JP2000046702A - Filter for collecting sample - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter for collecting samples capable of reliably transferring minute samples collected from the inside of a liquid in a state adhered and fixed to the filter and speedily performing infrared spectroscopic analysis. SOLUTION: An adhesive layer 3 formed of a chemical substance with viscosity capable of adhering fine powdery samples and with little absorption in an infrared region is provided on the surface of a filter film 1 formed of a chemical substance which is superior in resistance to water and chemicals and is high in the transmissivity of infrared rays. A plurality of through holes 4b capable of collecting samples when passing a fluid are bored along the thickness of the filter film 1 and the adhesive layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample collecting filter suitable for collecting minute substances present in a gas or liquid and performing infrared spectroscopic analysis thereof.

[0002]

2. Description of the Related Art In recent years, in the fields of electronics, biochemistry, medicine, and the like, products have been rapidly increasing in functionality and performance, and a very severe clean environment is required for research and development and production thereof. .

[0003] In general, various devices and equipment are present in a clean room, and there is always a risk of dust generation from these devices and human bodies.

For this reason, detecting and analyzing dust contained in air in a clean room, cleaning liquid used in a manufacturing process, etc. maintains or improves cleanness and produces a product of stable quality. Is a must.

Conventionally, when a fine powder sample such as dust in a gas or a liquid is collected and its organic components are analyzed by infrared spectroscopy, for example, as disclosed in Japanese Patent Application No. 8-13677. Sample collection filters have been used.

First, the configuration of this conventional sample collecting filter will be described with reference to FIG.

FIGS. 6 (a) and 6 (b) are a plan view and a sectional view of a conventional sample collecting filter. In the figure, reference numeral 1 denotes a filtration membrane made of a chemical substance having a low absorption in the infrared region and a high infrared transmittance, and having a plurality of through holes 4b perforated in the thickness direction. Reference numeral 2 denotes a support ring made of a material having higher heat resistance and solvent resistance than the filtration membrane 1 and having rigidity capable of supporting the filtration membrane 1. The filtration membrane 1 and the support ring 2 are integrated by heat fusion or adhesion.

Next, the procedure of an analysis operation performed using the conventional sample collection filter configured as described above will be described. 1) First, the sample fluid is passed through the filter configured as described above, so that the sample present in the gas or liquid and having a size that cannot pass through the through hole 4b is left on the filter and collected. . 2) Then, without transferring the collected sample to another substrate for infrared spectroscopic analysis consisting of potassium bromide or sodium chloride crystals, use a pair of tweezers, etc. Set in a spectrometer and perform infrared spectroscopy. 3) As a result, the obtained infrared absorption spectrum does not include the absorption peak of the filter that hinders the component analysis of the sample, and is sufficient for performing various analysis processes such as detailed structural analysis and quantitative analysis of functional groups. Indicates signal strength.

[0009]

However, in the structure of the above-mentioned conventional sample collecting filter, the sample filtered from the sample fluid is collected on the filter, but is only allowed to stand here. It is not fixed to the filter. For this reason, careful handling is required for handling the filter after collecting the sample, and there has always been a problem that a minute sample is lost due to the flow of air in the surrounding environment or the vibration during transportation. In particular, to prevent foreign substances from entering during the analysis process, a series of analysis processes are performed in a clean room or clean bench where air circulation is remarkable, or samples are collected and transported for performing infrared spectroscopy in different places. This problem was more serious and serious where necessary.

[0010]

In order to solve the above-mentioned problems, a filter for collecting a sample according to the present invention (Claim 1) collects a fine powdery sample in a sample fluid, and collects the infrared ray of the sample. In the sample collection filter for performing spectroscopic analysis, the filter membrane made of a chemical substance having excellent water resistance, chemical resistance, low absorption in the infrared region, and high infrared transmittance, and the surface of the filter membrane Provided, having a low absorption in the infrared region, a chemical substance having a high infrared transmittance, and having an adhesive layer having a viscosity capable of adhering the fine powder sample, the filtration membrane and the adhesive layer, In this configuration, a plurality of through-holes having a size that allows a fluid to pass through and collect a sample are formed, and according to this configuration, the sample is adhesively fixed to the adhesive layer on the filter surface.

Further, in the sample collecting filter according to the present invention (claim 2), in the sample collecting filter according to claim 1, the through hole has a large diameter on a side into which a fluid flows.
According to this configuration, the loss coefficient relating to the velocity of the fluid near the entrance of the through hole is reduced, and the outflow speed is increased by increasing the outflow velocity. The amount increases.

[0012]

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described. The sample collection filter according to the first embodiment corresponds to the above-described first aspect. Hereinafter, the first embodiment will be described with reference to the drawings.
The configuration of the sample collection filter according to the first embodiment will be described.

FIGS. 1A and 1B are a plan view and a cross-sectional view of a sample collecting filter according to the first embodiment. In the figure, reference numeral 1 denotes a filtration membrane formed of a polyethylene film having a thickness of about 10 μm formed by hot pressing.

The material for forming the filtration membrane 1 may be any material that is excellent in water resistance and chemical resistance, has a low absorption in the infrared region, and has a high infrared transmittance. Fluoroethylene).

Reference numeral 3 denotes an adhesive layer formed on the filtration membrane 1 by screen printing and made of liquid paraffin having a thickness of about 3 μm.

As a material for forming the adhesive layer 3, any material such as liquid paraffin or a fluororesin monomer or a low molecular weight substance thereof has a viscosity that allows a small sample to be adhered and has little absorption in the infrared region. It suffices if not limited to this. In addition, a dip method, a spin coating method, or the like can be applied to the forming method, and the method is not particularly limited thereto. Here, a screen printing method using a stainless mesh is used.

Reference numeral 4b denotes a plurality of through holes having a diameter of about 10 to 20 μm, which are formed in the thickness direction of the filtration membrane 1 and the adhesive layer 3 in a plurality.

The through-hole 4b can be processed by an electron beam method, a neutron method, an ion beam method, a photo etching method or the like, and is not particularly limited.
By using an excimer laser with F as a light source, the filtration membrane 1 on which the adhesive layer 3 is formed is irradiated with a laser having an irradiation energy of 0.5 to 1 J / cm @ 2 to form a number of these pores.

Reference numeral 2 denotes a support ring for supporting the filtration membrane 1 and the adhesive layer 3. The filtration membrane 1 and the support ring 2 are integrated by heat fusion or adhesion.

The material for forming the support ring 2 is superior in heat resistance to polyethylene and has less eluted material than polyethylene.
A material having rigidity capable of supporting the filtration membrane 1, that is, a metal such as stainless steel, or a resin such as PTFE is preferable.

Referring now to FIG. 2, a description will be given of the configuration of a sample collection unit that incorporates and uses the sample collection filter having the above-described configuration. FIG. 2 (a) and (b)
Shows a cross-sectional view and a main part cross-sectional view of the sample collection unit,
In the drawing, reference numeral 7 denotes a reinforcing plate made of a metal mesh and holding the above-mentioned filter for collecting a sample.

Reference numerals 8a and 8b denote housings which are vertically divided and hold the reinforcing plate 7. Reference numeral 10 denotes an introduction pipe into which a sample flows. Reference numeral 11 denotes an introduction portion 11 having an opening in the upper portion 8a of the housing. The introduction tube 10 and the introduction portion 11 are connected to each other. Reference numeral 12 denotes a cavity 12 for storing the introduced fluid. Reference numeral 13 denotes a fluid discharge port 13 opened at the lower portion 8b of the housing. Reference numeral 14 denotes a discharge pipe 14 in which a suction pump or the like is incorporated. The drain port 13 and the drain pipe 14 are connected to each other. Reference numeral 15 denotes a funnel-shaped cavity for guiding the fluid that has passed through the filtration membrane 1 to the outlet 13.

Hereinafter, a method of using the sample collection filter of the first embodiment incorporated in the sample collection unit configured as described above and its operation will be described with reference to FIG. The above-described sample collection filter is used by being incorporated in a sample collection unit as shown in FIG. As described above, this unit includes the reinforcing plate 7 made of a metal mesh for holding the sample collecting filter, and the vertically divided housings 8a and 8b for sandwiching the reinforcing plate. The upper portion 8a of the housing includes a sample introduction tube 10, an introduction port 11 connected to the tip of the sample introduction tube 10, and a cavity 12 for storing the introduced fluid. Further, the lower portion 8b of the housing is provided with a drain port 13 for fluid, a drain pipe 14 in which a suction pump or the like is incorporated, and a drain port 1 for passing the fluid passing through the filtration membrane 1.
3 and a funnel-shaped cavity 15 leading to the cavity 3.

1) Introductory tube 10 of this sample collection unit
The sample fluid flowing through passes through the filtration membrane 1 via the inlet 11. 2) At that time, the sample 5 larger than the diameter of the through-hole 4b of the filtration membrane 1 cannot pass through the through-hole 4b, remains on the upper surface of the filtration membrane 1, and is fixed by the adhesive force of the adhesive layer 3. 3) On the other hand, particles and fluid 6 smaller than the diameter of the through-hole 4b of the filtration membrane 1 flow through the through-hole 4b of the filtration membrane 1 and the reinforcing plate 7, and then flow out of the discharge pipe 14 through the discharge port 13.
Thus, the sample can be collected, that is, the sample fluid can be filtered. 4) After filtration, remove the housings 8a and 8b, hold the support ring 2 with tweezers or the like, and take out the filter.

Next, FIG. 3 shows the configuration of an infrared spectrometer for performing infrared spectroscopy analysis of the sample thus collected. In FIG. 3, reference numeral 20 denotes an infrared detector. 21 is an infrared optical system. Reference numeral 22 denotes a sample table on which a filter is mounted. Reference numeral 23 denotes a moving stage on which the sample stage 22 is mounted. Reference numeral 24 denotes an infrared ray generator. Reference numeral 25 denotes a Cassegrain mirror that reflects infrared rays generated by the infrared ray generator 24. 26 is a monitor. 27 is a computer.
28 is a printer.

The operation of the infrared spectrometer for performing infrared spectroscopy analysis of the collected sample will be described below with reference to FIG. A sample stage 22 on which the above-mentioned filter for filtering a sample fluid is mounted is set on a moving stage 23 of the measuring instrument.
The infrared rays generated by the infrared ray generating device 24 are transmitted to the Cassegrain mirror 2
5 and pass through the filter and the infrared optics 21 and enter the detector 20. This infrared light is converted into an electric signal by the detector 20, and after being processed by the computer 27, the infrared absorption spectrum is displayed on the monitor 26, and the analysis result is output from the printer 28 as necessary.

As described above, according to the configuration of the first embodiment, a sample can be easily collected in a form of being adhered and fixed to the filter surface, and the collected sample can be removed from the air of the surrounding environment as in the related art. It can be transported securely without being lost due to the flow of the fluid or vibration during transport, and infrared spectrometry can be quickly performed while the filter is mounted on the filter.

(Embodiment 2) A filter for collecting a sample according to Embodiment 2 corresponds to the invention described in claim 2. The second embodiment is a modification of the first embodiment, and is more effective.

The configuration of the sample collecting filter according to the second embodiment will be described below with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIGS. 4A and 4B are a plan view and a cross-sectional view of the sample collection filter according to the second embodiment. In FIG. 4, reference numeral 4a denotes a through hole having a structure in which the diameter of the sample fluid inflow side, that is, the side on which the adhesive layer 3 is formed, is large, and the diameter gradually decreases toward the outflow side.

The through-hole 4a can be formed by processing the filtration membrane 1 and the adhesive layer 3 by an electron beam method, an ion beam method or the like. The processing method is not particularly limited, but here, KrF is used. Using an excimer laser as a light source, a laser having an irradiation energy of 0.3 to 1.2 J / cm <2> is pulse-irradiated onto the filtration membrane 1 having an adhesive layer 3 formed on the upper surface, and a diameter of about 12 [mu] m on the inflow side and about 8 [mu] m on the outflow side. A large number of pores having

Hereinafter, a method of using the sample collecting filter according to the second embodiment and the operation thereof will be described with reference to FIG. FIG. 5 shows a sample collection unit having the same configuration as that of FIG. 2 used in the first embodiment, and incorporates and uses a filter having the above configuration.

1) Introductory tube 10 of this sample collecting unit
The sample fluid flowing through passes through the filtration membrane 1 via the inlet 11. At that time, the time required for the filtration depends on the flow rate of the fluid 6 passing through the filtration membrane 1. 2) Here, as a feature of the second embodiment, the through hole 4a
Has a structure with a large inlet diameter and a small outlet diameter, so that the loss factor related to the velocity of the fluid near the inlet becomes smaller and the outflow velocity increases as compared with the case where the inlet diameter and the outlet diameter are the same. This increases the outflow.

Therefore, according to the configuration of the second embodiment, when the viscosity of the fluid is high or the amount of the sample in the fluid is large, the filtration time can be particularly effectively reduced, and the efficiency can be reduced. Analytical operation can be performed, and samples can be easily collected by sticking and fixing to the filter surface.The collected samples can be transported securely without being lost due to the flow of air in the surrounding environment or vibration during transportation. The infrared spectroscopy can be quickly performed while being mounted on the filter.

[0034]

As described above, according to the sample collecting filter according to the first aspect of the present invention, a fine powder sample in a fluid is collected and its infrared spectroscopic analysis is performed. In the sample collection filter to be performed, the filter membrane made of a chemical substance having excellent water resistance, chemical resistance, low absorption in the infrared region, and high infrared transmittance, and provided on the surface of the filter membrane An adhesive layer having a low absorption in the infrared region and a high infrared transmittance, and having a viscosity capable of adhering the fine powder sample, and passing the fluid through the filtration membrane and the adhesion layer. Because it was configured to make a plurality of through-holes large enough to collect the sample by the above, by the adhesive layer,
The filtered sample can be fixed, and there is an effect that a sample having a size that cannot pass through a through-hole existing in a gas or a liquid can be easily collected by being adhesively fixed to the filter surface.

Further, the sample collected on the filter can be transported reliably without being lost due to the flow of air in the surrounding environment, vibration during transport, etc., and can be quickly carried out while being mounted on the filter. There is an effect that infrared spectroscopy can be performed.

According to the sample collecting filter of the present invention, in the sample collecting filter of the first aspect, the through hole has a diameter on a side where a fluid flows. Has a large diameter and a structure with a small diameter on the outflow side, so that the loss factor related to the velocity of the fluid near the entrance of the through hole decreases and the outflow rate increases due to an increase in the outflow velocity, so that the outflow rate increases, so There is an effect that analysis processing can be performed.

In addition, when the viscosity of the fluid is high, or when the amount of the sample in the fluid is large, the filtration time can be particularly effectively reduced, and the analysis can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a diagram showing a sample collecting filter according to Embodiment 1 of the present invention, and FIG.
(B) is a sectional view thereof.

FIG. 2 is a diagram showing a sample collection unit according to Embodiment 1 of the present invention, and FIG.
(B) is a sectional view of the main part.

FIG. 3 is a diagram showing a configuration of an infrared spectrometer according to Embodiment 1 of the present invention.

FIG. 4 is a view showing a sample collecting filter according to Embodiment 2 of the present invention, and FIG.
(B) is a sectional view thereof.

FIG. 5 is a view showing a sample collecting unit according to Embodiment 2 of the present invention, and FIG.
(B) is a sectional view of the main part.

6A and 6B are views showing a conventional sample collecting filter, FIG. 6A is a plan view thereof, and FIG. 6B is a sectional view thereof.

[Explanation of symbols]

 1: Filtration membrane 2: Support ring 3: Adhesive layer 4a, 4b: Through hole 5: Sample 6: Fluid 7: Reinforcement plate 8a, 8b: Housing 10: Inlet tube 11: Inlet 12, 15: Cavity 13: Outlet 14: Drain pipe 20: Detector 21: Infrared optical system 22: Sample stage 23: Moving stage 24: Infrared ray generator 25: Cassegrain mirror 26: Monitor 27: Computer 28: Printer

Claims (2)

[Claims] 1. A sample collection filter for collecting a fine powder sample in a fluid and performing infrared spectroscopic analysis thereof, which is excellent in water resistance and chemical resistance and has an absorption in an infrared region. A filter membrane made of a chemical substance having a low infrared transmittance and a chemical substance having a low infrared absorption and a high infrared transmittance provided on the surface of the filter membrane. An adhesive layer having a stickable viscosity, wherein the filtration membrane and the adhesive layer are formed by perforating a plurality of through-holes large enough to allow the fluid to pass through and collect a sample. Sample collection filter. 2. The sample collection filter according to claim 1, wherein the through-hole has a structure in which a diameter of a fluid inflow side is large and a diameter of a fluid outflow side is small. Collection filter.