JPS63289455A - Electrolyte measuring apparatus - Google Patents

Abstract

PURPOSE:To reduce a processing time with a higher operating speed of dilution containers along with a higher measuring accuracy and reproducibility, by providing a thermostatic tank which maintains the dilution container set on a disk at a specified temperature to keep temperature conditions of a sample. CONSTITUTION:This measuring apparatus is made up of a flow type electrode 3 kept at a specified temperature with an electrode thermostatic tank 22, a shipper syringe 19 for sucking sample to the electrode 3, a disk 10 having a plurality of dilution container 1 set thereon, a sampling mechanism 4 which injects sample into the containers 1, dilution liquid discharging mechanism for diluting samples in the containers 1 and the like. Then, the thermostatic tank 2 is provided to keep the container 1 set on the disk 10 at a specified temperature. Then before the sample diluted with the electrode 3 and an internal reference liquid are sucked up, the electrode 3 and solution are the same in the temperature to keep an electromotive force from the electrode 3 constant thereby achieving a higher accuracy and reproducibility. The constant temperature of the solution eliminates the need for waiting until the temperature becomes constant after the suction of the solution with the shipper syringe 19 thereby enabling a reduction in the processing time per sample.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrolyte measuring device, and more particularly to an electrolyte measuring device suitable for high-speed processing used in automatic analyzers for clinical tests.

[Conventional technology]

In the conventional flow type electrolyte measuring device,
The sample concentration is measured according to the principle described in Japanese Patent No. 29759.

However, when processing multiple samples of 150 or more samples per hour, the analysis time per sample becomes short, making it difficult to bring the sample to a sufficient temperature. In the electrode method, an electromotive force is generated according to Nernst's equation, and this is used to convert the concentration, but Nernst's equation includes a temperature term, so the temperature of the sample at the electrode is non-uniform. This appears as a deviation in the electromotive force, resulting in poor data accuracy.

The Nernst equation is: Eo: constant voltage R determined by the measurement system; gas constant T; absolute temperature F; Faraday's constant aI; cleaning of ion i n; If the temperature of the aspirated sample is non-uniform, it is necessary to maintain the sample (diluted sample or internal standard solution) aspirated into the electrode and the electrode at a constant temperature to enable highly accurate measurements. It is. In order to keep the sample at a constant temperature, it is appropriate to heat it in the tube before it enters the electrode section, but heating the tube lengthens the tube, causing the tube to be contaminated by the sample and the sample to be affected by the sample. It becomes easier to receive. If you simply want to improve the temperature response of the electrode part, you can lengthen the tube in the sample suction part of the electrode part and install a heating part, but since a minute electromotive force is measured at the electrode part, If the tube is too long, it will cause electrical noise. Furthermore, it is possible to heat the sample that has entered the electrode section to a certain temperature by leaving it for a long time. However, although this method allows measurement of a small number of samples, it is not possible to process a large number of samples.

In the conventional technology, when processing a large number of samples, the internal standard solution is measured once for every five samples to make time, making it possible to process 150 samples/hour. In this case, since the internal standard solution is measured only once every five samples, the electromotive force drifts and accurate data cannot be obtained. There is a problem in that when there is an abnormal sample, abnormal data is generated even if the next sample is a normal sample.

The electrolyte measurement device of Hitachi's new model 736 automatic analyzer has a chain type dilution container, which has the disadvantage that the dilution container moves slowly and it takes a long time to clean the dilution container. In addition, as a cleaning method, since there is no dilution tank exclusively for sampling probes, the method of discharging diluent into a dilution container and cleaning the inside of the probe is used. After that, the 24 dilution containers were again washed every 20 seconds using the internal standard solution. For this reason, a minimum of about 14 minutes was required from pressing the start key to starting the analysis, resulting in extremely poor operability.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, when processing a large number of samples, no consideration was given to keeping the temperature conditions of the samples constant, and it was impossible to process a large number of samples. Further, there were disadvantages in that the movement of the dilution container was slow and it took a long time to clean the dilution container.

The purpose of the present invention is to easily maintain a constant temperature condition of a sample, and to improve the operation speed of a dilution container.
An object of the present invention is to provide an electrolyte measuring device that can be highly accurate.

[Means for solving problems]

The above object is achieved by providing a constant temperature bath for keeping the dilution container set on the disk at a predetermined temperature.

[Effect]

A sample is dispensed from a sample container by a sampling mechanism, a predetermined amount of the sample is discharged into a dilution container, and a predetermined amount of diluent is discharged into this sample.

The internal standard solution is dispensed into dilution containers once before and after the sample is dispensed, and these dilution containers are placed in a water bath maintained at a constant temperature. The diluted sample or internal standard solution is dispensed, and after a certain period of time has elapsed, the diluted sample or internal standard solution is sucked into the flow type electrode. heated to a constant temperature. As a result, when it is attracted to the electrode part, there is no temperature difference with the flow type electrode, and measurement can be performed without being affected by temperature.

Further, the dilution container is set on a reaction disk rotated by a motor, and a cleaning mechanism, an internal standard solution discharge mechanism, and a dilution solution discharge mechanism are also provided for cleaning the dilution container. Since the dilution container is fixed to the reaction disk, it is possible to stop a specific dilution container on the reaction disk at a specific position by rotating the reaction disk with a motor, and the stopping position is determined by the dilution container position detection mechanism. This is the position detected by . At the stopped position, it becomes possible to wash the dilution container and discharge the internal standard solution and dilution solution. These make it possible to freely operate the dilution container at high speed, while the temperature of the diluted sample and internal standard solution sucked into the electrode remains constant, so the temperature response is good and It becomes possible to measure electrolytes of large amounts of samples.

〔Example〕

The present invention will be described in detail below with reference to the embodiments shown in FIGS. 1 to 4 and FIGS. 5 and 6.

Fig. 1 is a layout diagram showing an embodiment of the thermostat arrangement of the electrolyte measuring device of the present invention, Fig. 2 is a schematic diagram showing an embodiment of the electrolyte measuring device of the present invention, and Fig. 3 is a schematic diagram of the sampling process. , FIG. 4 is a schematic diagram of the cleaning mechanism.

In FIG. 1, 1 is a dilution container for diluting the sample with a diluent, 2 is a constant temperature bath that keeps the dilution container 1 at a constant temperature, 3 is a flow type electrode, and 4 is a sample container 21 in FIG.
5 is a heater for controlling the temperature of constant temperature bath 2, 6 is a pump for circulating constant temperature water, 7 is a cooling tank, and 8 is a diluted sample. and a zipper tube for aspirating the internal standard solution from the dilution container 1; 9 is a vertical mechanism for the zipper tube 8; 10 is a disk for fixing a plurality of dilution containers 1; 48 dilution containers 1 are set at equal intervals on the circumference. 11 is disk 1
0 is a motor that rotates, 19 is a sipper syringe for sucking the sample into the flow type electrode 3, 20 is a reference electrode, 22 is an electrode constant temperature bath that keeps the flow type electrode 3 at a constant temperature,
23 is a temperature sensor for the constant temperature bath 2, 24 is a controller, and 29 is a position detector for the disk 10.

In Fig. 2, 1, 3, 4, 8, 19, 20゜22 are the ones explained in Fig. 1, 12 is a diluent discharge tube, and 13 is an internal standard solution discharge tube, respectively. The mechanism 14 is connected to the internal standard solution discharge mechanism 15. The diluent discharge mechanism 14 sucks the diluted liquid from the diluted liquid container 16 and discharges it from the diluted liquid discharge tube 12 into the diluted container 1, and the internal standard liquid discharge mechanism 15 sucks the internal standard liquid from the internal standard liquid container 17. The internal standard solution is discharged from the discharge tube 13 into the dilution container 1 . 18 is a KCI solution, and 21 is a sample container, which are arranged on a sample disk 32. 25 is a cleaning tank, and 28 is a dilution container cleaning mechanism.

Water controlled at a constant temperature (37° C.) is circulated in a constant temperature bath 2 that keeps the dilution container 1 set on the disk 10 at a constant concentration.
The circulation pump 6, the cooling tank 7, and the heater 5 are circulated in this order. The temperature of the water in the constant temperature bath 2 is detected by the constant temperature bath temperature detector 23, and if the temperature is higher than a predetermined temperature, the heater 5 is turned off. In this case, the water is cooled by the cooling tank 7, and when the temperature drops below a predetermined temperature, the heater 5 is turned on and the water is heated. The water in the constant temperature bath 2 is maintained at a predetermined temperature by controlling the heater 5 to turn on and off. The heater 5 is controlled by a controller 24.

FIG. 5 shows an electrolyte measurement cycle. As shown in FIG. 3, the sample container 21 containing the sample moves to the sampling position and stops, and the sample dispensing mechanism 4 descends into the sample container 21 and aspirates a fixed amount of 30 μQ of sample. The dispensing mechanism 4 rises, rotates, and descends into the dilution container 1, and discharges a fixed amount of 20 μQ of sample into the bottom of the dilution container 1. Dilution container 1 is disk 1
0, and the disk 10 is rotated by a motor 11. The dilution container 1 into which the sample has been discharged rotates one rotation and one pitch and then stops. This operation is performed as a half cycle. In the next half cycle, the empty dilution container 1 comes to the sample discharge position and stops, but no sampling is performed.

In Figure 5, the dilution container 1 sampled in the first half cycle is A, and the dilution container 1 sampled in the second half cycle is B.
The operation of the dilution container 1 will be explained as follows.

A total of 48 dilution containers 1 are attached, and the operation time is 18 seconds for the ■ cycle. After two cycles, the dilution container 1-A stops at the diluent discharge position, and a fixed amount of 600 μQ of diluent is discharged, and the sample is diluted 31 times with the diluent. Similarly, after three cycles, the dilution container 1-B stops at the internal standard solution discharge position, and a fixed amount of 600 μQ of internal standard solution is discharged.

Thereafter, the (lO) dilution container 1-A stops at the position of the zipper tube 8 for aspirating the diluted sample and internal standard solution into the electrode section after 6 cycles. Zipper tube 8 is zipper
It is lowered by the tube up and down mechanism 9 and stopped at the bottom of the dilution container 1-A. The sipper syringe 19 descends and a certain amount of 5
00μQ of diluted sample is pulled onto the electrode section. After 6 cycles of dispensing the internal standard solution dispensed into the dilution container 1-B, a fixed amount of 50
0μQ is aspirated. In this way, suction is applied to the flow type electrode 3 every 9 seconds. At the flow type electrode 3, the aspirated sample is measured as an electromotive force by the reference electrode 20 and the flow type electrode 3, converted to a digital value by an amplifier and an A-D converter, converted to a concentration by a CPU, and outputted from a printer. .

Figure 3 shows the sampling process. After discharging the sample, purified water from the outside of the sample dispensing mechanism 4 is discharged from the cleaning tank 25 to clean the outer wall of the sample dispensing mechanism 4 . Further, purified water pressurized by a sampling syringe is connected through a tube 26, and the inside of the sample dispensing mechanism 4 is cleaned by opening a solenoid valve 27. After cleaning, solenoid valve 27
is closed and purified water no longer comes out.

After aspirating the diluted sample or internal standard solution, the zipper tube up-and-down mechanism 9 moves up and stops above the dilution container 1 . After suction through zipper tube 8, dilute container 1
operates for 5 cycles. After five cycles, as shown in FIG.
The purified water is discharged from the dilution container cleaning water discharge mechanism 31.

This washing is repeated three times, and finally the purified water remaining in the dilution container 1 is vacuum-suctioned. The washed dilution container 1 is used again for the next sample or internal standard solution. The dilution container cleaning mechanism 28 can be moved up and down, and in the case of cleaning, the nozzle tip descends to the bottom of the dilution container 1 for cleaning.

In other cases, be careful not to collide with the dilution container 1, which is rising and rotating.

When measuring a sample, first wash the dilution container, measure the internal standard solution, and then measure the sample. As shown in Figure 5,
Perform measurements in the order of internal standard solution, diluted sample, and internal standard solution.

According to the embodiment of the present invention, the temperature characteristics at the flow electrode 3 are improved, and as shown in FIG. The temperature is constant, that is, the flow type electrode 3 and the solution part are at the same temperature, and the electromotive force from the flow type electrode 3 can be kept constant. Therefore, accuracy is improved and good reproducibility is obtained.

Table 1 shows a comparison of data obtained as a result of temperature control between the conventional method and the embodiment of the present invention at 100 samples/hour, and the reproducibility has been improved approximately twice.

Table 1 In addition, since the temperature of the solution remains constant, there is no need to wait until the temperature becomes constant after suctioning the solution with a sipper syringe, which shortens the processing time per sample and allows for large amounts of Sample processing becomes possible.

Table 2 shows a comparison of 150 samples/hour for the conventional method and 200 samples/hour for the embodiment of the present invention.

Table 2 With the conventional method, CV was only about 1% with 150 samples/hour, but with the method of the embodiment of the present invention, CV of 20 samples/hour was obtained.
Not only is high-speed processing of 0 sample/hour possible, but c
vfJ'Xo, 3-0.4%, which is approximately the same accuracy as in the case of 100 samples/hour, was obtained.

Furthermore, since the internal standard solution was measured for every other sample, the influence of the previous sample was small, and the results are shown in Table 3. In the conventional method, when a normal sample is measured after an abnormal sample, data with a high or low value of several percent is obtained, but according to the embodiment of the present invention, the effect is less than about 1%.

In addition, whereas previously it took about 14 minutes from start to start of analysis, it is now possible to start analysis in about 7 minutes.

〔Effect of the invention〕

As explained above, according to the present invention, the temperature characteristics of the flow type electrode are improved, and the solution is also at the same temperature, so the electromotive force can be kept constant, accuracy is improved, and good reproducibility is achieved. and - shorter processing time per sample;
It has the advantage that it is possible to process a large amount of samples and obtain equivalent accuracy.

[Brief explanation of drawings]

Fig. 1 is a layout diagram showing an embodiment of the thermostat arrangement of the electrolyte measuring device of the present invention, Fig. 2 is a schematic diagram showing an embodiment of the electrolyte measuring device of the present invention, and Fig. 3 is a schematic diagram of the sampling process. , FIG. 4 is a schematic diagram of the cleaning mechanism, FIG. 5 is a schematic diagram of the analysis cycle, and FIG. 6 is an electrode electromotive force diagram.

Claims (1)

[Claims] 1. A flow type electrode for measuring the concentration of electrolyte, a sipper syringe for sucking a sample into the flow type electrode, an electrode constant temperature bath for keeping the flow type electrode at a predetermined temperature, a reference electrode, and multiple dilution containers. a disk to be set; a sampling dispensing mechanism dispensing the sample into the dilution container;
In an electrolyte measuring device comprising a diluent discharge mechanism for diluting the sample in the dilution container with a diluent, and a sample disk in which a plurality of sample containers are set, the dilution container set in the disk is heated to a predetermined temperature. An electrolyte measuring device characterized by being equipped with a constant temperature bath.