JP2011031199A - Liquid/liquid extraction system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid/liquid extraction system that can simultaneously carry out extraction and concentration using a small amount of an organic solvent, employs compact and easily transportable devices, and can be used in combination with commonly used tools. <P>SOLUTION: The liquid/liquid extraction system includes a specimen container, a means of generating a swirl flow that horizontally rotates a specimen solution present in the specimen container to generate a swirl flow of the specimen solution with its central part descending, and an extraction solvent disposed in the central part of the swirl flow. There is disclosed a magnetic rotary cell for use in liquid/liquid extraction that is caused to horizontally rotate by an external rotary magnetic field, and includes a magnet enclosed in the lower part thereof to enable the rotation and a container for storing the extraction solvent disposed on the rotation center in the upper part of the cell. The liquid/liquid extraction method includes causing the specimen solution to horizontally rotate to generate a swirl flow of the specimen solution with its central part descending, and extracting/concentrating a component to be extracted present in the specimen solution into the extraction solvent disposed in the central part of the swirl flow. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid-liquid extraction system, a magnetic rotating cell for liquid-liquid extraction, and a liquid-liquid extraction method using them.

  A typical method for extracting a target component in an aqueous solution is liquid-liquid extraction, which is widely used. In a normal liquid-liquid extraction operation, an organic solvent is added to a sample solution in a separatory funnel and shaken, and then allowed to stand to separate into a solvent layer and an aqueous layer, the aqueous layer is removed, and the solvent layer is removed. After removing water by adding sodium sulfate or the like for dehydration, the organic solvent is distilled off under reduced pressure using a rotary evaporator or the like and concentrated.

  However, normal liquid-liquid extraction requires a human operation for each step of the above procedure and is complicated, and requires a considerable amount of organic solvent, and the organic solvent recovered during concentration is often discarded. In the case of reuse, further purification processing is required.

  Accordingly, it is desired to develop a new liquid-liquid extraction technique that reduces the organic solvent used for extraction and simplifies the extraction operation. As such a technique, for example, a solvent having a specific gravity greater than that of a liquid sample is accommodated in an extraction tank having a cylindrical inner peripheral surface, and the extraction tank is rotated at a high speed to cause a cylindrical inner surface of the extraction tank to be rotated by centrifugal force. A solvent layer is formed on the extraction tank, and a liquid sample is continuously injected into the extraction tank, thereby moving the sample from one end side to the other end side of the solvent layer while forming a sample layer in contact with the surface of the solvent layer. Thus, a solvent extraction method for flowing out of the extraction tank has been proposed (Patent Document 1).

  However, the above method requires a large dedicated extraction device, and this device is not suitable for carrying. In addition, the amount of the organic solvent required is at least several mL due to its structure, and was not suitable for extraction / concentration at the μL level.

JP 2001-159591

  Accordingly, the present invention is a liquid-liquid that can be extracted and concentrated simultaneously with a small amount of organic solvent, and that the apparatus used is compact and excellent in portability and can be used in combination with a general-purpose instrument. It aims to provide an extraction system.

  The present inventors pay attention to the fact that when the sample solution is rotated horizontally, a vortex in which the central part descends is generated, and by utilizing this descending vortex, a small amount of extraction solvent is present in the central part, thereby improving efficiency. The present invention was completed with the idea of conducting extraction and further research.

  The present invention relates to a liquid-liquid extraction system having a sample container, eddy current generating means for generating a vortex flow in which the sample solution in the sample container is rotated horizontally and the solution center portion descends, and an extraction solvent arranged in the vortex flow center portion. Is to provide.

  The present invention also relates to a magnetic rotating cell that rotates horizontally by an external rotating magnetic field, in which a magnet that enables the rotation is enclosed at the bottom of the cell, and an extraction solvent container is provided at the center of rotation at the top of the cell. A magnetic rotating cell for liquid extraction is provided.

  In addition, the present invention generates a vortex in which the central portion of the solution descends by horizontally rotating the sample solution, and extracts and concentrates the extraction target component in the sample solution in the extraction solvent installed in the central portion of the vortex. A featured liquid-liquid extraction method is provided.

  According to the present invention, extraction and concentration can be performed simultaneously with a small amount of organic solvent, and the apparatus used is extremely compact and excellent in portability, and can be used in combination with a general-purpose instrument. The liquid-liquid extraction system of the present invention can be applied to all liquid-liquid extraction systems using organic solvents by selecting an extraction solvent according to the polarity of the substance to be extracted. It can be applied to a sample solution having a surface activity as well as in a small amount, as in the case of extraction of a biological substance.

It is a figure which shows the structure of one embodiment of the liquid-liquid extraction system of this invention. It is a perspective view which shows one embodiment of the magnetic rotation cell of this invention. It is a figure which shows a commercially available magnetic stirring bar. It is a figure which shows the state at the time of rotation in the liquid-liquid extraction system of this invention. It is a cut end view which shows one embodiment of the container for extraction solvents. It is a figure which shows the relationship between the light absorbency of a sample solution at the time of extracting sulforhodamine B using the liquid-liquid extraction system of this invention, and extraction time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The liquid-liquid extraction system of the present invention is realized by an apparatus as shown in FIG. In FIG. 1, a sample solution 2 in a sample container 1 is submerged with a liquid-liquid extraction magnetic rotating cell (hereinafter abbreviated as “magnetic rotating cell”) 3, which is a magnetic stirrer 4. It is placed on the top.

  The magnetic rotating cell 3 functions as eddy current generating means for horizontally rotating the rotating magnetic field generated by the magnetic stirrer 4 and generating a vortex in which the central portion of the solution descends by horizontally rotating the sample solution 2 in the sample container 1. is there. The main body of the magnetic rotating cell 3 is made of a chemically inert material, for example, Teflon (registered trademark), glass, ceramic, etc., and as shown in FIG. An extraction solvent container 5 for containing the extraction solvent 6 is provided at the center of rotation of the cell.

  The magnet 7 horizontally rotates the cell by a rotating magnetic field generated by the magnetic stirrer 4. As the magnet 7, a commercially available magnetic stirrer can be used. For example, a disk-shaped magnetic stirrer in which a bar-shaped magnet is embedded as shown in FIG. 3 is suitable.

  The outer shape of the magnetic rotating cell 3 is preferably tapered toward the top (conical frustum shape) in order to make the sample solution easy to give a descending vortex and to improve the stability during rotation. In order to increase, it is preferable that the side surface of the cell has an uneven shape or has a stirring blade. Moreover, as a magnetic rotation cell, you may use what attached the container for extraction solvents directly on the rotation center part of a commercially available magnetic stirring bar as shown in FIG.

  As the extraction solvent 6 accommodated in the extraction solvent container 5, a solvent having a specific gravity greater than that of the sample solution 2 and phase-separating with the sample solvent is selected. For example, when the sample solvent is water, chloroform, octafluoro-1-pentanol, perfluorohexane, or the like is used. Further, if an inorganic salt is added to the sample aqueous solution, an extraction solvent such as hexafluoroisopropanol (HFIP) or trifluoro-1-propanol can also be used.

  As shown in FIG. 4, when the magnetic stirrer 4 is turned on, the cell 3 is rotated horizontally by the generated rotating magnetic field, and the sample solution 2 is rotated in the horizontal direction. As a result, a vortex in which the central portion of the sample solution descends is generated, and the sample solution 2 efficiently contacts the extraction solvent 6 in the container 5.

  Further, since the extraction solvent 6 is also rotated by the rotation of the magnetic rotation cell 3, the extraction solvent 6 spreads along the side surface of the extraction solvent container 5 to form a liquid film, and the contact area with the sample solution is increased. This will improve the extraction efficiency. In order to efficiently form this liquid film, the extraction solvent container 5 is preferably cylindrical and round-bottomed. In order to prevent the extraction solvent from overflowing at the time of rotation, it is also preferable that the mouth portion of the extraction solvent container 5 has a shape constricted inward as shown in FIG.

  In the sample solution, it is preferable to dissolve inorganic salts such as sodium chloride in order to promote extraction of the target substance by salting out.

Example 1
The extraction system was composed of a cylindrical sample container (made of glass, internal volume 20 mL), a truncated cone-shaped magnetic rotating cell (bottom and top diameter 9 mm, height 15 mm), and a magnetic stirrer (FIG. 1). The magnetic rotating cell had a cylindrical round bottom extraction solvent container (made of glass) at the center of the upper surface, a commercially available stirring bar built in the bottom, and a polypropylene stirring blade around the side.
Using this extraction system, the liquid-liquid extraction was performed by the following method using sulforhodamine B as a model sample.

(1) The magnetic rotating cell was put in a sample container on a magnetic stirrer, and 15 mL of a 20% by mass sodium chloride aqueous solution (1.9 × 10 ⁻⁷ M) containing sulforhodamine B was gently added.
(2) Using a microsyringe, 20 μL of hexafluoroisopropanol (HFIP) was gently added to an extraction container (inner diameter: 4 mm, inner volume: about 10 μL).
(3) The stirrer was operated for a certain period of time and the cell was rotated at about 200 rpm, and then the absorbance (λmax = 570 mm) of the sample solution was measured to examine the change in the concentration of sulforhodamine B.

It was visually confirmed that a downward vortex was generated in the sample solution when the cell was rotated. On the other hand, the HFIP in the extraction container slightly rose to the wall surface side by centrifugal force, and it was confirmed with the naked eye that the HFIP was colored over time. FIG. 6 shows the relationship between the absorbance (A _t ) of the sample solution after t minutes and the extraction time (t) from the measured absorbance at 570 nm of the sample solution after rotation for 10 minutes, 30 minutes and 60 minutes.
From this result, it was confirmed that the transfer of sulforhodamine B from the sample solvent to the extraction solvent proceeded in a primary reaction. From the volume ratio of the sample solution to the extraction solution, sulforhodamine B became the extraction solvent at each time. It was estimated that it was concentrated 18 times (10 min), 52 times (30 min) and 100 times (60 min). However, HFIP itself was actually distributed in the sample solution, and the amount of HFIP that had been phase-separated after 60 minutes was about 3 μL. Considering this result, sulforhodamine B is concentrated about 665 times in 60 min.

DESCRIPTION OF SYMBOLS 1 Sample container 2 Sample solution 3 Magnetic stirring cell 4 Magnetic stirrer 5 Extraction solvent container 6 Extraction solvent 7 Magnet

Claims (8)

  A liquid-liquid extraction system having a sample container, vortex generating means for generating a vortex in which the sample solution in the sample container is rotated horizontally and the center of the solution descends, and an extraction solvent arranged in the center of the vortex.   2. The liquid according to claim 1, wherein the eddy current generating means comprises a magnetic rotating cell which is horizontally rotated by an external rotating magnetic field and has an extraction solvent container in the center of rotation at the upper part of the cell, and a magnetic stirrer. Liquid extraction system.   The liquid-liquid extraction system according to claim 1 or 2, wherein the extraction solvent has a specific gravity greater than that of the sample solution and phase-separates with the sample solvent.   4. The liquid-liquid extraction system according to claim 2, wherein the extraction solvent container has a cylindrical shape and a round bottom.   A magnetic rotating cell that rotates horizontally by an external rotating magnetic field, and a magnet that enables the rotation is enclosed in the lower part of the cell, and an extraction solvent container is provided at the center of rotation of the upper part of the cell. cell.   The magnetic rotating cell for liquid-liquid extraction according to claim 5, which is tapered toward the upper part and has irregularities or stirring blades around the side surface.   The magnetic rotating cell for liquid-liquid extraction according to claim 5 or 6, wherein the extraction solvent container has a cylindrical shape and a round bottom.   A liquid characterized by generating a vortex in which the central part of the solution descends by horizontally rotating the sample solution, and extracting and concentrating an extraction target component in the sample solution in an extraction solvent installed in the central part of the vortex Liquid extraction method.

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