JP2000214154A - Analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve automation and reduction of labor by adapting a wet analyzing method accompanied by long-time reaction to flow injection analysis without lowering sensitivity. SOLUTION: In an analyzer equipped with a pump 3 feeding a reaction soln. 1 reacting with a component to be analyzed, a sample introducing part 5 for introducing a sample into the stream of the reaction soln., a reaction pipe being the flow channel part where the sample is reacted with the reaction soln. on the downstream side of the sample introducing part and a detector 8 provided on the downstream side of the reaction pipe to detect a substance formed by reaction, a plurality of reaction pipes are provided and a valve 6 changing over a flow channel state wherein one reaction pipe 7a among the reaction pipes constitutes the main flow channel reaching the detector 8 through the sample introducing part 5 and a flow channel state wherein the reaction pipe 7a constitutes a flow subchannel not going through the sample introducing part 5 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer particularly suitable for analyzing boron in environmental water.

[0002]

2. Description of the Related Art One of the methods for quantifying trace amounts of boron contained in tap water, waste water, environmental water, etc. is an azomethine H absorption spectrophotometry. This is because boron has a pH of about 6 and azomethine H
This is a laboratory wet analysis method for determining boron by measuring the absorbance at around 410 nm of a yellow complex produced by the reaction with a yellow complex. Automating such wet chemical analysis by hand,
In recent years, flow injection analysis has been actively used as a means for saving labor. Flow injection analysis is a method in which a sample introduced into a reaction solution flowing at a constant flow rate by a pump reacts with the reaction solution while mixing with the reaction solution and changes to a substance that can be detected by a highly selective detector. This is an analytical method for detecting and quantifying this.

[0003]

When the analysis of boron based on the azomethine H method is to be automated and labor-saving by using flow injection analysis, the azomethine H
The problem is that the reaction time between boron and boron is long. That is,
In the conventional manual azomethine H method, it is specified that a sample solution and an azomethine H reagent are mixed in a beaker and then left at 20 ° C. for 2 hours (JIS-K0102). It takes a long time. on the other hand,
In general flow injection analysis, the time from the introduction of a sample to the arrival at the detector is at most a few minutes, so simply applying the azomethine H method to the flow injection analysis results in a short reaction time. Insufficient coloring and low detection sensitivity. Therefore, since the analysis target is limited to a sample having a considerably high concentration of about 10 ppm or more, there is a problem that it cannot be applied to environmental analysis for a sample having a still lower concentration. The present invention has been made in view of such circumstances, and applies a wet analysis method involving a long-time reaction as described above to flow injection analysis without lowering sensitivity, thereby achieving automation and labor saving. The purpose is to aim. Another object of the present invention is to provide an analyzer that can perform analysis of a high-concentration sample and analysis of a low-concentration sample by one unit, or can perform simultaneous and parallel analysis. Still another object of the present invention is to provide a flow injection analyzer suitable for analyzing boron in environmental water.

[0004]

In order to solve the above-mentioned problems, the present invention provides a liquid sending section for sending a reaction solution that reacts with a component to be analyzed, and a sample introducing section for introducing a sample into the liquid flow. And a reaction tube in which the sample and the reaction solution react inside the flow path portion downstream thereof and a detector downstream thereof and sensitive to a substance generated by the reaction. And a plurality of the reaction tubes,
One of the reaction tubes is in a state of a flow path constituting a main flow path leading to the detector via the sample introduction part, and the same reaction tube is in a state of a flow path constituting a sub flow path not passing through the sample introduction part. And a valve for switching between the two.

[0005] With this configuration, it is possible to automate and save labor by using a flow injection analysis method for an analysis requiring a long time for the reaction, such as analysis of boron in environmental water based on the azomethine H method. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a flow path configuration diagram of a flow injection analyzer according to an embodiment of the present invention. In the figure, a reaction solution 1 is supplied from a reservoir 2 to a pump 3
Through the sample introduction unit 5 to reach a valve 6 that switches the flow path to one of two directions. The reaction liquid flowing through one of the reaction tubes 7a and 7b selected by the valve 6 passes through the detector 8 and is discharged. This is the main flow path in this analyzer, but a part of the reaction solution 1 is divided at a branching section 4 provided separately upstream of the sample introduction section 5, and a sub-flow path whose flow rate is adjusted by a resistance tube 9 is provided. is there. The flow rate of the sub flow path is, for example, about 1/10 of the liquid sending amount,
It flows to the detector 8 through the reaction tube 7a. Therefore, in a state where the main flow path is switched to the reaction tube 7b side (flow path indicated by a solid line) by the valve 6, the reaction tube 7a is placed in the sub flow path, and the small flow rate through the resistance pipe 9 is provided therein. There is a flow.

The reaction tubes 7a and 7b are generally formed by winding a tube of a required length in a coil shape, but if the length may be short, a part of the flow pipe is used as a reaction tube. In some cases, a special reaction tube is not provided.
In the following, a flow path portion that functions as a reaction tube even when it does not have such a form as a reaction tube is referred to as a reaction tube.

In the configuration shown in FIG. 1, boron can be analyzed based on the azomethine H method according to the following procedure. First, as a reaction solution, 52.8 g of diammonium hydrogen phosphate, 5 g of ascorbic acid, and 5 g of EDTA were added to 400 ml of distilled water, and 1.25 g of azomethine H was dissolved in the solution to adjust the pH to 7.2. Thereafter, a liquid having a volume of 500 ml by adding distilled water is prepared in the reservoir 2, and the pump 3 is operated with the flow rate set at about 0.5 ml / min. As the detector 8, an ultraviolet / visible spectrophotometer was used.
It is set so that the absorbance can be measured at a wavelength near 0 nm. The sample introduction unit 5 may be either a method of piercing a septum and introducing with a syringe or a sampling valve method, and injects 0.1 to 0.3 ml of the sample solution from here.

At the time of sample introduction, if the valve 6 is switched to the flow path on the dotted line side, the sample rides on the flow of the reaction solution 1 and enters the reaction tube 7a a few seconds after the introduction. Switch to the flow path. Thereafter, only a small flow rate of the sub-flow path flows through the reaction tube 7a, so that the speed at which the introduced sample travels through the reaction tube 7a also decreases. If the length of the reaction tube 7a and the magnitude of the resistance of the resistance tube 9 are appropriately adjusted in advance,
It can be set so that the sample passes through the reaction tube 7a for a sufficient time to react. If the reaction proceeds sufficiently, the detector 8
And can be quantified.

On the other hand, even in this state (switched to the solid line side), the main flow path includes a flow path as a normal flow injection analysis device including the pump 3, the sample introduction section 5, the reaction tube 7b, and the detector 8. With this configuration, if a sample is introduced into the sample introduction unit 5 as it is, flow injection analysis can be performed. Since the introduced sample passes through the reaction tube 7b in a short time, the reaction is insufficient. However, a sample having a high concentration can be detected. Therefore, the high-concentration sample can be analyzed simultaneously and in parallel using the waiting time while the low-concentration sample passes through the reaction tube 7a over a long time. Since the analysis time of the high-concentration sample is about 1/10 or less of that of the low-concentration sample, the high-concentration sample can be analyzed many times while the low-concentration sample is analyzed once.

FIG. 2 shows a modification of the present invention.
This is equivalent to a configuration in which the resistance tube 9 is removed from the configuration in FIG. 1, in other words, a state in which the resistance of the sub flow path is infinitely large and no flow exists in the sub flow path. In the figure, the same members as those shown in FIG.
(Hereinafter, the same applies to FIG. 3 and subsequent drawings.) In the analyzer configured as shown in FIG. 2, the sample is introduced with the valve 6 switched to the dotted line side, and a few seconds after that, the solid line To the reaction tube 7a
The inside of the sample stops, and the introduced sample reacts with the reaction solution 1 while staying in the reaction tube 7a. If the reaction does not proceed easily because the liquid does not move, auxiliary means for promoting the reaction may be taken, such as raising the temperature of the reaction tube 7a or stirring the reaction tube 7a by applying ultrasonic waves. After the time required for the reaction to sufficiently proceed has elapsed, the valve 6 is returned to the dotted line side, and the flow again occurs in the reaction tube 7a. After a few minutes, the sample that has stayed reaches the detector 8 and is analyzed. The result is obtained. As described above, the analysis of the high-concentration sample can be performed many times in the flow path on the reaction tube 7b side while the sample is retained in the reaction tube 7a. In the configuration of FIG. 2, the reaction time can be arbitrarily and easily determined only by the timing of returning the valve 6, which is an advantage as compared with the case of FIG.

The valve 6 in FIG. 1 or FIG. 2 is replaced with two solenoid valves, and only one of them is selectively opened to function in exactly the same manner. FIG. 3 shows such a modified example. In this example, normally closed solenoid valves 61 and 62 are provided, and only one of them is selected by a switch 10 having a transfer contact and flows from an excitation power supply 11. The valve is configured to be opened by being excited by an electric current. Each solenoid valve is a reaction tube 7a, 7b, respectively.
And the other end of each reaction tube is connected to the same detector 8.

In the analyzer constructed as shown in FIG. 3, selectively energizing the solenoid valves 61 and 62 by the switch 10 is exactly the same as switching the rotary valve 6 in the configuration of FIG. In addition to the fact that the operation does not change, the electromagnetic valve is used, so that it can be operated by an electric control signal and is suitable for automation using a program controller. When a sub-flow path having a resistance tube 9 is provided as shown by a dotted line in FIG. 3, the configuration becomes the same as that in FIG. The number of solenoid valves is not limited to two, and a large number of solenoid valves may be provided, and the number of reaction tubes may be provided by the same number so that a large number of samples can be analyzed in parallel.

The valve 6 in FIG. 1 is not limited to a three-port valve. FIG. 4 shows a modified example using a 6-port valve, and its operation is almost the same as that of FIG. That is, in the same figure, the sample is introduced from the sample introduction part 5 with the valve 6a in the state of the flow path on the dotted line side, and when it enters the reaction tube 7a several seconds later, the valve 6a is switched to the solid line side. Thereafter, the sample slowly travels in the reaction tube 7a by the liquid flow in the sub-flow path via the resistance tube 9, and after sufficient reaction during that time, reaches the detector 8 to complete the analysis.
During this time, another high-concentration sample can be analyzed in parallel using the flow path on the side of the reaction tube 7b, as in the case of FIG. Although the reaction tube 7b in FIG. 4 functions as a reaction tube in function, it is assumed that the tube is structurally a simple pipe.

FIG. 5 is a further modified example of the configuration of FIG. 4, in which a liquid feed pump for the sub flow path is separately provided.
The sub flow path pump 3a is set so that the amount of liquid to be sent is considerably smaller than that of the main flow path pump 3 (about 1/10 or less). As in FIG. 4, the valve 6a introduces a sample from the sample introduction unit 5 in the state of the flow path on the dotted line side, and switches the valve 6a to the solid line side a few seconds later when it enters the reaction tube 7a. Thereafter, the sample slowly advances by the liquid flow in the sub flow path sent by the pump 3a, and the reaction tube 7a
When the valve 6a is returned to the dotted line side (return the reaction tube 7a into the main flow path) at a timing slightly before passing through the reaction tube 7b,
(Simply piping) to the detector 8 and the analysis is completed. If the pump 3a is intermittently operated and the liquid is supplied in a pulse form, and if the time average flow rate is adjusted to be a value much lower than the liquid supply amount of the pump 3, the reaction is caused by the pulsed flow. The liquid in the tube 7a is easily stirred, and an effect of promoting the reaction is obtained. Further, if the pump 3a is stopped to stop the flow of the sub-flow path, the sample can be retained in the reaction tube 7a for an arbitrary time as in the configuration of FIG.

FIG. 6 shows an example of analysis by the analyzer of the present invention. This analysis was performed using the analyzer having the flow path configuration shown in FIG. 4, and the composition and flow rate of the reaction solution were as described above. FIG. 7A shows an example of analysis of a low-concentration sample in which the reaction time is set to 30 minutes (the sample is passed through the reaction tube 7a).
Standard solutions prepared in five stages from ppm to 1 ppm were introduced. FIG. 2B shows an example of analysis of a high-concentration sample with a reaction time of 30 seconds (the sample is passed through the reaction tube 7b).
The same standard solution of m was repeatedly introduced five times.

In general, a flow injection analyzer can be used as a detection unit in a post-column reaction analysis by introducing a column eluate of a liquid chromatograph. Generally, there is a possibility that the present invention can be applied to the analyzer. Note that the composition, concentration, and other numerical values in the above description are merely examples, and the present invention is not limited thereto.

[0018]

Since the present invention is configured as described above, it is possible not only to perform an analysis involving a reaction requiring a long time but with a flow injection analyzer without lowering the sensitivity, and it is also possible to carry out the analysis. Since one analyzer can be used for analyzing a low-concentration sample and another for analyzing a high-concentration sample, the efficiency of the analysis operation and the operating efficiency of the analyzer can be improved. In particular, when the analysis of boron based on the conventionally known azomethine H absorption spectrophotometry is performed using the apparatus of the present invention, the above effects are remarkable.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a modification of the present invention.

FIG. 3 is a diagram showing another modified example of the present invention.

FIG. 4 is a diagram showing another modified example of the present invention.

FIG. 5 is a diagram showing another modified example of the present invention.

FIG. 6 is a diagram showing an analysis example according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reaction liquid 2 ... Reservoir 3 ... Pump 4 ... Branch part 5 ... Sample introduction part 6 ... Valve 7 (7a, 7b) ... Reaction tube 8 ... Detector 9 ... Resistance tube

Claims (3)

[Claims] 1. A liquid sending section for sending a reaction solution that reacts with an analysis target component, a sample introducing section for introducing a sample into the liquid flow,
An analysis apparatus comprising a reaction tube in which the sample and the reaction solution react inside a flow path portion downstream thereof and a detector downstream thereof and sensitive to a substance generated by the reaction, A plurality of reaction tubes are provided, and one of the reaction tubes has the same state as the state of the flow path constituting the main flow path leading to the detector via the sample introduction section. An analyzer comprising a valve for switching a state of a flow path constituting a path. 2. The reactor according to claim 1, wherein at least one end of the reaction tube in which there is no liquid flow in the sub flow path or which is placed in the sub flow path is closed by the valve. The analyzer described in 1. 3. The analyzer according to claim 1, wherein the reaction solution is a solution containing azomethine H, and the detector is a spectrophotometer. Boron analyzer.