Fine particle sampling method and infection risk estimation method

Abstract

To provide a technique that can maintain the activity of collected fine particles while suppressing decrease in hydrophilicity of a rotating cylindrical electrode surface, in a method for sampling fine particles.SOLUTION: A fine particle sampling method uses a first electrode that is cylindrical and has both ends open in the axial direction, and a second electrode that extends in the axial direction of the first electrode and is disposed within the first electrode at a distance from the inner surface of the first electrode, to capture fine particles contained in the air flowing inside. When capturing the fine particles, a first liquid containing an amphipathic polymer is supplied into the first electrode to bring the amphipathic polymer into contact with the inner surface of the first electrode, and then a second liquid not containing the amphipathic polymer is supplied to capture the fine particles contained in the air flowing inside in the second liquid.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a particulate sampling method for sampling particulates and a method for estimating an infection risk. [Background technology]

[0002] Conventionally, there is known an apparatus and method for sampling fine particles in a gas using a device that utilizes the inertia or centrifugal force of the fine particles (see, for example, Patent Document 1). More specifically, Patent Document 1 discloses an apparatus and method for generating an electrostatic force using a rotating cylindrical electrode to which a liquid for collection is supplied, separating objects to be collected, such as fine particles, from the air and collecting them in the liquid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 153155 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional devices and methods, there is a concern that when collection is performed continuously for a long period of time, the hydrophilicity of the inner surface of the rotating cylindrical electrode decreases, causing a loss of fine particles due to adsorption to the surface of the rotating cylindrical electrode or deactivation due to denaturation, or that the collection liquid does not spread evenly inside the rotating cylindrical electrode but becomes droplet-like, causing the electric field between the electrode and the collection liquid to become locally large and causing insulation breakdown, resulting in a failure of dust collection and a decrease in collection performance. For this reason, in recent years, there has been a demand for suppressing the decrease in collection performance due to such factors.

[0005] Therefore, the present disclosure has been made in consideration of the above-mentioned problems in the conventional art, and its purpose is to provide a technology in a method for sampling microparticles that makes it possible to maintain the activity of the collected microparticles while suppressing a decrease in the hydrophilicity of the surface of a rotating cylindrical electrode. [Means for solving the problem]

[0006] The particle sampling method according to the present disclosure is a particle sampling method that uses a cylindrical first electrode having open ends in the axial direction and a second electrode that extends in the axial direction of the first electrode and is positioned within the first electrode at a distance from the inner surface of the first electrode to capture particle samples contained in the air flowing inside, in which a first liquid containing an amphipathic polymer is supplied into the first electrode to bring the amphipathic polymer into contact with the inner surface of the first electrode, and then a second liquid not containing the amphipathic polymer is supplied to capture particle samples contained in the air flowing inside in the second liquid.

[0007] In addition, the infection risk estimation method according to the present disclosure includes a quantification step of quantifying the infectivity titer of viruses contained in the second liquid collected by the above-mentioned particulate sampling method using an analytical device capable of measuring the infectivity titer, and an estimation step of estimating the infectivity titer concentration of viruses contained in the air that has circulated inside based on the infectivity titer quantified in the quantification step, the amount of air that has circulated inside, and the collection performance value defined in the particulate sampling method. Effect of the Invention

[0008] According to the present disclosure, in a method for sampling fine particles, it is possible to maintain the activity of collected fine particles and sample them while suppressing a decrease in the hydrophilicity of the surface of a rotating cylindrical electrode. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the appearance of a particulate sampling device according to an embodiment. [Diagram 2]FIG. 2 is a side view showing the appearance of the particulate sampling device of FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is an end view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a block diagram showing the configuration of the particle sampling device of FIG. [Figure 6] FIG. 6 is a flow chart showing an example of the operation of the particulate sampling device of FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line III-III in FIG. 1, and is an explanatory view for explaining an example of an operation performed by the particle sampling device in FIG. [Figure 8] FIG. 8 is an end view taken along line IV-IV when the first liquid or the second liquid is supplied to the particulate sampling device of FIG. [Figure 9] FIG. 9 is a flow diagram for estimating the infection risk of a virus contained in the collection liquid collected by the series of operations in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] However, the particle sampling device and particle sampling method according to the present disclosure are not intended to be limited to the configurations shown in the embodiments or drawings described below, and also include configurations equivalent thereto.

[0012] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the scope of the claims. In addition, each figure is not necessarily a strict illustration. In each figure, substantially the same configuration is given the same reference numeral, and duplicated explanations may be omitted or simplified.

[0013] In the following, terms indicating the relationship between elements, such as parallel and perpendicular, terms indicating the shape of an element, such as cylindrical shape, and numerical ranges do not only indicate the strict meaning, but also include a substantially equivalent range, for example, a difference of about a few percent.

[0014] In the following figures, the X-axis and Y-axis are mutually perpendicular axes on a horizontal plane. The Z-axis is an axis perpendicular to the horizontal plane. On the Z-axis, the positive direction represents vertical upwards, and the negative direction represents vertical downwards.

[0015] (Embodiment 1) Fig. 1 is a perspective view showing the appearance of a particle sampling device 10 according to an embodiment. Fig. 2 is a side view showing the appearance of the particle sampling device 10 of Fig. 1. Fig. 3 is an internal view of the particle sampling device 10 of Fig. 1, and is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is an end view taken along line IV-IV in Fig. 1. The particle sampling device 10 according to an embodiment will be described with reference to Figs. 1 to 4.

[0016] As shown in Fig. 1 to Fig. 4, the particle sampling device 10 is a device that samples particles in a liquid. Specifically, the particle sampling device 10 is a device that samples particles in a liquid by collecting particles in a gas in the liquid 68 (described later). For example, the particles include fungi, bacteria, viruses, aerosols, and the like. The particle sampling device 10 includes a duct 12, a first bearing seal 14, a second bearing seal 16, a first flange member 18, a second flange member 20, a first electrode 22, a second electrode 24, a voltage application unit 26, a supply unit 28, a collection unit 30, and a drive unit 32. .

[0017] The particulate sampling device 10 is configured by surrounding a rotating first electrode 22 and a second electrode 24 disposed at the center of the first electrode 22 with a duct 12, a first flange member 18, and a second flange member 20. A gas such as air is passed through the inside of the particulate sampling device 10 in a direction that passes through the particulate sampling device 10 (the direction shown by the arrow A in FIG. 2). For example, air may be directly drawn into the particulate sampling device 10 by a pump (not shown) or the like, and the gas may be passed through the particulate sampling device 10. In addition, the particulate sampling device 10 may be installed in a device that has a flow of a gas such as air, such as an air conditioner, an air purifier, or a ventilation opening, and the air may be drawn into the particulate sampling device 10 for processing. In this way, by attaching the particulate sampling device 10 to a device that generates a gas flow, it is not necessary to incorporate a pump or the like for generating a gas flow into the particulate sampling device 10, and a device that is small, quiet, and has a low pressure loss can be easily realized. This allows the particulate sampling device 10 to be installed and incorporated in various places relatively freely. Each component of the particle sampling device 10 will be described below.

[0018] The duct 12 is cylindrical, and rotatably supports the first electrode 22 inside the duct 12. The duct 12 has a main body 42, a first support portion 44, and a second support portion 46. The main body 42, the first support portion 44, and the second support portion 46 are insulating.

[0019] The main body 42 is cylindrical, and one end and the other end in the axial direction of the main body 42 are open. The first support part 44 protrudes radially outward from one end of the main body 42 in the axial direction of the main body 42, and is formed integrally with the main body 42. The first support part 44 is recessed radially outward of the main body 42 and is substantially U-shaped (see FIG. 3). The first support part 44 is annular when viewed from the axial direction of the main body 42. A first bearing seal 14 is disposed inside the first support part 44. The first bearing seal 14 seals the gap between the first support part 44 and a first outer flange part 58 (described later) so that gas does not leak between the first support part 44 and a first outer flange part 58. The first support part 44 rotatably supports the first electrode 22 via the first bearing seal 14. The second support part 46 protrudes from the other end of the main body 42 in the axial direction outward in the radial direction of the main body 42 and is formed integrally with the main body 42. The second support part 46 is recessed outward in the radial direction of the main body 42 and is substantially U-shaped (see FIG. 3). The second support part 46 is annular when viewed from the axial direction of the main body 42. A second bearing seal 16 is disposed inside the second support part 46. The second bearing seal 16 seals the gap between the second support part 46 and a second outer flange part 60 (described later) so that gas does not leak between the second support part 46 and a second outer flange part 60. The second support part 46 rotatably supports the first electrode 22 via the second bearing seal 16.

[0020] The first flange member 18 is cylindrical, and is connected to the duct 12. The first flange member 18 has a main body 48 and a flange 50.

[0021] The main body 48 is cylindrical, and one and the other axial ends of the main body 48 are open. The flange 50 protrudes radially outward from one axial end of the main body 48, and is formed integrally with the main body 48. The flange 50 is annular when viewed from the axial direction of the main body 48. The other axial end of the main body 48 is connected to one axial end of the duct 12.

[0022] The second flange member 20 is cylindrical, and is connected to the duct 12. The second flange member 20 has a main body 52 and a flange .

[0023] The main body 52 is cylindrical, and one end and the other end in the axial direction of the main body 52 are open. One axial end of the main body 52 is connected to the other axial end of the duct 12. The flange 54 protrudes radially outward from the other axial end of the main body 52 and is formed integrally with the main body 52. ​​The flange 54 is annular when viewed from the axial direction of the main body 52.

[0024] The first electrode 22 is cylindrical, and both ends in the axial direction of the first electrode 22 are open. The first electrode 22 is connected to the ground via a second electric wire 76 (described later) or the like. The first electrode 22 has a main body 56, a first outer flange portion 58, a second outer flange portion 60, a first inner flange portion 62, and a second inner flange portion 64. For example, the main body 56, the first outer flange portion 58, the second outer flange portion 60, the first inner flange portion 62, and the second inner flange portion 64 are formed using stainless steel such as SUS (Steel Special Use Stainless).

[0025] The main body 56 is cylindrical, and one end and the other end in the axial direction of the main body 56 are open. The axial direction of the main body 56 is the direction in which the axis B of the main body 56 extends (X-axis direction). The main body 56 has external teeth (not shown) on the outer circumferential surface of the main body 56 that mesh with external teeth (not shown) of a gear 86 (described later). An inner surface 66 of the main body 56 is subjected to a hydrophilic treatment. The hydrophilic treatment here is a treatment for processing the inner surface 66 into a minute uneven shape. For example, the hydrophilic treatment is performed by plasma treatment. Also, for example, the hydrophilic treatment is performed by alkali treatment using potassium hydroxide (KOH). Also, an adhesion suppressing member that suppresses adhesion of fine particles is attached to the inner surface 66 of the main body 56. For example, the adhesion suppressing member is a blocking agent such as skim milk, BSA (Bovine Serum Albumin), and PEG (Polyethylene Glycol).

[0026] In this embodiment, which will be described in more detail later, when sampling is performed, the inner surface 66 of the first electrode 22 is hydrophilized using a first liquid 67 containing an amphiphilic polymer (described later), and then a second liquid 68 not containing an amphiphilic polymer is supplied into the electrode as a sampling solution (collection liquid). Therefore, the amphiphilic polymer contained in the first liquid 67 comes into contact with and adheres to the entire inner surface of the electrode, initializing the hydrophilic state of the inner surface of the electrode, and the microparticles are then sampled by the second liquid 68.

[0027] The first outer flange 58 protrudes radially outward from one end of the main body 56 in the axial direction of the main body 56 and is formed integrally with the main body 56. The first outer flange 58 is annular about the axis B of the main body 56. In other words, the first outer flange 58 is annular when viewed from the axial direction of the main body 56. The first outer flange 58 is disposed inward of the first bearing seal 14.

[0028] The second outer flange 60 protrudes radially outward from the other end of the main body 56 in the axial direction, and is formed integrally with the main body 56. The second outer flange 60 is annular about the axial center B of the main body 56. In other words, the second outer flange 60 is annular when viewed from the axial direction of the main body 56. The second outer flange 60 is disposed inside the second bearing seal 16.

[0029] The first inner flange portion 62 protrudes radially inward from one end portion of the main body 56 in the axial direction of the main body 56, and is formed integrally with the main body 56. The first inner flange portion 62 is annular about the axial center B of the main body 56. In other words, the first inner flange portion 62 is annular when viewed from the axial direction of the main body 56.

[0030] The second inner flange 64 protrudes radially inward from the other end of the main body 56 in the axial direction, and is formed integrally with the main body 56. The second inner flange 64 is annular around the axis B of the main body 56. In other words, the second inner flange 64 is annular when viewed from the axial direction of the main body 56.

[0031] The first electrode 22 is installed in a position in which the axis B of the main body 56 is parallel to the horizontal direction. The first electrode 22 is supported so as to be rotatable around the axis B of the main body 56 (see arrow C in FIG. 4). In other words, the first electrode 22 is supported so as to be rotatable on its own axis. That is, the first electrode 22 is a member that corresponds to the "rotating cylindrical electrode" in the claims.

[0032] The first electrode 22 stores the first liquid 67 or the second liquid 68 on the inner surface 66 of the main body 56. Specifically, the first electrode 22 stores the first liquid 67 or the second liquid 68 in a part of the inner surface 66 in the direction around the axis B of the main body 56 (see arrow D in FIG. 4). The stored first liquid 67 or the second liquid 68 is located below the axis B of the main body 56. Moreover, the first electrode 22 stores the first liquid 67 or the second liquid 68 in the part of the inner surface 66 along the axial direction of the main body 56. The first inner flange portion 62 holds the first liquid 67 or the second liquid 68 so that the first liquid 67 or the second liquid 68 stored in the part of the inner surface 66 of the main body 56 does not spill out from one end of the main body 56 in the axial direction. The second inner flange portion 64 holds the first liquid 67 or the second liquid 68 so that the first liquid 67 or the second liquid 68 held in a part of the inner surface 66 of the main body 56 does not spill out from the other end in the axial direction of the main body 56. In this way, the first electrode 22 stores the first liquid 67 or the second liquid 68 in a part of the inner surface 66 of the main body 56 so that the first liquid 67 or the second liquid 68 does not flow out to the outside of the main body 56. Within the main body 56, above the stored first liquid 67 or second liquid 68, a space 69 is formed penetrating the main body 56 in the axial direction.

[0033] The second electrode 24 is linear and extends in the axial direction of the body 56 of the first electrode 22. The second electrode 24 is inserted radially inside the body 56 of the first electrode 22 and is located inside the body 56. That is, the second electrode 24 protrudes outward from one end of the body 56 in the axial direction of the body 56 and protrudes outward from the other end of the body 56. The second electrode 24 is disposed at a distance from the inner surface 66 of the body 56 of the first electrode 22 and is disposed near the center of the first electrode 22. The second electrode 24 is disposed in the space 69. In this embodiment, the second electrode 24 is disposed in such a position that the axis of the second electrode 24 coincides with the axis B of the body 56 of the first electrode 22. For example, the second electrode 24 is formed of tungsten or the like.

[0034] The voltage application unit applies a voltage between the first electrode 22 and the second electrode 24. The voltage application unit has a first support 70, a second support 72, a first electric wire 74, and a second electric wire .

[0035] The first support 70 is fixed to the first flange member 18 and is located inside the first flange member 18. The first support 70 is connected to one end of the second electrode 24 in the axial direction and supports the second electrode 24. The second support 72 is fixed to the second flange member 20 and is located inside the second flange member 20. The second support 72 is connected to the other end of the second electrode 24 in the axial direction and supports the second electrode 24. The first support 70 and the second support 72 are conductive and electrically connected to the second electrode 24. The first electric wire 74 is electrically connected to the second electrode 24 via the second support 72. The second electric wire 76 is electrically connected to the first electrode 22 via a gear 86 or the like.

[0036] The voltage application unit 26 is capable of passing electricity of any magnitude and waveform through the first electrode 22 and the second electrode 24 installed near the center of the first electrode 22 via the first electric wire 74 and the second electric wire 76. In this way, the particulate sampling device 10 performs electrostatic collection of particulate matter. The structure of the second electrode 24 does not have to be linear, and it may be plate-like or needle-like, and there are no limitations on the structure or installation position as long as it is possible to form an uneven electric field. For example, the voltage application unit 26 may be realized by a power supply circuit including a converter, etc. Furthermore, for example, the voltage application unit 26 applies a DC voltage of 6 kV.

[0037] For example, the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24 so that the second electrode 24 side has a higher potential than the first electrode 22 side. This generates an electric field in the space 69 from the second electrode 24 toward the first electrode 22 (see arrow E in FIG. 3 and arrow E in FIG. 4).

[0038] The supply unit 28 supplies the first liquid 67 or the second liquid 68 into the first electrode 22, and causes the first liquid 67 or the second liquid 68 to accumulate in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. In other words, the supply unit 28 supplies the first liquid 67 or the second liquid 68 into the first electrode 22 in order to cause the first liquid 67 or the second liquid 68 to accumulate in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. In this manner, the first liquid 67 or the second liquid 68 supplied by the supply unit 28 is accumulated on the inner surface 66 of the body 56 of the first electrode 22. The supply unit 28 has a tank 78, a tank 79, and an injection unit 80. The liquid may be supplied by this supply unit 28 from the opening side of the first electrode 22 (one end side in the axial direction of the main body 42) as shown in Figure 3, or a hole may be made in part of the side of the first electrode 22 and the liquid may be supplied from the opening.

[0039] The tank 79 holds the first liquid 67 to be supplied into the first electrode 22. The first liquid 67 held in the tank 79 is discharged from an injection part 80 by a pump (not shown) or the like, and is supplied into the body 56 of the first electrode 22. In this manner, the tank 79 is provided for storing in advance the first liquid 67 for the hydrophilic treatment of the inner surface 66 of the first electrode 22, and the first liquid 67 is supplied into the inside of the first electrode 22 through the injection part 80. Note that, although shown in an isolated state in FIG. 3 and the like, the tank 79 is provided with a similar structure to the tank 78.

[0040] The tank 78 holds the second liquid 68 to be supplied into the first electrode 22. The second liquid 68 held in the tank 78 is discharged from the injection section 80 by a pump (not shown) or the like, and is supplied into the main body 56 of the first electrode 22. In this manner, the tank 78 is provided for storing the second liquid 68, such as a collection liquid for influenza virus sensing, in advance, and the second liquid 68 is supplied into the first electrode 22 through the injection section 80. The supply of the second liquid 68 is not limited to once per sampling, and may be supplied multiple times depending on the amount of liquid in the first electrode 22, or in combination with collection before starting sampling.

[0041] In this embodiment, the supply unit 28 supplies a liquid for hydrophilic treatment of the inner surface 66 of the first electrode 22 as a first liquid 67, collects the particles adhering to the inner surface 66 of the first electrode 22, and supplies a liquid for analysis of the collected particles as a second liquid 68.

[0042] The first liquid 67 is a liquid containing an amphipathic substance such as an amphipathic polymer. The amphipathic polymer is a polymer having a hydrophilic site and a hydrophobic site in the polymer. For example, PEG (Polyethylene Glycol) or dextran is used as the hydrophilic site, and PLA (Polylactic Acid) or PLGA (Polylactic co Glycolic Acid) is used as the hydrophobic site. In this case, the amount of the substance contained in the liquid such as pure water is preferably at least 0.1 weight percent (wt%) or more. If the amount of the substance is less than 0.1 weight percent, there is a concern that the hydrophilicity required for efficient collection by the second liquid 68 cannot be maintained. By supplying the second liquid 68 containing this amphipathic polymer and rotating the first electrode 22, the hydrophobic site of the amphipathic polymer is adsorbed on the surface of the inner surface 66 of the first electrode 22, and the hydrophilic site is oriented so as to be exposed to the second liquid 68 side. This increases the affinity at the interface between the inner surface 66 of the first electrode 22 and the second liquid 68, making it possible to hydrophilize the surface of the inner surface 66 of the first electrode 22. In other words, the hydrophilic state of the inner surface 66 of the first electrode 22 can be maintained. can be done.

[0043] The liquid for analyzing the microparticles used as the second liquid 68 means a liquid used for analysis, a liquid that maintains the activity of the target substance contained in the microparticles for analysis, a liquid that imparts a label or the like to the target substance contained in the microparticles for analysis, a liquid that protects the target substance contained in the microparticles for analysis, or any combination thereof. For example, when the target substance is an influenza virus, the second liquid 68 may be physiological saline, PBS (Phosphate-Buffered Saline) buffer, EDTA (Ethylene Diamine The second liquid 68 may be a liquid for dissolving and preserving the virus, such as a tetraacetic acid (TEA) buffer solution or a bicarbonate buffer solution, or a liquid containing a substance that specifically binds to the virus and emits magnetism or fluorescence. The second liquid 68 may not be a liquid for analyzing the microparticles, and may be, for example, pure water. However, the substance contained in this liquid does not weaken the biological properties of the target substance, such as the infectivity or antigenicity.

[0044] The target substance is not limited to influenza viruses. For example, the target substance may be other viruses or a living organism other than a virus (e.g., bacteria). The target substance does not have to be a living organism, and may be an environmental pollutant or an allergen. This can prevent the target substance, such as influenza viruses, from being adsorbed onto the inner surface 66 of the first electrode 22, and can reduce the loss of the target substance in the second liquid 68.

[0045] Although details will be described later, in this embodiment, when sampling a target substance, a first liquid 67 is supplied for each sampling to hydrophilize the inner surface 66 of the first electrode 22, and then a second liquid 68 is supplied to sample the target substance.

[0046] By initializing the hydrophilic state of the inner surface 66 of the first electrode 22 with the first liquid 67, the second liquid 68 thereafter spreads uniformly within the first electrode 22, and the distance between the central second electrode 24 and the second liquid 68 can be kept constant with good reproducibility. This suppresses dielectric breakdown between the second liquid 68 and the second electrode 24, and enables normal discharge of the second electrode 24 (described later) and the formation of a desired electric field between the second electrode 24 and the first electrode 22, enabling normal sampling. Here, initialization of the hydrophilic state refers to restoring the surface state of the inner surface 66 of the first electrode 22 that has deteriorated due to the sampling operation of the target substance.

[0047] The recovery unit 30 recovers the first liquid 67 or the second liquid 68 stored in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. The recovery unit 30 has a tank 82, a tank 83, and an extraction unit 84. The first liquid 67 or the second liquid 68 stored in a part of the inner surface 66 in the direction around the axis B of the first electrode 22 is sucked from the extraction unit 84 by a pump (not shown) or the like, and is held and recovered in the tank 82 or the tank 83.

[0048] The tank 82 is a container for storing the first liquid 67 recovered as waste liquid, and is connected to the extraction unit 84. The first liquid 67 supplied for hydrophilization is sucked through the extraction unit 84 and held in the tank 82 after performing the hydrophilization treatment operation on the inner surface 66 of the first electrode 22. In addition, the second liquid 68 supplied for the purpose of cleaning, such as co-washing, to the inner surface 66 of the first electrode 22 is also sucked through the extraction unit 84 and held in the tank 82 after performing the cleaning operation.

[0049] The tank 83 is a container for storing the second liquid 68 collected as the collection liquid, and is connected to the extraction unit 84 in a manner that switches it with the tank 82. Note that, although the tank 83 is shown in an isolated state in FIG. 3 and the like, it is installed with a similar structure to the tank 82. The second liquid 68 for analyzing the fine particles is sucked through the extraction unit 84 and held in the tank 83 after a processing operation for collecting the fine particles and recovering them in the second liquid 68 is performed.

[0050] 3, each liquid may be collected by the collection unit 30 from the opening side of the first electrode 22 (the other end side in the axial direction of the main body 42), or a hole may be formed in a part of the side surface of the first electrode 22 and the liquid may be collected from the opening. Note that the second liquid 68 does not necessarily have to be collected in one supply or one sampling, and may be collected after multiple supply and sampling.

[0051] The driving unit 32 rotates the first electrode 22 around a rotation axis that extends in the axial direction of the body 56 of the first electrode 22 and passes through the first electrode 22. In this embodiment, the rotation axis coincides with the axis B of the body 56. That is, in this embodiment, the driving unit 32 rotates the first electrode 22 around the axis B of the body 56 of the first electrode 22. The driving unit 32 has a gear 86 and a motor 88 for rotating the gear 86. The gear 86 has external teeth (not shown) that mesh with external teeth (not shown) of the first electrode 22. The gear 86 is rotated by the motor 88 (see arrow F in FIG. 4), so that the first electrode 22 rotates around the axis B of the body 56 (see arrow C in FIG. 4). In this manner, the first electrode 22 is rotated by the gear 86 driven by the motor 88.

[0052] In addition, gas outside the particle sampling device 10 may pass through the inside of the second flange member 20, pass through the inside of the main body 56 of the first electrode 22, and be released to the outside of the particle sampling device 10 from the first flange member 18.

[0053] Fig. 5 is a block diagram showing the functional configuration of the particle sampling device 10. The functional configuration of the particle sampling device 10 will be described with reference to Fig. 5.

[0054] As shown in FIG. 5, the particle sampling device 10 further includes a control unit 90.

[0055] The control unit 90 is electrically connected to the voltage application unit 26, the supply unit 28, the collection unit 30, and the drive unit 32. The control unit 90 controls the voltage application unit 26, the supply unit 28, the collection unit 30, and the drive unit 32. For example, the control unit 90 is realized by a microcomputer, but may also be realized by a processor or a dedicated circuit.

[0056] Next, the operation of the particle sampling device 10 configured as above will be described. FIG. 6 is a flow chart showing an example of the operation of the particle sampling device 10. FIG. 7 is an explanatory diagram for explaining an example of the operation of the particle sampling device 10, showing the movement of the virus inside the particle sampling device 10 until the virus is actually collected. With reference to FIG. 6 and FIG. 7, an example of the operation of the particle sampling device 10 including the flow of capturing influenza viruses 1, collecting influenza viruses 1 in liquid, and collecting the first liquid 67 or the second liquid 68 in this embodiment will be described. Here, in order to collect influenza viruses 1, which are thought to be airbornely transmitted, as a liquid sample that can be analyzed by a sensor or the like, collection in liquid is performed by the particle sampling device 10.

[0057] 6, first, the supply unit 28 supplies a first liquid 67 as a hydrophilic treatment liquid into the first electrode 22, and causes the first liquid 67 to accumulate in a part of the inner surface 66 in the direction around the axis B of the first electrode 22 (step S1: first supply step). For example, the user operates an arbitrary operation button (illustrated) or the like to operate the supply unit 28, and the first liquid 67 is supplied into the body 56 of the first electrode 22.

[0058] When step S1 is performed, as shown in FIG. 7, a first liquid 67 is supplied into the body 56 of the first electrode 22, and a part of the inner surface 66 in the direction around the axis B of the body 56 of the first electrode 22 is filled with the first liquid 67. A first liquid 67 is stored.

[0059] The driving unit 32 rotates the first electrode 22 around the axis B (step S2: first driving step). For example, the user may operate an arbitrary operation button (illustrated) or the like to operate the driving unit 32 and rotate the first electrode 22.

[0060] As shown in FIG. 7, the first electrode 22 rotates around the axis B in a state where the first liquid 67 is stored in a part of the inner surface 66 in the direction around the axis B of the main body 56 of the first electrode 22. In other words, the first electrode 22 rotates around the axis B in a state where the first liquid 67 is stored below the axis B so that the first liquid 67 does not flow out of the main body 56. As a result, the inner surface 66 of the first electrode 22 contacts the stored first liquid 67 sequentially. As a result, the amphiphilic polymer contained in the first liquid 67 contacts and adheres to the surface of the inner surface 66 of the first electrode 22, making the inner surface 66 of the first electrode 22 hydrophilic. In other words, the hydrophilic state of the inner surface 66 of the first electrode 22 is initialized and maintained. As a result, it is possible to suppress the adsorption of the target substance such as the influenza virus 1 onto the inner surface 66 of the first electrode 22, and the loss of the target substance captured by the second liquid 68 supplied thereafter is reduced. Furthermore, the second liquid 68 supplied thereafter spreads uniformly inside the first electrode 22, so that the distance between the central second electrode 24 and the second liquid 68 can be kept constant with good reproducibility. This suppresses dielectric breakdown between the second liquid 68 and the second electrode 24, and enables normal discharge of the second electrode 24 (described later) and the formation of a desired electric field between the second electrode 24 and the first electrode 22, enabling normal sampling.

[0061] Furthermore, by using the first liquid 67 containing an amphiphilic polymer as a hydrophilic treatment liquid, it becomes unnecessary to treat the electrodes each time a hydrophilic treatment such as a plasma treatment is performed.

[0062] Returning to Fig. 6, in step S2, the driving unit 32 is stopped, and the rotation of the first electrode 22 is stopped. Thereafter, the stored first liquid 67 is collected (step S3: first collection step). For example, in step S2, at an arbitrary timing after a certain period of operation, the first liquid 67 is collected into the collection unit 30 (tank 82) through the extraction unit 84. Also, for example, the user may operate an arbitrary operation button (illustrated) or the like to operate the collection unit 30 and collect the first liquid 67 stored in the main body 56 of the first electrode 22.

[0063] Next, the supply unit 28 supplies the second liquid 68 into the first electrode 22, and causes the second liquid 68 to accumulate in a part of the inner surface 66 in the direction around the axis B of the first electrode 22 (step S4: second supply step). For example, the user operates an arbitrary operation button (illustrated) or the like, which causes the supply unit 28 to operate, and the second liquid 68 is supplied into the body 56 of the first electrode 22.

[0064] As shown in Fig. 7, the second liquid 68 is supplied into the body 56 of the first electrode 22, and the second liquid 68 is stored in a part of the inner surface 66 in the direction around the axis B of the body 56 of the first electrode 22. Prior to step S4, a separate washing process is performed so that the residual liquid of the first liquid 67 containing the amphipathic polymer is not contained in the second liquid 68, thereby suppressing a decrease in the infectivity of the virus caused by the amphipathic polymer during analysis of the second liquid 68 that is the collection liquid. The washing process here refers to, for example, supplying the second liquid 68 to wash the inside of the first electrode 22, and after supplying the second liquid 68, rotating the first electrode 22 for a certain period of time, and then recovering the second liquid 68.

[0065] Next, a gas such as air is caused to flow through the inside of the particle sampling device 10 in a direction passing through the particle sampling device 10 (the direction shown by the arrow A in FIG. 7) (step S5). For example, air is directly drawn into the particle sampling device 10 by a pump (not shown) or the like, and the gas is caused to flow through the particle sampling device 10.

[0066] 6, the driving unit 32 rotates the first electrode 22 around the axis B (step S6: second driving step). For example, the user may operate an arbitrary operation button (illustrated) or the like to operate the driving unit 32 and rotate the first electrode 22.

[0067] 7, the first electrode 22 rotates about the axis B in a state in which the second liquid 68 is stored in a part of an inner surface 66 of the first electrode 22 in a direction around the axis B of the main body 56. In other words, the first electrode 22 rotates about the axis B in a state in which the second liquid 68 is stored below the axis B so that the second liquid 68 does not flow out to the outside of the main body 56. As a result, the inner surface 66 of the first electrode 22 sequentially comes into contact with the stored second liquid 68.

[0068] 6, voltage application unit 26 applies a voltage between first electrode 22 and second electrode 24 (step S7: voltage application step). For example, a user may operate an arbitrary operation button (illustrated) or the like to operate voltage application unit 26 and apply a voltage between first electrode 22 and second electrode 24.

[0069] As shown in Fig. 7, influenza viruses 1 in gas introduced into the inside of the particle sampling device 10 by an arbitrary air flow (see arrow A in Fig. 7) are first charged either positively or negatively by ions 2 released by the discharge of the second electrode 24 to which a high voltage is applied. Here, a case where influenza viruses 1 are positively charged will be described.

[0070] The influenza viruses 1 in an electrically charged state move along a trajectory 3 due to an electric field (see arrow E in FIG. 7) formed between the second electrode 24 and the first electrode 22, and are collected on the inner surface 66 of the first electrode 22. In this manner, the influenza viruses 1 adhere to the inner surface 66 of the first electrode 22 and are collected on the inner surface 66.

[0071] 7, the influenza viruses 1 collected on the inner surface 66 are collected by the second liquid 68 stored in the main body 56 of the first electrode 22 at any timing. Specifically, the influenza viruses 1 attached to the inner surface 66 of the main body 56 of the first electrode 22 come into contact with the stored second liquid 68, and are separated from the inner surface 66 and collected in the second liquid 68. The movement (rotation) of the first electrode 22 rotated by the motor 88 and the gear 86 makes it possible to wash away the entire surface of the inner surface 66 of the first electrode 22 with the accumulated (stored) second liquid 68.

[0072] In addition, when the inner surface 66 of the first electrode 22 has been hydrophilized, a voltage may be applied between the first electrode 22 and the second electrode 24 before rotating the first electrode 22 around the axis B, and the first electrode 22 may be rotated around the axis B with a voltage being applied between the first electrode 22 and the second electrode 24.

[0073] In step S7, after a certain period of time has elapsed, the voltage application unit 26 is stopped. Here, the certain period of time is a period of time that is preset for capturing the influenza viruses 1, and is set to, for example, 10 minutes. This certain period of time is also used to determine the amount of air flow that is used to estimate the infection risk.

[0074] Next, the driving unit 32 is stopped, and the rotation of the first electrode 22 is stopped (step S8).

[0075] Furthermore, the flow of gas such as air into the inside of the particle sampling device 10 is stopped (step S9: flow stopping step). For example, the operation of a pump (not shown) or the like is directly stopped.

[0076] Finally, the recovery unit 30 recovers the second liquid 68 stored in the first electrode 22 ( (Step S10: second recovery step). For example, at the timing when the voltage application in step S7 reaches a certain time, the second liquid 68 is recovered into the recovery section 30 (tank 83) through the extraction section 84. This makes it possible to obtain a liquid sample (second liquid 68) containing influenza viruses 1 separated from the gas. Also, for example, the user may operate any operation button (illustrated) or the like to operate the recovery section 30 and recover the second liquid 68 stored in the main body 56 of the first electrode 22.

[0077] As described above, the particle sampling device 10 according to this embodiment is capable of recovering influenza viruses 1 from the air into the second liquid 68 at a high concentration.

[0078] Furthermore, the particle sampling device 10 can accumulate particles in the second liquid 68 stored in the first electrode 22 without circulating the second liquid 68, so that it is easy to collect particles so that the concentration of particles in the second liquid 68 becomes high. Furthermore, the particle sampling device 10 does not require the provision of a device for circulating the second liquid 68, and is therefore a device that can easily achieve miniaturization and energy saving.

[0079] Furthermore, by containing an amphiphilic polymer in the first liquid 67, the inner surface 66 of the first electrode 22 can be kept hydrophilic at all times, which suppresses insulation breakdown caused by the subsequently supplied second liquid 68 coming into close contact with a part of the second electrode 24 on the central side, thereby enabling the device to be used safely.

[0080] Next, an infection risk estimation method performed using the second liquid 68 collected in step S10 will be described with reference to Fig. 9. Fig. 9 is a flow diagram for estimating the infection risk of viruses contained in the collection liquid (second liquid 68) collected by the series of operations in Fig. 6.

[0081] 9, in the infection risk estimation method, first, second liquid 68 containing influenza viruses 1, which are particles, is obtained as a liquid sample from tank 82 of particle sampling device 10 (step S21). For example, a user removes tank 82, and removes second liquid 68 from tank 82 to use it as a liquid sample.

[0082] Next, the liquid sample is set in an analyzer capable of measuring the infectivity of the virus (for example, an analyzer using cells for TCID50 evaluation, etc.), and the infectivity of the virus contained in the liquid sample is quantified. That is, the infectivity of the influenza virus 1 contained in the second liquid 68 collected by the above-mentioned microparticle sampling method is quantified (step S22: quantification step).

[0083] Then, based on the infectivity (infectivity of influenza virus 1) quantified in step S22, the amount of air flowing through the interior during the fixed period of time during which voltage was applied in step S7, and the collection performance value defined by the particulate sampling method, the infectivity concentration of influenza virus 1 contained in the air flowing through the interior is estimated (step S23: estimation step).

[0084] Finally, the estimated infectivity titer concentration of the influenza viruses 1 is notified to the user (step S24), allowing the user to grasp the status of the influenza viruses 1 in the space in which the particle sampling device 10 is installed.

[0085] As described above, the particle sampling device 10 according to this embodiment is a particle sampling device for sampling particles in a liquid, and includes a cylindrical first electrode 22 having both ends open in the axial direction, a second electrode 24 extending in the axial direction of the first electrode 22 and disposed within the first electrode 22 at an interval from the inner surface 66 of the first electrode 22, and a second electrode 24 disposed within the first electrode 22. The liquid supplying device includes a supplying unit 28 that supplies a liquid and accumulates a first liquid 67 or a second liquid 68 in a part of an inner surface 66 in a direction around the axis B of the first electrode 22, a voltage applying unit 26 that applies a voltage between the first electrode 22 and the second electrode 24, a driving unit 32 that rotates the first electrode 22 around a rotation axis that extends in the direction of the axis B of the first electrode 22 and passes through the first electrode 22, and a recovery unit 30 that recovers the accumulated first liquid 67 or the second liquid 68. The first liquid 67 is a liquid containing an amphipathic polymer, and the second liquid 68 is a liquid for analyzing the particles that does not contain an amphipathic polymer. When sampling the particles, the first liquid 67 is supplied to perform a surface treatment (hydrophilization treatment) of the inner surface 66 of the first electrode 22, and then the second liquid 68 is supplied to collect the particles.

[0086] According to this, the activity of the collected sample can be maintained and sampled while suppressing the decrease in hydrophilicity of the inner surface 66 of the first electrode 22. More specifically, since the first liquid 67 contains an amphipathic polymer, the affinity at the interface between the inner surface 66 of the first electrode 22 and the second liquid 68 is increased, and the surface of the inner surface 66 of the first electrode 22 can be hydrophilized. That is, the hydrophilized state of the inner surface 66 of the first electrode 22 can be maintained. Meanwhile, when the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24, an electric field is generated between the first electrode 22 and the second electrode 24, and the fine particles in the gas in the first electrode 22 adhere to the inner surface 66 of the first electrode 22. Since the inner surface 66 of the first electrode 22 is hydrophilized, the second liquid 68 supplied thereafter spreads uniformly within the first electrode 22. Furthermore, by the driving unit 32 rotating the first electrode 22, the inner surface 66 of the first electrode 22 sequentially comes into contact with the second liquid 68 that is uniformly spread and stored on a portion of the inner surface 66 in the direction around the axis B of the main body 56, and the fine particles adhering to the inner surface 66 are accumulated in the second liquid 68. The recovery unit 30 recovers the accumulated second liquid 68, thereby obtaining the second liquid 68 in which the fine particles have accumulated. At this time, since the second liquid 68 does not contain an amphipathic polymer, it is possible to suppress a decrease in the infectivity of the virus and a negative effect on the subsequent quantitative analysis.

[0087] In this way, the fine particles guided into the fine particle sampling device 10 are deposited on the inner surface 66 of the first electrode 22 by electrostatic precipitator, and then accumulated in the second liquid 68 by the rotation of the first electrode 22, so that the fine particles can be sampled efficiently. Also, since there is no need to circulate the second liquid 68, the amount of the second liquid 68 can be reduced. By accumulating the fine particles in a small amount of the second liquid 68, the concentration of the fine particles in the second liquid 68 can be easily increased, and the fine particles can be sampled efficiently.

[0088] In the particle sampling device 10 according to this embodiment, the inner surface 66 of the first electrode 22 is subjected to a hydrophilic treatment with the first liquid 67.

[0089] According to this, when the fine particles adhering to the inner surface 66 come into contact with the stored second liquid 68, they are easily detached from the inner surface 66. Therefore, loss when collecting the fine particles on the inner surface 66 can be suppressed, and the fine particles can be sampled more efficiently.

[0090] In the particle sampling device 10 according to this embodiment, an adhesion suppression member for suppressing adhesion of particles is attached to the inner surface 66 of the first electrode 22.

[0091] According to this, when the fine particles adhering to the inner surface 66 come into contact with the stored second liquid 68, they are easily detached from the inner surface 66. Therefore, loss when collecting the fine particles on the inner surface 66 can be suppressed, and the fine particles can be sampled more efficiently.

[0092] In the particle sampling device 10 according to the present embodiment, the supply unit 28 supplies, as the second liquid 68, a liquid for analyzing particles.

[0093] This allows the target substance contained in the particles to be easily extracted. In addition, by selecting an appropriate second liquid 68 according to the purpose or application, it is possible to implement an appropriate detection protocol and suppress damage to the sample.

[0094] Furthermore, in the particle sampling device 10 of this embodiment, the amphipathic polymer contained in the first liquid 67 has a hydrophilic portion and a hydrophobic portion, the hydrophilic portion being composed of PEG (Polyethylene Glycol) or dextran, and the hydrophobic portion being composed of PLA (Polylactic Acid) or PLGA (Polylactic co Glycolic Acid).

[0095] According to this, by attaching the amphiphilic polymer to the inner surface 66 of the first electrode 22, the surface of the inner surface 66 of the first electrode 22 can be reliably made hydrophilic.

[0096] Moreover, in the particle sampling device 10 according to the present embodiment, the first liquid 67 is a liquid containing 0.1 weight percent or more of the amphiphilic polymer.

[0097] This allows the surface of the inner surface 66 of the first electrode 22 to be in a hydrophilic state that allows the target substance and the like contained in the fine particles to be efficiently captured.

[0098] Furthermore, in the particle sampling device 10 of this embodiment, the second liquid 68 (collected liquid) obtained by the recovery section 30 may be subjected to an infectivity analysis using cells by TCID50 evaluation or the like to quantify the concentration of viruses having an infectivity, and the amount of viruses present in the space may be quantified based on the obtained quantification results, the amount of air processed by the particle sampling device 10, and the collection efficiency specific to the device.

[0099] This makes it possible to estimate the concentration of viruses contained in the space, and by comparing it with the virus concentration in the space during a known infectious disease epidemic, it is possible to quantify the infection risk in the sampled space. Furthermore, quantification using this analysis device may be performed at a different location after collecting the second liquid 68, or may be performed in-line by connecting it to the particle sampling device 10.

[0100] Furthermore, in the particle sampling device 10 of this embodiment, in a space in which a device used as a virus infection countermeasure, such as a UV generator or an ozone generator, is installed, viruses in the space are sampled before and after operation of the virus infection countermeasure device, and the infectivity of the virus is evaluated, making it possible to visualize the reduction in virus infectivity by operating the virus infection countermeasure device, and thus the effectiveness of the virus infection countermeasure device.

[0101] Furthermore, in the particle sampling device 10 of this embodiment, by supplying a first liquid 67 containing an amphiphilic polymer, the decrease in hydrophilicity of the inner surface 66 is initialized each time sampling is performed, and the loss rate of the target substance during sampling by the second liquid 68 becomes constant, making it possible to suppress variation from sampling to sampling.

[0102] The particle sampling method according to the present embodiment uses a cylindrical first electrode 22 that is open at both ends in the axial direction and has a hydrophilized inner surface, and a second electrode 24 that extends in the axial direction of the first electrode 22 and is disposed within the first electrode 22 at a distance from an inner surface 66 of the first electrode 22 to capture particles (e.g., influenza viruses 1) contained in the air flowing inside. When capturing the particles, a first liquid 67 containing an amphipathic polymer is supplied into the first electrode 22 to bring the amphipathic polymer into contact with the inner surface 66 of the first electrode 22, and then a second liquid 68 not containing the amphipathic polymer is supplied to capture the particles contained in the air flowing inside. The particles are collected in the second liquid 68.

[0103] Specifically, the method includes a first supply step (step S1) of supplying a first liquid 67 containing an amphiphilic polymer into the first electrode 22 and storing the first liquid 67 in a part of the inner surface 66 in the direction around the axis of the first electrode 22, a first drive step (step S2) of rotating the first electrode 22, with the first liquid 67 stored in a part of the inner surface 66, around a rotation axis that extends in the axial direction of the first electrode 22 and passes through the first electrode 22, a first recovery step (step S3) of recovering the first liquid 67 stored in the part of the inner surface 66, and a second liquid 68 for particle analysis in the first electrode 22 after the first recovery step. the second liquid 68 being stored in a portion of the inner surface 66 in a direction around the axis of the first electrode 22; a second driving step (step S5) of rotating the first electrode 22, which has the second liquid 68 stored in a portion of the inner surface 66, around a rotation axis that extends in the axial direction of the first electrode 22 and passes through the first electrode 22; a voltage application step (step S6) of applying a voltage between the first electrode 22 and the second electrode 24, which have the second liquid 68 stored in a portion of the inner surface 66; and a second recovery step (step S7) of recovering the second liquid 68 stored in the portion of the inner surface 66.

[0104] According to this, the activity of the collected sample can be maintained while suppressing the decrease in hydrophilicity of the inner surface 66 of the first electrode 22, and the collected sample can be sampled. More specifically, the inner surface 66 of the first electrode 22 is successively brought into contact with the stored first liquid 67 by the rotation of the first electrode 22 in the first driving step (step S2), so that the amphiphilic polymer contained in the first liquid 67 comes into contact with and adheres to the surface of the inner surface 66 of the first electrode 22, thereby making the inner surface 66 of the first electrode 22 hydrophilic. Then, in the first collecting step (step S3), the first liquid 67 is discharged as waste liquid, and in the second supplying step (step S4), a second liquid 68 is newly supplied into the first electrode 22 for analyzing the particles. Then, air containing the particles is circulated inside, and the particles are collected using the second liquid 68 by applying a voltage between the electrodes in the voltage applying step (step S7). That is, the particles adhering to the inner surface 66 of the first electrode 22 are accumulated in the second liquid 68. Even in this case, adsorption of the attached microparticles is suppressed by the amphipathic polymer on the surface of the inner surface 66 of the first electrode 22. On the other hand, the absence of an amphipathic polymer in the second liquid 68 suppresses a decrease in activity of the accumulated microparticles. Then, in a second recovery step (step S10), the stored second liquid 68 is recovered, thereby obtaining second liquid 68 in which the microparticles have accumulated.

[0105] Furthermore, since the decrease in hydrophilicity of the inner surface 66 of the first electrode 22 is initialized each time sampling is performed, the rate of loss of the target substance during sampling by the second liquid 68 becomes constant, making it possible to suppress variation from sampling to sampling.

[0106] In addition, in the particle sampling method of this embodiment, the second supply step (step S4) may be performed at regular time intervals, and while keeping the amount of stored second liquid 68 constant, the second drive step (step S6) and voltage application step (step S7) may be performed, and the stored second liquid 68 may be recovered in the second recovery step (step S10).

[0107] In this way, the amount of stored second liquid 68 becomes constant, which suppresses the variation in concentration resulting from the amount of stored second liquid 68 between each sampling, and the sampling accuracy can be improved. Similarly, by keeping the amount of stored second liquid 68 constant, it becomes possible to keep the distance between the second liquid 68 and the second electrode 24 constant, and the variation between and during each sampling of the electric field between the second liquid 68 and the second electrode 24 generated when a voltage is applied can be suppressed, which improves the sampling accuracy and simplifies the estimation of the sampling performance. Also, when the environmental humidity is higher or lower than normal, the amount of evaporation of the stored second liquid 68 changes depending on the environmental humidity. Ultimately, there is a risk of discharge failure of the second electrode 24 due to an excess of the second liquid 68, and of the loss or inactivation of the sampled microparticles due to depletion of the second liquid 68, but these occurrences can be suppressed by supplying the second liquid at a fixed time interval that can be set arbitrarily.

[0108] In the particle sampling method according to this embodiment, prior to the second supply step (step S4) of supplying the second liquid 68 to be collected for analysis purposes, the supply of the second liquid 68 for the purpose of co-washing the inside of the first electrode 22, the rotation of the first electrode 22, and the collection of the second liquid 68 as waste liquid in the tank 82 may be repeated once or multiple times.

[0109] By doing this, residual liquid of the first liquid 67 containing the amphipathic polymer remains in the second liquid 68, and a decrease in the infectivity of the virus due to the amphipathic polymer can be suppressed when analyzing the second liquid 68, which serves as the collection liquid.

[0110] The infection risk estimation method also includes a quantification step (step S22) of quantifying the infectivity of influenza viruses 1 contained in the second liquid 68 collected by the above-mentioned particulate sampling method using an analytical device capable of measuring the infectivity, and an estimation step (step S23) of estimating the infectivity concentration of the virus contained in the air that has circulated inside based on the infectivity quantified in the quantification step, the amount of air that has circulated inside, and the collection performance value defined by the particulate sampling method.

[0111] This allows the user to grasp with high accuracy the status of the influenza viruses 1 in the space in which the particle sampling device 10 is installed.

[0112] (Other embodiments) In the particle sampling device 10 according to the first embodiment described above, the main body 56 of the first electrode 22 is cylindrical, but is not limited thereto. For example, the main body of the first electrode 22 may be an elliptical cylinder, a polygonal cylinder, or the like.

[0113] In the particle sampling device 10 according to the first embodiment described above, the first electrode 22 is installed with the axis B of the main body 56 parallel to the horizontal direction, but the present invention is not limited to this, and the first electrode 22 does not have to be installed with the axis B of the main body 56 parallel to the horizontal direction. For example, the first electrode 22 may be installed with the axis B of the main body 56 tilted relative to the horizontal direction, and it is sufficient that the first liquid 67 or the second liquid 68 can be stored in a part of the inner surface 66 in the direction around the axis B of the main body 56 so that the first liquid 67 or the second liquid 68 does not flow out of the main body 56. In other words, it is sufficient that the first electrode 22 is disposed in a position that allows the first liquid 67 or the second liquid 68 to be stored on the inner surface 66.

[0114] In the particle sampling device 10 according to the first embodiment described above, the second electrode 24 is installed in a position where the axis of the second electrode 24 coincides with the axis B of the body 56 of the first electrode 22. However, the present invention is not limited to this, and the second electrode 24 does not have to be installed in a position where the axis of the second electrode 24 coincides with the axis B of the body 56 of the first electrode 22. For example, the second electrode 24 may be installed in a position where the axis of the second electrode 24 is inclined with respect to the axis B of the body 56, and it is sufficient that the second electrode 24 extends at least in the axial direction of the body 56 of the first electrode 22. In addition, for example, the second electrode 24 may be installed in a position where the axis of the second electrode 24 does not coincide with the axis B of the body 56 of the first electrode 22, and the axis of the second electrode 24 is parallel to the axis B of the body 56 of the first electrode 22.

[0115] In the particle sampling device 10 according to the first embodiment described above, the second electrode 24 is linear, but is not limited thereto. For example, the second electrode may be plate-shaped or needle-shaped.

[0116] In the particle sampling device 10 according to the above-mentioned first embodiment, the case where one second electrode 24 is disposed within the first electrode 22 has been described, but the present invention is not limited to this. For example, a plurality of second electrodes may be disposed within the first electrode.

[0117] In the particle sampling device 10 according to the above-mentioned first embodiment, the second electrode 24 protrudes outward from one end of the main body 56 and protrudes outward from the other end of the main body 56. However, the present invention is not limited to this. For example, the length of the second electrode 24 may be the same as the length of the main body 56, or may be shorter than the length of the main body 56.

[0118] In the particle sampling device 10 according to the above-mentioned first embodiment, the driving unit 32 rotates the first electrode 22 around the axis B of the body 56 of the first electrode 22. However, the present invention is not limited to this. For example, the driving unit 32 may rotate the first electrode 22 around a rotation axis that is slightly inclined with respect to the axis of the body 56 of the first electrode 22. The driving unit 32 may also rotate the first electrode 22 around a rotation axis that is parallel to the axis of the body 56 of the first electrode 22. The driving unit 32 may rotate the first electrode 22 around a rotation axis that extends in the axial direction of the first electrode 22 and passes through the first electrode. [Industrial Applicability]

[0119] The present disclosure is widely applicable to devices and methods for sampling fine particles such as aerosols from a gas such as air. [Explanation of symbols]

[0120] 10. Particulate sampling device 12 Duct 14 No. 1 bearing seal 16 No. 2 bearing seal 18 First flange member 20 Second flange member 22 1st electrode 24 2nd electrode 26 Voltage application section 28 Supply section 30 Collection Department 32 Drive unit 42, 48, 52, 56 Main unit 44 1st support part 46 Second support part 50, 54 flange 58 First outer flange 60 Second outer flange 62 First inner flange 64 Second inner flange 66 Inside 67 1st liquid 68 Second liquid 69 Space 70 First support 72 Second support 74 First Electric Wire 76 Second Wire 78, 79 Tank 80 Injection part 82, 83 Tank 84 Extraction part 86 Gear 88 Motor 90 Control section

Claims

1. A particulate sampling method for collecting particulate matter contained in air flowing through a first electrode having a cylindrical shape and open at both ends in an axial direction thereof, and a second electrode extending in an axial direction of the first electrode and disposed within the first electrode at a distance from an inner surface of the first electrode, comprising: supplying a first liquid containing an amphipathic polymer into the first electrode to bring the amphipathic polymer into contact with an inner surface of the first electrode, and then supplying a second liquid not containing the amphipathic polymer to capture fine particles contained in air flowing inside the first electrode in the second liquid; Particulate sampling methods.

2. a first supplying step of supplying the first liquid into the first electrode and storing the first liquid in a part of the inner surface in a direction around the axis of the first electrode; a first driving step of rotating the first electrode, which stores the first liquid in a part of the inner surface, about a rotation axis extending in an axial direction of the first electrode and passing through the first electrode; a first recovery step of recovering the first liquid stored in a portion of the inner surface; a second supplying step of supplying the second liquid into the first electrode after the first recovering step, and storing the second liquid in a part of the inner surface in a direction around the axis of the first electrode; a second driving step of rotating the first electrode, the second liquid being stored in a part of the inner surface, about a rotation axis extending in an axial direction of the first electrode and passing through the first electrode; a voltage application step of applying a voltage between the first electrode and the second electrode that stores the second liquid in a part of the inner surface; a second recovery step of recovering the second liquid stored in a portion of the inner surface; Equipped with The method for sampling fine particles according to claim 1.

3. In the second supplying step, when the fine particles contained in the air circulating inside are viruses, a collection liquid having a small effect of reducing the infectivity of the viruses is used as the second liquid. The method for sampling fine particles according to claim 1 or 2.

4. The collection liquid is any one of physiological saline, PBS (Phosphate-Buffered Saline) buffer, EDTA (Ethylene Diamine Tetraacetic Acid) buffer, bicarbonate buffer, and pure water; The method for sampling fine particles according to claim 3.

5. The first driving step is performed for a predetermined time, and then the first recovery step is performed. the second driving step and the voltage applying step are performed while maintaining a predetermined amount of the second liquid stored in a portion of the inner surface by performing the second supplying step at regular time intervals. The method for sampling fine particles according to claim 3.

6. a quantification step of quantifying an infectivity titer of the viruses contained in the second liquid collected by the particulate sampling method according to claim 3 using an analyzer capable of measuring an infectivity titer; an estimation step of estimating an infectivity titer concentration of the virus contained in the air that has circulated inside based on the infectivity titer quantified in the quantification step, the amount of air that has circulated inside, and a collection performance value defined by the fine particle sampling method; An infection risk estimation method comprising:

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