JPS59190665A - Flow system analytical apparatus - Google Patents

Abstract

PURPOSE:To enhance analytical capacity by increasing the size of a detection signal, in a flow system analytical apparatus, by introducing a reaction liquid into a main flowline in such a state that a reagent region is interposed between specimen sections. CONSTITUTION:At first, a carrier liquid 2 is sent to a conduit 3 by a pump 1 and a definite amount of the specimen 5 held by an automatic sampler 16 is sucked and metered into two specimen loops 6 of a change-over valve 10 by a pump 14 and, at the same time, a reagent 8 is sucked and metered into the reagent loop 9 of a change-over valve 30 in a definite amount by a pump 15. In the next step, valves 10, 30 are changed over and the reagent is introduced into a main flowline so as to be interposed between the specimens. Whereupon, the introduced specimens advance through a reaction coil 12 while mixed and reacted with the reagent between them and the change amount of the reaction is detected by a detector 13. By this method, the introduction of a large amount of specimens is enabled and the dilution ratio of the specimen with the carrier liquid is small while reaction advances in a high specimen concn. state and a large change amount can be detected.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a flow-type analysis device, and particularly to flow-type analysis in which a sample and a reagent are placed on a flow of a carrier liquid, the two are reacted, and the reaction liquid is detected. Regarding equipment.

[Background of the invention]

For example, a flow type analyzer is disclosed in Japanese Patent Application Laid-Open No. 55-29791.
No. This example will be explained with reference to FIG. The liquid carrier solution 2 is transferred to the conduit 3 by the liquid sending pumps 1 and 21.
．． 23. A fixed amount of sample 5 is sucked and measured into sample loop 6 by pump 4. Further, a fixed amount of reagent 8 is suctioned and measured into reagent lube 9 by another pump 7 . Sample and reagent are then introduced into separate channels in the carrier stream by switching switch 10.30.

The sample and reagent meet at confluence point A, and while mixing and reacting,
The reaction liquid advances through a reaction coil 12 in a constant temperature bath 11 set at a constant temperature, and the amount of chemical and physical changes caused by the reaction is detected by a detector 13, after which the reaction liquid is drained.

In this method, the merging of the sample and reagent at the merging point affects the accuracy of analysis. For example, due to slight variations in the inner diameter of the conduit or the stability of the flow rate of the liquid pump,
At the confluence point A, the sample and reagent do not necessarily converge under optimal conditions.

Therefore, the applicant of the present application is studying a method for introducing samples and reagents that compensates for this drawback and has even higher reliability. The technology described below has not been published.

In this introduction method, the sample is sandwiched between reagents on both sides and introduced into the flow path, so that the sample and reagent always mix and react in the same state, allowing signal detection with good reproducibility. This will be called the sample sandwich method. However, with this method, when the amount of sample introduced into the center is increased, the concentration distribution of the reagents on both sides is divided into two peaks as shown in Figure 2, and as a result of this, the amount of change due to the reaction is also lower than that at the center. The disadvantage is that the detection signal is not increased beyond a certain level and the detection sensitivity is low. If the amount of sample introduced is limited to the extent that the detection signal does not split into two peaks, the sample will be diluted by the carrier solution to a large extent, and the reaction will only proceed at low sample concentrations, so there is also a limit to the amount of detection signal here. .

[Purpose of the invention]

An object of the present invention is to provide a flow type analyzer that can increase the magnitude of a detection signal and improve analytical performance while reducing the amount of reagents used.

[Summary of the invention]

The present invention is characterized in that the sample area is divided into front and back areas, and the reagent area is sandwiched between the areas and introduced into the main flow path.

[Embodiments of the invention]

An embodiment of the invention is shown in FIGS. 3 and 4.

A carrier solution 2 is sent to a conduit 3 by a liquid sending pump 1 . As shown in FIG. 3, a fixed amount of the sample 5 held in the autosampler 16 is sucked and measured by the pump 14 into the two sample loops 6 of the switching pulp 10, and at the same time, the reagent 8 is pumped into the reagent loop 9 of the switching pulp 30 by the pump 15. Suction and measure a certain amount. Next, the switching pulps 10 and 30 are switched,
As shown in FIG. 4, the reagent is sandwiched between samples and introduced into the main channel. The introduced sample moves through the reaction coil 12 in the constant temperature bath 11 set at a constant temperature while mixing and reacting with the reagent in the middle, and the amount of change caused by the reaction is detected by the detector 13. It is then drained. Sample/reagent suction pump 14゜15, off jl) Replacement pulp 10,
All controls for the autosampler 16 are performed by a control unit 17, and the control unit 17 can control the suction time of the sample/reagent, the timing of switching the switching pulp, and the timing of sample supply by the autosampler. .

According to this example, a large amount of sample can be introduced by dividing the sample into two areas, the front and the back, so the proportion of the sample diluted with the carrier solution is small, and the reaction can proceed while the sample concentration remains high. However, large amounts of change can be detected.

As an example of actual measurement, the analysis results of nitrite ions are shown in FIG. The sample has a nitrite nitrogen concentration of 1 ppm. Tables 1 and 2 show the various system characteristics, sample amounts, and reagent amounts at that time.

As can be seen from Table 1, Table 2, and Figure 5, the absorbance was 0.5 in the sample sandwich method A described above, whereas the absorbance was 1.5 using this method B, which tripled the absorbance. To increase. For this reason, the detection limit was increased several times, and the analytical performance was greatly improved. Furthermore, reagents can be saved regardless of the amount of reagent used, which is 200 μt. The sample consumption increased from 30μt to 400μt, but this is still 1/1 of the commonly used method.
It is about 0. For example, this method is very effective for general samples that can be easily collected in large quantities, such as industrial water and factory wastewater.

Next, FIGS. 6 and 7 show another embodiment of the present invention.

In this example, one piece of hemi-switching pulp 18'ff is used. As shown in FIG.
1, a fixed amount of reagent 8 is aspirated and measured into reagent loop 9. Next, by switching the forward switching pulp 18, the reagent is introduced into the main flow path in the form of being sandwiched between samples as shown in FIG.

In the switching pulp 10 in FIG. 3, there is a dead volume of several millimeters from the inlet to the discharge port, but in the switching pulp 18 in FIG. 6, the inlet and discharge port are directly connected. Since there is a large amount of data, there is almost no target volume, which is advantageous in improving analysis accuracy.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the dilution of a sample with a reagent during mixing, and therefore, there is an effect that detection sensitivity can be improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the flow path of the prior art, Fig. 2 is a diagram for explaining all the regular procedures on the large sample side in the unpublished sample sandwich method, and Figs. 3 and 4 are the operations of an embodiment of the present invention. FIG. 5 is a diagram showing an analysis example of nitrite ions according to the embodiment of FIG. 3, and FIGS. 6 and 7 are diagrams for explaining the operation of other embodiments of the present invention. It is a diagram. 3... Conduit, 5... Sample, 6.9... Constant volume loop, 8... Reagent, lo, 18.30... Switching pulp, 12... Reaction coil, 13... Detector, 16...
・Autosamp 1st figure 2nd figure m -

Claims (1)

[Claims] 1. In a flow type analyzer equipped with a channel for mixing a sample and a reagent introduced through a detector for detecting a reaction solution, and a means for flowing a carrier solution into the channel, the above-mentioned The method is characterized in that a means is provided in the middle of the flow path for fractionating the sample introduced from the sample container into a plurality of areas, and for introducing the reagent solution into the flow path between the divided areas. Flow method analyzer.