WO2002004931A1

WO2002004931A1 - Luminous reaction measuring device

Info

Publication number: WO2002004931A1
Application number: PCT/JP2001/005881
Authority: WO
Inventors: Yoshihito Suzuki; Akifumi Kamiya; Seiji Suzuki; Teruhiko Yamaguchi
Original assignee: Hamamatsu Photonics K.K.
Priority date: 2000-07-07
Filing date: 2001-07-06
Publication date: 2002-01-17
Also published as: JP2002022662A; AU2001269465A1

Abstract

A luminous reaction measuring device (10) wherein a sample gas (NO) and an oxidizing gas (O3) are subjected to chemical reaction within a reaction chamber (2) and the intensity of the chemiluminescence produced during the chemical reaction is detected by a photodetector (32), characterized by comprising an optically transparent window (3) for admitting the light produced by chemiluminescence into the photodetector (32), a sample gas introducing portion (6) for introducing the sample gas into the reaction chamber in a direction perpendicular to the optically transparent window (3), an oxidizing gas introducing portion (8) for introducing the oxidizing gas into the reaction chamber in a direction substantially orthogonal to the direction of introduction of the sample gas so that the oxidizing gas may collide with the sample gas introduced from the sample gas introducing portion (6), and a gas discharging portion (12) for discharging the gas, produced by chemical reaction between the sample gas and the oxidizing gas, out of the reaction chamber into the outside of the system, the sample gas introducing portion (6) being offset from the center (L) of the reaction chamber in a direction away from the installed position of the gas discharge portion (12).

Description

Specification

Luminescence reaction measuring device

The present invention includes a sample gas nitric oxide (NO) or the like contained in the exhaust gas or the like of asthmatics breath and automobiles, ozone (0 ₃₎ the intensity of chemiluminescence generated when the oxidizing gas is reacted such More particularly, the present invention relates to a luminescence reaction measuring device suitable for measuring the concentration of a sample gas such as NO. Background art

Recently, nitric oxide and (NO) and ozone (0 ₃₎ by chemical reaction, an increasing demand for the concentration measuring apparatus for measuring the concentration of nitrogen monoxide based on the intensity of the chemiluminescence generated during reaction I have. According to this device, the therapeutic effect can be monitored by measuring the concentration of nitric oxide in the breath of an asthmatic patient, or the concentration of nitric oxide in the exhaust gas of automobiles can be measured to address environmental issues. References disclosing such a device include, for example, Japanese Patent Application Laid-Open Nos. Hei 9-115,055, Hei 9-145,621, and Hei 6-114 No. 45 is known.

According to a chemiluminescent nitrogen oxide meter above publication (luminescent reaction measurement device), then chemiluminescence by reacting both by introducing a N 0 0 ₃ in the anti応室, the chemiluminescent Is converted into an electric signal by the semiconductor photoelectric conversion element, whereby the concentration of N 0 can be measured. Disclosure of the invention

However, the luminescence reaction measuring devices described in the above publications have the following problems. That is, in the apparatuses described in the above publications, the capillaries for introducing NO into the reaction chamber are inclined with respect to the light transmission window disposed above the semiconductor photoelectric conversion element. Therefore, NO enters obliquely toward the light transmission window. When NO is obliquely incident on the light transmission window in this way, it is difficult for NO to stay on the glass window. Therefore, hardly made incident light by chemiluminescence by the reaction of NO and 0 ₃ to the light receiving surface, the measurement accuracy of the NO concentration can not be said to be high.

The present invention has been made to solve the above-described problem, and has as its object to provide a luminescence reaction measuring device with high measurement accuracy of chemiluminescence.

The present invention relates to a luminescence reaction measuring apparatus in which a sample gas and an oxidizing gas are chemically reacted in a reaction chamber and the intensity of chemiluminescence generated during the reaction is detected by a photodetector. A light transmitting window for causing the sample gas to be introduced into the reaction chamber from a direction perpendicular to the light transmitting window, and a sample gas introduced from the sample gas introducing portion. An oxidizing gas introduction unit that introduces an oxidizing gas into the reaction chamber from a direction substantially perpendicular to the sample gas introduction direction, and a gas reaction chamber generated by a chemical reaction between the sample gas and the oxidizing gas to discharge the system outside. And a gas exhaust portion, wherein the sample gas introduction portion is eccentric from the center of the reaction chamber in a direction away from the gas exhaust portion.

According to the luminescence reaction measurement device of the present invention, the sample gas such as nitric oxide is perpendicularly incident on the light transmission window by the sample gas introduction unit, so that the sample gas easily stays near the light transmission window. Become. For this reason, most of the sample gas introduced into the reaction chamber reacts with an oxidizing gas such as ozone introduced from the oxidizing gas introduction section in the vicinity of the light transmission window to generate chemiluminescence. A large amount of light is detected. In addition, since the sample gas inlet is eccentric from the center of the reaction chamber in a direction away from the gas exhaust unit, the sample gas can stay in the reaction chamber for a long time, and as a result, more light can be detected by the photodetector. Can be incident. Furthermore, since the oxidizing gas introduction unit introduces the oxidizing gas into the reaction chamber from a direction substantially perpendicular to the sample gas introduction direction, the probability of contact between the oxidizing gas and the sample gas increases, and more light is emitted. It is possible to produce them. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing a first embodiment of the luminescence reaction measuring device according to the present invention. FIG. 2 is a cross-sectional view of the luminescence reaction measuring device shown in FIG.

FIG. 3 is a front view of the luminescence reaction measuring device shown in FIG.

FIG. 4 is a graph showing the relationship between pressure and output current for the luminescence reaction measurement device and the comparison device of the first embodiment. '

FIG. 5 is a perspective view showing a second embodiment of the luminescence reaction measuring device according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of a luminescence reaction measuring device according to the present invention will be described in detail with reference to the accompanying drawings. The same elements will be denoted by the same reference symbols, without redundant description.

[First Embodiment]

FIG. 1 is a schematic perspective view showing a luminescence reaction measuring device 10 of the present embodiment, and FIG.

FIG. 3 is a cross-sectional view of the luminescence reaction measurement device 10 shown in FIG. 1, and FIG. 3 is a front view showing the luminescence reaction measurement device 10. Luminescent reaction measuring apparatus 1 0 of the present embodiment, in order to measure the concentration of nitric oxide (NO) of the sample gas is reacted with ozone (0 ₃₎ and this NO and oxidizing gas This causes chemiluminescence to occur, and the intensity of the luminescence is measured.

The luminescence reaction measuring device 10 mainly includes a reaction module 20 for reacting NO with ozone to generate chemiluminescence, and a light measurement module 30 for measuring the intensity of luminescence generated in the reaction module 20. And

The reaction module 20 includes a reaction chamber 4 (see FIGS. 2 and 3) in which a cylindrical reaction chamber 2 for generating the chemiluminescence is formed, and a reaction chamber 4 for introducing NO into the reaction chamber 2. Nitrogen oxide inlet tube (sample gas inlet) 6 and ozone introduced into reaction chamber 2 Ozone introduction pipe (oxidizing gas introduction section) 8 for injecting gas, gas exhaust pipe (gas exhaust section) for exhausting the reacted gas in the reaction chamber 2 out of the system, and reaction chamber 2 And a pressure sensor 16 for detecting the internal pressure. The reaction module 20 is fixed to the light measurement module 30 by being bolted to a plate 11 attached to the side of the case of the light measurement module 30. The optical measurement module 30 is supported by a support 14.

As shown in FIG. 2, the reaction chamber 2 is surrounded by a light transmitting window 3 made of glass and a reflecting mirror 5 arranged opposite thereto, and both the light transmitting window 3 and the reflecting mirror 5 are circular flat plates. Have been. The light transmission window 3 allows the light due to the chemiluminescence generated in the reaction chamber 2 to be incident on the light measurement module 30 and also functions as a long-wavelength transmission file adapted to the spectrum of the chemiluminescence. In addition, the reflecting mirror 5 is for reflecting the light emitted in the opposite direction to the light measurement module 30 out of the light by the light emission to the light measurement module 30 side. Further, a circular lid 7 is bolted to the reaction chamber 4 so as to cover the reaction chamber 2. FIG. 3 shows a state where the lid 7 is removed.

As shown in FIG. 2, the nitric oxide introducing pipe 6 is inserted through the lid 7 and the reflecting mirror 5 so that the longitudinal direction thereof is along the normal direction of the light transmitting window 3. The inlet 6 a at the tip of the nitric oxide inlet pipe 6 is located in the reaction chamber 2 and faces the light transmission window 3. Further, as shown in FIG. 3, the nitric oxide introduction pipe 6 is eccentric from the central axis L of the columnar reaction chamber 2. Here, the central axis L means a cross section parallel to the light transmission window 3 of the reaction chamber 2 and an axis passing through the center of gravity of this cross section.

The ozone introduction tube 8 is mounted on the reaction chamber 4 so as to be orthogonal to the nitric oxide introduction tube 6 and horizontal to the installation surface of the luminescence reaction measurement device 10. The inlet 8a at the end of the ozone inlet tube 8 is located on the side of the columnar reaction chamber 2 and above the central axis.

The gas exhaust pipe 12 has an outlet 12 a at the tip thereof at the side of the cylindrical reaction chamber 2 and The reaction chamber 4 is mounted below the center axis L. In addition, the gas exhaust pipe 12 is arranged such that its outlet 12 a is point-symmetric with the inlet 8 a of the ozone inlet pipe 8 with respect to the central axis L. Further, the gas exhaust pipe 12 is provided with a valve 13 for adjusting the exhaust speed of NO and ozone.

Further, as shown in FIG. 3, the nitric oxide introduction pipe 6 is eccentric from the center axis L of the reaction chamber 2 in a direction away from the position where the gas exhaust pipe 12 is provided. More specifically, the nitrogen monoxide introducing pipe 6 moves away from the installation location of the outlet 12 a of the gas exhaust pipe 12, and is eccentric from the center axis L in a direction approaching the inlet 8 a of the ozone introducing pipe 8. I have. That is, the distance between the inlet 6a of the nitric oxide inlet pipe 6 and the outlet 12a of the gas exhaust pipe 12 is determined by the distance between the central axis L and the outlet 12a of the gas exhaust pipe 12. It is longer than the distance between them. The inlet 8a of the ozone inlet tube 8 is located above the inlet 6a of the nitric oxide inlet tube 6, but the ozone introduced into the reaction chamber 2 is It is positioned high enough to collide with the introduced NO.

As shown in Fig. 2, the light measurement module 30 is equipped with a side-on type PMT (photomultiplier tube) 32 for measuring the intensity of light due to chemiluminescence generated in the reaction chamber 2. ing. A lens 34 for condensing light transmitted through the light transmission window 3 toward the PMT 32 is provided closer to the reaction chamber 4 than the PMT 32. The PMT 32 multiplies the light passing through the lens 34, converts the amount of light into an electric signal at the photocathode 32a, and detects the intensity of chemiluminescence. Although not shown, the luminescence reaction measuring apparatus 10 of the present embodiment has a calculation for obtaining the concentration of nitric oxide contributing to the luminescence based on the intensity of the chemiluminescence in the reaction chamber 2. The device is connected. As shown in FIGS. 1 and 3, a Peltier cooler 36 and an air cooling fan 38 for cooling the PMT 32 are provided above the PMT 32.

The above is the configuration of the luminescence reaction measuring device 10 of the present embodiment. Next, the operation of the luminescence reaction measuring device 10 will be described. Here, the operation when the luminescence reaction measuring device 10 is applied to a device for measuring the concentration of nitric oxide in the breath of an asthmatic patient will be described. First, ozone gas is introduced into the reaction chamber 2 through the ozone introduction pipe 8, while exhalation of a patient is introduced into the reaction chamber 2 through the nitrogen monoxide introduction pipe 6. The exhalation of this patient contains NO. Then, the ozone and NO cause a chemical reaction represented by the following formula in the reaction chamber 2 to generate chemiluminescence. Incidentally, N0 ₂ * refers to N0 ₂ in an excited state.

NO + 0 ₃ → N0 ₂ * + 0 ₂

N0 ₂ * → N0 ₂ + h

The light by the chemiluminescence passes through the light transmission window 3 and the lens 34 and enters the PMT 32. The light reflected by the reflecting mirror 5 also enters the PMT 32. Then, the intensity (light quantity) of the chemiluminescence is detected in the PMT 32, and the concentration of NO is measured based on the intensity of the chemiluminescence by the above-mentioned arithmetic unit (not shown). The light intensity due to the chemiluminescence is proportional to the NO concentration when the amount of ozone in the reaction chamber 2 is sufficient, and the NO concentration can be obtained by measuring the amount of light.

The gas generated by the chemical reaction is exhausted from the gas exhaust pipe 12 by operating a pump (not shown). At this time, by operating the valve 13 to adjust the pumping speed, N0 ₂ * from being aspirated from the reaction chamber 2 before emitting. Here, according to the luminescence reaction measuring device 10 of the present embodiment, the longitudinal direction of the nitric oxide introduction tube 6 is along the normal direction of the light transmission window 3, and the introduction port 6a faces the light transmission window 3. Therefore, the exhaled air (NO) that has passed through the nitric oxide introducing pipe 6 flows perpendicularly to the light transmitting window 3. For this reason, NO easily stays near the light transmission window 3, and most of N 0 introduced into the reaction chamber 2 reacts with ozone near the light transmission window 3 to generate chemiluminescence. Thereby, a large amount of light can be detected by the PMT 32, and the measurement accuracy of the chemiluminescence is improved, and the measurement accuracy of the NO concentration is also improved. In addition, the nitric oxide introducing pipe 6 Since it is eccentric from the center axis L, the distance between the introduction position of N 0 and the exhaust position is increased, so that NO can stay in the reaction chamber 2 for a long time. Therefore, a large amount of NO can react with ozone, and more light can be detected by the PMT32. Further, ozone is introduced into the reaction chamber 2 from the direction orthogonal to the NO introduction direction by the ozone introduction pipe 8, so that the contact efficiency between NO and ozone is increased, and the light emission amount is increased. Note that the angle between the ozone introduction pipe 8 and the nitric oxide introduction pipe 6 does not necessarily need to be 90 degrees, and such an effect can be obtained if it is in the range of 80 to 100 degrees.

Furthermore, since the outlet 12a of the gas exhaust pipe 12 and the inlet 8a of the ozone inlet pipe 8 are point-symmetric with respect to the center axis L of the reaction chamber 2, ozone is accumulated in the reaction chamber 2. The time to stay is also longer. For this reason, a sufficient amount of ozone to react with NO introduced into the reaction chamber 2 can be retained in the reaction chamber 2.

Next, with reference to FIG. 4, experimental results using the luminescence reaction measuring device 10 of the present embodiment will be described. As a device for comparison, a luminescence reaction measuring device was used in which the nitric oxide introduction tube was installed not along the normal of the light transmission window 3 but along the vertical direction (the height direction of the luminescence reaction measuring device). . FIG. 4 is a graph showing the relationship between the pressure in the reaction chamber 2 and the output current of the PMT 32. The same amounts of nitric oxide and ozone were introduced into each device. Further, the reaction chamber pressure of ^{2 1. 26 x 10 4, 2.} 13 X 10 \ 3. 46 x 10 4, 4. For the case where the 798 X 10 ⁴ P a, the intensity of the output or chemiluminescence of PMT 32 Was measured.

In the graph of FIG. 4, the output result of the comparative example is indicated by a triangle, and the output result of the luminescence reaction measuring apparatus 10 of the present embodiment is indicated by a circle. As can be seen from the graph, the output current from the PMT 32 of the device according to the present embodiment in which NO is perpendicularly incident on the light transmission window 3 is about 30% higher than the output current of the comparative example. ing. This indicates that the use of the luminescence reaction measurement device 10 of the present embodiment has higher luminescence detection accuracy and allows accurate measurement of the concentration of nitric oxide. [Second embodiment]

Next, a second embodiment of the luminescence reaction measuring device 10 according to the present invention will be described with reference to FIG. In the present embodiment, the nitric oxide introduction pipe 6 is eccentric vertically above the center axis L of the reaction chamber 2. Further, similarly to the first embodiment, N 2 O passing through the nitric oxide introducing pipe 6 flows into the reaction chamber 2 from a direction perpendicular to the light transmission window 3. Further, the ozone introduction pipe 8 is disposed above the reaction chamber 2, and the ozone passing through the ozone introduction pipe 8 flows vertically downward and flows into the reaction chamber 2 from a direction orthogonal to the NO introduction direction. . Further, in the present embodiment, gas exhaust pipes 12 are provided on both side surfaces of the reaction chamber 4, and the height position of each gas exhaust pipe 12 is lower than the central axis L of the reaction chamber 2. .

Also in the luminescence reaction measuring apparatus 10 of the present embodiment having the above-described configuration, the nitric oxide introduction pipe 6 is decentered vertically upward from the central axis L of the reaction chamber 2 so that the nitrogen oxide introduction pipe 6 The distance between the inlet 6a of the gas exhaust pipe 12 and the outlet 12a of the gas exhaust pipe 12 is longer than the distance between the central axis L and the outlet 12a of the gas exhaust pipe 12. It can be kept in the reaction chamber 2 for a long time, and the luminescence measurement accuracy can be improved. Further, even if the ozone introduction pipe 8 is set to be vertical in the vicinity of the reaction chamber 2, the ozone flows into the reaction chamber 2 so as to be orthogonal to the NO inflow direction. And the amount of light emission increases.

As described above, the invention made by the present inventors has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments. For example, the photodetector for detecting the intensity of chemiluminescence is not limited to a photomultiplier, but may be a silicon photodiode or the like.

The luminescence reaction measured by the luminescence reaction measuring device is not limited to the reaction between nitric oxide and ozone. For example, as a sample gas instead of nitric oxide, ethylene, isoprene, ammonia, formaldehyde (formalin), etc., which emit light by reacting with ozone, can be used. In addition, as oxidizing gas, in addition to ozone, Elemental and chlorine can be used. Industrial applicability

As described above, according to the luminescence reaction measuring apparatus according to the present invention, the sample gas such as nitric oxide is perpendicularly incident on the light transmission window by the sample gas introduction unit, so that the sample is placed near the light transmission window. Gas tends to stay. For this reason, most of the sample gas introduced into the reaction chamber reacts with an oxidizing gas such as ozone introduced from the oxidizing gas in the vicinity of the light transmitting window to generate chemiluminescence. Is detected. In addition, since the sample gas inlet is eccentric from the center of the reaction chamber in a direction away from the gas exhaust unit, the sample gas can stay in the reaction chamber for a long time. Can be incident. Furthermore, the oxidizing gas introduction unit introduces the oxidizing gas into the reaction chamber from a direction substantially perpendicular to the sample gas introduction direction, so that the contact probability between the sample gas and the oxidizing gas is increased. As a result, the amount of luminescence is increased, and the detection sensitivity of chemiluminescence can be improved.

Claims

The scope of the claims

1. In a luminescence reaction measuring device in which a sample gas and an oxidizing gas are chemically reacted in a reaction chamber and the intensity of chemiluminescence generated during the reaction is detected by a photodetector, the light due to the chemiluminescence is transmitted to the photodetector. A light transmission window for incidence, a sample gas introduction unit for introducing the sample gas into the reaction chamber from a direction perpendicular to the light transmission window,

An oxidizing gas introduction unit that introduces the oxidizing gas into the reaction chamber from a direction substantially perpendicular to a direction in which the sample gas is introduced, so as to collide with the sample gas introduced from the sample gas introduction unit;

A gas exhaust unit for discharging a gas generated by a chemical reaction between the sample gas and the oxidizing gas from the reaction chamber to the outside of the system,

The luminescence reaction measuring apparatus, wherein the sample gas introduction unit is eccentric from a center of the reaction chamber in a direction away from a position where the gas exhaust unit is provided.