JPS59136637A - Optoacoustic analyzer - Google Patents

Abstract

PURPOSE:To enable the formation of an optoacoustic analyzing cell having very small capacity and to enable a reduction in the amt. of a measuring sample and an improvement in the sensitivity of chemical analysis by using a thin film-like piezo-electric element having high processability as a detector. CONSTITUTION:The output from an Ar laser 1 is modulated to 10kHz pulse light by an acoustooptic type optical modulator 3 and is made incident to a photodetecting part of an optical fiber 4. The fiber 4 and an optoacoustic analyzing cell 5 are joined by aligning the optical axes thereof. The light from the fiber 4 is made incident to an optoacoustic analyzing cell 5 formed of ''Teflon'' and induces the optical sound in a liquid sample. The optoacoustic signal 6 piezo- electrically converted by a polyvinylidene fluoride piezo-electric element buried in the cell 5 is amplified in a lock-in amplifier 8 by referencing to the signal 7 from the modulator 3 and is outputted to a recorder 9. The optoacoustic analyzing cell having very small capacity is formed by using the thin film-like piezo- electric element having high processability.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a photoacoustic analysis device.

[Prior art]

Conventional photoacoustic analyzers@ used ceramic-based piezoelectric elements with poor workability as detectors, which often resulted in the drawbacks of being unable to reduce the capacity of the measurement cell and not being able to analyze microscopic samples.

[Purpose of the invention]

An object of the present invention is to provide a photoacoustic analyzer capable of analyzing a minute volume of a sample sample.

[Summary of the invention]

The reason why it is not possible to reduce the capacity of a conventional photoacoustic analysis cell using a ceramic-based piezoelectric element as a detector is that ceramics lack elasticity, flexibility, and workability. Therefore, this problem was completely solved by applying thin film piezoelectric materials such as polyvinyritine fluoride, which has excellent flexibility and processability. Additionally, with the miniaturization of photoacoustic analysis cells, it becomes difficult to align the optical axes, but this problem was solved by using an optical fiber as the optical path and aligning the optical axes of the optical fiber and the cell. be.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. In this embodiment, the device configuration is shown in FIG. incident on the part. The optical fiber 4 and the photoacoustic analysis cell 5 are joined together with their optical axes completely aligned. The light from the optical fiber 4 enters a photoacoustic analysis cell 5 made of Teflon and dissects the photoacoustic tube of the liquid sample.

A photoacoustic signal 6 piezoelectrically converted by a rolling element made of polyvinyritine fluoride embedded in a photoacoustic analysis cell 5 is amplified by a lock-in amplifier 8 with reference to a signal 7 from an optical modulator 3, and then sent to a recorder. 9 is output.

Figure 2 shows a cross-sectional view of the photoacoustic analysis cell of this device, and Figure 3 shows a vertical cross-section. In this photoacoustic analysis cell, the shape? It has a cylindrical shape, and a polyvinyritine fluoride piezoelectric material 10 is sandwiched between concentric Teflon cylinders 11 and 12. Polyvinyritine fluoride piezoelectric material 10
In this case, all sides of the analysis cell except for the liquid sample inlet 13 and outlet 14 are covered with a tank, and the pressure-sensitive surface #t is made as wide as possible.

Analysis cell? The original I passed was a complete set of optical evil 15 made of quartz.
Emitted to the outside of the analysis cell.

According to this example, the inner volume of the photoacoustic analysis cell is 1.6
μt.

〔Effect of the invention〕

According to the present invention, by using a thin-film piezoelectric element with excellent workability as a detector, it is possible to create an entire photoacoustic analysis cell with a microcapacity, thereby reducing the amount of sample to be measured and increasing the sensitivity of chemical analysis. be. Moreover, by using an optical fiber as the entire optical path, there is no need to arrange the optical fiber and the measurement cell directly on the bulge, which has the effect of downsizing the device. Furthermore, since the optical axes of the optical fiber and the photoacoustic analysis cell are aligned in advance and then the two are joined, there is an effect of omitting the optical axis adjustment fee associated with sample exchange.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the photoacoustic analysis device of the present invention, Fig. 2 is a cross-sectional view of the photoacoustic analysis cell shown in Fig. 1, and Fig. 3 is a longitudinal cross-section of the professional acoustic analysis cell shown in Fig. 2. It is a diagram. 1...Argon energizer device, 2...V-boo light,
3... Acousto-optic light modulator, 5... Photoacoustic analysis cell, 6... Photoacoustic signal.

Claims (1)

[Claims] 1. A photoacoustic analyzer consisting of a light source, a light modulator, a measuring cell, an amplifier, a recorder, etc., characterized in that it is equipped with a microcapacitance measuring cell using a thin film piezoelectric material as a detector. Acoustic analysis device.