JPS5942822B2 - Analysis equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an analytical device, specifically an analytical device that includes a means for extracting fluctuations in surrounding gas as an acoustic spectrum by irradiating a solid or liquid with light including infrared rays, ultraviolet rays, or X-rays. It is related to the device.

When a target substance to be analyzed is placed in a sealed container and light modulated to a certain frequency is irradiated onto the substance, the substance absorbs the light and generates heat corresponding to this frequency, causing fluctuations in the gas inside the container. Analysis is a measurement method that has been known for several decades, in which the target substance is analyzed by causing compression waves to be generated, which are then detected by a sonic detector such as a microphone inside a container and extracted as an electrical signal. It's technology.

0 FIG. 1 shows an example of a conventional analytical device to which such an analytical method is applied.

The usage of this example is as follows.

That is, the light from a xenon lamp 1 as a light source is passed through a spectroscope 2 to convert it into monochromatic light, the light is modulated by five modulated lights through a chopper 3, and a sample 5 placed in a container 4 is irradiated with this modulated light. The irradiated sample 5 absorbs the light and generates heat, which is transmitted to the gas inside the container 4 as a pressure wave. This pressure wave is transmitted to the microphone 6 directed into the container 4, and the pre-main up □,
Lock-in '0 Only the signal synchronized with the chopping frequency is extracted via the amplifier 8. On the other hand, a container 11 containing a reference sample (not shown) is irradiated via a half mirror 9 and a reflector 10, and at the same time as described above, the intensity of the incident light is monitored via an integrated amplifier 12 and a lock 5-in amplifier 13. are doing.

A difference signal between the demodulated signals of the reference material and the sample 5 is obtained by the differential amplifier 14, and the difference signal thus obtained is displayed on the recorder 15. In the conventional system described above, in addition to the container 4 containing the sample 5, a container 11 containing the reference sample must be prepared, and therefore an integrated amplifier 12 and a lock-in amplifier 13 are also required. As the overall size of the device becomes larger, the device itself becomes more expensive.

Furthermore, if the characteristics of the sample microphone 6 and the reference sample microphone (not shown) change, the signals extracted from them will change, and the output difference based thereon will directly become a measurement error.

Furthermore, since the sample container 4 and the reference sample container 11 are arranged geometrically differently, the influence of external noise changes, which also causes measurement errors. Furthermore, although not shown, in another example of a conventional analyzer using a single container,
Separate measurements had to be made on the reference sample and the sample. The purpose of this invention is to provide an analysis device that solves all of these problems, and the gist of the invention is to provide an airtight container containing each of the target substances of a reference sample and a sample to be measured; a variable amplitude energy source that produces detectable pressure fluctuations in a closed container by supplying the target substances alternately; The present invention is characterized in that it has a measuring means and indicates the net signal intensity of the sample to be measured with respect to the energy supplied to each of the target substances. The present invention will be described in detail below with reference to an illustrated embodiment. FIG. 2 shows an embodiment of the present invention.

101 is a xenon lamp as a light source; 102 is a lens;
103 is a spectrometer, and 104 is a chipper that modulates light to a certain frequency.As will be described later, two slot ports 05 and 106 are provided in order to alternately irradiate each target substance of the reference sample and the sample to be measured with light. It is provided.

A container 107 houses a reference sample 108 and a sample 109 to be measured.

Reference numeral 110 is a table on which the samples 108 and 109 are fixed.

Reference numeral 111 denotes a sound wave detector, specifically a microphone, an electret, etc., which detects pressure fluctuations from the samples 108 and 109 caused by alternate irradiation of light.

The pressure wave detected by the sonic detector 111 passes through the integrated amplifier 112 and the lock-in amplifier 113 to extract only the signal synchronized with the chopping frequency.
The difference in the periodic pressure fluctuations of 109 is shown on recorder 114. When a substrate containing no impurities or additives is used as the reference sample 108 and a substrate containing impurities or additives as the sample to be measured 109, the signal generated from the substrate itself is erased, and the signal caused only by the impurities or additives is transmitted to the recorder 114. appears in Of the above configurations, the xenon lamp 101 as a light source serves as an energy source in the wavelength range from infrared to ultraviolet rays that generates heat from the samples 108 and 109 and causes pressure fluctuations in the sealed container 107. Other energy sources include X-rays.

Also, the sound wave detector 111, the integrated amplifier 112, the lock-in amplifier 113, and the recorder 114 are connected to the airtight container 1.
This constitutes means for measuring changes in periodic fluctuations within 0.07. Next, the photoacoustic spectrum of a trace impurity (aluminum lake) contained in the substrate (quinalizarin) was measured using the analyzer configured as described above and the analyzer shown in FIG. The solid line a in FIG. 3 is the analysis result according to the present invention. Note that the dashed line b and the dashed-dotted line c in FIG. 3 show spectra obtained by the conventional apparatus, of which the dashed line b shows the spectrum of the substrate, and the dashed-dotted line c shows the spectrum of the substrate containing trace impurities. As is clear from Figure 3,
The conventional apparatus shown in FIG. 1 records a spectrum in which the spectrum of the substrate (dashed line b) and the spectrum of the substrate containing trace impurities (dotted chain line c) are superimposed, but the analyzer according to the present invention records a spectrum due only to trace impurities. is recorded.

As is clear from the above embodiments, according to the present invention,
Because the target substances of the reference sample and the sample to be measured are housed in one sealed container, the device becomes smaller, and the sonic detector, integrated amplifier, and Rotstein amplifier for the reference sample are no longer required, which reduces the cost by about half. Can be configured at a cost.

Furthermore, by alternately irradiating each target substance, a signal of only the impurity to be measured appears, so there is no need for a differential amplifier as in the past, and further miniaturization can be achieved.

Furthermore, since the pressure waves are detected by one sonic detector, the error is extremely reduced compared to the conventional case where the pressure waves are detected by separate sonic detectors.

Furthermore, the degree of influence of external noise due to the geometrical arrangement is reduced, and detection accuracy is increased.

Furthermore, since the analysis conditions are the same, such as being housed in the same container and having the same heat capacity, the same heat loss, and the same sensitivity characteristics, the spectrum can be almost completely corrected.

It should be noted that the above-described embodiment is merely an example of the present invention.

For example, in order to alternately irradiate each target substance with the same light beam, a chopper with two slits formed in a disk was used, but as shown in FIG.
2. A device with a window 203 formed therein may be used, and although not shown, a reflector plate may be operated to alternately illuminate each object. Furthermore, when using the chopper shown in FIGS. 2 and 4, it is necessary to increase the beam width so that each target substance can be irradiated, but this can be achieved by using the light source intermediate imaging method. Moreover, any sample for which a difference spectrum is desired can be used as the reference sample. Further, in the above-mentioned embodiments, solid analysis examples were shown, but it is also possible to apply the present invention to liquids.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing a conventional example, FIG. 2 is a schematic explanatory diagram showing an embodiment of the present invention, and FIG. 3 is an example of a photoacoustic spectrum obtained by the apparatus shown in FIG. FIG. 4 is a perspective view showing an example of a chopper. 101...Xenon lamp, 103...
・Spectrometer, 104... Chiyotsupa, 107...
...Airtight container, 108...Reference sample, 109
...Measurement sample, 111...Sonic wave detector.

Claims (1)

[Scope of Claims] 1. A closed container containing target substances of a reference sample and a material to be measured, and a variable amplitude that causes detectable pressure fluctuations in the closed container by alternately supplying each target substance to the target substances. comprising an energy source and a means for measuring changes in periodic pressure fluctuations in the closed container caused by the supply of energy from each of the target substances, and indicating a measurement signal intensity with respect to the energy supplied to each of the target substances. Characteristic analysis equipment. 2. The analysis device according to claim 1, wherein the variable amplitude energy source is light or X-rays.