JP2017181110A - Deaerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deaerator that enables gas and foam dissolved in liquid to be removed in a simple structure.SOLUTION: A deaerator comprises a decompression chamber, and a deaeration tube stored in the decompression chamber. The deaeration tube includes a foam trap. The foam trap has a wall composed of a gas-permeable material.SELECTED DRAWING: None

Description

  The present invention relates to a deaeration device for removing gas or bubbles dissolved in a liquid. More specifically, the present invention relates to an on-line degassing apparatus using a vacuum permeable degassing method using a gas permeable material for removing dissolved gas or bubbles from an eluent or the like used for liquid chromatography.

  In the liquid chromatograph, the injected sample is separated by a column and transferred to a detector together with an eluent. The separated components are detected by a method such as ultraviolet absorption or refractive index change in the detector, and the signal from the detector is collected in the data processing device as a waveform that changes over time. Control of the eluent flow rate is important for chromatographic accuracy. In a general liquid chromatograph apparatus, a reciprocating plunger pump is used for feeding a sample and an eluent in order to maintain the accuracy and stability of the flow rate of the eluent sent at a high pressure.

  However, since the upstream side of the plunger pump has a negative pressure due to suction by the pump, the dissolved gas in the eluent may become bubbles. As another bubble generation mechanism, when the temperature of the solvent rises, the saturated dissolution amount of the gas in the solvent decreases. Therefore, when the temperature of the eluent rises due to fluctuations in the environmental temperature, the excessively dissolved gas is separated from the bubbles. May come out. As another bubble generation mechanism, when different types of solvents are confused, or when solutions of different salt concentrations are mixed even if the same type of solvent is used, the amount of saturated gas dissolved in the solvent changes. May occur. These bubbles cause various adverse effects on the analysis results. For example, when it flows into a pump, liquid feeding failure may occur, and the detected peak retention time may fluctuate. In addition, if it flows into the column, it may cause deformation of the detection peak. Furthermore, if it flows into the detector, it may cause baseline fluctuations and noise. In order to suppress or prevent the generation of bubbles that affect the analysis result, an operation for removing dissolved gas in the eluent is performed.

  There are several methods for removing the dissolved gas, but typical examples include an offline degassing method and an online degassing method. The off-line degassing method is a method in which dissolved gas is removed in advance before setting a storage container such as an eluent on the pump suction side (upstream side of the plunger pump). However, in this method, since air is redissolved in the liquid, the dissolved gas in the liquid gradually increases with time. In other words, the effect of off-line degassing dissolved gas removal does not last for a long time.

  The online degassing method is a method in which a vacuum degassing device using a gas permeable material is installed in the flow path upstream of the plunger pump, and the dissolved gas is continuously removed during liquid feeding. Compared with offline degassing method, online degassing method with vacuum degassing device has no restrictions on the shape and stopper of liquid storage container, liquid composition is difficult to change, running cost is low, easy to handle, This is why it is widely used. The dissolved gas removing device is usually installed on the upstream side of the plunger pump, and continuously removes the dissolved gas from the liquid flowing into the pump.

  Patent Documents 1 and 2 and Non-Patent Document 1 describe a deaeration device including a deaeration tube made of a gas-permeable material that allows gas to pass but not liquid to pass through a decompression chamber that is decompressed by a vacuum pump. Has been. When the liquid sucked from the storage container flows through the deaeration tube, the dissolved gas in the eluent passes through the wall surface of the deaeration tube and is taken out to the decompression space in the decompression chamber.

  However, the above-described conventional dissolved gas removal device cannot remove bubbles generated upstream of the device, and may adversely affect the analysis result. In other words, the conventional dissolved gas removing device is suitable for removing dissolved gas, but is not suitable for removing bubbles due to its nature. Therefore, in the conventional liquid chromatography, bubbles are removed using a means different from the removal of dissolved gas.

  As a device for removing bubbles from a liquid, there is a bubble removing device. In the devices described in Patent Documents 3 and 4 and Non-Patent Document 2, a gas-liquid separation tank or a defoaming chamber (so-called bubble trap) is connected in the middle of an infusion tube made of metal or resin, and bubbles are in the liquid. The bubbles in the liquid are captured and stored in the bubble trap by utilizing the property of floating in the bubble trap. The stored bubbles are removed from the bubble trap by an evacuation unit such as a syringe or a vacuum pump.

  Patent Document 5 discloses a defoaming device that removes bubbles from the degassing tube by increasing the pressure inside the tube more than the pressure outside the tube when a liquid containing bubbles is passed through the degassing tube. Has been. In Patent Document 5, the inner pressure of the outflow side infusion tube is made smaller than that of the inflow side infusion tube, or the outflow side infusion tube is squeezed with a squeezing device to achieve an increase in the pressure in the tube. However, this method is not suitable for removing non-fine bubbles.

JP 2001-87601 A JP 2012-161723 A JP-A 62-42708 JP 2001-314701 A JP 60-48104 A

"Degassing mobile phase 5. Degassing method 5-4) Vacuum degassing using gas-liquid separation membrane", Shimadzu Corporation, [Search on March 17, 2016], Internet <URL: http: / /www.an.shimadzu.co.jp/hplc/support/lib/lctalk/s5/054.htm> "Degassing of mobile phase 5. Degassing method 5-6) Other than degassing method", Shimadzu Corporation, [Search March 17, 2016], Internet <URL: http: //www.an.shimadzu. co.jp/hplc/support/lib/lctalk/s5/056.htm>

  In the above-described conventional dissolved gas removing device, in order to remove more bubbles in the liquid, the degassing tube is lengthened and / or narrowed to extend the liquid degassing tube passage time. However, this method requires a degassing tube of 10 to 20 m to remove bubbles, which is not practical. On the other hand, in the conventional bubble removing device, the bubble trap needs to be provided with an exhaust means for removing the trapped bubbles, and the device is complicated. Further, when both the dissolved gas removing device and the bubble removing device are installed, there is a problem that the device becomes large and expensive.

  This invention makes it a subject to provide the deaeration apparatus which enables the removal of the dissolved gas and bubble in a liquid with a simple structure.

That is, the present invention
A vacuum chamber and a deaeration tube housed in the vacuum chamber;
The degassing tube comprises a bubble trap;
The bubble trap comprises a wall made of a gas permeable material,
A deaeration device is provided.

  Moreover, this invention provides the deaeration method using the said deaeration apparatus.

  According to the degassing apparatus of the present invention, since a degassing tube and a bubble trap are provided in one decompression chamber, both removal of dissolved gas in the liquid and trapping and removal of bubbles are combined by one mechanism. Can be performed. Therefore, the degassing apparatus of the present invention has an advantage that the dissolved gas and bubbles in the liquid can be efficiently removed with a simple configuration.

2 illustrates an exemplary embodiment of the degassing device of the present invention. Sectional drawing of the connection part of a bubble trap in the deaeration apparatus of this invention.

  The present invention provides a degassing device, preferably an on-line degassing device for use in a liquid chromatograph or the like.

  The deaeration device of the present invention includes a decompression chamber and a deaeration tube accommodated in the decompression chamber. The degassing tube includes a bubble trap, and therefore, the depressurization chamber houses the degassing tube and the bubble trap. Within the vacuum chamber, the degassing tube and bubble trap are in fluid communication.

  The liquid introduced into the decompression chamber passes through the deaeration tube. While the liquid passes through the degassing tube, the gas dissolved in the liquid passes through the degassing tube and is removed to the chamber, while bubbles in the liquid are connected to the degassing tube. Trapped in a bubble trap. Since the bubble trap has a wall made of a gas permeable material, the trapped bubbles are gradually permeated through the gas permeable material and removed into the chamber in a decompressed chamber.

  The decompression chamber is made of a material having substantially no gas permeability, such as stainless steel or a highly airtight synthetic resin. In the degassing apparatus of the present invention, the pressure in the vacuum chamber during the degassing of the liquid is preferably 10 to 200 Torr, and more preferably 30 to 100 Torr. In a preferred embodiment, the decompression chamber is connected to a pump (such as a vacuum pump) for reducing the pressure in the chamber to the above range.

  The decompression chamber is provided with a flow path inlet and a flow path outlet for connecting an external flow path to a deaeration tube to be housed. Preferably, one flow path inlet and one outlet are provided for each deaeration tube in the chamber. The liquid to be degassed is introduced into the degassing tube from the outside of the chamber through the flow path inlet, passes through the degassing tube, and then flows out of the chamber through the flow path outlet.

  The deaeration tube is made of a gas permeable material that allows gas to pass but does not allow liquid to pass. The gas permeable material preferably has high gas permeability. Examples of the gas permeable material include organic polymer porous materials such as Polystyrene, Poly (isobutylene-isoprene) 982, Polyethylene, Poly (vinylidene fluoride-hexafluoropropylene), Polypropylene, Fluorinated ethylene-propylene copolymer, and Silicone rubber. A polymer can be illustrated. Among these, Polyethylene, Poly (vinylidene fluoride-hexafluoropropylene), Polypropylene, Fluorinated ethylene-propylene copolymer, and Silicone rubber are preferable, and Polypropylene, Fluorinated ethylene-propylene copolymer, and Silicone rubber are more preferable.

  Although the shape of the said deaeration tube is not specifically limited, It is preferable that it is circular tube shape. The length of the degassing tube is not particularly limited, and may be appropriately adjusted according to the flow rate of the liquid to be degassed or the pressure of the liquid feeding so that the dissolved gas in the liquid can be removed. It is about 1 m, more preferably about 20 to 60 cm. In the deaeration device of the present invention, the deaeration tube accommodated in the decompression chamber may be one or plural.

  The bubble trap, which is also called a gas-liquid separation tank or a defoaming chamber, is a component for capturing or further storing bubbles in the liquid by utilizing the property that the bubbles float in the liquid. In the degassing apparatus of the present invention, the bubble trap is connected to the flow path of the degassing tube in the decompression chamber. For example, the bubble trap can be connected upstream, downstream, or anywhere between the degassing tubes in the chamber.

  The bubble trap includes a wall made of a gas permeable material. Preferably, the bubble trap is composed of a gas permeable material. The gas permeable material preferably has high gas permeability. Examples of the gas permeable material include organic polymer porous materials such as Polystyrene, Poly (isobutylene-isoprene) 982, Polyethylene, Poly (vinylidene fluoride-hexafluoropropylene), Polypropylene, Fluorinated ethylene-propylene copolymer, and Silicone rubber. A polymer can be illustrated. Among these, Polyethylene, Poly (vinylidene fluoride-hexafluoropropylene), Polypropylene, Fluorinated ethylene-propylene copolymer, and Silicone rubber are preferable, and Polypropylene, Fluorinated ethylene-propylene copolymer, and Silicone rubber are more preferable. The gas permeable material constituting the bubble trap and the deaeration tube may be the same material or different materials.

  The shape of the bubble trap is not particularly limited, but is preferably a circular tube shape. If the bubble trap has a circular tube shape and its connection target (for example, a degassing tube or a liquid introduction flow path described later) is also a circular tube shape, the bubble trap needs to be connected without having to adjust the direction or angle. And can be easily connected. For example, if a bubble trap is installed in the direction in which the liquid is fed in the horizontal direction, the bubble can be captured.

  In a preferred embodiment of the degassing apparatus of the present invention, the degassing tube and the bubble trap have a circular tube shape. The inner diameter and the thickness of the degassing tube and the bubble trap tube are preferably within a range that can be used in an on-line degassing apparatus for general liquid chromatography, and more preferably, the inner diameter is 0.5 mm to 4.0 mm. A thickness of 0.25 mm to 2.0 mm can be exemplified.

  A flow path that is connected to the bubble trap and introduces the liquid is referred to as a liquid introduction flow path in the present specification. In addition, a channel that is connected to the bubble trap and causes the liquid to flow out is referred to as a liquid outflow channel in this specification. The form of the liquid introduction flow path and the liquid outflow flow path may be the flow path inlet or outlet of the above-described decompression chamber or the degassing tube, but may be another member. For example, the bubble trap may be directly connected downstream of the channel inlet or upstream of the channel outlet, may be directly connected to the degassing tube, or may be connected to the channel inlet, channel outlet or outlet. You may connect to the flow-path connection member which fluidly connects an air tube and a bubble trap. Preferably, the liquid introduction channel and the liquid outflow channel are the channel connection members.

  Examples of the channel inlet, the channel outlet, and the channel connecting member include a metal tube, a synthetic resin tube, a tube made of a gas permeable material, and more specifically, a stainless steel tube, a PEEK tube, PTFE ( Examples thereof include a Teflon (registered trademark) AF tube and a silicon rubber tube. From the viewpoint of ease of connection, stainless steel tubes, PEEK tubes, and Teflon (registered trademark) AF tubes are preferred.

  From the viewpoint of suppressing the pressure fluctuation of the liquid, it is preferable that the inner diameters of the liquid introduction channel and the liquid outflow channel are substantially the same. Depending on the type and flow rate of the liquid, if the pressure in the flow path is high and the connection between the liquid introduction flow path or the liquid outflow flow path and the bubble trap is disconnected, an engagement member for preventing detachment is used. May be.

  A spacer may be interposed between the bubble trap and the liquid introduction channel and / or the liquid outflow channel. By interposing the spacer, the height difference (for example, a step part) of the flow path in the bubble trap described later can be enlarged. The spacer preferably has a circular tube shape. The spacer may be made of a material that does not allow liquid to pass. For example, a PTFE synthetic resin (for example, Teflon (registered trademark) AF) is preferable.

  In the present invention, in the longitudinal direction when the bubble trap is placed on a horizontal plane, the position of the upper surface of the inner wall of the bubble trap is higher than that of the liquid introduction channel and the liquid outflow channel. Therefore, a difference in height is formed in the upper part of the channel inside and outside the bubble trap by connecting the liquid introduction channel and the liquid outflow channel to the bubble trap. The height difference may be formed by gradually changing the height, but it is preferable to form a stepped portion whose height changes abruptly. As a result of the difference in height, a liquid linear velocity difference is generated in the bubble trap, and bubbles in the liquid are efficiently captured. Specifically, step-by-step, first, when a liquid containing bubbles enters the bubble trap, the bubbles move to the upper part of the flow path (for example, a stepped portion) due to the property that the bubbles rise in the liquid. Next, since the linear velocity of the liquid near the inner wall of the bubble trap is slower than the linear velocity of the liquid near the central axis of the bubble trap, the bubbles in the stepped portion are trapped in the stepped portion without flowing out of the bubble trap. The Since the bubble trap has the wall of the gas permeable material, the trapped bubble gradually permeates the wall surface, is taken out to the decompression space in the decompression chamber, and is exhausted through the vacuum channel. Thereby, bubbles are removed from the liquid.

  In one embodiment, the liquid introduction channel, the liquid outflow channel, and the bubble trap are separate tubes. At this time, the inner diameter B of the bubble trap tube is larger than the inner diameter A of the tube of the liquid introduction channel and / or the liquid outflow channel. Preferably, the inner diameter B is larger than the outer diameters of the tubes of the liquid introduction channel and the liquid outflow channel. When these tubes are connected, the stepped portion is formed in the bubble trap.

  The ratio of the inner diameter A of the liquid introduction channel and / or the liquid outlet channel to the inner diameter B of the bubble trap is preferably 1.1 ≦ B / A ≦ 10.0, more preferably 1.5 ≦ B / A ≦ 8.0, and more preferably 2.0 ≦ B / A ≦ 6.0. If the inner diameter ratio B / A is smaller than 1.1, there is a case where bubbles cannot be trapped because the step between the liquid introduction channel and the bubble trap is small. On the other hand, if the inner diameter ratio B / A is greater than 10.0, the capacity of the bubble trap increases, so that the liquid is excessively concentrated, which may affect measurement results such as liquid chromatography. Further, when the inner diameter ratio B / A is large, an operation for filling the flow path of the apparatus of the present invention such as an operation for filling the flow path with the eluent before starting measurement by liquid chromatography (initial priming). The liquid may not be filled in the bubble trap (bubbles may be mixed in).

  Alternatively, the bubble trap may be a tube formed integrally with the deaeration tube. In one embodiment, the inner diameter of the portion that contacts the bubble trap is larger than the inner diameter of the degassing tube, and the bubble trap has the above-described height difference (for example, a stepped portion). For example, the bubble trap portion is a region protruding upward from the outer wall of the deaeration tube. Further, for example, the bubble trap portion is a recessed region provided in the upper portion of the inner wall of the deaeration tube. In another embodiment, the bubble trap portion and the deaeration tube have substantially the same inner diameter, but the position of the upper surface of the inner wall is higher in the bubble trap portion, and the step portion is formed. . For example, in the bubble trap portion, the upper portion of the inner wall of the tube is depressed, while the lower portion of the inner wall of the tube protrudes, so that the inner diameter thereof is substantially the same as that of the deaeration tube.

  In the deaeration device of the present invention, the height difference (for example, the stepped portion) (the difference between the position of the upper surface of the inner wall of the bubble trap and the position of the upper surface of the inner wall of the liquid introduction channel and / or the liquid outflow channel) is Preferably, it is 5 to 450% of the inner diameter of the liquid introduction channel and / or the liquid outflow channel, more preferably 25 to 350%, and still more preferably 150 to 250%.

  In the degassing apparatus of the present invention, the length of the bubble trap (distance in contact with the liquid) is appropriately adjusted according to the flow rate of the liquid to be degassed and the pressure of the liquid feeding so that the bubbles in the liquid can be trapped. do it. For example, when the liquid flow rate is in the range of 0.01 to 10 mL / min, the length of the bubble trap is preferably 10 mm to 70 mm, more preferably 15 mm to 60 mm, and even more preferably 20 mm to 50 mm. Further, the number of bubble traps connected to one deaeration tube is not limited to one, and a plurality of bubble traps may be installed according to the size and amount of bubbles.

  In a preferred embodiment, the degassing apparatus of the present invention is used as an online degassing apparatus for liquid chromatography. Preferably, the liquid degassed by the degassing apparatus of the present invention is an eluent for liquid chromatography.

  The aspects of the present invention will be described below in more detail with reference to the drawings. However, the embodiments of the present invention shown in the drawings are merely examples of the present invention, and the present invention is limited only to these embodiments. It is not something. It goes without saying that the present invention encompasses various improvements and modifications made by those skilled in the art within the scope of the claims in addition to those directly shown by the described embodiments.

  FIG. 1 shows a schematic diagram of an exemplary embodiment of the degassing apparatus of the present invention. The deaeration device 1 according to this embodiment includes a box-shaped decompression chamber 2 that can be sealed, a vacuum channel 10 having one end connected to the decompression chamber 2, and a vacuum pump 11 provided on the vacuum channel 10. And a pressure sensor 12 connected to the vacuum flow path 10 between the decompression chamber 2 and the vacuum pump 11. The chamber lid portion 20 constituting one wall surface of the decompression chamber 2 includes a passage inlet 21 and a passage outlet 22 for connecting the passage inside the decompression chamber 2 and the outside passage. A bubble trap 3 made of a gas permeable material and a degassing tube 4 made of a gas permeable material are both housed in the decompression chamber 2. Inside the decompression chamber 2, the deaeration tube and the bubble trap are connected by a flow path connection part 23. On the liquid inflow side of the bubble trap 3, the flow channel inlet 21 and the bubble trap 3 are connected in this order from the upstream to the downstream of the flow channel. On the other hand, on the liquid outflow side of the bubble trap 3, the bubble trap 3 and the flow path connection portion 23 are connected in this order from the upstream to the downstream of the flow path. One end of the deaeration tube 4 is connected to the flow path connection portion 23. The other end of the deaeration tube 4 is connected to the flow path outlet 22. The state of the deaeration tube 4 in the decompression chamber 2 is preferably a state in which a plurality of loops are wound in a loop shape as shown in FIG. 1, but is not limited thereto.

  Outside the decompression chamber 2, a liquid storage container 30 in which liquid is stored is connected to the flow path inlet 21 via the flow path pipe 5. On the other hand, a liquid feed pump 31 is connected to the channel outlet 22 via the channel pipe 6. In other words, the channel pipe 5, the bubble trap 3, the deaeration tube 4, and the channel pipe 6 are connected via the channel inlet 21, the channel outlet 22, and the channel connecting portion 23.

  FIG. 2 shows an exemplary embodiment of the connecting part of the bubble trap 3 in FIG. The spacer tube 7 is disposed between the flow path inlet 21 and the bubble trap 3. In other words, on the liquid inflow side of the bubble trap 3, the flow path inlet 21, the spacer tube 7, and the bubbles are arranged in the order of the flow path inlet 21, the spacer tube 7, and the bubble trap 3 from the upstream to the downstream of the flow path. The trap 3 is connected. Due to the difference between the inner diameter A of the flow path inlet 21 and the inner diameter B of the bubble trap 3, a stepped portion 24 is provided at the boundary between them. On the other hand, on the liquid outflow side of the bubble trap 3, the spacer tube 8 is disposed between the bubble trap 3 and the flow path connection portion 23. In other words, the flow path connection portion 23, the spacer tube 8, and the bubble trap 3 are connected so that the flow path connection portion 23, the spacer tube 8, and the bubble trap 3 are arranged in this order from the downstream to the upstream of the flow path. .

  In this embodiment, the bubble trap 3 is made of silicone rubber, which is a gas permeable material, and has an outer diameter of 3.0 mm, an inner diameter of 2.0 mm, and a length of 30 mm. The deaeration tube 4 is made of silicone rubber, which is a gas permeable material, and has an outer diameter of 2.0 mm and an inner diameter of 1.0 mm. The channel inlet 21 and the channel outlet 22 are made of stainless steel and have an outer diameter of 2.58 mm (1/16 inch) and an inner diameter of 0.8 mm. The channel connecting portion 23 is made of stainless steel, and has an outer diameter of 2.58 mm (1/16 inch), an inner diameter of 0.8 mm, and a length of 15 mm. The spacer tubes 7 and 8 are Teflon (registered trademark) tubes having an outer diameter of 2.5 mm, an inner diameter of 1.5 mm, and a length of 10 mm.

  When the liquid feed pump 31 is driven at the time of measurement, the liquid in the liquid storage container 30 flows through the bubble pipe 3 and the deaeration tube 4 in the decompression chamber 2 of the deaeration device 1 through the flow path pipe 5. It flows into the liquid feed pump 31 through the flow path pipe 6. The space in the decompression chamber 2 is decompressed by the vacuum pump 11. Therefore, the dissolved gas in the liquid passing through the bubble trap 3 and the degassing tube 4 mainly passes through the wall surface of the degassing tube 4 and is taken out into the decompression space in the decompression chamber 2 and exhausted through the vacuum channel 10. Is done. Thereby, the dissolved gas is removed from the liquid.

  Bubbles in the liquid are captured by the bubble trap 3. Since the bubble trap 3 has the wall of the gas permeable material, the trapped bubbles gradually permeate the wall surface and are taken out into the decompression space in the decompression chamber 2 and exhausted through the vacuum channel 10. Thereby, bubbles are removed from the eluent.

  In the present embodiment, the bubble trap 3 is arranged upstream of the deaeration tube 4, but the bubble trap 3 may be arranged downstream or midway of the deaeration tube 4 within the range accommodated in the decompression chamber 2. Furthermore, a plurality of bubble traps 3 and deaeration tubes 4 may be arranged in the decompression chamber 2. As a modification of the present embodiment, for example, the bubble trap 3 a may be arranged upstream of the deaeration tube 4 and the bubble trap 3 b may be arranged downstream of the deaeration tube 4.

  Further, the bubble trap 3 may be disposed in the middle of the deaeration tube 4 as long as it is accommodated in the decompression chamber 2. As a modification, for example, the bubble trap 3 may be disposed between the deaeration tube 4a and the deaeration tube 4b.

DESCRIPTION OF SYMBOLS 1 Deaeration device 2 Depressurization chamber 3 Bubble trap 4 Deaeration tube 5 Channel piping 6 Channel piping 7 Spacer tube 8 Spacer tube 10 Vacuum channel 11 Vacuum pump 12 Pressure sensor 20 Chamber lid 21 Channel inlet 22 Channel outlet 23 Flow path connection part 24 Step part 30 Liquid storage container 31 Liquid feed pump

Claims (5)

A vacuum chamber and a deaeration tube housed in the vacuum chamber;
The degassing tube comprises a bubble trap;
The bubble trap comprises a wall made of a gas permeable material,
Deaeration device.   The bubble trap is a tube connected to a liquid introduction channel and a liquid outflow channel, and the inner diameter of the tube of the bubble trap is larger than the inner diameters of the liquid introduction channel and the liquid outflow channel. the method of.   The method according to claim 2, wherein 1.1 ≦ B / A ≦ 10.0, where A is an inner diameter of the liquid introduction channel and the liquid outflow channel, and B is an inner diameter of the bubble trap tube.   The degassing apparatus according to any one of claims 1 to 3, which is used for degassing an eluent for liquid chromatography.   The deaeration method using the deaeration apparatus of any one of Claims 1-4.

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