JPH0337552A - Method and apparatus for multiple-inner-reflection type component analysis - Google Patents

Abstract

PURPOSE:To make it possible to measure a plurality of samples with one high refractive material by containing the samples in a container so that the samples are brought into contact tightly with a pair of facing surfaces, inserting the high refractive material into another sample, and bringing the samples into contact with the other pair of facing surfaces tightly. CONSTITUTION:A light source 1 is lit, and only the light rays having the specified wavelength region are made to pass through an interference filter 2. The light rays are equally split through a half mirror 3. The light rays are sent in to light input surfaces 12A and 12B through light emitting fibers 4A and 4B, respectively, and inputted into a prism 9 which is manufac tured with a high refractive material. The light rays are reflected with facing surfaces 11A, 11A, 11B and 11B internally in a multiple pattern. The light rays radiate downward. The light rays are totally reflected from a reflecting surface 14 and reflected internally in a multiple pattern again. The light rays radiate upward and are emitted from the light emitting surfaces 13A and 13B. The spectrums of the wavelengths inherent to the materials are absorbed with materials which are contained in a reference sample S0 and the material to be measured S which are in contact tightly when the reflections occur on the facing surfaces 11A, 11A, 11B and 11B. The outputs of photodetectors 6A and 6B are operated, and the components can be analyzed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a high refractive index material with opposing surfaces facing parallel to each other, a sample is brought into close contact with the outside of this opposing surface, and a sample is placed in close contact with the outside of this opposing surface, and the light beam incident on the high refractive index material is The present invention relates to a multiple internal reflection type component analysis method and an apparatus thereof, in which a light ray that is multiple internally reflected on the inner side of the opposing surface and then emitted from the high refractive material is measured.

[Conventional technology]

First, the multiple internal reflection type component analysis method will be briefly explained.

As shown in FIG. 8, an opposing surface (11A) facing parallel to the high refractive material (9) (generally a prism is used);
(11A) and this opposing surface (11A).

The sample (S) is brought into close contact with (11A). Then, a light beam is made incident on the interface between the opposing surfaces (11A) and (11A) at a total reflection angle, and the reflected spectrum of the emitted light after multiple internal reflections is measured. If there is no absorption in the sample (S) in contact with the high refractive material (9), there will be no light intensity loss (attenuation) of the emitted light due to multiple internal reflections, but if there is absorption in the sample (S), there will be a light intensity loss in the emitted light. will occur. The degree of light loss becomes more significant as the absorption coefficient of the sample (S) increases.

Therefore, the reflectance R due to multiple internal reflections is approximately:
If the number of reflections is n and the reflectance of light incident on the sample (S) having an absorption coefficient k from the high refractive material (9) is R4, it can be expressed as R''Rh'.

In general, the absorption of the sample (S) is wavelength dependent, so if the reflectance at wavelength λ is R(λ), the above equation becomes R(λ)−[Rk(λ)°). Therefore, by scanning the wavelength, it is possible to investigate the components of the substance from this reflection spectrum.

When using this component analysis method to measure the proportion of components of substances contained in a sample, as shown in Figure 9, the light rays emitted from the light source are divided into equal parts by a half mirror (3), and each The light beam is connected to the reference sample (S0)
The sample (S) to be measured is made to enter the first high refractive material (9A) in close contact with the second high refractive material (9B) in close contact with each other for multiple internal reflections. Material (9A),
Calculate the difference between the light rays emitted from (9B). In this way, a spectrum of the amount absorbed by the contained substance can be obtained, and it is possible to specify the contained substance and analyze its component ratio.

[Problem to be solved by the invention]

The high refractive material (9) used in this component analysis method is the 8th
As shown in the figure, since there is only one set of opposing surfaces (11A) and (11A), it is possible to measure the spectrum of only one sample at a time. Therefore, as mentioned above, the spectra of two samples are measured simultaneously and the difference is taken.
When attempting to perform component analysis, two expensive high refractive materials (9) are required, as shown in FIG. 9, resulting in high costs.

The present invention aims to solve these difficulties by making it possible to simultaneously measure a plurality of samples using one high refractive index material.

[Means to solve the problem]

In order to achieve the above object, the method of the present invention includes:
The high refractive material is provided with a second opposing surface different from the opposing surface, and a second sample different from the sample is brought into close contact with the second opposing surface, and the high refractive material is provided with a second opposing surface different from the opposing surface. The method is characterized in that a second light beam that is incident, undergoes multiple internal reflections inside the second opposing surface, and then exits from the high refractive material is measured.

In addition, the apparatus of the present invention is provided with two or more sets of opposing surfaces facing parallel to the high refractive index material, and the opposing surfaces of the two sets have a structure for accommodating the sample in close contact with the opposing surfaces. A light emitting means for emitting a light beam that is incident on the high refractive material and subjected to multiple internal reflections on opposing surfaces of each set; and a light receiving means for receiving the light beam that has been multiple internally reflected and exits from the high refractive material. means, the high refractive material;
Each of the container, the light emitting means, and the light receiving means,
It is characterized by being assembled into one unit.

[For production]

In the method of the present invention, a sample is brought into close contact with an opposing surface provided on a high refractive index material, and a second sample is brought into close contact with a second opposing surface that is different from this opposing surface.

Then, the light beam incident on the high refractive material is subjected to multiple internal reflections on the inside of the opposing surface, the light rays emitted from the high refractive material are measured, and a second light beam different from the above light beam is multiplexed on the inside of the second opposing surface. The second light beam that is internally reflected and emitted from the high refractive material is measured.

In the apparatus of the present invention, a sample is housed in a container and brought into close contact with one set of opposing surfaces, and a high refractive material is inserted into another sample so that the sample also comes into close contact with another set of opposing surfaces. Make it.

Then, the light emitting means is caused to emit light, and after two or more light beams undergo multiple internal reflections on each set of opposing surfaces, they are emitted from the high refractive material and are received by the light receiving means.

〔Effect of the invention〕

According to the method of the present invention, multiple samples can be measured simultaneously using one high refractive index material, so even when analyzing the components of contained substances in comparison with a reference sample, it can be done at low cost. Become. Moreover, since the characteristics of the high refractive materials are the same for each measurement, more precise measurements can be made than when two high refractive materials are used.

According to the device of the present invention, it is possible to easily analyze the components of substances contained in a sample by simply inserting a high refractive material into the sample, and it is possible to provide a component analyzer that is compact and easy to handle.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

What is shown in FIG. 2 is a component analyzer of multiple internal reflection type. This component analyzer is a portable unit with a detection section (B) installed at the bottom of a main body (A) containing various parts. It is designed so that it can be inserted into the main body (A) and analyzed in the main body (A).

As shown in FIG. 1, the main body (A) includes a light source (1).
, an interference filter (2), a half mirror (3), two light emitting fibers (4A), (4B), two light receiving fibers (5A), (5B), and two light receiving elements (6A).

(6B), an arithmetic unit (7), a display device (8), etc.

The detection section (B) includes a prism (
9) and a pair of containers (
10). The prism (9) has two sets of opposing surfaces (11A) and (11A) facing each other in parallel.

(11B), (11B), and its upper end has two light incident surfaces (12A), (12
B) and two light emitting surfaces (13A) and (13B) in the shape of a square pyramid (see Figure 3), the lower end of which is mirror-finished.
It is formed into a quadrangular pyramid shape with two reflective surfaces (14).

The container (10) also includes a set of opposing surfaces (11B),
(11B) is attached to surround the entire area. The upper part of this container (10) has 1. An opening (10a) for introducing the reference sample (S0) (corresponds to the second sample, specifically water)
), and the side wall portion on the opposite surface side is the reference sample (
When S0) is accommodated, the facing surface (11B), (11B)
The reference sample (S0) was removed so that it was in close contact with the reference sample (S0).

Next, a method for performing component analysis of the measurement sample (S) using this component analyzer will be explained.

First, after filling the container (10) with the reference sample (S0), insert the detection part (B) into the measurement sample (S), being careful not to let the measurement sample (S) enter through the opening (10a). The measurement sample (S) is placed on the opposite surface (11A).

(11A) so that it is in close contact with the entire surface. And the light source (
1) Turn on the light and start measuring the absorption spectrum. still,
The reference sample (S0) is a sample whose specific substance and its component ratio are known, whereas the measurement sample (S)
is a sample in which the component ratio of a specific substance is unknown.

When the light source (1) is turned on and a light beam is emitted, only a specific wavelength region of the light passes through the interference filter (2) and is split into two equal parts by the half mirror (3). The two light beams are transmitted through the two light emitting fibers (4A) and (4B) to each light incident surface (1
2A), (12B) and enters the prism (9).

The two light rays entering the prism (9) have respective opposing surfaces (11A), (11A), (11B), (1
1B), travels downward while undergoing multiple internal reflections, is totally reflected at the reflecting surface (14), and is reflected by each opposing surface (11A).
, (11A).

(11B), Proceeds upward while undergoing multiple internal reflections again at (11B), and reaches two light exit surfaces (13A), (13B)
Light is emitted from. Therefore, the facing surface (11A), (11
A), (11B).

When reflection is performed at (11B), the spectra of wavelengths specific to the substance are absorbed by the specific substance contained in the reference sample (S0) and measurement sample (S) that are in close contact with each other.

The light beams emitted from the prism (9) are sent to the respective light receiving elements (6A), (6B) by two light receiving fibers (5A), (5B) and converted into electrical signals. These electrical signals are sent to an arithmetic unit (7) where their intensity is corrected, and the difference is taken to analyze the absorption spectrum and displayed on a display unit (8). In this case, the reference sample (
Figure 4 shows the relationship between wavelength and transmittance based on the electrical signal of the light beam reflected and received at the interface with the measurement sample (S). The relationship between wavelength and transmittance is shown in the graph of FIG. 5, and the relationship between wavelength and transmittance is determined from the difference between the electric signals, as shown in FIG. 6.

Therefore, by measuring the wavelength and transmittance shown in the graph of Figure 6, it is possible to determine the proportion of a specific substance contained in the measurement sample (S) compared to the reference sample (S0). It can be done.

[Another example]

To carry out the present invention, a prism (
A single reflective surface (14) may be formed by cutting a horizontal surface on the lower end of the mirror 9) and applying a mirror finish.

Alternatively, the high refractive index material (9) may be shaped into a hexagonal column or an octagonal column, and may be provided with three or more sets of opposing surfaces, so that three or more types of samples can be measured simultaneously.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the multiple internal reflection type component analysis method and its apparatus according to the present invention, and FIG. 1 is a perspective view of the detection section, and FIG.
The figure shows the overall configuration, Figure 3 is a plan view of the detection section, and Figure 4 shows the overall configuration.
The figure is a graph showing the relationship between the wavelength and transmittance of the reference sample.
The figure is a graph showing the relationship between the wavelength and transmittance of the measurement sample.
The figure is a graph showing the relationship between two wavelengths and absorbance of the measurement sample when the difference from the reference sample is taken, and FIG. 7 is a side view showing an example of an improved reflective surface. Moreover, FIG. 8 is a side view of a conventional high refractive index material, and FIG. 9 is a schematic diagram showing an example of use when measuring with the conventional high refractive index material. (S0)... Second sample, (S)...
...Measurement sample, (1) ...Light-emitting means, (
6)......Light receiving means, (9)...
...High refractive index material, (10) ...... Container, (
11A). (11A)...... Opposite surface, (11B),
(11B)...Second opposing surface.

Claims (1)

[Claims] 1. Opposing surface (11A) facing parallel to the high refractive index material (9)
, (11A), and the opposing surfaces (11A), (1
The sample (S) is brought into close contact with the outside of the material (1A), and the sample (S) is incident on the high refractive index material (9) to form the opposite surface (11A), (
11A) The high refractive material (9) undergoes multiple internal reflections on the inside.
This is a multiple internal reflection type component analysis method for measuring light rays emitted from the high refractive material (9) and the opposing surface (11A).
), (11A), the second opposing surface (11B), (11
B), and this second opposing surface (11B), (11B
), a second sample (S_0) different from the sample (S) is brought into close contact with the sample (S), and the light beam is incident on the high refractive material (9) separately from the light beam, and the second opposing surface (11B), (11B) A multiple internal reflection type component analysis method that measures a second light beam that undergoes multiple internal reflections and exits from the high refractive material (9). 2. Two or more sets of opposing surfaces (11A), (11A), (11B), (11B) facing parallel to the high refractive index material (9) are provided, and one set of opposing surfaces has this opposing surface. (11B
), (11B) is provided, and a container (10) is provided for accommodating the sample (S_0) in close contact with the high refractive material (9), and the opposing surfaces (11A), (
11A), (11B), and (11B) for emitting a light beam that is subjected to multiple internal reflections; and a light receiving means (6) that receives the light beam that has been subjected to multiple internal reflections and is emitted from the high refractive material (9). ), the high refractive material (9), the container (10), the light emitting means (1), and the light receiving means (6).
) is a multiple internal reflection type component analyzer that is assembled into one unit.