JP2003036809A - Generated gas analysis-method and equipment for interface in mass analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and its equipment for interface in mass analysis- generated gas analysis. SOLUTION: It is to provide the method and the equipment for interface between an ambient pressure/low vacuum chamber and a high vacuum chamber which is characterized, by providing the interface method between the ambient pressure/low vacuum chamber and the high vacuum chamber, which performs a generated gas analysis by introducing effectively a gas element generated from a measured sample material into the high vacuum chamber, in a generated gas analysis equipment comprised of a heating part and an analysis part of a sample material, by interfacing a double pipe including arrangement of two pipes with a pore at its head in two stages, between the ambient pressure/low vacuum and the high vacuum, and by reducing pressure by a pump at an intermediate position of the double pipe and carrying the gas element generated from the measured sample material by a carrier gas flow and allowing to permeate the pore of the rear stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evolved gas analysis / evaluation apparatus using a skimmer type interface as an interface between atmospheric pressure / low vacuum and high vacuum in evolved gas-mass spectrometry. More specifically, by using a skimmer type interface having a double-tube structure, it can be applied to, for example, an infrared image furnace type electric furnace, and a generated gas-mass spectrometer capable of supporting a rapid thermal change program. It is about.

[0002]

2. Description of the Related Art In evolved gas analysis-mass spectrometry, sample heating is performed under atmospheric pressure, whereas mass spectrometry is performed in high vacuum. The gas component generated by thermal decomposition and desorption utilizing this differential pressure from atmospheric pressure to high vacuum is introduced into the mass spectrometer, but if the amount of introduced gas is too large, the degree of vacuum required for mass spectrometry operation is maintained. The interface between the two is very important as it will disappear. Conventionally, as the interface, it is general to use a fused silica capillary having an inner diameter of about 0.1 to 0.2 μm or an inner wall deactivated SUS capillary. However, in both cases, reduction of the amount of the generated gas component introduced by adsorption to the inner wall is unavoidable, and the capillary holding temperature for the purpose of preventing adsorption to the inner wall is also about 300 to 400 ° C. It has a drawback that adsorption of components on the inner wall is unavoidable.

On the other hand, in an apparatus adopting a skimmer type interface without using a capillary, only an electric heating type electric furnace can be adopted as a heating furnace, and an infrared image furnace is characterized by an atmosphere control and a high temperature rising measurement condition. It has the drawback of not being able to realize the diversity of. As for the prior art, for example, there is a commercially available device (Netch Gereittebau) in the past. In this type of device, a skimmer interface made of stainless steel, alumina, etc. is used in an electric heating type electric furnace, and an infrared image It cannot support temperature programs such as high-speed temperature rise realized in the furnace.

A method for highly sensitively analyzing and evaluating a gas component produced by thermal decomposition or thermal desorption by mass spectrometry is widely applicable to so-called thermal analysis in general such as differential thermal analysis and thermogravimetric analysis. Since the evaluation of the thermophysical properties and thermal reactions of substances evaluated by these combinations greatly contributes to the design of substance processing and material manufacturing processes involving heating, an interface that provides more sensitive and precise analysis conditions was used. The development of an evolved gas analysis-mass spectrometer has been strongly desired.

[0005]

SUMMARY OF THE INVENTION In consideration of the above-mentioned various problems, the present invention connects the atmospheric pressure / low vacuum portion and the high vacuum portion when performing the generated gas analysis-mass analysis. It is important to develop an interface method and its apparatus that can realize highly sensitive analysis and that can be combined with various thermal analysis methods, and also to develop a gas evolution analysis-mass spectrometry apparatus using the interface method. It was developed with the recognition that this is a major issue.

[0006]

The present invention for solving the above-mentioned problems comprises the following technical means. (1) In an evolved gas analyzer including a sample heating unit and an analysis unit, an atmospheric pressure that efficiently introduces a gas component generated from a measurement sample into a high vacuum chamber and realizes the evolved gas analysis.
A method for interfacing between a low vacuum chamber and a high vacuum chamber, wherein a double pipe having two pipes having pores at the tip arranged in two stages is used as an interface between atmospheric pressure / low vacuum and high vacuum, Atmospheric pressure / low vacuum chamber and high vacuum, characterized in that the pressure in the middle of the double tube is reduced by a pump, the gas component generated from the measurement sample is conveyed by a carrier gas flow, and is passed through the pores in the latter stage. Room interface method. (2) In an evolved gas analyzer that includes a sample heating unit and an analysis unit, an interface device of the evolved gas analyzer that analyzes the thermal behavior of a substance by analyzing a gas component generated from the sample by heating the sample And an interface of atmospheric pressure / low vacuum and high vacuum, which is composed of a double tube in which two tubes having pores at the tip are arranged in two stages, a pump for reducing the pressure in the middle of the double tube An interface device for an evolved gas analyzer, characterized by including, as a constituent element, a gas component generated from a measurement sample by a carrier gas flow, and permeating through a fine hole in a subsequent stage. (3) The interface device according to (2), wherein a quartz double tube is used as the double tube. (4) The interface device according to (2), wherein the high vacuum chamber of the analysis unit is equipped with a mass spectrometer. (5) The interface device according to (2), which uses an infrared image furnace in the sample heating unit and has a temperature control means for high-speed temperature rising / falling. (6) Using an infrared image furnace for the sample heating section,
The interface device according to (2) above, which has a sample heating unit in an inert gas such as nitrogen or a rare gas, or a humidified atmosphere thereof. (7) An evolved gas analyzer, wherein the interface device according to (2) is used as an interface of an infrared image furnace-mass spectrometer. (8) An analysis and evaluation device characterized by using the interface device according to (2) above as an interface between a thermal analysis device and a mass analysis device.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail. The present inventor has conducted extensive studies and researches to solve the above-mentioned problems, and as a result, the skimmer using the principle of the jet separator as an interface between the atmospheric pressure / low vacuum portion and the high vacuum portion in the generated gas analysis-mass analysis. -Type double tube structure interface, decompress the middle of the double tube, carry the gas component by carrier gas flow,
The above-mentioned problems have been solved by allowing the latter-stage pores to pass therethrough and by making the material thereof quartz. That is, in the present invention, the gas component generated in the heating furnace is transported to the carrier gas, and is relatively concentrated by carrier gas diffusion in the interface of the double-tube structure to achieve high sensitivity, Further, in order to suppress as much as possible the reduction of the maximum attainable temperature due to the inhibition of the infrared irradiation in the image furnace, the skimmer is made of quartz having a high infrared transmissivity to solve the above problems. As a result, the present invention improves the permeability of a high boiling point component and a high mass number desorbing component that are easily adsorbed on the inner wall of the capillary interface, that is, improves the measurement sensitivity, and analyzes the generated gas for the highest temperature reached in the infrared image furnace. Enables mass spectrometry.

The analyzers of the present invention are: evolved gas analysis-mass spectrometry, differential thermogravimetric analysis-mass spectrometry,
It can be applied to all types of thermal analysis-mass spectrometry, and the interface device of the present invention can be used as an interface of all thermal analysis devices-mass spectrometry. The analysis / evaluation apparatus targeted by the present invention employs an interface for connecting an infrared image furnace capable of various temperature control program patterns such as high-speed temperature rise and mass spectrometry capable of high-sensitivity measurement,
Highly sensitive measurement of high boiling point gas components and high temperature pyrolysis desorption components. The present invention is characterized in that the capillary type interface has a higher sensitivity for a high mass number component having a lower measurement sensitivity.

FIG. 1 shows a schematic view of an example of a generated gas analysis-mass spectrometer using the skimmer type interface of the present invention. This equipment is a sample heating infrared image furnace (Furn
ance), its temperature control section (not shown), an interface section consisting of a double tube and a pump (Rotary pump), and a mass spectrometric section (Q-MS). He is typically used as the carrier gas,
Other inert gases (N ₂ , Ar, etc.) and O ₂
It is also possible to use a mixed gas to which is added (when O _{2 is} 20%, it is called a pseudo-atmosphere), a humidifying flow, or the like.

The sample heating infrared image furnace is not particularly limited, but preferably, for example, a gold mirror type infrared image furnace having a short focal length, which can reduce the heat load on the interface tip, is used. The temperature control unit is not particularly limited, but preferably, for example, a power control thyristor capable of highly accurate heating control or a program temperature controller is used.

The interface section is of a skimmer type which is composed of a double tube in which two tubes having pores (orifices) at the tip are arranged in two stages.
The orifice conditions depend on the carrier gas flow rate, but if the first-stage orifice diameter is, for example, about 0.7 mmφ, a flow rate of about 120 ml / minHe or more is required, and the second-stage orifice diameter is about 0 mm. A mass spectrometric section of about 10 ⁻³ Pa is maintained at a diameter of 0.12 mm. The middle of the double pipe is decompressed by a pump, and the condition is, for example, decompression by a small rotary pump having an exhaust speed of about 50 l / min. As the double tube, preferably,
Those made of quartz are used. Thereby, heating of the interface due to infrared radiation can be avoided, and there is almost no thermal damage even when the sample temperature reaches, for example, about 1500 ° C. Further, by doing so, it is possible to reduce the influence on the infrared light collection for heating the sample.

The mass spectrometric section is not particularly limited, but preferably, for example, a quadrupole mass spectrometer is used. The measurement mass number range depends on the performance of the mass spectrometer used and is not particularly limited. INDUSTRIAL APPLICABILITY The present invention can greatly contribute to the design / evaluation of a material / material manufacturing process by heating, and the analytical evaluation of various decomposition / desorption behaviors by heating a material.

[0013]

In the present invention, by using the interface of the above double tube structure, the gas component generated from the measurement sample is conveyed to the carrier gas flow, and the desorbed gas component is allowed to permeate through the pores in the subsequent stage, so that the gas component is efficiently transferred. It can be introduced into the high vacuum chamber of the analysis unit. In this case, in particular, the gas component having a higher mass is more concentrated and permeates through the pores in the latter stage. Further, by reducing the pressure in the middle of the double tube with a pump, in particular, a carrier gas having a small mass is diffused, and the desorbed gas component of the gas component can be efficiently permeated through the pores in the subsequent stage,
As a result, the gas component to be measured can be separated with high efficiency. This makes it possible to analyze a high-boiling substance with high accuracy. The double tube is heated only by infrared rays from the image furnace or radiant heat of the sample cell, for example, so that it is not necessary to keep it warm. Also,
By using a quartz interface, it is possible to minimize the influence on the performance degradation of the infrared image furnace that heats the sample by infrared light collection. Since the interface device of the present invention is particularly excellent in the permeability of high-mass gas components and sublimable components, high-sensitivity material analysis can be realized by using this device.

[0014]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. Example 1 In this example, aluminum hydroxide, which is a hydrolysis product of aluminum alkoxide, was used as a sample. That is, there are three kinds of aluminum ethoxide, isopropoxide and butoxide, and the hydrolysis products of each are X
It was confirmed by RD measurement that it was a hydroxide. For these three types of samples, comparative measurement was performed when the interface was a capillary and when the interface of the present invention was used. As a result, the ethoxide,
Comparing the detection intensities of the decomposition products of unreacted alkoxyl groups for isopropoxide, no significant difference was observed, but with butoxide having a large mass number, the interface of the present invention is about 2.5 times larger. Detected by intensity. The data are shown in FIGS. From these results, it was found that the interface of the present invention is effective in increasing the sensitivity of the gas component analysis of pyrolysis desorption product gas having a large mass number.

Example 2 In this example, aluminum acetylacetonate
([CH₃ COCH = CCH₃ O-]₃ Al) as a sample
did. This sample has a melting point of 190-193 ° C and a boiling point of 31.
Since it is 5 ℃, it depends on the capillary interface.
In the measurement, the normal capillary insulation temperature of 200 ℃
However, even if the heat retention temperature is set as high as 320 ° C,
Measurement became impossible due to aggregation in the capillary. Meanwhile, the book
In the interface of the invention, about 190 ℃ near the melting point
From acetylacetonate (CH₃ COCH = CCH₃
 O-) was used to detect gas components with mass numbers 99 and 84.
I put it out. The data is shown in FIG. From this result,
The present invention is applied to high boiling point substances that cannot be measured by the pilary type.
I have found that the interface is valid.

[0016]

As described above in detail, the present invention relates to an interface method and apparatus in the generated gas analysis-mass analysis, and the present invention has the following effects. (1) With respect to gas components generated by decomposition and desorption by heating, in particular, a high boiling point component, a high temperature generating component, and a high mass number component can be efficiently introduced into the mass spectrometer. Highly sensitive analysis can be realized. (2) It is possible to provide an interface that replaces a capillary whose measurement object is easily adsorbed on the inner wall and is applicable to an infrared image furnace. (3) The carrier gas having a small mass is diffused, and the desorbed gas component of the gas component can efficiently permeate through the pores in the subsequent stage. (4) It is not necessary to keep the interface warm, and the heat load on the tip of the interface can be reduced. (5) An infrared image furnace can be applied to the sample heating unit, and measurement corresponding to a temperature program such as rapid temperature rise can be realized.

[Brief description of drawings]

FIG. 1 Skimmer type interface of the present invention (upper stage)
It is a schematic diagram showing an example of generated gas analysis-mass spectrometry which adopted.

FIG. 2 shows the results of comparison of the detection intensities of decomposition products of Al ethoxide by the method of the present invention and the conventional method.

FIG. 3 shows the results of comparing the detection intensities of decomposition products of Al isopropoxide by the method of the present invention and the conventional method.

FIG. 4 shows the results of comparing the detection intensities of decomposition products of Al butoxide by the method of the present invention and the conventional method.

FIG. 5 shows the results of measurement of Al acetylacetonate by evolved gas analysis-mass spectrometry employing the interface device of the present invention.

[Explanation of symbols]

1 Sample heating part (Furnace) 2 Double tube structure interface 3 Analytical part (Q-MS) 4 pumps (Rotary pump) 5 Carrier gas

Claims (8)

[Claims] 1. In an evolved gas analyzer comprising a sample heating section and an analysis section, between an atmospheric pressure / low vacuum chamber for efficiently introducing a gas component produced from a measurement sample into a high vacuum chamber and analyzing the evolved gas. And a high-vacuum chamber interface method, wherein a double-tube having two tubes with holes at the tip arranged in two stages serves as an interface between atmospheric pressure / low vacuum and high vacuum. An interface method between the atmospheric pressure / low vacuum chamber and high vacuum chamber, characterized in that the pressure in the middle of is reduced by a pump, the gas component generated from the measurement sample is conveyed by a carrier gas flow, and is passed through the pores in the latter stage. . 2. A generated gas analyzer comprising a sample heating section and an analysis section, which analyzes a gas component generated from the sample by heating the sample to analyze and evaluate the thermal behavior of the substance. Interface device, which is an interface of atmospheric pressure / low vacuum and high vacuum, consisting of a double tube with two tubes with holes at the tip arranged in two stages, decompressing the middle of the double tube. An interface device of the generated gas analyzer, which comprises a pump for controlling the gas component generated from the measurement sample as a carrier gas flow and allows the gas to pass through the pores in the subsequent stage. 3. A quartz double tube is used as the double tube.
The interface device according to claim 2. 4. The interface device according to claim 2, wherein the high vacuum chamber of the analysis unit is equipped with a mass spectrometer. 5. An infrared image furnace is used for the sample heating section,
The interface device according to claim 2, further comprising temperature control means for high-speed temperature rise / fall. 6. An infrared image furnace is used for the sample heating section,
The interface device according to claim 2, further comprising a sample heating unit in the atmosphere, an inert gas such as nitrogen or a rare gas, or a humidified atmosphere thereof. 7. An evolved gas analyzer, wherein the interface device according to claim 2 is used as an interface of an infrared image furnace-mass spectrometer. 8. An analysis and evaluation device using the interface device according to claim 2 as an interface between a thermal analysis device and a mass analysis device.