JPS6082968A - Method for flow injection analysis - Google Patents

Abstract

PURPOSE:To perform extraction of substance to be tested quickly and efficiently so as to perform detection by causing confluence of a first solvent phase and a second solvent phase being immiscible with each other, then introducing a sample to be measured into the flow of the confluent fluid. CONSTITUTION:The analytical apparatus suitable for the practice of this invention is constituted of pumps 1, 1' for forcing a first solvent phase and a second solvent phase immiscible with each other to a confluence device 10, a sample introducing device 4 for transporting sample liquid injected by a specified amt. by a microsyringe, etc. into the passage and transported to a reaction tube 5 by the confluent liquid from the confluence device 10, a reaction tube 5, a phase separation device 6 for separating the fluid transported from the reaction tube 5 into a first solvent phase and a second solvent phase, and a detection part 9. The substance to be detected contained in the sample which has been transported together with the confluent liquid separated to the first solvent phase segment and the second solvent phase segment is dissolved or separated in either one of the two solvent phases in the reaction tube 5, and then separated into the first or second solvent phase, and detected in the detection part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow injection analysis method.

In analytical chemistry, it is required to be able to analyze many samples per unit time, and to be able to analyze even small amounts of samples with high accuracy.

By the way, in daily analysis, the component to be analyzed often coexists with many other components, and therefore it is necessary to separate and analyze only the component to be analyzed from those coexisting components. The best conventional method for separating a component to be analyzed from among many coexisting components is to extract the component to be analyzed from a sample into another phase that is immiscible with the sample and analyze it, for example, by spectrophotometry. It is something to do.

Conventionally, these extraction operations have been performed manually, which is complicated and time-consuming. However, with the recent development of automatic analysis using fluid flow, the so-called flow injection analysis method, it has become possible to perform the extraction process automatically. The extraction method using this flow injection analytical method involves introducing a sample to be dissolved in a first solvent phase into a fluid stream of the first solvent phase, and then and the immiscible fluid stream of the second solvent phase are combined and segmented to undergo an extraction reaction and are directed to a phase separator that separates the first and second solvent phases. It is said that it will be destroyed.

However, in this extraction method, unnecessary diffusion of the sample occurs during sample introduction, making it impossible to analyze with high sensitivity. There are still many problems, such as the fact that the extraction reaction is greatly affected by the properties of the extract.

As a result of searching for a method for extracting a flow injection analysis method that can improve these drawbacks, the present inventors found that
The present invention was completed by discovering a quick and efficient extraction method.

That is, the present invention provides a flow injection analysis method in which a first solvent phase and a second solvent phase that are immiscible with each other are combined and then a measurement sample substance is introduced into the fluid stream. It is something to do.

The present invention will be explained in detail below.

A 70-diagram of one embodiment of the invention is illustrated in FIG. 1 and will be described with reference to FIG.

Figure 1 shows a pump (1) for pumping a mutually immiscible first solvent phase to a merging device (1) and a pump (1) for pumping a second solvent phase to a merging device (G), each arranged separately. and pipes (2) so that the discharge liquids of pumps (1) and (1') join together in a confluencer C1O.
.

(3) is connected. Furthermore, there is a merging device ■Q.

A sample introduction device (system) that transports a predetermined amount of sample liquid injected into the flow channel by a microsyringe or the like to the reaction tube (5) by a combined liquid of 1 (liter).

Reaction tube (5) 1 The fluid conveyed from the reaction tube (5) is transferred to the tube (8) that leads the first solvent phase to the tube (7) and the second solvent phase to the detection section (9). 70-diagram in which phase separators (6) to be separated are each connected in series.

In the present invention, in FIG.
This is a flow injection analysis method in which the first and second solvent phases, which are immiscible with each other, are combined and segmented into the combined liquid using a sample introduction device.

The first and second solvent phases are composed of solvents used in normal solvent extraction that are immiscible with each other and can dissolve and separate at least one component substance in the measurement sample substance. Although any solvent phase can be selected as long as it is suitable, water/chloroform, water/carbon tetrachloride, water/benzene, and methanol/decalin are particularly preferred as the solvent phase.

A segmented combined liquid is one in which the fluid flow consists of alternating first and second solvent phase segments.

The flow rate of each solvent phase is 0.3 to 2 ml/min, preferably (L5 to 1.5 ml/ml). If the flow rate is less than 0.3 ml/min, the diffusion of the sample during liquid transfer will be significant ( If the peak of the chromatogram is broad, it is difficult to obtain high precision.Also, if it exceeds 2 ral/min, the pressure loss during liquid transfer is significant, making it difficult to transfer liquid with high precision and difficult to perform phase separation efficiently. .

The measurement sample substance can be arbitrarily selected as long as it is a metal ion, anion, surfactant, or other substance that can be used for normal 70-injection analysis.

The injection volume is difficult to specify depending on the type and concentration of the measurement sample substance and the solvent phase used, but it ranges from several μl to 5 μl.
0 μl is preferred.

The component substances in the measurement sample substance conveyed together with the segmented combined liquid of the first and second solvent phases are dissolved and separated into one of the solvent phases in the reaction tube (5). The solvent is then separated into a first and second solvent phase by a phase separator (6) having a porous membrane, and then detected by a detection unit (9).

The reaction tube had an inner diameter of [13 to 0.8 mm, a length of 5 to 10 mm]
m0) A tube made of Teflon or stainless steel is preferably formed into a coiled shape that generates secondary flow in the axial direction and facilitates efficient extraction reaction. If the inner diameter is less than α5 mm, the pressure loss during liquid feeding will be large and it will be difficult to transfer the liquid with high precision.If the inner diameter exceeds CL8ts, the sample will be diffused so much that it will be difficult to proceed with an efficient extraction reaction. Also,
If the length is less than 5 m, the extraction reaction will not proceed completely;
If it exceeds 0 m, the sample will diffuse too much and it will be difficult to perform a good analysis.

The present invention will be specifically explained below using Examples and Comparative Examples.

Example 1 In FIG. 1, pump (1), Q, I N N
An aqueous solution with a composition of H, OI (/'NI%C), pH 9.5, was pumped at a flow rate of 1 ml/min, and at the same time, a chloroform solution containing 200rn9/l of dimethylglyoxime was pumped by one pump (1 ml/min). rttl/
It flows into the converging device (6) at a flow rate of min. After the two liquids are combined, they are segmented and flow from the sample introduction device (4) or the reaction chamber (5) to the phase separation device (6). The aqueous phase is sent to the waste tube (7) and the organic phase is sent to the tube (8). -+ Flows to the detection section <9).

While this combined liquid is flowing, the sample introduction device (brown) contains a nickel standard solution prepared by dissolving nickel chloride in 0.1N hydrochloric acid aqueous solution, that is, 1, 2.1 as N12+.
s, i arm)/l (ppm) of ionic species was injected into the eluent stream, with an inner diameter of O65.
The reaction was carried out in a reaction tube with a length of 10 m, and the flow of the phase-separated organic phase was measured using an ultraviolet-visible absorbance photometer (manufactured by Toyo Soda Kogyo Co., Ltd., UV-visible absorbance photometer, product name: UV-8mod).
ei> at a wavelength of 450 nm.

The resulting chromatogram is shown in FIG. Further, FIG. 6 shows the results of comparing the peak height and concentration of nickel from this chromatogram. It can be seen that nickel was analyzed with extremely high accuracy. Also, nickel 1o
FIG. 6-(a) shows an enlarged time axis of the chromatogram of 1/1 (ppm). It can be seen that the analysis was performed with extremely high sensitivity and in a short time.

Comparative Example 1 In a normal 70-injection analysis in which the sample introduction device (4) shown in FIG. 1 was connected in series between the pump (1) and the merging device (2) shown in FIG. As a result of measurement under the same analytical conditions as above, the chromadogsim shown in FIG. 4 was obtained. The results of comparing the peak height and concentration of nickel from this chromatogram are shown in FIG.

Titration results with both sensitivity and precision could not be obtained. In addition, the time axis of the chromatogram of nickel 10/7 (ppm) in Figure 4 is magnified as shown in Figure 6-(b).
Shown below.

It can be seen that the sensitivity is low and the analysis time is long.

Example 2 In Example 1, l I N NaO from pump (1)
An aqueous solution with a composition of H/Na, B, O, pHiα0 is α8
ml/min.

Pump (one piece I) using carbon tetrachloride containing 20 my/l methylene blue at t 2 ml/ml,
Try measuring 5.10 q/l! Measurement was carried out in the same manner as in Example 1, except that 20 μl of a solution containing (ppm) of ion species was injected and the wavelength was set to 650 nm. The resulting chromatogram is shown in FIG. It can be seen that the analysis is performed with extremely high sensitivity and in a short time.

[Brief explanation of drawings]

Figure 1 is a flow diagram showing one embodiment of the present invention, Figures 2, 4, 6 and 7 are the obtained chromatograms, and Figures 6 and 5 are the chromatograms obtained. 4 is a diagram showing the relationship between the peak height and concentration of the chromatogram obtained in FIG. 4. FIG. (1), (1') Pump (28 (3), (7L) (8) Tube (4) Sample introduction device (5) Reaction tube (6) Phase separation device (9) Detector tube Merging device Patent applicant Toyo Soda Kogyo Co., Ltd. Figure 1 7 Figure 2 0 12 3 5 10ppm Figure 5 012 3 5 10ppm Figure 6 "" (b) Figure 7 4m], n.

Claims (1)

[Claims] A flow injection analysis method, characterized in that a first solvent phase and a second solvent phase that are immiscible with each other are combined, and then a measurement sample substance is introduced into the fluid stream.