JP5019663B2 - Impurity ion remover - Google Patents

Abstract

[Problem] To provide, as a means for removing impurity ions from a solution, a column-shaped ion removal device in which an active substance or gas that generates in the vicinity of the electrodes does not come into the system and with which ions to be examined can be taken out with satisfactory detection sensitivity. [Solution] A horizontal column packed with an ion exchanger that adsorbs impurity ions is provided with a solution inlet at the top of the column and near one of the electrodes and with an outlet at the bottom of the column and on the side of the other electrode to configure a narrow liquid channel. An ion-exchange membrane and an ion exchanger are used in combination to form an ion interface at each end of the column, and ions which generate as a result of a shift from water dissociation equilibrium are allowed to move toward the electrodes. Impurity ions to be removed are discharged from the column while regenerating the ion exchanger that adsorbs the impurity ions. In combination therewith, water is introduced externally and passed through the region between each electrode and the corresponding ion-exchange membrane to accelerate the discharge of the gases, the bases and acids, which are impurity ions to be removed, and active substances from the column.

Description

  The present invention relates to an apparatus for removing impurity ions contained in a solution.

  The present invention relates generally to a device for removing impurity ions contained in a solution suitable for general use in chemical analysis, synthesis and processing, and in particular, a suppressor (ion removing device) suitably used for an ion chromatograph (device), An eluent purification apparatus is provided. It has been a long time since a suppressor was proposed in ion chromatography (separation method), and it is not necessary to explain it again. When an eluent is passed through a separation column, ions adsorbed on the separation column are separated and eluted, and this is applied to a detector. In this case, electrolyte ions serving as a background other than the detection target ions are removed to obtain a highly sensitive analysis value. There are roughly two types of suppressor methods, the column type and the ion exchange membrane type. The former is a detection method in which the column is filled with H-type cation exchange resin or OH-type anion exchange resin and becomes a background. Ions other than the target are removed by ion exchange, and the latter is a method of removing ions other than the detection target that are the background through the ion exchange membrane. Furthermore, an electric field is applied to enable continuous operation in combination with electrolysis.

The present invention is a column type that applies an electric field. To name a few typical suppressors close to the present invention, there is a suppressor described in JP-T-2002-509238, which combines a column type electric field. The column is filled with cation exchange resin, and electrodes (upper: cathode, lower: anode) are attached to the upper and lower sides of the column via cation exchange membranes. When an eluent containing an anion) is introduced, the cation that becomes the background is adsorbed and removed by the cation exchange resin in the column. Furthermore, water is introduced into both electrode chambers partitioned by a cation exchange membrane and attached with electrodes, and hydronium ions and hydroxide ions are produced in the same chamber by electrolysis of water. The cations adsorbed in the column through the cation exchange membrane are electromoved into the cathode chamber and reacted with the generated hydroxide ions to generate a base, which is discharged out of the system together with water. On the other hand, in the anode chamber where hydronium ions are generated, the generated hydronium ions permeate through the cation exchange membrane and electrotransfer into the column system, and the cation exchange resin adsorbing sodium ions is regenerated with hydronium ions. However, it is possible to operate continuously.

As another typical suppressor, there is a suppressor described in Japanese Patent Application Laid-Open No. 2001-188063, which is also a column type combined with an electric field. A column placed horizontally is filled with cation exchange resin, electrodes are attached to both ends via filters, and a solution inlet is provided near the electrode at the top of the column and a solution outlet is provided near the opposite electrode at the bottom. . When an eluent containing ions to be inspected (anions in this case) is introduced from the upper end of the column, the cation that becomes the background is adsorbed and removed by the cation exchange resin in the column. At the same time, electrolysis of water occurs at the electrodes provided at both ends of the column, and the generated hydronium ions and hydroxide ions move toward the opposite electrodes. It reacts with the cations that have been electromoved by the electric field to generate base and water, and is discharged together with the electrode reaction product gas (oxygen / hydrogen gas) from the outlet near the electrode. This enables continuous decation.
However, each method has its pros and cons, and it is required to operate for a longer time, prevent gas from being mixed into the detection solution, and improve basic performance. In addition, it restricts the use of return water from the viewpoint of promoting recycling. The device which does not give is also required.

JP 2001-188063 A JP 2000-510957 A Special table 2002-509238 gazette Special table 2004-508540 gazette JP 2005-538382 A Special table 2008-513790 gazette

   In a typical suppressor in which an electric field is applied to the column type described above, there is a limit that it is difficult to obtain stable data with good detection sensitivity in the former vertical column type, and in the latter, it is difficult to obtain data with good detection sensitivity. Due to the influence of the mixed gas, there has been a problem that a degassing process cannot be avoided as a pretreatment applied to the detector.

  In order to solve the above problems, as a result of examining elements that directly affect detection sensitivity, it is only necessary to suppress diffusion of ions to be inspected in a solution flowing through the column. For this purpose, a resin layer packed in the column is used. I noticed that the flow of the flowing solution was narrow and the flow was fast with little disturbance. Furthermore, from the viewpoint of removing impurity ions, it is more advantageous to provide an outlet so that the solution passes through the vicinity of the anion exchange membrane 27b in which a large amount of H-type cation exchange resin capable of exchanging impurity cations exists. So I decided to arrange the entrance and exit.

However, fine control of the flow of the solution flowing through the resin layer packed in the column is unfortunately difficult to control the device of the ultimate trace liquid flow. I must.
Through trial and error, we came up with the invention of the basic structure as a balanced device.

From the viewpoint of improving detection sensitivity and ensuring stability, it is necessary to prevent part of ions to be detected from being dissipated out of the system. As the amount of ions decreases, the conductivity detector shows only a small peak. That is, it becomes a factor of sensitivity reduction. Among the prior arts described above, the latter ions pass through the solution along with the solution from two lateral outlets of the column.
Therefore, a partition membrane is provided with an ion exchange membrane between the electrode and the ion exchange resin so that the sample ions are not electrolyzed by the electrode, and further, the electrode reaction is performed while preventing the solution from being discharged out of the system. Prevent the resulting gas from entering the system. Furthermore, by restricting the quality of the recirculated water, it is possible to prevent impurities from entering the system from the water for promoting bubble discharge introduced from the outside into the electrode portion by selecting the partition membrane. In addition, high-concentration acids and bases tend to accumulate around the electrode, and the electrode is easily corroded.To prevent this, and to further improve the removal efficiency of ions to be removed, water is injected near the electrode and diluted. Discharge out of the system. Furthermore, it has been found that the operation life of the device can be extended by using a highly durable ion exchange membrane.

According to the present invention, it is possible to provide an apparatus with excellent detection sensitivity, a continuous and stable impurity ion removal operation, and a long operating life.

It is explanatory drawing which showed the basic structure cross section of the impurity ion removal apparatus for positive ion removal. It is explanatory drawing which showed the impurity ion removal apparatus cross section for cation removal which incorporated the bubble discharge | emission promotion part by a pure water in the basic structure. It is explanatory drawing which showed the impurity ion removal apparatus cross section for a cation removal which incorporated the bubble discharge | emission promotion part by a pure water in the basic structure at both ends. It is explanatory drawing which showed the apparatus cross section which connected two impurity ion removal apparatuses for cation removal shown in FIG. 3 in series. It is explanatory drawing which showed the same type as FIG. 1 with the impurity ion removal apparatus for anion removal. It is explanatory drawing which showed the same type as FIG. 2 with the impurity impurity ion removal apparatus for anion removal. It is explanatory drawing which showed the same type as FIG. 3 with the impurity impurity ion removal apparatus for anion removal. Schematic diagram of ion chromatography system (2 electrolyte solution purifiers are in front of 1 electrolyte solution generator, and purified water is supplied to 1 electrolyte solution generator) Schematic diagram of an ion chromatography system (2 electrolyte solution purifiers are located after 1 electrolyte solution generator and purifies an electrolyte solution containing impurity ions derived from pure water) Impurity removing device for removing cations (without region 53) Anion removal impurity removal device (using Neoceptor (registered trademark) C66 membrane for ion exchange membrane 27b) Ion removal capability of impurity ion remover with basic structure Effect of impurity ion removal equipment Ion chromatogram with anion standards Ion chromatogram with cation standard Effect of Nafion (R) NRE-117 membrane Ion chromatogram using a single-stage suppressor Ion chromatogram when using a two-stage suppressor Ion chromatogram when using a three-stage suppressor Durability comparison of impurity ion removal equipment Effect of bubble discharge promotion means Ion chromatogram with anion standards Ion chromatogram with anion standards Effect of bubbles generated at electrodes of impurity ion removal equipment for cation removal Influence of polarity of ion exchange membrane used for ion exchange membrane 27b Impurity ion removal device for anion removal (electrolyte purification device used in ion analysis system 100)

BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described, and then detailed with examples.
First, the basic structure of the apparatus for removing impurity ions, the impurity ion removing apparatus in which a bubble discharge promoting part by pure water is incorporated in the basic structure, and the bubble discharge promoting part by pure water are incorporated in both ends by arranging the present invention. The present invention relates to a device in which a plurality of impurity ion removal devices and a plurality of impurity ion removal devices are connected.
(1) Basic structure of the device for removing impurity ions

The present invention is the invention described in claim 1, and will be described with reference to FIG.
FIG. 1 illustrates a configuration for removing cations. However, in principle, those skilled in the art can fully use the case of anion removal if the case of cation removal is described. Since both are more concise and clearer than described together, the case of cation removal will be described.
The apparatus has a horizontally long container (21) sandwiched with a layer filled with a cation exchanger (23), fixed on both ends of the container with ion exchange membranes (27a, 27b), and an electrode (31a) on the outside of the cation exchange membrane. , 31b), pipes for injecting pure water into the inlets (21b, 21c) and discharging from the outlets (22b, 22c) are attached, and impurity ions are added to one electrode side (cathode side) at the upper end of the container. Is provided with an inlet (21a) for introducing a solution containing, an outlet (22a) on the other electrode side (anode side) at the lower end, and further connected to both electrodes from an external power source (33).
Incidentally, in the case of anion removal, as shown in FIG. 5, an anion exchanger (23) is used instead of the cation exchanger (23), an anion exchange membrane is used for the ion exchange membrane 27a, and a cation is used for 27b. An exchange membrane is used, and the electrode 31a whose electrode setting is reversed is an anode, and the electrode 31b is a cathode. This is the only difference in the configuration of the apparatus. 6 and FIG. 7 can be applied correspondingly to the difference in the configuration of the apparatus corresponding to the cation removing apparatus of FIG. 2 and FIG.

Here, the main body container (21) is made of PEEK (polyetheretherketone), PP (polypropylene), etc., because it has a strong acid / base resistance and needs to be made of an electrically insulating material. The column shape is preferably a horizontally long shape. This is because, as described above, it is easy to balance the formation of the liquid flow path.
The ion exchanger (23) refers to a substance having an ion exchange function, and in particular, an ion exchange resin having an ion exchange group in an insoluble polymer compound can be suitably used. The beads, flakes, fibers, and nonwoven fabrics can be used. Shaped in the form of film or film.
As the cation exchange resin, Amberlite IR120B (manufactured by Dow Chemical Company, registered trademark), DOWEX 50WX2, 50WX4, 50WX8 (manufactured by Dow Chemical Company, registered trademark) can be suitably used. Among these, DOWEX50WX8 (registered trademark) is preferable in terms of strong acid resistance and high exchange capacity.
Although a cation exchange resin is used in FIG. 1, an anion exchange resin is used in an apparatus for removing anions.
As the anion exchange resin, DOWEX1X8, 2X8 (registered trademark) having an ion exchange group having a charge opposite to that of the cation exchange resin and having a strong base resistance and a high exchange capacity can be suitably used.

As the ion exchange membrane, a cation exchange membrane (27a) is used on the cathode side, and an anion exchange membrane (27b) is used on the anode side. Each of the cation exchange membranes has a function of permeating cations but not liquid. The anion exchange membrane has a function of allowing anions to pass but not allowing liquids to pass. In the present invention, the cation exchange membrane (27a) has a function of transmitting the cation of the impurity through the cooperation with a voltage-applied cathode and discharging it from the outlet (22b). I try not to get inside. In this respect, the anion exchange membrane (27b) has a similar function. That is, since it has a function of suppressing the intrusion of anions from the outside, the restriction on the quality of water flowing to the outlets (22b, 22c) can be relaxed.
Furthermore, it plays the role of a partition membrane that prevents the solution containing ions to be inspected from leaking out of the system.
Moreover, it plays a role of pressing and fixing the resin filled in the container from the left and right.
Further, it has a role of preventing the electrode from coming into direct contact with the ion exchanger, and a tough material that can withstand a strong acid and a strong base generated around the electrode is required.
Such cation exchange membranes include Neoceptor (registered trademark) C66 (manufactured by Tokuyama), Teflon (registered trademark) -based Nafion (registered trademark) NRE-212, 115, 117, 324, 424, 551 (manufactured by DuPont). ) Is preferably used.
Further, Neoceptor (registered trademark) AHA (trade name: manufactured by Atoms), AMX, ACM, ACS, AFN, and AFX are preferably used as the anion exchange membrane.

As materials used for the electrodes (31a, 31b), various conductors such as metals, alloys, graphite, semiconductors, and metal oxides are used. In particular, those having corrosion resistance such as platinum, titanium, gold and rhodium are preferable, and can be a mesh, a line, a rod, a plate or the like. In consideration of liquid permeability, a mesh or the like is preferable.
When the current flow direction is in a specific direction, an ion flow is formed, and the target removal ions are moved to and discharged from a nearby electrode, so that direct current is preferable in terms of ease of control. The type of voltage to be applied may be either a DC voltage or an AC voltage to which a positive bias voltage is added.

Next, the operation of this apparatus will be described.
A solution containing the anion to be analyzed separated and eluted in the column (7) is introduced into the inlet (21a) of this apparatus, enters the zone (51) filled with the cation exchange resin, and the solution enters the outlet (22a). It flows toward. The cations contained in the solution are adsorbed on the cation exchange resin, but since an electric field is applied from both electrodes, the cation in the solution and the cation adsorbed on the cation exchange resin are electrophoresed toward the cathode ( Ion movement).
On the other hand, when water is introduced into the electrodes in both electrodes (FIGS. 1, 2, and 3), hydrogen and oxygen gas are generated and hydronium ions and hydroxide ions are generated by electrolysis of the introduced water. ing. At the cathode, a base is generated by the reaction between the cation and the hydroxide ion leached through the cation exchange membrane, and discharged together with hydrogen gas from the outlet (22b). At the anode, the hydronium ions are prevented from entering due to electrostatic repulsion with the anion exchange membrane, do not enter the system, react with the hydroxide ions discharged from the system, become water, and together with oxygen gas It is discharged to the outside from the outlet (22c).
That is, the gas generated by the electrolysis of water, and the hydronium ion and the hydroxide ion are blocked by the ion exchanger formed by the ion exchange membrane and the ion exchange resin and cannot enter the system. The hydronium ions and hydroxide ions that move in the system described above are produced from the dissociation equilibrium of water that occurs at the interface between the anion exchange membrane and the cation exchange membrane resin (hereinafter referred to as “ion interface”). It is a nium ion and a hydroxide ion, and is generated by supplying water. That is, it is considered that the hydroxide ions generated from the dissociation equilibrium of water are taken into the anion exchange membrane, and the hydronium ions are supplied into the system by being taken into the cation exchange resin. Hydronium ions supplied through the ion interface move toward the cathode, hydroxide ions move toward the anode, and both ions move in directions opposite to each other.
Impurity cations adsorbed in the cation exchange resin packed bed in the system are interfacial conductive phenomena such as electrophoresis (ion movement) and electroosmotic flow (the surrounding solvent surrounding the ions as the ions move). It is thought that it moves toward the cathode as the counter electrode and is discharged to the outside. At that time, the hydronium ions move toward the cathode as the counter electrode while ion exchange with the impurity cations adsorbed on the cation exchange resin filled in the system.
From the above, in the apparatus of the present invention (FIGS. 1, 2, 3, 5, 6, and 7), the hydronium ions generated at the anode and the hydroxide ions generated at the cathode are anion-exchanged in the system. Due to the electrostatic repulsion between the membrane and the cation exchange membrane, it is discharged out of the system with the flow of introduced water as soon as it is generated. Therefore, ions derived from electrolysis of water generated at the external electrode are not supplied into the system. The fact that hydronium ions and hydroxide ions generated by electrolysis of water are not used as exchange ions for eluting impurity ions adsorbed on the resin is the most characteristic method of the present invention not found in other inventions. It is.
Although the suppressor is used as a model in the description of the present invention, it is needless to say that the apparatus used for removing impurity ions is not limited to the suppressor.
(2) Impurity ion removal device incorporating a bubble discharge promoting part with pure water in the basic structure

The present invention is the invention described in claim 2, and will be described with reference to FIG.
Since the present invention is an impurity ion removing apparatus in which a bubble discharge promoting part by pure water is incorporated in the basic structure described in (1) above, the configuration of the additional part will be described mainly.
The apparatus shown in FIG. 2 is also an apparatus for removing cations, and a pure water injection zone is provided between the electrode (31a) and the cation exchange membrane (27a) in the cathode portion. That is, the cross section is composed of a cation exchange membrane (27a), a cation exchanger (25B) layer, a cation exchange membrane (28a) imparted with liquid permeability, and an electrode (31a), and the cation exchanger (25B). A pure water inlet is provided at the top of the bed.
The cation exchange membrane imparted with liquid permeability is obtained by imparting liquid permeability by subjecting a normal cation exchange membrane to slit processing or the like. This slit processing, on the contrary, cannot avoid the ingress of liquid or gas containing impurities from the outside into the system. For this reason, pure water is always supplied from the pure water supply device 41a, and impurities from the outside into the system are contained. Prevents liquid and gas contamination.
Further, the cation exchange membrane (28a) is placed between the electrode (31a) and the cation exchanger (25B) so that the electrode (31a) and the cation exchanger (25B) are not in direct contact with each other. This is because the exchanger (25B) is not exposed to electrolysis.
However, such a structure is rather more effective in the anion removing device (FIG. 6), and the anion exchanger (25B) and the electrode (31a) are slightly less durable than the cation exchanger. By inserting a cation exchange membrane (28a) between them, it is possible to avoid the electrolysis of the anion exchanger (25B).
As such a cation exchange membrane, Nafion (registered trademark) NRE-212, 115, 117, 324, 424, 551 (manufactured by DuPont) is a Teflon (registered trademark) cation exchange membrane having excellent durability. Preferably used.
Instead of the cation exchange membrane imparted with the liquid permeability, a cation exchanger such as a non-woven fabric ion exchange resin, a mesh-shaped ion exchange resin, or the like exhibiting an equivalent function may be used.
The description of other structures is omitted because the description is the same as in (1) above.
Next, the operation of this apparatus will be described.

The overlapping description described in the above (1) will be avoided, and the changed part will be described mainly.
In a word, the pure water injection zone provided in the cathode portion can be said to be injected from the inside of the main body and discharged outside. As a result, discharge of hydrogen gas generated by electrolysis can be further promoted. Furthermore, the strong base produced near the cathode and the reduced active substance can be diluted and discharged to the outside. As a result, the life of an electrode, for example, a platinum electrode can be extended, and the deionization efficiency can be improved as shown in Example 8.
The generation and discharge of base and water from the outlet 22b in the basic structure described in the above (1) is called electroosmotic flow, which is a flow of solvent accompanying electrophoresis (ion movement) of cations and hydronium ions. Inferred. However, since this flow is very small, the discharge flow is increased by injecting pure water by pump lift.
(3) Impurity ion removal device incorporating a bubble discharge promoting part with pure water at both ends in the basic structure

The present invention is the invention described in claim 3, and will be described with reference to FIG.
The present invention relates to an impurity ion removing apparatus in which a bubble discharge promoting portion by pure water is incorporated at both ends in the basic structure described in (1), and the configuration of the additional portion is explained mainly as in (2). To do.
The apparatus shown in FIG. 3 is also an apparatus intended to remove cations, and is provided with pure water injection zones at both electrode portions. That is, the pure water injection zone is also provided between the electrode (31b) and the anion exchange membrane (27b) in the anode portion. That is, the cross section is composed of an anion exchange membrane (27b), an anion exchanger (25A) layer, a liquid-permeable cation exchange membrane (28b), and an electrode (31b), and the anion exchanger (25A). A pure water inlet is provided at the top of the bed.
The cation exchange membrane imparted with liquid permeability is the same as that used on the cathode side, as described above, which is provided with liquid permeability by subjecting a normal cation exchange membrane to slit processing or the like. Ideally, it is advantageous to use an anion exchange membrane, but none of the material has excellent durability. Therefore, pure water is poured from the inlet (21c), passes through the ion exchanger (25A) layer, passes through the cation exchange membrane (28b) imparted with liquid permeability, and is discharged from the outlet (22c). Nafion (registered trademark) NRE-212, 115, 117, 324, 424, 551 (manufactured by DuPont), which is a Teflon (registered trademark) cation exchange membrane having excellent durability, can be preferably used. In addition, as a result of imparting liquid permeability by this slit processing or the like, it is unavoidable that liquid or gas containing impurities enter the system from the outside. However, pure water is always supplied from the pure water supply device 41b. This prevents liquids and gases containing impurities from entering the system from the outside.
Instead of the cation exchange membrane imparted with the liquid permeability, a cation exchanger such as a non-woven fabric ion exchange resin, a mesh-shaped ion exchange resin, or the like exhibiting an equivalent function may be used.
The description of the other configuration is omitted because the description overlaps with (1) and (2).

Next, the operation of this apparatus will be described.
The overlapping description described in the above (1) and (2) will be avoided, and the part to be changed will be described mainly.
By providing a pure water injection zone in both electrode parts, oxygen gas generated by electrolysis, strong acid, and oxidized active substance are diluted and discharged to the outside on the anode side, and hydrogen generated by electrolysis on the cathode side. It dilutes gases, strong bases, and reduced active substances to further promote discharge to the outside. As a result, the life of an electrode, for example, a platinum electrode can be extended, and the deionization efficiency can be improved as shown in Example 8.
(4) Equipment connecting multiple impurity ion removal devices

The present invention is the invention described in claim 4, and will be described with reference to FIG. The present invention is a device in which a plurality of impurity ion removing devices are connected, and is a device that removes either anions or cations.
As shown in FIG. 4, the invention described in claim 4 is one in which two impurity ion removing devices described in FIG. 3 are connected in series. In other words, a pipe connection is made from the solution outlet of the first device to the solution inlet of the second device to reduce the deionization load in a single device, and two devices try to achieve the desired deionization target. is there.
The reason why the load on the apparatus is reduced is that the consumption of the electrode, ion exchange membrane and the like can be reduced, and the lifetime of the impurity ion removing apparatus can be extended.
The combination of a plurality of impurity ion removing apparatuses in the present invention includes the apparatus shown in FIGS. 1 and 2 proposed in the present application, and is not limited to two. However, when a plurality of suppressors are used in an ion chromatograph (apparatus), the influence of the diffusion of ions to be detected (the same effect as mixing) appears, and the connection of the two is preferable.
Since the description of the other configuration and operation overlaps with the above (1), (2), (3), it will be omitted.

Of the ion analysis systems shown in FIGS. 8 and 9, the ion analysis system 100 having the same configuration as that of FIG. 9 is used, and the impurity ion removing device 2e for anion removal having the same configuration as that of FIG. The ion removal capability of the impurity ion removal apparatus 9 having the same structure as that shown in FIG. In the experiment, the injector 5 and the separation column 7 were removed from the ion analysis system 100 of FIG.
The electrolyte solution generating device 1 is a basic electrolyte solution generating device (manufactured by Nichi Kogyo), the electrolyte solution purifying device 2e is an impurity ion removing device for removing anions (manufactured by Nichi Kogyo), and the impurity ion removing device 9 is for removing cations. Impurity ion removal device (manufactured by Nichi Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), and DC power supply 33 for electrophoresis is EX-375U2 (Takasago Manufacturing Co., Ltd.) The detector 11 was an electrical conductivity detector CM432 (manufactured by Nichi Kogyo). The electrolyte solution generating apparatus 1 has a constant current of 20 mA (about 38 V, about 1604 μS / cm NaOH solution), the electrolyte solution purifying apparatus 2 e has a constant current of 30 mA (about 44 V), and the impurity ion removing apparatus 9 has a constant current of 2 0.8 mA (about 9 V), a platinum electrode was used as the electrode for electrophoresis, pure water (1.0 ml / min) was supplied from the pumps 47a and 47b, and the flow rate of the pump 3 was 0.75 ml / min. The results are shown in FIG. 12 is divided into 1: the impurity ion removing device 9 having the same structure as in FIG. 1 is used, and the impurity ion removing device 9 at a constant current of 2.8 mA (about 9 V) is used. The electrical conductivity of the eluate (about 1325 μS / cm), 2: the electrical conductivity of the eluate from the impurity ion removal device 9 when the operation of the impurity ion removal device 9 was stopped (about 1604 μS / cm).

From FIG. 12, it was confirmed that about 279 μS / cm of Na ions can be removed under the condition of a constant current of 2.8 mA (about 9 V) using the impurity ion removing device 9 having the same structure as that of FIG.
There is a reason for setting the current value to 2.8 mA, and when using the ion exchange membrane Neoceptor (registered trademark) AHA and Neoceptor (registered trademark) C66 so as to be in contact with the electrode as in the apparatus shown in FIG. Due to the restriction of an appropriate current density of 40 mA / cm ² , 2.8 mA is the maximum current value. That is, the amount of Na ions for about 279 μS / cm is the maximum removal amount in the apparatus of FIG.

The ion analysis system 100 having the same configuration as that in FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2f having the same configuration as in FIG. 2 is used, and the cation impurity ion removing device 9a having the same configuration as that shown in FIG. 2 is used as the impurity ion removing device 9, and the sodium hydroxide solution (about 12.5 mM, about 1965 μS / cm) generated by the electrolyte solution generating device 1 is used. The electrical conductivity of the eluate when the suppressor was activated and when it was not activated was compared. In the experiment, the injector 5 and the separation column 7 were removed from the ion analysis system 100 of FIG. The electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), the electrolyte solution purifier 2f is an impurity ion removing device for removing anions (manufactured by Nichi Kogyo), and the impurity ion removing device 9a is for removing cations. Impurity ion removal device (manufactured by Nichi Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), and DC power supply 33 for electrophoresis is EX-375U2 (Takasago Manufacturing Co., Ltd.) The detector 11 used was CM432 (manufactured by Tosoh Corporation). The electrolyte solution generator 1 has a constant current of 20 mA (about 74.5 V, about 1965 μS / cm NaOH solution), the electrolyte solution purifier 2 f has a constant current of 30 mA (about 40.6 V), and the impurity ion removing device 9 a A constant current of 40 mA (about 52 V), a platinum electrode as an electrode for electrophoresis, pure water (1.0 ml / min) is supplied from the pumps 47a and 47b, and the flow rate of the pump 3 is 0.75 ml / min. did. The results are shown in FIG. Note that reference numerals 1 and 2 in FIG. 13 indicate that the electrical conductivity of the effluent from the impurity ion removing device 9a when the operation of the impurity ion removing device 9a having the same structure as in FIG. 1965 μS / cm) 2: Using the impurity ion removing device 9a having the same structure as in FIG. 2, the electric conductivity (about 3 μS / cm) from the impurity ion removing device 9a at a constant current of 40 mA (about 52 V). cm).
From FIG. 13, the background conductivity of the eluent when the impurity ion removing device 9a was operated at a constant current of 40 mA was about 3 μS / cm, indicating almost complete suppression of sodium hydroxide.

The ion analysis system 100 having the same configuration as that in FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2f having the same configuration as in FIG. The impurity ion removing device 9 was used, and the cation removing impurity ion removing device 9a having the same configuration as that shown in FIG. The electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), the electrolyte solution purifier 2f is an impurity ion removing device for removing anions (manufactured by Nichi Kogyo), and the impurity ion removing device 9a is for removing cations. Impurity ion removing device (manufactured by Nichi Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), injector is model 7125 (manufactured by RHEODYNE, 20 μL), for electrophoresis The DC power source 33 used was EX-375U2 (manufactured by Takasago Seisakusho Co., Ltd.), the separation column 7 was TSKgel superIC Anion AZ (manufactured by Tosoh Corp.), and the detector 11 was a non-contact type conductivity detector (manufactured by Nichi Kogyo). The electrolyte solution generating apparatus 1 has a constant current of 20 mA (about 85.6 V, about 2065 μS / cm NaOH solution), the electrolyte solution purifying apparatus 2 f has a constant current of 30 mA (40.2 V), and the impurity ion removing apparatus 9 a has A constant current was 40 mA (about 55 V), a platinum electrode was used as an electrode for electrophoresis, pure water (1.0 ml / min) was supplied from the pumps 47a and 47b, and the flow rate of the pump 3 was 0.75 ml / min. . Sample concentration, F ^- ions; 5 ppb, Cl ^- ions; 10 ppb, NO ₂ ^- ions; 15 ppb, Br ^- ions; 10 ppb, NO ₃ ^- ion; 30ppb, _SO ^{4 2-} ion; 40 ppb, _PO ^{4 3-} ions; 30 ppb. The measurement results are shown in FIG.
In the chart of FIG. 14, 1 peak is F ⁻ ion, 2 peak is Cl ⁻ ion, 3 peak is NO ₂ ⁻ ion, 4 peak is Br ⁻ ion, 5 peak is NO ₃ ⁻ ion, 6 peak The peaks are unknown CO ₃ ⁻ ions and SO ₄ ²⁻ ions, and the peak 7 is PO ₄ ³⁻ ions. From this result, it was confirmed that the ions were completely separated and detected except that the peaks of carbonate ion and sulfate ion overlapped.

The ion analysis system 100 having the same configuration as in FIG. 9 in the ion analysis system shown in FIGS. 8 and 9 is used, and the cation removing impurity ion removing device 2a having the same configuration as in FIG. The anion removal impurity ion removal device 9e having the same configuration as that shown in FIG. 6 was used as the impurity ion removal device 9, and ion analysis of standard cations was performed. The electrolyte solution generator 1 is an acidic electrolyte solution generator (manufactured by Nichi Kogyo), the electrolyte solution purifier 2a is a cation removing impurity ion removing device (manufactured by Nichi Kogyo), and the impurity ion removing device 9e is an anion removing impurity. Ion remover (manufactured by Nikko Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), injector is model 7125 (manufactured by RHEODYNE, 20 μL), for electrophoresis The DC power source 33 was EX-375U2 (manufactured by Takasago Seisakusho), the separation column 7 was TSKgel superIC-CR (manufactured by Tosoh Corporation), and the detector 11 was a non-contact electric conductivity detector (manufactured by Nichi Kogyo). The electrolyte solution generator 1 has a constant current of 3.5 mA (about 20 V, about 600 μS / cm of HNO ₃ solution), the electrolyte solution purifier 2 a has a constant current of 40 mA (about 45.4 V), and the impurity ion removing device 9 e. Has a constant current of 30 mA (about 61.6 V), uses a platinum electrode as an electrode for electrophoresis, supplies pure water (1.0 ml / min) from pumps 47a and 47b, and the flow rate of pump 3 is 0.75 ml. / Min. The sample concentrations were: Li ⁺ ion; 5 ppb, Na ⁺ ion; 20 ppb, NH ₃ ⁺ ion; 20 ppb, K ⁺ ion; 50 ppb, Ca ²⁺ ion; 50 ppb, Mg ²⁺ ion; 50 ppb. The measurement results are shown in FIG.
In the chart of FIG. 15, peak 1 is Li ⁺ ion, peak 2 is Na ⁺ ion, peak ₃ is NH ₃ ⁺ ion, peak 4 is K ⁺ ion, peak 5 is Ca ²⁺ ion, peak 6 Are Mg ²⁺ ions. From this result, it was confirmed that each ion was completely separated and detected for the standard cation.

The ion analysis system 100 having the same configuration as that of FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2e having the same configuration as that of FIG. The effect of using a Nafion (registered trademark) NRE-117 membrane for the ion exchange membrane 27b was verified using the anion removal impurity ion removal apparatus 2i having the same configuration as that of FIG. In the experiment, the joint 15, the pump 3, the injector 5, the separation column 7, the impurity ion removing device 9, and the detector were removed from the ion analysis system 100 of FIG. Electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), electrolyte solution purifiers 2e and 2i are impurity ion removers for removing anions (manufactured by Nichi Kogyo), and pumps 47a and 47b are CCPM (Tosoh Corporation). EX-375U2 (manufactured by Takasago Seisakusho Co., Ltd.) was used as the DC power source 33 for electrophoresis. The electrolyte solution generator 1 has a constant current of 20 mA, the electrolyte solution purifiers 2e and 2i have a constant current of 30 mA, platinum electrodes are used as the electrodes for electrophoresis, and pure water (1.0 ml / min) is supplied from the pumps 47a and 47b. Each supplied.
A graph in which the sodium hydroxide solution generated by the electrolyte solution generator 1 (electrolyte solution generated under the condition of a constant current of 20 mA) is purified by the electrolyte solution purifier under the condition of the constant current of 30 mA, and the time variation of the applied voltage is plotted. As shown in FIG.
When the electrolyte solution purification apparatus 2i using Neoceptor (registered trademark) C66 for the ion exchange membrane 27b and the electrolyte solution purification apparatus 2e using Nafion (registered trademark) NRE-117 membrane were compared, Neocepta (registered trademark) C66 was used. The applied voltage of the electrolyte solution purifying apparatus 2i has a large slope and rises to the right, whereas the applied voltage of the electrolyte solution purifying apparatus 2e using a Nafion (registered trademark) NRE-117 membrane for the ion exchange membrane 27b. The applied voltage is stable around 39V.

The ion analysis system 100 having the same configuration as that shown in FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2e having the same configuration as that shown in FIG. The impurity ion removing device 9 uses the cation removing impurity ion removing device 9b having the same configuration as in FIG. 3 and the cation removing impurity ion removing device 9c having the same configuration as in FIG. 4, and uses two suppressors. The effect of the connected ion analysis system was verified. The electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), the electrolyte solution purifier 2e is an impurity ion removing device for removing anions (manufactured by Nichi Kogyo), and the impurity ion removing devices 9b and 9c are cations. Impurity ion removing device for removal (manufactured by Nichi Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), injector is model 7125 (manufactured by RHEODYNE, 20 μL), electricity The DC power supply 33 for electrophoresis is EX-375U2 (manufactured by Takasago Seisakusho), TSKgel superIC Anion AZ (manufactured by Tosoh Corporation) is used as a separation column, and the detector 11 is a non-contact electric conductivity detector (manufactured by Nichi Kogyo). It was used. The electrolyte solution generator 1 has a constant current of 20 mA (about 32.6 V), the electrolyte solution purifier 2 e has a constant current of 30 mA (about 39.4 V), a platinum electrode as an electrode for electrophoresis, and pumps 47 a and 47 b. The pure water (1.0 ml / min) was supplied from each, and the flow rate of the pump 3 was 0.75 ml / min. Sample concentration, F ^- ions; 50 ppb, Cl ^- ions; 100 ppb, NO ₂ ^- ions; 150 ppb, Br ^- ions; 100 ppb, NO ₃ ^- ions; 300 ppb, _SO ^{4 2-ions;} 400 ppb, _PO ^{4 3-} ions; It was 300 ppb.

FIG. 17 shows a chromatogram when an ion analysis system having a configuration in which only one impurity ion removing device is installed (impurity ion removing device 9b having the configuration shown in FIG. 3) and measurement is performed at a constant current of 40 mA (about 45 V). Shown in Using an ion analysis system having a configuration in which two impurity ion removing devices 9b are installed (impurity ion removing device 9c having the configuration in FIG. 4), the first stage impurity ion removing device has a constant current of 20 mA (about 31.9 V), FIG. 18 shows a chromatogram when the second stage impurity ion removing apparatus is measured under the condition of a constant current of 5 mA (about 9.5 V). Further, an ion analysis system having a configuration in which a total of three impurity ion removal devices connected to two impurity ion removal devices 9b configured as shown in FIG. 3 and one impurity ion removal device 9a configured as shown in FIG. The first stage impurity ion removal device 9 has a constant current of 10 mA (about 33.2 V), the second stage impurity ion removal device has a constant current of 5 mA (about 22.2 V), and the impurity ion removal device has a constant current. FIG. 19 shows a chromatogram when measured under the condition of 5 mA (about 11.4 V).

17, 18, and 19, the peak 1 is F ⁻ ion, the peak 2 is Cl ⁻ ion, the peak 3 is NO ₂ ⁻ ion, the peak 4 is Br ⁻ ion, and the peak 5 is NO ₃ ^−. ions, the peak of the 6 unknown CO ₃ ^- ions and _SO ^{4 2-ions,} peak 7 is _PO ^{4 3-} ions. In an ion chromatographic system in which two impurity ion removal devices are connected, the eluent can be sufficiently suppressed even though the total current flowing through the impurity ion removal device is 25 mA, which is the smallest amount. The peak height of each sample obtained is the largest, and highly sensitive detection is possible.
In suppressing an eluent containing an electrolyte of 2 mM or more, the amount of current flowing through the system and the amount of ions that can be suppressed are proportional to each other where the amount of current is small. However, as the amount of current increases, the proportional relationship breaks, and even if an excessive current is passed, ions are left behind in the in-line and the background conductivity cannot be lowered. For this reason, the amount of current flowing through the system is reduced, and another ion that cannot be removed by one impurity ion removing device in a current range in which a proportional relationship exists between the amount of current flowing through the system and the amount of ions that can be suppressed. By removing it with an impurity ion removal device, the eluent can be efficiently suppressed in a two-stage system. Further, since the amount of current flowing through each system is reduced, the load on the system can be reduced, and the life of the system can be extended. However, if the number of impurity ion removal devices is increased to 3 or more to increase the elution suppression efficiency, the amount of diffusion of the sample in the impurity ion removal device will increase, resulting in signal / noise. Becomes smaller and the detection sensitivity decreases. From the above, it can be seen that it is effective to use two impurity ion removing devices and suppress the eluent in a two-stage system.

The ion analysis system 100 having the same configuration as that of FIG. 9 in the ion analysis system shown in FIGS. 8 and 9 is used, and the impurity ion removing device 9 has a cation removing impurity ion removing device 9a having the same configuration as that of FIG. The cation removing impurity ion removing device 9b having the same configuration as in FIG. 3, the anion removing impurity ion removing device 9e having the same configuration as FIG. 6, and the anion removing impurity ion removing device 9i having the same configuration as FIG. The durability of four impurity ion removing devices having different structures was examined. In the experiment, the electrolyte solution purification apparatus 2, the injector 5, and the separation column 7 were removed from the ion analysis system 100 of FIG. The electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), the impurity ion removing devices 9a and 9b are cation removing impurity ion removing devices (manufactured by Nichi Kogyo), and the impurity ion removing devices 9e and 9i are Impurity ion removal device for anion removal (manufactured by Niri Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), and DC power supply 33 for electrophoresis is EX-375U2. The detector 11 was an electrical conductivity detector CM432 (manufactured by Nichi Kogyo). The electrolyte solution generator 1 uses a constant current of 20 mA, a platinum electrode as an electrode for electrophoresis, supplies pure water (1.0 ml / min) from the pumps 47a and 47b, and the flow rate of the pump 3 is 0.75 ml / min. It was set to min. In the case of the impurity ion removing devices 9a and 9b having the same structure as that shown in FIGS. 2 and 3, the experiment is performed using the electrophoresis DC power source 33 at a constant current of 40 mA, and the impurity ion removing device 9e having the same structure as that shown in FIGS. In the case of 9i and 9i, the experiment was conducted with the DC power source 33 for electrophoresis at a constant current of 30 mA.
The results are shown in FIG.

In the chart of FIG. 20, the impurity ion removing device 9a having the same structure as that in FIG. 2 is broken in 1 hour of use, and the impurity ion removing device having a structure in which Neoceptor (registered trademark) C66 is used for the ion exchange membrane 27b in FIG. In 9i, the applied voltage increased as the time passed. It was confirmed that the impurity ion removing devices 9b and 9e having the same structure as in FIGS. 3 and 6 were stable without changing the applied voltage for a long time.
The impurity ion removing devices 9b and 9e having the same structure as those in FIGS. 3 and 6 are stable without changing the applied voltage for a long time. The exchange membrane 27b is not in contact with the electrode 31b, the ion exchange resin is filled between the ion exchange membrane 27b and the electrode (anode 31b), the region 52 is provided, and a salt bridge is formed by the ion exchange resin. Thus, the electrodes are electrically connected by ionic conduction. Secondly, as in the apparatus of FIGS. 3 and 6, a Teflon (registered trademark) -based cation exchange membrane (28b in FIG. 3, 28b in FIG. 6) that is chemically stable to the ion exchanger in contact with the electrode. 27b).
With these two improvements, the apparatus can be used for a long time even under a current condition of a current density of 4 A / cm 2 (2.8 mA in this apparatus) or more.

The ion analysis system 100 having the same configuration as that shown in FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2e having the same configuration as that shown in FIG. Using the impurity ion removing device 9 as the impurity ion removing device 9b for cation removal having the same configuration as that shown in FIG. 3 and the impurity ion removing device 9h for cation removing having the same configuration as that shown in FIG. The effect of was investigated. In the experiment, the injector 5 and the separation column 7 were removed from the ion analysis system 100 of FIG. The electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), the electrolyte solution purifier 2e is an anion removing impurity ion removing device (manufactured by Nichi Kogyo), and the impurity ion removing devices 9b and 9h are cations. Impurity ion removing device for removal (manufactured by Nichi Kogyo), pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), pump 3 is DP-8020 (manufactured by Tosoh Corporation), and DC power supply 33 for electrophoresis is EX-375U2 (Takasago) (Manufactured by Seisakusho Co., Ltd.), the detector 11 was an electrical conductivity detector CM432 (manufactured by Nichi Kogyo). The electrolyte solution generator 1 has a constant current of 20 mA (about 37 V, about 1505 μS / cm NaOH solution), the electrolyte solution purifier 2 has a constant current of 30 mA (about 44 V), and uses a platinum electrode as an electrode for electrophoresis. Pure water (1.0 ml / min) was supplied from the pumps 47a and 47b, and the flow rate of the pump 3 was 0.75 ml / min. The results are shown in FIG.

In addition, the division | segmentation of the codes | symbols 1-4 of FIG. 21 is 1: Electric conductivity (about 1505 microseconds) of the eluate from the impurity ion removal apparatus 9b when the operation | movement of the impurity removal apparatus 9b of the structure similar to FIG. 3 is stopped. / Cm) 2: Using the impurity ion removing device 9h having the same structure as in FIG. 10, the electric conductivity (about 461 μS) of the eluate from the impurity ion removing device 9h at a constant current of 10 mA (about 15.4 V). / Cm) 3: Using the impurity removing device 9b having the same structure as in FIG. 3, the pump 47a is stopped, and the electric conductivity of the effluent from the impurity ion removing device 9b at a constant current of 10 mA (about 31.5 V) (About 388 μS / cm) 4: Using the impurity removal device 9b having the same structure as that shown in FIG. 3, the electric conductivity of the eluate from the impurity ion removal device 9b at a constant current of 10 mA (about 38.5 V) (about 69μS / cm) .

From FIG. 21, the ion removal efficiency when the impurity ion removing device 9h having the same structure as that of FIG. 10 is used and when the impurity removing device 9b having the same structure as that of FIG. It was the same. When the impurity ion removing device 9b having the same structure as that in FIG. 3 was used, it was confirmed that the highest ion removal efficiency (ion removal amount per energization current amount) was the highest.
This is because the bubble discharge promoting means installed at the cathode allows pure water from the pump 47a to flow, discharges cations moving to the vicinity of the cathode 31a out of the system, and lowers the cation concentration near the cathode. This is because it can.

In order to examine the liquid flow path in the region 51 of the impurity ion removing apparatus 9b shown in FIG. 3, the influence on the analysis sensitivity by changing the liquid flow path is examined. As a comparison, the eluate from the separation column 7 is allowed to flow from the first outlet 22a to the first inlet 21a, and the peak height of the standard anion chromatogram obtained at that time is confirmed.

The ion analysis system 100 having the same configuration as that shown in FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2e having the same configuration as that shown in FIG. In order to study the liquid flow path in the region 51 of the impurity ion removing device 9b shown in FIG. 3, using the impurity ion removing device 9b for cation removal having the same configuration as that shown in FIG. Investigate the effect on analysis sensitivity by changing the liquid flow path. The pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), the pump 3 is DP-8020 (manufactured by Tosoh Corporation), the electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), and the electrolyte solution purifier 2e is negative. Impurity ion removal device for ion removal (manufactured by Niri Kogyo), impurity ion removal device 9b is an impurity ion removal device for cation removal (manufactured by Niri Kogyo), and the injector is model 7125 (manufactured by RHEODYNE, 20 μL), for electrophoresis The DC power source 33 used was EX-375U2 (manufactured by Takasago Seisakusho Co., Ltd.), the separation column 7 was TSKgel superIC Anion AZ (manufactured by Tosoh Corp.), and the detector 11 was a non-contact type conductivity detector (manufactured by Nichi Kogyo). The electrolyte solution generator 1 has a constant current of 20 mA (66.5 V, approximately 1836 μS / cm NaOH solution), the electrolyte solution purifier 2 e has a constant current of 30 mA (approximately 41.2 V), and the impurity ion removing device 9 b has a constant current. 40 mA (about 38.8), a platinum electrode was used as the electrode for electrophoresis, pure water (1.0 ml / min) was supplied from the pumps 47a and 47b, and the flow rate of the pump 3 was 0.75 ml / min. . Sample concentration, F ^- ions; 50 ppb, Cl ^- ions; 100 ppb, NO ₂ ^- ions; 150 ppb, Br ^- ions; 100 ppb, NO ₃ ^- ions; 300 ppb, _SO ^{4 2-ions;} 400 ppb, _PO ^{4 3-} ions; It was 300 ppb.
The measurement results are shown in FIG.

In the chart of FIG. 22, 1 peak is F ⁻ ion, 2 peak is Cl ⁻ ion, 3 peak is NO ₂ ⁻ ion, 4 peak is Br ⁻ ion, 5 peak is NO ₃ ⁻ ion, 6 peak The peaks are unknown CO ₃ ⁻ ions and SO ₄ ²⁻ ions, and the peak 7 is PO ₄ ³⁻ ions. From this result, it was confirmed that the ions were completely separated and detected except that the peaks of carbonate ion and sulfate ion overlapped.

Next, the peak height of the standard anion chromatogram obtained when the eluate from the separation column 7 is allowed to flow from the first outlet 22a to the first inlet 21a is confirmed.
The experimental conditions and analysis method are the same as in the case of the model except that the eluate from the separation column 7 is allowed to flow from the first outlet 22a to the first inlet 21a. The measurement results are shown in FIG.
From this result, it was confirmed that when the eluate from the separation column 7 was flowed from the first outlet 22a to the first inlet 21a, the peak height of the standard anion chromatogram was reduced, that is, the sensitivity was lowered. .
In general, it is well known that increasing the diffusion of ions to be inspected leads to a decrease in sensitivity. Therefore, in this experiment, the liquid channel flowing from the normal inlet is more inspected than the liquid channel flowing from the outlet. It means that the diffusion of was small.

In order to show that the gas generated by the electrode reaction, which is a feature of the present invention, is prevented from being mixed into the system, the influence of the mixing of the gas contained in the eluate from the impurity ion removing device 9 is electrically conducted. Measure in degrees.

The ion analysis system 100 having the same configuration as that shown in FIG. 9 is used in the ion analysis system shown in FIGS. 8 and 9, and the anion removing impurity ion removing device 2e having the same configuration as that shown in FIG. 4 and the impurity ion removing device 9c having the same configuration as that shown in FIG. 4 is used as the impurity ion removing device 9. In the experiment, the injector 5 and the separation column 7 are removed from the ion analysis system 100 shown in FIG. did. The pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), the electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), and the electrolyte solution purifier 2e is an impurity ion removing device for removing anions (manufactured by Nichi Kogyo). ), The impurity ion removing device 9c is a positive ion removing impurity ion removing device 9c (Nichi Kogyo), the pump 3 is DP-8020 (manufactured by Tosoh Corporation), and the DC power supply 33 for electrophoresis is EX-375U2 (Takasago Seisakusho). The detector 11 was an electrical conductivity detector CM432 (manufactured by Nichi Kogyo). The electrolyte solution generator 1 has a constant current of 20 mA (about 35.8 V, NaOH solution), the electrolyte solution purifier 2 e has a constant current of 30 mA (about 31.7 V), and the impurity ion removing device 9 c has a constant first stage. The current is 15 mA (about 28.6 V), the second stage is a constant current of 5 mA (17.6 V), a platinum electrode is used as the electrophoresis electrode, and pure water (1.0 ml / min) is supplied from the pumps 47a and 47b, respectively. The flow rate of the pump 3 was 0.75 ml / min. The measurement results are shown in FIG.
From FIG. 24, it has been confirmed that spike noise that appears due to gas mixture does not appear.

Next, in the electrolyte solution purifying apparatus 2 which is the feature of this apparatus, in order to confirm that the introduction of impurity ions from the outside can be prevented, Neoceptor (registered trademark) AHA is installed in the ion exchange membrane 27b as a comparison. The contamination of foreign impurities was measured using the purified electrolyte solution purifier.

The ion analysis system 100 having the same configuration as in FIG. 9 in the ion analysis system shown in FIGS. 8 and 9 is used, and the anion removing impurity ion removing device 2f having the same configuration as in FIG. An anion removing impurity ion removing device 2j having the same configuration as that shown in FIG. 26 is used, and a cation removing impurity ion removing device 9b having the same configuration as that shown in FIG. The influence of the polarity of the ion exchange membrane used in the experiment was investigated. Pumps 47a and 47b are CCPM (manufactured by Tosoh Corporation), electrolyte solution generator 1 is a basic electrolyte solution generator (manufactured by Nichi Kogyo), and electrolyte solution purifiers 2f and 2j are impurity ion removers for removing anions (Nichiri). Industrial), impurity ion removing device 9b is an impurity ion removing device for removing cations (Nichi Kogyo), pump 3 is DP-8020 (manufactured by Tosoh Corporation), and DC power supply 33 for electrophoresis is EX-375U2 (Takasago Seisakusho Co., Ltd.) The detector 11 was an electrical conductivity detector CM432 (manufactured by Nichi Kogyo). The electrolyte solution generator 1 has a constant current of 20 mA (about 59.3 V, NaOH solution), the impurity ion remover 9 b has a constant current of 40 mA (63 V), platinum electrodes are used as the electrodes for electrophoresis, and the pumps 47 a and 47 b The pure water (1.0 ml / min) was supplied from each, and the flow rate of the pump 3 was 0.75 ml / min. The measurement results are shown in FIG. 25 is divided into 1: the electrolyte solution purification apparatus 2f having the same structure as in FIG. 7, and the ion exchange membrane 27b is replaced with a cation exchange membrane (Nafion (registered trademark) NRE-117). The DC power source 33 for electrophoresis has a constant current of 30 mA (45.3 V), and the electric conductivity of the effluent from the impurity ion removing device 9b when the electrolyte solution is purified, 2: as in FIG. The electrolyte solution purification apparatus 2j having the structure shown in FIG. 5 is used, the ion exchange membrane 27b is Neoceptor (registered trademark) AHA, the electrophoresis DC power source 33 is constant current 30 mA (67.5 V), and the electrolyte solution is purified. The electric conductivity of the eluate from the impurity ion removing device 9b at that time was used.

From FIG. 25, it was confirmed that when Neoceptor (registered trademark) AHA was used for the ion exchange membrane 27b, foreign impurities were mixed and the baseline was increased by about 0.125 μS / cm.

The present invention relates generally to a device for removing impurity ions contained in a solution suitable for general use in chemical analysis, synthesis and processing, and in particular, a suppressor (ion removing device) suitably used for an ion chromatograph (device), An eluent purification apparatus is provided.

DESCRIPTION OF SYMBOLS 1 Electrolyte solution production | generation apparatus 2 Electrolyte solution refinement | purification apparatus 3 Pump 5 Injector port 7 Separation column 9 Impurity ion removal apparatus 11 Detector 13 Pipe 21 Container 21a Solution inlet 21b Solution inlet 21c Solution inlet 22a Solution outlet 22b Solution outlet 22c Solution outlet 23 Ion Exchanger 25A Ion exchanger 25B Ion exchanger 27a Ion exchange membrane 27b Ion exchange membrane 28a Ion exchange membrane 28b provided with liquid permeability Ion exchange membrane 31a provided with liquid permeability Electrode 31b Electrode 33 Power supply 41a Pure water supply device 41b Pure water supply device 45a Pure water storage tank 45b Pure water storage tank 47a Pump 47b Pump 49a Pipe 49b Pipe 51 First area 52 Second area 53 Third area

Claims (8)

As means for removing either positive or negative impurity ions from a solution containing impurity ions (X1), an ion exchanger A1 layer that adsorbs ions having the same polarity as the impurity ions to be removed is sandwiched.
The electrode C1, through an ion exchange membrane B1 that is resistant to strong acid or strong base, which is an ion exchange membrane having the same polarity as the polarity of the impurity ion to be removed, on the one electrode C1 side having the same polarity as the polarity of the impurity ion to be removed ,
The electrode C2 is disposed on the other electrode C2 side opposite to the polarity of the impurity ion to be removed via an ion exchange membrane B2 that can withstand a strong acid or a strong base that is an ion exchange membrane of the polarity opposite to the polarity of the impurity ion to be removed.
With
(X2) A raw material solution inlet is provided at the upper end of the ion exchanger A1 layer, and a purified solution outlet is provided at the lower end of the ion exchanger A1 at a position off from directly below the inlet, and the inlet is on the ion exchange membrane B2 side. , The outlet is provided on the ion exchange membrane B1 side,
A drain outlet and a pure water supply port are provided outside the electrodes,
(X3) an external current source connected to both electrodes;
An impurity ion removing apparatus comprising: As means for removing either positive or negative impurity ions from a solution containing impurity ions (X1), an ion exchanger A1 layer that adsorbs ions having the same polarity as the impurity ions to be removed is sandwiched.
The electrode C1, through an ion exchange membrane B1 that is resistant to strong acid or strong base, which is an ion exchange membrane having the same polarity as the polarity of the impurity ion to be removed, on the one electrode C1 side having the same polarity as the polarity of the impurity ion to be removed ,
The ion exchange membrane B2 that can withstand strong acid or strong base, which is an ion exchange membrane opposite to the polarity of the removal target impurity ion polarity, on the other electrode C2 side that is the opposite polarity to the polarity of the removal target impurity ion, and the same polarity as the polarity of the removal target impurity ion The electrode C2 is passed through an ion exchanger A2 layer that is an ion exchanger that adsorbs ions of the ion exchange membrane B3 or an ion exchanger A3 layer that can withstand liquid permeability and strong acid or strong base.
With
(X2) A raw material solution inlet is provided at the upper end of the ion exchanger A1 layer, and a purified solution outlet is provided at the lower end of the ion exchanger A1 at a position off from directly below the inlet, and the inlet is on the ion exchange membrane B2 side. , The outlet is provided on the ion exchange membrane B1 side,
A drain outlet is provided outside the electrodes, a pure water supply port is provided on the electrode C1 side, and a pure water supply port is provided at the upper end of the ion exchanger A2 layer (X3). An external current source to connect,
An impurity ion removing apparatus comprising: As a means for removing either positive or negative impurity ions from the solution containing impurity ions, (X1) sandwiching an ion exchanger A1 layer that adsorbs ions having the same polarity as the impurity ions to be removed
The ion exchange membrane B1 that can withstand strong acid or strong base, which is an ion exchange membrane having the same polarity as the polarity of the removal target impurity ions, on one electrode C1 side that is the same polarity as the polarity of the removal target impurity ions, and the polarity of the removal target impurity ions Polarity of the electrode C1 and the impurity ions to be removed through the ion exchanger A4 layer, which is an ion exchanger that does not adsorb ions of the same polarity , the liquid permeability and the ion exchange membrane B5 or ion exchanger A5 layer that can withstand strong acid or strong base The ion exchange membrane B2 that can withstand strong acid or strong base, which is an ion exchange membrane having a polarity opposite to the polarity of the impurity ion to be removed , and an ion that adsorbs ions having the same polarity as the polarity of the impurity ion to be removed The electrode C2 is passed through an ion exchanger A2 layer which is an exchanger, an ion exchange membrane B3 or an ion exchanger A3 layer which can withstand liquid permeability and strong acid or strong base.
With
(X2) A raw material solution inlet is provided at the upper end of the ion exchanger A1 layer, and a purified solution outlet is provided at the lower end of the ion exchanger A1 at a position off from directly below the inlet, and the inlet is on the ion exchange membrane B2 side. , The outlet is provided on the ion exchange membrane B1 side,
A drain outlet is provided outside the electrodes,
A pure water supply port is provided at the upper end of the ion exchanger A2 layer, A4 layer (X3), and an external current source connected to both electrodes;
An impurity ion removing apparatus comprising: A multistage system in which a plurality of impurity ion removing devices having the same polarity are connected to each other as a means for removing either positive or negative impurity ions from a solution containing impurity ions. Impurity ion removal device.   5. The impurity ion removing apparatus according to claim 1, which is used for purifying an eluent of an ion chromatograph. 5. The impurity ion removing apparatus according to claim 1, which is used for a suppressor of an ion chromatograph. In the ion chromatograph, (A) the introduction part into which the electrolyte raw material solution is charged, and (A-1) the introduction part is filled with a cation exchange resin , forming a first region,
(B) (B-1) The introduction part is sandwiched between electrodes at both ends, and a drain outlet is provided outside the electrodes.
A second region is formed by providing a cation exchange membrane that is in contact with the anode electrode and capable of withstanding liquid permeability and strong acid or strong base, an anion exchange resin layer, an anion exchange membrane that can withstand strong acid or strong base ,
A third region is formed by providing a cation exchange membrane that is in contact with the cathode electrode and is permeable to liquid and strong acid or strong base , a cation exchange resin layer, a cation exchange membrane that is strong acid or strong base ,
(B-2) An electrolyte raw material solution inlet is provided on the cation exchange membrane position side of the first region, a charging pipe is attached, and a target purified liquid outlet is provided on the anion exchange membrane position side. The take-out piping is installed,
(B-3) A pure water inlet is provided at the upper ends of the anion exchange resin layer in the second region and the cation exchange resin layer in the third region, and a supply pipe is attached. (C) (B) An cation removing device for an electrolyte solution, comprising an external current source for connecting the electrodes described in 1. In the ion chromatograph, (A) the introduction part into which the electrolyte raw material solution is charged, and (A-1) the introduction part is filled with an anion exchange resin to form a first region,
(B) (B-1) The introduction part is sandwiched between electrodes at both ends, and a drain outlet is provided outside the electrodes.
Liquid permeability and a strong acid or a cation exchange membrane to withstand the strong base inward in contact with the cathode, cation-exchange resin layer, to form a second region provided with a cation exchange membrane to withstand strong acid or base,
A third region is formed by providing a cation exchange membrane that is in contact with the anode electrode and capable of withstanding liquid permeability and strong acid or strong base, an anion exchange resin layer, an anion exchange membrane that can withstand strong acid or strong base ,
(B-2) An electrolyte raw material solution inlet is provided on the anion exchange membrane position side of the first region, a charging pipe is attached, and a target purified liquid outlet is provided on the cation exchange membrane position side. The take-out piping is installed,
(B-3) A pure water inlet is provided at the upper ends of the cation exchange resin layer in the second region and the anion exchange resin layer in the third region, and a supply pipe is attached. (C) (B) An anion removal device for an electrolyte solution, comprising an external current source that connects the electrodes described in 1.

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