JP2000338018A - Method for measuring organic stain on surface of solid sample and its pretreating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect organic stains on the surface of even a minute solid sample and to measure the stains on the surfaces of a large number of solid samples at one measurement. SOLUTION: Lead particles 1 are mixed with silica beads 3 in a mixing container 5 to have organic stains adhered to the lead particles 1 adhered to the silica beads 3. Then the lead particles 1 are separated from the silica beads 3 by a sieve 9, and the silica beads 3 are placed in a combustion boat 13 and introduced into an oxidizing reaction tube 19. Organic matter adhered to the silica beads 3 is oxidized by the heat of a heating furnace 21 to generate organic gas. The organic gas is transferred to an oxidation catalyst 17 together with a carrier gas, converted into carbon dioxide, and transferred to a NDIR 37 via a cooling tube 31 and an electronic cooler 35 to determine the concentration of carbon dioxide by a signal processing part 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring organic stains on the surface of a solid sample for measuring organic stains adhering to the surface of a solid sample, and a pretreatment apparatus for preparing a sample for the measurement. The measurement of organic contamination on the surface of a solid sample is performed by monitoring the prevention of organic contamination, such as electronic equipment such as semiconductor devices, manufacturers of pharmaceuticals and foods,
It is being implemented at various testing organizations.

[0002]

2. Description of the Related Art Conventional methods for measuring organic dirt on the surface of a solid sample include a combustion method in which the organic dirt on the surface of the solid sample is measured by burning it and converting it to carbon dioxide.
There is a chemical oxidation method in which measurement is performed by oxidizing an organic substance stain on the surface of a solid sample by a chemical reaction and converting it into carbon dioxide. However, in the combustion method and the chemical oxidation method, when the solid sample itself contains an organic component, the organic component is also oxidized, so that there is a problem that only the attached component on the surface of the solid sample cannot be measured. If the solid sample does not contain organic components, it is possible to measure the components attached to the surface, but it cannot be measured when non-destructive inspection is required because the sample is deformed or corroded by combustion or chemical reaction There was a problem. Also, it is difficult or impossible to measure a sample that generates an interference gas or a toxic gas to the detector.

Therefore, as another measuring method, the surface of a solid sample is wiped with a nonflammable paper material containing no organic components, such as glass fiber filter paper, and the organic components attached to the paper material are converted into carbon dioxide and quantified. There is a method (wiping method). As still another measurement method, there is a method of observing the degree of contamination on the surface of a solid sample using an electron microscope such as a scanning electron microscope (SEM). As yet another measurement method,
For example, there is a method in which organic dirt on the surface of a solid sample is extracted with a solvent such as carbon tetrachloride or water, and then the organic components in the solvent are measured by absorptiometry (solvent extraction method).

[0004]

However, in the wiping method, it is difficult to wipe a small area of 5 mm ² or less. Therefore, when the object to be measured is a solid sample such as solid fine particles having a small surface area, the surface contamination is reduced. There was a problem that it could not be measured. In the surface observation using an electron microscope, when a large number of solid samples are targeted, it is possible to take out and observe a part of the samples, but it is difficult to observe all the samples individually. There was a problem that surface dirt cannot be measured uniformly. Also, in the wiping method,
It is difficult to wipe organic stains from a large number of samples.

Further, in the solvent extraction method, there is a problem that an organic stain extracted by the solvent is limited depending on the kind of the solvent, and furthermore, since the measurement is performed by detecting the absorbance at a predetermined wavelength, the measurable organic stain is limited. Was. Further, there is a problem that the detection sensitivity is low because the organic matter is extracted with a large amount of solvent. Therefore, the present invention provides a method for detecting organic dirt on the surface of a solid sample that can be wiped off, and that can measure the surface dirt of a large number of samples in a single measurement. It is an object of the present invention to provide a method for measuring contamination and a pretreatment device for preparing a sample for the measurement.

[0006]

In the method for measuring organic contamination on the surface of a solid sample according to the present invention, the solid sample is brought into contact with carbon-free inorganic medium particles, and then the inorganic medium particles are separated from the solid sample. Then, the organic soil transferred to the surface of the inorganic medium particles is oxidized and measured as carbon dioxide.

The pretreatment apparatus for measuring organic soil on the surface of a solid sample according to the present invention mixes a solid sample with inorganic medium particles containing no carbon to bring the organic soil on the surface of the solid sample into inorganic medium particles. It is provided with a mixing means for transferring to the surface, and a separating means for separating the solid sample and the inorganic medium particles mixed by the mixing means and providing the inorganic medium particles to the sample.

After the solid sample and the inorganic medium particles are introduced into the mixing means and brought into contact with each other, and the organic stain on the surface of the solid sample is transferred to the inorganic medium particles, the solid sample and the inorganic medium particles are separated by the separating means. Thereafter, the organic stain transferred to the surface of the inorganic medium particles is converted into carbon dioxide and measured.

[0009]

FIG. 1 is a schematic diagram showing one embodiment of a pretreatment device and a carbon dioxide measuring device. A mixing container 5 containing a solid sample 1 and inorganic medium particles 3 is installed with an inclination. A spiral blade is formed on the inner wall of the mixing vessel 5 and is connected to the opening from the bottom surface.
When the is rotated in one direction (take-out direction), the contents are lifted to the opening side along the spiral wing, and when rotated in the opposite direction (mixing direction), the contents can be mixed near the bottom surface. . The mixing means constituting the pretreatment device of the present invention is constituted by the mixing vessel 5 and a rotating mechanism.

Near the opening of the mixing vessel 5, a funnel 7 for guiding the solid sample 1 and the inorganic medium particles 3 to the opening of the mixing vessel 5 is arranged. The funnel 7 has an opening for charging the solid sample 1,
Openings for charging the inorganic medium particles 3 are provided, and predetermined amounts of the solid sample 1 and the inorganic medium particles 3 are respectively introduced into the openings. As the inorganic medium particles 3, particles smaller than the particle diameter of the solid sample 1 are used. A sieve 9 having a mesh structure having a size smaller than the diameter of the solid sample 1 and larger than the diameter of the inorganic medium particles 3 is disposed below the opening of the mixing container 5. A vibration mechanism (not shown) for vibrating the sieve 9 is connected to the sieve 9. The inorganic medium particles 3 passing through the sieve 9 are located below the sieve 9.
11 to the sample port 23 of the carbon dioxide measuring device
Is arranged. The separating means constituting the pretreatment device of the present invention is constituted by the sieve 9 and the vibration mechanism.

In the carbon dioxide measuring device, the inorganic medium particles 3
A sample oxidizing device 15 for converting organic substances adhering to the substrate to carbon dioxide is provided. The sample oxidizing device 15 includes an oxidation catalyst 17 that converts organic gas generated from organic dirt attached to the inorganic medium particles 3 to carbon dioxide,
Reaction tube 19 filled at one end with oxidation catalyst 17
And a heating furnace 21 for heating the oxidation reaction tube 19. The other end of the oxidation reaction tube 19 is sealed by a sample port 23. An opening is provided on the upper surface of the sample port 23, and a sample port cover 25 for opening and closing the opening is provided. The outlet of the funnel 11 is arranged at a position corresponding to the opening of the sample port 23.

Inside the sample port 23, a sample boat 13 for accommodating the inorganic medium particles 3 supplied from the funnel 11 is provided. The sample boat 13 is moved between the inside of the sample port 23 and the inside of the oxidation reaction tube 19 by a sample boat moving rod 27 slidably provided in the sample port 23. The sample port 23 is connected from the other end of the oxidation reaction tube 19 to a carrier gas control unit 29 for supplying a carrier gas containing oxygen and no carbon. At one end of the oxidation reaction tube 19, a cooling tube 31 for cooling the gas supplied from the oxidation reaction tube 19, and an electronic cooler 3 for removing moisture and dust in the gas and discharging the gas to the drain 33
An NDIR (Non-Dispersive Infrared Spectrophotometer) 37 for measuring carbon dioxide in the gas supplied from the oxidation reaction tube 19 is connected via the port 5. NDIR37 has NDI
A signal processing unit 39 for processing the detection signal of R37 is electrically connected.

Referring to FIG. 1, one embodiment of the measuring method will be described together with the operation of this apparatus. Here, lead particles having a particle size of 0.7 mm are used as the solid sample, and as the inorganic medium particles, no organic matter is attached, and the particle size is 0.4 to 0.6.
mm silica beads are used. For example, a predetermined amount of lead particles 1 and silica beads 3 are respectively collected by a measuring cup, and put into the mixing container 5 via the funnel 7. Lead particles 1
The volume ratio between the silica beads 3 is, for example, 1: 1.

Next, in order to transfer the organic dirt adhering to the lead particles 1 to the silica beads 3, the mixing container 5 is rotated in the mixing direction so that the lead particles 1 and the silica beads 3 are, for example, 1%.
Mix for 0 minutes. After that, the mixing container is rotated in the reverse direction (take-out direction) to take out the lead particles 1 and the silica beads 3 from the mixing container 5 into the sieve 9. At this time, the cover 25 of the carbon dioxide measuring device has been moved to the position indicated by the solid line in FIG. 1, and the sample boat 13 has been moved below the opening of the sample port 23. Then, the vibration mechanism is operated to separate the lead particles 1 and the silica beads 3 by the sieve 9, and the silica beads 3 passing through the sieve 9 are stored in the sample boat 13 through the opening of the funnel 11 and the sample port 23. .

All the silica beads 3 are transferred to the sample boat 13
After that, the cover 25 is moved to the position indicated by the broken line in FIG.
7 moves the sample boat 13 into the oxidation reaction tube 19. At this time, the oxidation catalyst 17 and the oxidation reaction tube 19 are heated to a predetermined temperature by the heating furnace 21 and the sample port 2 is heated.
3, a carrier gas is supplied from the carrier gas control unit 29. Organic contaminants attached to the silica beads 3 introduced into the oxidation reaction tube 19 are oxidized by heat to generate organic gas. The organic gas is supplied to the carrier gas control unit 29.
Is sent to the oxidation catalyst 17 together with the carrier gas supplied from the apparatus, and is entirely converted to carbon dioxide. After the gas supplied from one end of the oxidation reaction tube 19 is dehumidified and removed via the cooling pipe 31 and the electronic cooler 35, the gas is sent to the NDIR 37 to detect carbon dioxide. The detection signal of the NDIR 37 is processed by the signal processing unit 39 to quantify the concentration of carbon dioxide caused by organic contaminants attached to the surface of the silica beads 3. Since the organic soil on the surface of the silica beads 3 is a transfer of the organic soil adhered to the surface of the lead particles 1, according to this embodiment, the amount of the organic soil on the surface of the silica beads 3 is determined to obtain the lead particles. Organic contamination on one surface can be indirectly quantified.

In this embodiment, lead particles are used as the solid sample and silica beads are used as the inorganic medium particles. However, the solid sample and the inorganic medium particles are not limited to these. Further, in this embodiment, the mixing means constituting the pretreatment device of the present invention is constituted by a mixing vessel having a spiral blade therein and a rotating mechanism for rotating the mixing vessel, but is not limited thereto. However, any means can be used as long as the solid sample and the inorganic medium particles can be brought into contact by mixing. In addition, the separation means is constituted by a sieve and a vibration mechanism that vibrates the sieve, but is not limited thereto.For example, a solid sample and an inorganic medium particle are magnetized using a magnetic material as the inorganic medium particle. Any means capable of separating the solid sample and the inorganic medium particles, such as a means for separating or a means for separating magnetically using non-magnetic inorganic medium particles when the solid sample is a magnetic material, Means may be used. Also,
The means for measuring the organic soil is not limited to the carbon dioxide measuring apparatus shown in the examples, and any means can be used to convert the organic soil transferred to the inorganic medium particles to carbon dioxide for measurement. Such means may be used.

[0017]

According to the method for measuring organic contamination on the surface of a solid sample according to the present invention, the solid sample is brought into contact with carbon-free inorganic medium particles, then the inorganic medium particles are separated from the solid sample, and the inorganic medium particles are removed. Oxidized organic dirt transferred to the surface is measured as carbon dioxide, so even small solid samples that cannot be wiped can be detected through inorganic medium particles. . Furthermore, when measuring a large number of solid samples, it is possible to measure a large number of solid samples by one measurement without wiping one by one or observing with an electron microscope. Furthermore, since the solid sample is not heated, even if the sample is flammable or deformed by heat,
Non-destructive inspection can be performed. The pretreatment apparatus for measuring organic soil on the surface of a solid sample according to the present invention transfers the organic soil on the surface of the solid sample to the surface of the inorganic medium particles by mixing and contacting the solid sample and inorganic medium particles containing no carbon. A mixing means for separating the solid sample and the inorganic medium particles mixed by the mixing means, and a separation means for providing the inorganic medium particles to the sample, so that the organic soil on the surface of the solid sample is transferred to the inorganic medium particles, The inorganic medium particles can be supplied as a sample to a carbon dioxide measuring device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an embodiment of a pretreatment device and a carbon dioxide measurement device.

[Explanation of symbols]

 Reference Signs List 1 solid sample (lead particles) 3 inorganic medium particles (silica beads) 5 mixing container 9 sieve 7,11 funnel 13 sample boat 15 sample oxidizer 17 oxidation catalyst 19 oxidation reaction tube 21 heating furnace 23 sample port 25 sample port cover 27 sample Boat moving rod 29 Carrier gas control unit 31 Cooling pipe 33 Drain 35 Electronic cooler 37 NDIR 39 Signal processing unit

Claims (2)

[Claims] After a solid sample is brought into contact with inorganic medium particles not containing carbon, the inorganic medium particles are separated from the solid sample, and organic dirt transferred to the surface of the inorganic medium particles is oxidized to oxidize the organic medium. A method for measuring organic contamination on the surface of a solid sample, wherein the measurement is performed as carbon. Mixing means for mixing and contacting the solid sample and carbon-free inorganic medium particles to transfer organic stains on the surface of the solid sample to the surface of the inorganic medium particles;
A separation unit for separating the inorganic sample and the solid sample mixed by the mixing unit and providing the inorganic medium particle to the sample;