JP2001174406A - Optical part for photochemical detector, multi-optical part for photochemical detector, photochemical detector using the optical part or the multi-optical part for photochemical detector, and photochemical detection method, and manufacturing method of optical part for photochemical detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel optical part for a photochemical detector with minute capacity capable of absorbing light or emitting fluoresence with high efficiency, a photochemical detector, a method for manufacturing the same and a photochemical detection method. SOLUTION: The optical part for photochemical detector is constituted so that filter members each of which is formed by arranging a multilayered film, wherein two kinds of light-transmissible membranes A, B having an optical thickness being integral multiple of 1/4 of a center detection wavelength and different in refractive index are alternately laminated, to the end surface of a light-transmissible member 11 are arranged through a gap 12 being the half of the center detection wavelength and receiving a sample to be measured so that the end surfaces to which the multilayered films are arranged are opposed to each other. The photochemical detector using the optical part, photochemical detection method and the method of manufacturing the optical part for the photochemical detector of provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical component for photochemical detection, a multi-optical component for a photochemical detector, a photochemical detector using the optical component for photochemical detection or a multi-optical component for a photochemical detector, a photochemical detection method, and a photochemical detection. The present invention relates to a method for manufacturing optical components for instruments, and more particularly, to a detector or a chemical sensor used as a detection part of a microanalytical method such as high performance liquid chromatography, capillary electrophoresis, gas chromatography, and a method of using and manufacturing the same. Things.

[0002]

2. Description of the Related Art A variety of chemical substances discharged into the environment along with the increase in human social activities have become a serious social problem because they are substances that pollute the environment. It is said that even a trace amount of such contaminant chemicals has a large effect on living organisms and ecosystems, and high-sensitivity detection is desired. Currently p
As a method capable of highly sensitive detection at the pt level, there is gas chromatography mass spectrometry. However, this method requires expensive equipment, requires a skilled operator, requires a long time for analysis, and increases the analysis cost. In particular, since environmental analysis requires periodic analysis of samples from multiple points, a highly sensitive alternative to this analysis is desired.

[0003] Further, this method has a drawback that it cannot be applied to the analysis of non-volatile substances or thermally decomposable substances, and it is difficult to use gas chromatography or gas chromatography mass spectrometry among all organic substances present in water. Is said to be able to measure only a fraction of them.

In gas chromatography mass spectrometry, a sample is separated into components by gas chromatography,
In this method, mass spectrometry requires an evacuation system for ionization in order to perform mass spectrometry, and there is a limit to miniaturization and cost reduction of the apparatus. There is a need to develop a simpler and more sensitive detection technique that replaces mass spectrometry.

On the other hand, high-performance liquid chromatography and capillary electrophoresis are often used for high-sensitivity analysis of liquid samples. High-performance liquid chromatography is a method in which a sample is passed through an adsorption column to separate each component in the sample from differences in adsorptivity. Capillary electrophoresis is a method in which a sample is passed through a capillary (capillary), a high voltage is applied to both ends of the capillary, and the components are separated based on the difference in the moving speed of each component.

In principle, a technique common to both can be used to detect a separated sample, and light absorption detection, fluorescence detection, differential refractive index detection, thermo-optical detection, circular dichroism detection, and electrodes using light are used. Electrochemical detection, electrical conductivity detection, and electrochemiluminescence detection. In addition, high-performance liquid chromatography and capillary electrophoresis have been combined with mass spectrometry in the same manner as gas chromatography. This is because it can be applied to non-volatile substances and thermally decomposable substances, which are difficult in gas chromatography, and is excellent in versatility. However, there are still many problems to be solved in terms of miniaturization and simple analysis.

In capillary electrophoresis, it is important to incorporate a detector without impairing the feature that the sample volume can be made very small. In the case of absorption detection or fluorescence detection, it is performed by peeling off a part of the capillary to form an optical window. On the contrary,
In the detection method using electrodes, electrodes must be incorporated.

In the detection of electric conductivity, two fine holes are formed in a capillary with a laser and a fine platinum wire is used as a detection electrode (X. Huang, T. et al.).
K. J. Pang, M .; J. Gordon, R.A. N. Z
are, Anal. Chem. , 59, 2747 (19
87)). In the electrochemical detection measurement, a high voltage for separation hinders the detection, so that a fine liquid part is provided in the capillary and the liquid part is immersed in the electrochemical cell (RA). Wallingford, A .;
G. FIG. Ewing, Aal. Chem. , 61,1344
(1989)). Since the separation voltage is not applied from the liquid junction to the capillary outlet, electrochemical detection can be performed with an electrode disposed at the capillary outlet. As described above, in the electrochemical method, since the electrophoresis is stopped immediately before the detector, the off-column detection is basically performed, and the peak may spread before reaching the detector after the electrophoresis. Further, compounds that undergo an electrochemical reaction are limited to those having a metal complex or a substituent that causes oxidation and reduction.

As described above, in capillary electrophoresis, the capillaries are fine, so that microfabrication and micromachine technology are important for incorporating a detector. For example, in the laser-induced fluorescence method, which is considered to be the most sensitive, the flow path can be made small using micromachine technology, but the laser and the optical system become considerably large.

At present, absorption detection is the mainstream in capillary electrophoresis. However, in capillary electrophoresis, since the absolute amount of the sample is very small and the inside diameter of the capillary is small, it is difficult to increase the optical path length.
As long as a conventional photodetector is used, there is no suitable method other than making the detection possible by increasing the sample concentration as much as possible. It becomes very difficult to detect a real sample in which the sample itself has a low concentration and cannot be concentrated.
When a component having a molecular extinction coefficient of about 10,000 is detected using sufficiently concentrated ultraviolet light of high energy, the lowest concentration detectable by the absorption method is about 1 μM.

In order to increase the sensitivity of light absorption detection, a light detecting section has been devised to increase the optical path length. For example, a method of increasing the inner diameter of a part of the capillary and performing light detection at this part (a device manufactured by Hewlett-Packard), or covering the outside of the capillary with silver and opening two small windows to obliquely incident light. The optical path length is increased by multiple reflection in the insertion capillary (T. Wang, JHA)
Iken, C.I. W. Hui, R .; A. Hartwick
k, Anal. Chem. 63, 1372 (199
1)) are performed. However, there is a limit to increasing the optical path length, and the separation characteristics are reduced.

[0012]

In light detectors used in microanalytical methods such as high performance liquid chromatography, capillary electrophoresis, gas chromatography, and chemical sensors, the optical path length becomes shorter when the sample amount is small. As a result, light cannot be efficiently absorbed, and as a result, the sensitivity of the light absorption detection method or the fluorescence detection method decreases. In a cell having a long optical path length, the sample amount increases, and it is difficult to obtain high resolution.

An object of the present invention is to solve the above-mentioned problems.
An object of the present invention is to provide a novel optical component for a photochemical detector, a photochemical detector and a method for manufacturing the same, and a photochemical detection method, which are capable of absorbing light and emitting fluorescence with high efficiency.

[0014]

To summarize the present invention, the optical component for a photochemical detector according to the present invention has an optical film thickness which is an integral multiple of 1/4 of the center detection wavelength and which has a different refractive index.
A filter member in which a multilayer film formed by alternately laminating different types of light-transmitting thin films is disposed on the end face of the light-transmitting member, is sandwiched by a gap for introducing a sample to be measured having a wavelength of の of the wavelength. The end faces on which the films are arranged are arranged to face each other.

Further, the photochemical detector according to the present invention comprises a monochromatic light source, the optical component for the photochemical detector that receives incident light from the monochromatic light source, and a photodetector that detects light emitted from the optical component for photochemical detection. And a container.

Further, in the photochemical detector according to the present invention, there is provided a photochemical detector optical component for receiving incident light from the light source, and / or one or both of the opposed filter members of the photochemical generating optical component. Linear moving means for linearly changing the distance between the end faces of the filter member, spectral means for limiting the wavelength range of light emitted from the optical component for photochemical detector, and output means of the spectral means. It is characterized by including a photodetector for detecting emitted light.

Further, the third photochemical detector according to the present invention, in the photochemical detector in which one of the filter members is formed in a disk shape and a porous thin film is formed, a rotating mechanism for rotating the disk-shaped filter member; A mechanism for bringing the other filter member into contact with the disc-shaped filter member, an inner tube arranged so as to surround the other filter member as a center axis, and an inner tube arranged so as to further surround the inner tube and having a distal end portion A thin tube comprising an outer tube installed in a more protruding state, a mechanism for pre-contacting the thin tube with the disc-shaped filter member while maintaining the same relative positional relationship between the inner tube and the outer tube, and the inner tube A mechanism for flowing a gas to be measured from a hollow formed by an outer wall and an inner wall of the outer tube toward the inner tube and the hollow of the other filter member; the other filter member and the inner tube; Characterized in that it comprises a moving mechanism for relatively moving the whole of the outer tube in the radial direction of the disk-shaped filter member.

Further, in the photochemical detection method according to the present invention, the sample to be measured is sandwiched in a gap for introducing the sample to be measured in the optical component for a photochemical detector, and incident light passes through one of the two filter members. The incident light is localized as a standing wave at a portion where the sample to be measured is disposed by one filter member, and the localized standing wave light and the sample to be measured are optically interacted with each other. The light emitted from the filter member is detected.

Further, the method of manufacturing an optical component for a photochemical detector according to the present invention is characterized in that two types of optical materials having different refractive indices are vapor-deposited, sputtered, vapor-phase reacted,
A multilayer film of a light-transmitting thin film is formed by alternately stacking by any one of a sol-gel method, a coating method, and a spraying method, and the two types of light-transmitting thin films are laminated in the light-transmitting thin film laminating step. The optical film thickness of the thin film is set to an integral multiple of 1/4 of the detection center wavelength, and the multilayer film is arranged so that end faces thereof face each other with a gap for introducing a sample to be measured having a detection center wavelength of 1/2. It is characterized by.

That is, in a photodetector used for high-performance liquid chromatography, capillary electrophoresis, gas chromatography, or a microanalysis method such as a chemical sensor, an optical thin film of a material having a different refractive index is periodically provided in an optical path. The thickness of each optical thin film is arranged so as to be an integral multiple of 1/4 of the wavelength of light used for detection, and the structure is such that the sample to be measured can pass through the center of the period.

FIG. 1 is a basic structural view of an optical component for a photochemical detector according to the present invention, wherein two types of light-transmitting thin films A having different refractive indices are provided on an end face of a multimode optical fiber (light-transmitting member) 11. The conductive thin films B are alternately arranged, and their film thicknesses are n _A * λ / 4 and n _B * λ / 4. Where n
_A and n _B are the refractive indices of the respective films, and λ is the center wavelength of light used for light detection. Two optical fibers (filter members) each having a multilayer film composed of a light-transmitting thin film A and a light-transmitting thin film B on an end face are inserted into a minute gap (gap for introducing a sample to be measured) 12
Are opened to face each other to obtain an optical component for a photochemical detector according to the present invention.

In the above configuration, a sample is introduced into the gap 12, light is introduced from one of the optical fibers, and the transmitted light is observed by the other optical fiber to detect a substance in the gap. It is.

[0023]

According to the present invention, highly efficient absorption analysis and fluorescence analysis can be performed on a very small amount of sample. It is for the following reasons. First, the gap 1 through which the sample passes
Consider the case where there is no 2. When light is transmitted through such periodically arranged light-transmitting thin films having different refractive indices, each light-transmitting thin film is successively subjected to reflection according to the difference in refractive index. As a result, the light transmittance decreases.
In particular, when a large number of optical film thicknesses (product of the film thickness and the refractive index) are alternately arranged so as to be equal to each other, an opaque region (forbidden band) centered on light having a wavelength corresponding to four times the optical film thickness. Is formed.

FIG. 2 shows SiO ₂ (refractive index: 1.46) and Hf
The optically transparent thin film of O ₂ (refractive index 2.1) has an optical thickness of 400/4 nm (actual thickness is 68.5 n each).
(m, 47.6 nm). 40
It can be seen that an opaque region is formed around 0 nm. This is because light in this wavelength band cannot exist in the periodic structure, and light is reflected from the outside without entering the inside of the periodic structure. The dielectric multilayer mirror realizes high reflectance based on this principle.

Next, let us consider a case where there is a gap (called a defect layer in the sense of destroying the periodicity) at the center of the periodic thin film (multilayer film) so that its optical film thickness becomes half the wavelength. The transmission spectrum in this configuration is 400 n as shown in FIG.
A sharp peak appears at the position of m. That is,
Light having a wavelength of 400 nm can be transmitted 100%. This is because the presence of the defect layer causes a wavelength (standing wave) that can exist in the defect layer to appear, so that when light is incident from the outside, only light of this wavelength can be transmitted. .

The energy level of a wavelength that can be transmitted by introducing this defect due to the similarity with the semiconductor is called a defect level. When light having a wavelength corresponding to the defect level propagates through the periodic structure, the light is localized near the defect, so that the optical electric field in the defect is strengthened. Light transmitting material thin film A,
Optical field intensity for each pass through the B becomes the (n _B / n _A) times,
The electric field intensity at the defect after passing through the N layer is (n _B / n _A ) ∧N and is greatly amplified. When the light intensity is increased, the enhancement is further increased (n _B / n _A ) ∧2N. On the other hand, after passing through the defect, the intensity of the photoelectric field starts to decrease, and at the time of emission, the intensity becomes the intensity at the time of incidence, and the transmittance becomes 1. An increase in the optical field strength at the defect layer indicates that light is localized at this location. In other words, since a high-reflection dielectric multilayer mirror has a resonator structure, light reciprocates in this defect layer, resulting in an extremely high existence probability. The increase of the electric field intensity can be controlled by the number of periods, and the position and number of peaks can be controlled by the optical film thickness of the defect layer.

Next, if there is a substance that absorbs light in the defect layer, the intensity of the photoelectric field is attenuated by the absorption, and
The transmittance decreases. The transmittance is a function of the product of the absorbance at the defect layer and the increase in light intensity. Therefore, even when the molecular extinction coefficient and the concentration are very small, the transmittance can be measured in the optimum absorbance region by increasing the number of periods. This is because even when the molecular extinction coefficient or the concentration is very small, light is localized in the defect layer, so that the opportunity for molecules to absorb light can be increased. Also, in the fluorescence measurement, since the light is efficiently absorbed, the fluorescence efficiency is increased and the sensitivity is improved.

Many optical materials can be used as a material for forming the light transmitting thin film. As a material having a low refractive index, for example, quartz glass, fused glass, Vycor glass, Pyrex glass or Pyrex, plastic, NaF, LiF, CaF ₂ , NaCl, KB
r, MgO, and the like. As materials having a high refractive index, titanium oxide, zirconium oxide, HfO ₂ , T
a ₂ O ₅ , SrTiO _{3 and the} like. When applied to infrared absorption measurement, semiconductors such as Ge, InSb, and Si can be used. Examples of the substrate material include transparent optical materials and optical components such as optical fibers and optical waveguides.

Techniques for periodically disposing materials having different refractive indices include a method of alternately sputter depositing materials having different refractive indices, a photolithography and a dry etching method,
Alternatively, a method in which a microfabrication technique such as a lift-off method or an ion milling method is combined and formed on a substrate can be given. The fine gap for the sample can be formed by a method using a micrometer or a piezo element, a method using a scanning tunneling microscope (STM), a method using a suitable spacer to make the sample close to each other, and the like.

In the case of high performance liquid chromatography, capillary electrophoresis, gas chromatography, etc.
By intersecting the separation column with the gap for introducing the sample to be measured, the sample to be measured can be introduced into the gap.

Hereinafter, a photochemical detector and a photochemical detection method using the optical component for a photochemical detector, and a method for manufacturing the optical component for a photochemical detector will be described in detail with reference to examples.

[0032]

Embodiments of the present invention will be described below in detail with reference to the drawings. The present invention is not limited only to the following examples.

[0033]

Embodiment 1 As a first embodiment of the present invention, a photochemical detector (absorber) having optical components for optical chemical detector (sample introduction part) in which thin films of SiO ₂ and HfO ₂ are alternately formed on the end face of an optical fiber. The structure and manufacturing method of the detector will be described with reference to FIGS.

A UV transmission type multi-mode optical fiber (365 μm in core diameter, 400 μm in clad diameter, manufactured by Oz Optics) was cut to a length of 2 cm, and both end faces were cut with an optical fiber polishing machine (NTT-
AT Co., Ltd.), 1 cc of distilled water was applied and polished with a metal bond film for 3 minutes, and then 1 cc of distilled water was applied for 2 minutes each with an ultra-thin diamond polishing film for rough finishing and medium finishing. Polished. Finally, use Ce polished film for 4
1 cc of SiO ₂ solution was applied for one minute and polished. After washing the optical fiber with pure water, it was dried.

[0035] Then mounted for sputter deposited one end face of the optical fiber at a predetermined position of the optical fiber sputtering apparatus (manufactured by Nippon Seed Co.), SiO _2, discharge in the order of HfO ₂ Power 300 W, an argon atmosphere 0 .005
Sputter deposition at Torr, 43, 30 respectively
A film thickness of nm was obtained. This was repeated 32 times.

Thereafter, optical fibers (filter members) 41 and 42 were manufactured by depositing nickel to a thickness of 48 nm. A hole 44 having a diameter of 0.5 mm is formed in the center of a rectangular quartz substrate 43 (1 cm × 6 cm, thickness 0.5 mm) with a diamond drill, and then light is passed through the hole 44 using a dicing saw (manufactured by Disco Corporation). A groove 45 for the fiber was formed in the longitudinal direction. The nickel end faces of the optical fibers 41 and 42 are arranged so as to be in contact with the grooves 45 at the center hole 44, and the side faces of the optical fibers 41 and 42 are fixed to the grooves 45 using a UV curing resin (manufactured by Loctite). did. Thereafter, the nickel portion was dissolved with an acid to complete an optical chemical detector having a minute gap (gap for introducing a sample to be measured) 46 (96 nm) (see FIG. 4).

Using the optical chemical detector manufactured as described above, 254 nm from the mercury lamp 47 is taken out using the interference filter 48, and one optical fiber (filter member) 4 of the optical component for the optical chemical detector is taken out through an optical fiber.
1 was incident. The other optical fiber (filter member) 42 on the optical component for a photochemical detector was connected to a photodetector 49 (see FIG. 5). At this time, no transmitted light was observed.

Next, when pure water was dropped into the minute gap 46, transmitted light was observed, and its intensity was measured to be almost equal to the incident light intensity. This means that the distance of the minute gap is 96
water (refractive index: 1.33)
Is entered, the optical distance becomes 127 nm, and light of 254 nm having this value as a half wavelength can be transmitted.

Next, when an aqueous solution in which 1 μg / L of benzene was dissolved was added dropwise, the transmitted light intensity was reduced to about 60% of that in pure water. Further, when the benzene concentration is 0.5
In the case of the μg / L aqueous solution, it was 75% of that in the case of pure water.
The decrease in transmitted light intensity is because the absorption band of benzene is near 254 nm. Benzene is a substance regulated by the government to have a concentration of 10 μg / L or less in tap water, the environment, and wastewater, and 1 μg / L or less in underground permeated water.

As described above, according to the present invention, it is possible to measure the absorbance of a low-concentration trace sample. This is because the light absorption efficiency of molecules existing in the minute space could be increased by localizing the light in the minute space.

[0041]

Embodiment 2 As a second embodiment of the present invention, a method for producing a fluorescence detector which is an optical component for a photochemical detector will be described, and an application example of benzo [a] pyrene will be described. In the same manner as in the first embodiment, 30 layers of SiO ₂ and HfO ₂ were deposited at a thickness of 72 and 50 nm, respectively, and nickel was deposited at a thickness of 316 nm on the end face of the optical fiber. The nickel portion of the optical fiber was faced, fixed to a quartz substrate, and the nickel portion was melted to produce a photochemical detector chip which is a photochemical detector having a gap of 632 nm.

Pure water was dropped into the gap of the photochemical detector, white light from a halogen lamp was incident on the photochemical detector using an optical fiber, and the spectrum of the light emitted from the photochemical detector was measured. , 366, 420,
A sharp transmitted light peak was observed at 490 nm. This is because the gap distance is as large as 632 nm and three defect levels (standing waves) can exist.

Next, light of 366 nm from the mercury lamp was extracted by an interference filter, and was incident on one optical fiber of the chip for a photochemical detector through an optical fiber. The light emitted from the other optical fiber on the chip was measured by a photomultiplier tube through a filter transmitting near 420 nm. Since the incident light was limited to 366 nm and the emitted light was limited to 420 nm, no light could be observed with the photomultiplier.

Next, when an aqueous solution in which 1 μg / L of benzo [a] pyrene was dissolved was dropped into the gap, light could be detected with a photomultiplier tube. 10n more
When an aqueous solution in which g / L of benzo [a] pyrene was dissolved was dropped, the light intensity observed with the photomultiplier tube was 1 μg.
/ L was about 1/3 of the light intensity observed in the sample of / L. Benzo [a] pyrene is a substance which has an absorption band at around 370 nm and emits fluorescence at around 420 nm, is contained in exhaust gas of a diesel engine, smoke of tobacco, and the like, and is highly suspected of being carcinogenic. The sample of 1 μg / L absorbs almost all the incident light, whereas the sample of 10 ng / L absorbs about 1/3, so that the fluorescence intensity is 1/3.
It is something about.

As described above, according to the present invention, it is possible to measure the fluorescence of a low-concentration trace sample. This is because the efficiency of fluorescence emission was increased by increasing the light absorption efficiency of the molecules existing in the minute space by localizing the light in the minute space.

[0046]

Embodiment 3 As a third embodiment of the present invention, an absorption detector (optical component for a photochemical detector) having a sample introduction part in which thin films of SiO ₂ and HfO ₂ are alternately formed on the end face of an optical fiber.
FIG. 6 shows an example of detecting benzene in a photochemical detector using an optical component for a multi-fiber photochemical detector in which a plurality of are arranged (multi-optical components for a photochemical detector). Here, the number of periods of the light-transmitting thin film of SiO ₂ and HfO ₂ is changed, and those obtained by changing the enhancement of the electric field intensity are arranged in a line in the order of the number of periods. Each optical component for an optical fiber type photochemical detector was produced in the same manner as in Example 1. Here, the number of periods is the number of light transmitting thin films of SiO ₂ and HfO ₂ of one optical fiber.

Benzene was detected in the same manner as in Example 1. Since the transmittance obtained by the number of periods differs, the optical fibers 61, 62, 63, 64,
When observing the transmitted light at 65 and 66, the transmitted light intensity changes greatly before and after a specific fiber. Since the position of the optical fiber depends on the concentration of the sample, the sample concentration can be estimated only by reading the position of the optical fiber. In addition, the sample concentration can be accurately determined from the intensity distribution of each optical fiber.

[0048]

[Table 1]

[0049]

Embodiment 4 As a fourth embodiment of the present invention, thin films of SiO ₂ and HfO ₂ are alternately formed on the end face of an optical fiber, and a sample introduction portion (a gap between filter members of an optical component for a photochemical detector) is formed. The configuration and characteristics of a photochemical detector having a variable distance will be described with reference to FIG.

In the same manner as in Example 1, a multilayer film of SiO ₂ (62 nm) and 30 layers of HfO ₂ (43 nm) was sputtered on the end face of the optical fiber. However, nickel sputtering was not performed. The multilayer film 711 of the optical fibers (filter members) 71 and 72 is taken out from the sputtering apparatus.
721 was fixed to the fiber holders 73 and 74, respectively, so that the surface of 721 slightly protruded. One optical fiber holder 74 was fixed to a piezo stage 75. The optical fiber (filter member) 71 with a multilayer film was connected to an Xe light source 76 and the optical fiber (filter member) 72 with a multilayer film was connected to a spectroscope 77 and a photodetector 78 by optical fibers. The optical fibers (filter members) 71 and 72 with a multilayer film were arranged face to face so that the optical axes were aligned, and the multilayers were brought into contact. White light was made incident from the Xe light source 76, the emitted light was split by the spectroscope 77, and the spectrum was measured by the photodetector 78. The appearance of the peak of the transmitted light at a position of 360 nm confirmed that the two optical fibers were in correct contact.

Thereafter, the piezo element was moved 70 nm to form a gap. Benzo [a] pyrene (1 μg /
The aqueous solution of L) was added dropwise. At this time, the peak of the transmitted light is 3
It was 10 nm. Further, the gap was increased at intervals of 10 nm, and the transmission spectrum was measured. As the gap was increased, the wavelength of the transmission peak and its transmittance changed.
When the wavelength was plotted on the horizontal axis and the magnitude of the transmission peak was plotted on the vertical axis, a spectrum as shown in FIG. 8 could be obtained. This corresponds to the absorption spectrum of benzo [a] pyrene.

As described above, according to the present invention, an absorption spectrum can be measured even in a low-concentration trace sample.
This is because the transmission spectrum position can be scanned by changing the gap distance. For this reason, once the calibration curve of the gap distance and the transmission peak is obtained, a filter that cuts the wavelength outside the forbidden band is installed in place of the spectrometer, and the transmitted light intensity is functioned as a function of the gap distance. By measuring, a transmission spectrum can be obtained.

[0053]

[Embodiment 5] As a fifth embodiment of the present invention, an example of detecting a trace substance in the atmosphere will be described. In the same manner as in the first embodiment, SiO ₂ and HfO ₂ were respectively 53,
Optical components for photochemical detectors were formed in which 32 layers each having a thickness of 37 nm were formed and the interval between the end faces of the optical fiber was 156 nm.

Absorption detection was performed using the optical component for a photochemical detector prepared as described above. The optical component for a photochemical detector was housed in a cell for gas ventilation, 312 mm from a mercury lamp was taken out using an interference filter, and was incident on one optical fiber (filter member) of the optical component for a photochemical detector through an optical fiber. The other optical fiber (filter member) on the photochemical detector optical component was connected to the photodetector. Nitrogen was passed through the gas venting cell, and the transmitted light was measured. As a result, a sharp transmitted light peak at 312 nm was confirmed. When a nitrogen-diluted formaldehyde gas having a concentration of 0.5 mg / m ³ was passed, the transmitted light intensity was reduced to about 43% of that before the formaldehyde gas was passed.

When the concentration of formaldehyde gas is 0.1
At mg / m ³ , it was about 82% of that before formaldehyde gas ventilation. The decrease in transmitted light intensity is due to the absorption band of formaldehyde being around 310 nm. Formaldehyde is a substance determined by the Japan Society for Occupational Health to have a concentration in the atmosphere of 0.6 mg / m ³ or less.

As described above, according to the present invention, the absorption measurement of a low-concentration trace sample in the atmosphere can be performed without the need for a concentration operation. This is because the light absorption efficiency of molecules existing in the minute space could be increased by localizing the light in the minute space.

[0057]

[Embodiment 6] As a sixth embodiment of the present invention, a method for producing an absorption detector (photochemical detector) having a concentrating section made of a functional material and a color reagent is shown, and an example of application to chloroform is shown. 9).

In the same manner as in Example 1, 75 and 2 SiO ₂ and HfO ₂ were deposited on the end face of the optical fiber and the circular quartz substrate, respectively.
Ten layers were formed at a film thickness of 52 nm. An ethanol solution of tetraethoxysilane is dropped on the multilayer film surface of the quartz substrate (filter member) 91, and the quartz substrate 91 is rotated at 5000 rpm by a spin coating method to obtain 150
nm porous glass thin film was obtained. Next, the porous glass thin film was previously impregnated with orthotolidine, which reacts with iodine pentoxide, which is an oxidizing agent for releasing chlorine from chloroform, and liberated chlorine to turn orange.

A halogen lamp 94 and an optical system 95 are provided on the quartz substrate 91 so that a portion irradiated on the quartz substrate 91 by the halogen lamp 94 becomes linear in the radial direction.

Further, an optical fiber 97 with a multilayer film was accommodated in a double thin tube 96 having a double structure for ventilation. The double thin tube 96 includes an outer tube 961 serving as an outer cover and an inner tube 962 provided inside, and the inner tube 962 is an outer tube 961.
The outer wall of the inner tube 962 and the outer tube 96
The sample gas can be supplied into the double narrow tube 96 from the gap 963 on the inner wall of the first tube. On the other hand, an optical fiber (filter member) 97 is provided in the inner tube 962,
The capillary 96 has a mechanism for moving the optical fiber 97 up and down.

The double thin tube 96 is attached to a jig 98 which can move in the radial direction of the quartz substrate 91 and can bring the end face of the double thin tube 96 into contact with the quartz substrate 91.
The optical fiber was connected to a photodetector to complete an absorption detector (photochemical detector).

The end portion of the optical fiber 97 is a quartz substrate 91
9 (see the lower right figure in FIG. 9), the nitrogen gas g is brought into contact with the porous glass thin film through the gap 963 of the double thin tube 96 and further to the outside through the inner tube 962.
Through.

Next, white light from a halogen lamp was subjected to spectrum measurement with the end face of the optical fiber 97 in contact with the porous glass thin film (see the lower left figure in FIG. 9).
A sharp transmitted light peak was observed at 38 nm.

Next, the rotation of the quartz substrate 91 and the double capillary 96
Is moved in the radial direction, whereby the double thin tube 96 and the quartz substrate 91 are moved.
Changed the contact position. Concentration 1 on porous glass thin film
0.1 cc of 0 mg / m ³ nitrogen-diluted chloroform gas
As a result of measurement after 1 minute of ventilation at m, the intensity of transmitted light was reduced in the detector impregnated with the reagent, and was about 65% of that before chloroform gas ventilation. The decrease in transmitted light intensity was due to the absorption band of the product of the reaction between the reagent and chloroform being 4
This is because it is near 38 m.

The absorption bands of chloroform are 169 nm, 151 nm, and 143 nm, which are shorter than the absorption edge of the porous glass.
nm, and no direct absorption can be observed. Chloroform is a substance determined by the Japan Society for Occupational Health to have an atmospheric concentration of 49 mg / m ³ or less. Porous glass has micropores on its surface, so the area of contact with the atmosphere is about 100,000 times that of ordinary glass, and it functions by easy methods such as concentration and fixing of trace substances in the atmosphere and impregnation with reagents. It can be a conductive thin film.

By continuously controlling the positions of the quartz substrate and the thin tube, continuous monitoring can be performed for a long time, and the quartz substrate itself can be used as a recording medium of the monitoring result.

As described above, according to the present invention, it is possible to measure the absorption of a small amount of a low-concentration sample using a color reagent.

[0068]

[Embodiment 7] As a seventh embodiment of the present invention, a method for producing a multi-absorption detector (photochemical detector) having a concentrating section made of a functional material and a color reagent is shown, and two components of toluene and n-hexane are shown. An example of application to a mixed gas will be described. The thicknesses of SiO ₂ and TiO ₂ on the end face of the optical fiber (filter member) and the circular quartz substrate (filter member) are 93, 58, respectively.
Sixteen layers each having a thickness of nm were formed.

An ethanol solution of tetraethoxysilane was dropped on the multilayer film surface of the quartz substrate and the spin coating method was repeated to obtain a 1210 nm porous glass thin film. The porous glass thin film in the right half of the quartz substrate was impregnated with a sulfuric acid solution of iodine pentoxide, which turned brown when reacted with toluene. The left half was impregnated with a sulfuric acid solution of chromic acid that changed from yellow-brown to green-brown by reacting with n-hexane. An optical fiber and a quartz substrate were set in the same manner as in Example 6 to produce an absorption detector (photochemical detector).

At the portion impregnated with iodine pentoxide, nitrogen gas was passed so as to come into contact with the porous glass thin film from the inner wall of the outer tube and the gap between the inner wall of the inner tube and pass through the inner tube to the outside. Next, white light from a halogen lamp was subjected to spectrum measurement in a state where the end face of the optical fiber was in contact with the porous glass thin film, and a sharp transmitted light peak was confirmed at 512 and 579 nm. The same result was obtained in a portion where the quartz substrate was rotated by 180 degrees and impregnated with a sulfuric acid solution of chromic acid. Next, the portion impregnated with iodine pentoxide was added with a concentration of 10 m.
The transmitted light was measured after passing a binary mixed nitrogen dilution gas of g / m ³ and 10 mg / m ³ n-hexane at 0.1 ccm for 1 minute. Only at the peak of 512 nm, the transmitted light intensity was reduced to about 15% before the gas mixture was passed.

Next, the quartz substrate was rotated 180 degrees, and 0.1 cc of the mixed gas was applied to a portion impregnated with a sulfuric acid solution of chromic acid.
m for 5 minutes, and the transmitted light was measured. Only at the peak of 579 nm, the transmitted light intensity decreased to about 78% before the gas mixture was passed.

The decrease in the transmitted light intensity is due to the light absorption of the product of the reaction between the reagent and each component to be detected. The absorption bands of toluene and n-hexane are on the shorter wavelength side than the absorption edge of the porous glass, and direct absorption cannot be observed. As described above, according to the present invention, multi-component simultaneous measurement of a low concentration trace gas is possible.

[0073]

As described above, according to the present invention, absorption and fluorescence measurement can be performed on a very small amount of a sample at a low concentration. By alternately stacking light-transmitting thin films having different refractive indexes to form a periodic structure, a function of reflecting light in a specific wavelength band can be provided. If a layer (defect layer) that lacks periodicity exists in this periodic structure, only light of a specific wavelength can be transmitted. The intensity of the photoelectric field at this time is greatly amplified in the defect layer. This means that light is localized in this layer, and if there are molecules that absorb light in this layer, light can be absorbed with a very high probability.

That is, even when the absolute amount of the molecule is small, light is absorbed, and this is largely reflected on the transmittance. Since the enhancement of the photoelectric field can be controlled by changing the number of periods of the light-transmitting thin film, the transmittance can be measured in the optimum absorbance region even when the concentration is low.
Further, since an absorption spectrum can be obtained by controlling the thickness of the sample passage portion, it is possible to identify a trace amount of sample.

In general, the detection of absorption of a substance having no absorption band with respect to incident light is performed by an indirect method.
That is, a method in which a light-absorbing substance is dissolved in a solution in advance, a sample is added, and the decrease in absorbance (increase in transmittance) is measured to indirectly quantify the target substance in the sample. A high way.

In the present invention, the indirect method is also possible, and if the number of periods of the light-transmitting thin film is selected, it is possible to lower the baseline of the dissolved light-absorbing substance.
The dynamic range is widened and the use of a photomultiplier tube or the like becomes possible, and high sensitivity can be expected.

As described above, since the detection sensitivity of absorption detection and fluorescence detection, which are widely used in high-performance liquid chromatography and capillary electrophoresis, which are general-purpose detection methods, can be dramatically increased, they are very useful. High value.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an optical component for a photochemical detector of the present invention.

FIG. 2 is a view showing the transmittance of the optical component for a photochemical detector (when there is no sample passage portion).

FIG. 3 is a diagram showing the transmittance of the optical component for a photochemical detector (when there is a test slant passage portion).

FIG. 4 is a diagram illustrating a configuration of a photochemical detector according to the first embodiment.

FIG. 5 is a view for explaining an absorption detection method of the photochemical detector of Example 1.

FIG. 6 is a diagram illustrating a configuration of a photochemical detector according to a third embodiment.

FIG. 7 is a diagram illustrating a configuration of a photochemical detector according to a fourth embodiment.

FIG. 8 is a diagram showing an absorption spectrum measured by the photochemical detector of Example 4.

FIG. 9 is a diagram showing a configuration of a photochemical detector according to a sixth embodiment.

[Explanation of symbols]

 Reference Signs List 11 optical fiber 12 gap for introducing sample to be measured A light-transmitting thin film B light-transmitting thin film 41 optical fiber 42 optical fiber 43 quartz substrate 44 hole 45 groove 46 gap 47 mercury lamp 48 interference filter 49 photodetector 61 optical fiber 62 Optical fiber 63 Optical fiber 64 Optical fiber 65 Optical fiber 66 Optical fiber 71 Optical fiber 72 Optical fiber 73 Optical fiber holder 74 Optical fiber holder 75 Piezo stage 76 Xe light source 77 Spectroscope 78 Photodetector 91 Quartz substrate (filter member) 92 Substrate Rotating mechanism 93 Substrate setting stage 94 Halogen lamp 95 Optical system 96 Double thin tube 961 Outer tube 962 Inner tube 97 Optical fiber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 6/00 G01N 27/26 325A (72) Inventor Osamu Niwa 2-3-1 Otemachi, Chiyoda-ku, Tokyo No. F-term in Nippon Telegraph and Telephone Corporation (reference) 2G043 AA03 BA16 CA01 CA03 EA01 EA13 EA18 EA19 GA08 GB02 HA05 HA08 JA01 JA03 KA02 KA03 LA02 LA07 MA01 2G054 AA02 AA06 AB07 BB03 BB04 CA21 EA03 EA04 EB01 FA04 FA19 GB01 GB02 JA06 JA10 2G059 AA05 BB01 BB04 BB12 CC16 EE01 EE12 FF10 GG10 HH03 JJ03 JJ17 KK01 KK10 MM12 NN01 2H038 AA08 BA23 BA25 (54) Photochemical detectors using optical components or multi-optical components for photochemical detectors, photochemical The method of manufacturing output method and photochemical detector optics

Claims (15)

[Claims] 1. An end face of a light-transmitting member, wherein a multilayer film having an optical film thickness that is an integral multiple of 1/4 of the center detection wavelength and having two types of light-transmitting thin films having different refractive indices alternately stacked is formed. An optical component for a photochemical detector, characterized in that the filter member arranged in (1) is arranged with the end faces on which the multilayer films are arranged facing each other with a gap for introducing a sample to be measured at a half of the wavelength therebetween. 2. The optical component for a photochemical detector according to claim 1, wherein a multi-mode optical fiber having an end surface that is a plane perpendicular to a central axis is used as the light transmitting member. 3. The optical component for a photochemical detector according to claim 1, wherein the multilayer films of the opposing filter members have the same configuration. 4. The photochemical detector optical component according to claim 1, wherein a plurality of optical components for photochemical detector according to claim 1 having a plurality of multilayer films having different numbers of periods of said light-transmitting thin films are arranged. Multi optical components. 5. A monochromatic light source, and the optical component for a photochemical detector according to claim 1, which receives incident light from the monochromatic light source, and detects light emitted from the optical component for a photochemical detector. A photochemical detector, comprising: a photodetector; 6. A monochromatic light source; a multi-optical component for a photochemical detector according to claim 4, which receives incident light from the monochromatic light source; and a photodetector for detecting outgoing light from the multi-optical component for the photochemical detector. A photochemical detector comprising: 7. A light source, an optical component for a photochemical detector according to claim 1, which receives incident light from the light source, and any of the opposed filter members of the optical component for a photochemical detector. One or both filter members, linear moving means for linearly changing the distance between the end faces of the filter members, and spectral means for limiting a wavelength range of light emitted from the photochemical detector optical component, A photochemical detector comprising: a photodetector that detects light emitted from the spectroscopic means. 8. The photochemical detector according to claim 5, wherein a material exhibiting a chemical reaction with the sample to be measured is arranged in the gap for introducing the sample to be measured. 9. The photochemical detector according to claim 8, wherein:
A photochemical detector, wherein the material causing the chemical reaction is impregnated in a porous thin film formed on the multilayer film of the filter member. 10. The photochemical detector according to claim 9, wherein the porous thin film is impregnated with a color reagent that is colored by a reaction product generated as a result of a reaction between the material reacting with the sample to be measured. A photochemical detector, characterized in that: 11. The photochemical detector according to claim 5, wherein a separation column of any one of high performance liquid chromatography, gas chromatography, and capillary electrophoresis is provided in the gap for introducing the sample to be measured. A photochemical detector characterized by being arranged in a crossed manner. 12. The photochemical detector according to claim 9, wherein one of the filter members has a disk shape and a porous thin film is formed, and a rotation mechanism for rotating the disk filter member; and the other filter member. A mechanism for contacting the filter member with the disc-shaped filter member, and an inner tube arranged so as to surround the other filter member as a central axis, and a state in which a distal end portion protrudes from the inner tube so as to further surround the inner tube. A double thin tube comprising an outer tube installed in the inner tube, a mechanism for bringing the double thin tube into contact with the disc-shaped filter member while maintaining the same relative positional relationship between the inner tube and the outer tube, and the inner tube outer wall. And a mechanism for flowing the gas to be measured from the hollow formed by the inner wall of the outer tube toward the hollow of the inner tube and the other filter member; and the other filter member and the inner tube. A moving mechanism for relatively moving the entire outer tube in the radial direction of the disc-shaped filter member. 13. An end face of a light transmitting member, wherein a multilayer film having an optical film thickness that is an integral multiple of 1/4 of the center detection wavelength and two types of light transmitting thin films having different refractive indexes are alternately laminated. The sample to be measured of the optical component for a photochemical detector in which the filter member arranged in the above is disposed with the end faces on which the thin multilayer films are arranged facing each other with a gap for introducing the sample to be measured having a wavelength of 1/2 of the wavelength being interposed therebetween. The sample light is passed through one of the two filter members with the sample to be measured sandwiched in the gap for introduction, and the incident light is localized as a standing wave at the portion where the sample to be measured is arranged by the two filter members. And causing the localized standing wave light to optically interact with the sample to be measured, and detecting the light emitted from the other filter member after the interaction. 14. The photochemical detection method according to claim 13, wherein a wavelength of the localized standing wave light is an absorption wavelength or a fluorescence absorption wavelength of the sample to be measured. 15. Two kinds of optical materials having different refractive indexes are deposited on the end face of the light transmitting member by a vapor deposition method, a sputtering method, a gas phase reaction method,
A multilayer film of a light-transmitting thin film is formed by alternately stacking by any one of a sol-gel method, a coating method, and a spraying method, and the two types of light-transmitting thin films are laminated in the light-transmitting thin film laminating step. The optical film thickness of the thin film is set to an integral multiple of 1/4 of the detection center wavelength, and the multilayer film is arranged so that end faces thereof face each other with a gap for introducing a sample to be measured having a detection center wavelength of 1/2. A method for producing an optical component for a photochemical detector, comprising: