JPS5940259B2 - automatic analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic analyzer equipped with, for example, an ion-selective electrode.

Many of the conventional automatic analyzers simply mechanize and automate the operation of manual analysis, or use pumps, transport pipes, valves, etc. to automatically feed the sample liquid to be analyzed. Many expensive metering pumps and precision parts were used.

As a result, the equipment becomes larger and more expensive, and since such equipment often uses a relatively large amount of test liquid, the amount of reagents used increases, which requires maintenance such as reagent adjustment and replenishment. Maintenance costs were also rising due to the increased number of inspections. Furthermore, as mentioned above, since many precision parts are used, there is a high incidence of trouble and a low operating rate of the equipment. Furthermore, as devices became capable of continuous automatic measurement, the size of the device became even larger, and the above-mentioned drawbacks became more pronounced. The present invention aims to eliminate the above-mentioned drawbacks of the conventional art by making it possible to automatically analyze a test liquid supported on a tape using, for example, an ion-selective electrode. An example will be explained using the following.

FIG. 1 shows a state in which analysis is being carried out continuously using an automatic analyzer which is an embodiment of the present invention.

As shown in the figure, the automatic analyzer is equipped with the following elements. Namely, a tape supply reel 2, a take-up reel 3, and a plurality of guide rollers 4 for guiding the tape.
, a roller 6 for guiding the tape into the test liquid 5, a roller 1 for feeding the tape at a constant speed, and a roller 1 for feeding the tape at a constant speed. A fixed head type detector 8 generates a corresponding electric potential.The configuration of this detector 8 will be described in detail later.It is equipped with a switch 9, etc., and an operation section 10 for controlling power connection, tape running, stopping, etc., and an amplifier. (not shown) and instruction panel 11
, and includes a measurement unit 12 that amplifies the potential generated in the detector 8 and gives an indication. Reference numeral 13 denotes a sample liquid supporting tape mounted on the apparatus, which will also be described in detail later.

Next, the detector 8 shown in FIG. 1 will be explained using FIGS. 2A and 2B.

As shown in the figure, the detector 8 uses an ion-selective electrode formed by bonding a plate-shaped comparison electrode 14 and an indicator electrode 15 together with an insulating material 16 interposed therebetween. each electrode 14
, 15 are provided with terminal pieces 17, 17'. In addition, in FIG. 2a, the tape 13 sliding on the front surface of the detector 8 is shown.
is also shown. Next, regarding the tape for supporting the test liquid, see Figure 3A.
, b will be used for explanation.

In the figure, 18 is a liquid absorption part formed on a tape base material 19 made of paper, cloth, or foamed plastic that easily absorbs the solution, and is divided into multiple pieces by a partition part 19, and each piece carries the test liquid. I'm starting to do that. In addition, the liquid absorption part 18 may contain reagents or reagents that have the functions of pre-treatment of the sample liquid, such as ionizing the target substance, hiding interfering substances, removing interfering substances, regenerating the electrode, creating a calibration curve, and concentrating the target ions. By attaching at least one type of material in advance, the concentration of the target substance can be detected more accurately. The partition portion 19 is formed by impregnating the tape base material 19 with a water-repellent material such as silicone resin or vinyl chloride resin. By arranging the liquid suction parts 18 adjacent to each other with such a partition 20 interposed therebetween, the test liquids carried by the respective liquid suction parts 19 are prevented from mixing with each other. Here, a modified version of the test liquid supporting tape will be explained using FIG. 4.

As shown in the figure, each of the liquid suction parts 21t) is made of independent foamed urethane resin every five pieces, and both ends of each liquid suction part 21t) are connected by thermocompression bonding to a partition part 22 made of thermoplastic resin, for example. ing. A device having such a configuration is useful when a large amount of test liquid is to be supported. FIG. 5 shows a tape in which both edges are edged with water-repellent resin 23 to increase strength. Note that 24 is a liquid suction part, and 25 is a partition part. Now, to explain the operation of the analyzer with reference to FIG.
3b When the tape is fed by the S roller 7 at a constant speed in the force direction shown by the arrow in the figure, the tape supplied from the supply reel 2 is fed by the roller 6.
As a result, the sample liquid is absorbed and carried by the liquid absorption part of the tape (Fig. 3, 18), and then the liquid absorption part carrying the sample liquid is detected. When the detector 8 is slid on the front surface, a potential t) corresponding to the ion concentration in the sample liquid is generated in the detector, and this potential is amplified in the measuring section 12 and indicated on the indicator board 11.

Next, an example in which the concentration of cadmium ions in waste water was measured using the automatic analyzer shown in FIG. 1 will be described.

First, we will provide a supplementary explanation of the detector and sample liquid supporting tape included in the analyzer used at this time.

The ion-selective electrode used as a detector was made as follows. That is, as an indicator electrode, powders of silver sulfide and cadmium sulfide are mixed and hot pressed into a plate shape. Next, a shape as shown in FIG. 2 was cut out from this plate-like body, and a terminal piece was attached to the back side. Only silver sulfide powder was hot-pressed into a plate shape as a comparison electrode, and the same processing as described above was then carried out. The indicator electrode and reference electrode thus produced were bonded to each other using an epoxy resin via an insulating material to complete the assembly. Regarding the tape for supporting the test liquid, Cu2+, which was found to be present in the test liquid,
In order to hide interfering ions such as Fe3+, a mixture of 10-1M potassium nitrate, 10-2M scorbic acid, and 10-3M potassium iodide was impregnated into the liquid absorption part of the tape and dried.

Note that the base material of the tape was made of laminated paper, and the partitions were formed by printing and drying vinyl chloride resin. In addition, in order to automatically create a calibration curve, apply a cadmium nitrate solution to the liquid absorption part at the beginning of the tape for each frame at a concentration of 0.01ppm and 0.1p.
It was impregnated so that it contained 1 ppm. FIG. 6 shows the results of continuous measurement of the ion concentration in the waste water using the analyzer prepared in this way.

In the figure, the x mark indicates a value obtained by separately measuring the concentration using atomic absorption spectrometry by collecting wastewater at the same time as the measurement using the above-mentioned analyzer. As is clear from the figure, the calibration curve that appeared at the beginning of the measurement corresponds well to the amount of cadmium nitrate that was impregnated into the liquid absorption part to create the calibration curve as described above, and the value of the amount of cadmium measured for the wastewater also The values are close to those measured by atomic absorption spectrometry. In this way, changes in the concentration of the target substance in the test liquid are detected phase-by-moment.

As described above, according to the present invention, the tape that has been passed through the test liquid is slid on the surface of the detector, and at this time, the surface of the detector comes into contact with the test liquid carried by the tape and is exposed to the surface of the detector. Since the ion concentration in the test solution is detected, the structure is simpler and different from the conventional system in which the test solution is sent into the device through a pipe and detected there. It can be made small and inexpensive.

Since the amount of the test liquid to be sampled can be extremely small enough to be supported on the tape, even if a reagent is added to the test liquid, only a small amount of the reagent is required, and maintenance costs can be reduced. If it is necessary to add, for example, a pretreatment reagent to the test liquid, by adsorbing the reagent etc. to the liquid absorption part of the tape in advance as described above, you can avoid the trouble of adding the reagent etc. each time. This simplifies the structure of the device compared to a case where the operation is performed by a machine. Furthermore, in conventional ion concentration measurements, in which a pair of a reference electrode and an ion-selective electrode are immersed in a test liquid, the surfaces of these electrodes become covered with reaction products over time, as described above. However, in the present invention, the tape slides on the electrode surface and the surface that comes into contact with the test liquid is constantly updated, so the measurement H5 is always unstable. It is done stably.

The present invention can be widely applied not only to the measurement of ion concentration as described above, but also to, for example, the measurement of the electrical conductivity of a test liquid.

The present invention has many practical advantages, such as the simple structure described above, which facilitates continuous automatic analysis, and also allows the analysis to be performed stably and economically.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a state in which an analysis is performed using an automatic analyzer which is an embodiment of the present invention, FIGS. Figures 3a and b are a side view and a plan view, respectively, of the tape used in the automatic analyzer, Figure 4 is a side view of a first variant of the tape, and Figure 5 is a plane view of a second variant of the same tape. 6 are curve diagrams showing the results of measuring ion concentration using the above device. 2,3...゜...Reel, 4,6,7...Roller, 8...Detector, 12...Measuring section, 13...1... tape, 14...comparison electrode,
15... Indicator electrode, 16... Insulating material,
18, 21, 24...Liquid suction part, 20, 22, 2
5... Partition section.

Claims (1)

[Scope of Claims] 1. An automatic analysis device comprising: a tape feeding mechanism; and a detection body whose end surface comes into contact with the test liquid carried by the tape that has passed through the test liquid. 2 Claim 1 in which the detection body is of a fixed head type
Automated analyzer described in section. 3. The automatic analyzer according to claim 1, comprising an ion-selective electrode as a detection object. 4. The automatic analyzer according to claim 3, wherein the ion-selective electrode includes an indicator electrode and a reference electrode that are integrated with each other via an insulating material. 5. The automatic analyzer according to claim 1, wherein the tape feeding mechanism includes a guide section that guides the tape into the test liquid. 6. The automatic analyzer according to claim 1, comprising a display section that processes and displays signals generated in the detection object.