on one side of the substrate 41. The other substrate 42 is formed with a plurality of grooves 66 having a hydrophobic surface at a position connecting the flow paths 62 and 64 on one side, and penetrates the substrate 42 at a position corresponding to the ends of the flow paths 62 and 64. Thus, holes 45, 46 and 47 used for introducing and discharging liquid are formed.

The substrates 41 and 42 face each other so that the surface on which the flow paths 62 and 64 are formed and the surface on which the groove 66 is formed are inside, and holes 45, 46 and 47 are arranged at the ends of the flow paths 62 and 64. Then, the groove 66 is joined in a state of being positioned so as to connect the flow paths 62 and 64 to form an integrated base.
The groove 66 has a length and a width of several hundred μm or less, preferably a width and a height of 10 μm or less. When the liquid flows through the flow paths 62 and 64, the liquid does not enter the groove 66 and the gas moves through the groove 66.

The flow paths 62 and 64 and the groove 66 can be formed by, for example, a fine processing technique using photolithography and etching, and the holes 45, 46, and 47 can be formed by, for example, a sandblast method. Hydrophobization of the inner surface of the groove 66 can be achieved, for example, by performing RIE (reactive ion etching) while flowing a fluorine compound gas such as CHF ₃ gas or CF ₄ gas, or by decomposing it by light irradiation such as excimer laser. This can be done by fluorinating the inner surface of the groove.
When the substrates 41 and 42 are glass substrates such as quartz glass, they can be bonded by a hydrofluoric acid bonding method. In the hydrofluoric acid bonding method, for example, a 1% hydrofluoric acid aqueous solution is interposed at the interface between the substrates 41 and 42 and left at room temperature for about 24 hours while being loaded at about 1 MPa as necessary.

FIG. 7 is a diagram showing another example of the carbon dioxide extraction unit 53 in detail, (A) is a plan view showing the arrangement of flow paths and grooves, and (B) is a position at the AA line position of (A). It is sectional drawing.
The substrates 70 and 72 are silicon substrates. On one side of the silicon substrate 70, a plurality of grooves 66 having flow paths 62 and 64 and a hydrophobic surface connecting the flow paths 62 and 64 are formed. On the other silicon substrate 72, through holes 45, 46, 47 used for introducing and discharging liquid are formed at positions corresponding to the ends of the flow paths 62, 64.

  The silicon substrates 70 and 72 face each other so that the surfaces on which the flow paths 62 and 64 and the grooves 66 are formed are inward, and are positioned so that the holes 45, 46 and 47 are arranged at the ends of the flow paths 62 and 64. In this state, they are joined together to form an integrated base.

  The dimensions of the flow paths 62, 64 and the groove 66 are the same as those shown in the embodiment of FIG. 6, and the formation of the flow paths 62, 64, the groove 66 and the holes 45, 46, 47 and the hydrophobicity of the inner surface of the groove 66 are the same. The sexifying process can be performed in the same manner as in the embodiment of FIG. In this example, the groove 66 has a V-shaped cross section. Such a groove is formed by etching a silicon substrate having a (100) plane with an alkaline etchant. However, the shape of the groove 66 is not limited to this. The silicon substrates 70 and 72 can be bonded to each other by forming an oxide film on the surface of the silicon substrate and using the oxide film to bond hydrofluoric acid.

Returning to the embodiment shown in FIGS. 4 and 5, the method of use will be described.
In advance, the whole organic carbon measuring chip is vacuum deaerated for 30 minutes or more in a vacuum chamber of 1 kPa or less. When the measurement sample is supplied from the hole 44, the carbon dioxide dissolved in the sample water from the beginning is dissolved and removed into the PDMS 43 in the inorganic carbon removing unit 51. In order to easily remove this carbon dioxide, an acid may be added to the sample water.

  Next, the sample water is sent to the organic matter oxidative decomposition unit 52, and the organic matter in the sample water from which the carbon dioxide has been removed is oxidized by the ultraviolet energy given by the irradiation of the ultraviolet lamp 54 to become carbon dioxide. The sample water in which the carbon dioxide generated by the oxidative decomposition of the organic matter is dissolved is sent to the carbon dioxide extraction unit 53, and the carbon dioxide contained in the sample water moves to the pure water that is the measurement water. Pure water is sent to the detection / purification unit 55, and the concentration of carbon dioxide is quantified by measuring the conductivity of pure water. The pure water can be used after being purified by the detection / purification unit 55 to remove carbon dioxide and then circulated through the measurement water channel 64.

  The present invention is not limited to the above embodiments, but can be carried out within the scope of the claims.

  The present invention can be used in a degassing device for degassing gas components such as air and carbon dioxide contained in a liquid, and an analyzer such as a total organic carbon measuring apparatus using the degassing device.

It is a perspective view which shows one Example of the deaeration device of this invention. It is a perspective view which shows an example of the usage method of the Example. It is sectional drawing which shows another Example. It is a perspective view which shows one Example of a total organic carbon measuring apparatus. It is a principal part top view of the Example. It is a figure which shows an example of the carbon dioxide extraction part in the same Example in detail, (A) is a top view which shows arrangement | positioning of a flow path and a groove | channel, (B) is sectional drawing in the AA line position of (A). It is. It is a figure which shows the other example of the carbon dioxide extraction part in the same Example in detail, (A) is a top view which shows arrangement | positioning of a flow path and a groove | channel, (B) is in the AA line position of (A). It is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deaeration device 2 Syringe 3 Sample inlet 4 Total organic carbon measuring device 5 Gas impermeable cover 6 Through-hole 7 Film-like film | membrane 41,42 Board | substrate 43 PDMS
44, 45, 46, 47 Hole 51 Inorganic carbon removal part 52 Organic matter oxidative decomposition part 53 Carbon dioxide extraction part 54 Ultraviolet lamp 55 Detection / purification part

Claims (6)

It comprises a gas-soluble resin body that degass by degassing in advance by dissolving the gas in the liquid that has come into contact with it,
A degassing device in which the gas-soluble resin main body is provided with a contact portion with a liquid.   The deaeration device according to claim 1, wherein the resin body is made of PDMS.   The degassing device according to claim 1 or 2, wherein a through hole for circulating a liquid sample is formed in the resin body as the contact portion, and an outer surface of the resin body is covered with a gas impermeable cover.   The deaeration device according to claim 3, wherein the resin main body is deaerated before use, and openings at both ends of the through hole are sealed with a gas impermeable film. An organic matter oxidative decomposition part that converts organic carbon in sample water into carbon dioxide, a carbon dioxide extraction part that extracts carbon dioxide generated in the organic matter oxidative decomposition part into pure water, and an amount of carbon dioxide extracted by the carbon dioxide extraction part In the total organic carbon measuring device provided with a detection unit for measuring the conductivity of the pure water to measure,
An inorganic carbon removing unit that removes carbon dioxide in the sample water is provided in a flow path for supplying the sample water to the organic matter oxidative decomposition unit, and the degassing device according to claim 1 or 2 is used as the inorganic carbon removing unit. Total organic carbon measuring device characterized by that. The carbon dioxide extraction unit is
A substrate;
Two flow paths formed in the substrate, each having an inlet and an outlet;
A plurality of grooves connecting the two flow paths,
The all-organic structure according to claim 5, wherein at least a part of the inner surface of the groove is made hydrophobic and the size of the cross-sectional area is set so that the gas component can move without liquid passing through the groove. Carbon measuring device.

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