JP2001147223A - Column filler for ion chromatography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filler for ion chromatography eliminating the diffusion of ions to be treated into the packing material substantially and reducing the lowering of separation capacity caused by the diffusion of ions to be treated into the packing material and the migration between ion exchange groups of ions to be treated to realize high resolution ion chromatography. SOLUTION: The filler for ion chromatography is constituted by providing a monomolecular or bimorecular membrane, which is formed by arranging amphiphatic chain organic molecules each having an ion exchange group at least one end thereof and a hydrophobic part at the part other than the ion exchange group thereof by the hydrophobic interaction due to the hydrophobic parts, on a substrate as the uppermost layer. As the substrate, a general-purpose ion exchange resin is especially prefarable. As the amphiphatic chain organic molecule, one containing an azobenzene structure is especially preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a column packing for ion chromatography.

[0002]

2. Description of the Related Art In ion chromatography, a raw material solution / sample solution containing a plurality of types of ion dissociable substances is injected into one end of a stationary phase comprising a packing material packed in a separation column, and then an eluent Is a technology that separates and analyzes various ion-dissociative substances based on differences in the retention time of various ion-dissociable substances in the stationary phase. In addition to quantitative analysis of ionic species in water, amino acids, antibiotics, rare earths It is also widely used as an industrial-scale separation and purification technique such as separation and purification of metals and the like.

[0003] As a column packing for ion chromatography used for the above-mentioned separation and purification on an industrial scale, an ion exchange resin composed of a synthetic polymer is widely used. Ion-exchange resins include cation-exchange resins and anion-exchange resins due to the polarity of the ion-exchange groups, and these are furthermore strongly acidic and weakly acidic cations, depending on the degree of acidity or basicity of the ion-exchange groups. Ion exchange resins are divided into strongly basic and weakly basic anion exchange resins. In ion chromatography, these ion exchange resins are appropriately selected depending on the purpose and conditions of use, and are used as a column packing for ion chromatography.

[0004] As the strong acid cation exchange resins, sulfonic acid functional group ^{_{(R-SO 3 - H +}} ) that have, on the other hand, as the weakly acidic cation exchange resins, carboxylic acid functional groups ( R-COO ^- H ⁺ ), a phosphonic acid group [RP
(O) (O ⁻ H ⁺ ) ₂ ], a phosphinic acid group [R-PH
(O) (O ⁻ H ⁺ )], an arsenite group (R-OAsO)
^- H ^+), phenoxide group ^{_{(R-C 6 H 4 O}} - , and the like ^{H +)} that have.

The strongly basic anion exchange resin has a quaternary ammonium group (RN ⁺ R ₁ R ₂ R ₃ ) or a tertiary sulfonium group (RS ⁺ R ₁ R ₂ ) as a functional group. In the case of a quaternary ammonium group, the case where the group bonded to the nitrogen atom is only an alkyl group (for example, only a methyl group) is an I-type. Among the groups bonded to the nitrogen atom, an alkanol group (for example, , -C ₂ H ₄ OH, etc.) is referred to as Form II, and Form I shows a slightly stronger basicity than Form II. The functional groups of the weakly basic anion exchange resins are primary to tertiary amino groups, and many types are known depending on the type of amino group.

As described above, ion-exchange resins are basically classified into four types according to their acidity or basicity. The polymer bases constituting them are styrene-based, phenol-based, and acryl-based. Synthetic polymers such as methacrylic and methacrylic polymers are used, and the matrix structure is classified into a gel form, an expanded network gel form (porous form), and an MR form (macroporous form) depending on the difference in the synthesis method.

The gel ion exchange resin is, for example, a copolymer having a three-dimensional network structure obtained by copolymerizing styrene and divinylbenzene (DVB) in the presence of a catalyst and a dispersant. It is an ion exchange resin obtained by introducing a group. Porous ion-exchange resin, by performing copolymerization in the presence of an organic solvent capable of swelling the copolymer, swells and expands the resulting copolymer, and the copolymer is more swellable than the gel form. An ion exchange resin obtained by producing a copolymer having a large space (gel porosity) and introducing a functional group into the copolymer. The MR type ion exchange resin is a copolymer as an aggregate of small spherical gel particles by performing copolymerization in the presence of an organic solvent that is a solvent for the monomer and acts as a precipitant for the copolymer,
That is, it is an ion-exchange resin obtained by producing a matrix having macropores between the particles and introducing a functional group into the matrix.

[0008]

In the above-described conventional column packing for ion chromatography, ion-exchange groups that form ion pairs with ions in the liquid to be treated are also present inside the packing. After the ions in the liquid are adsorbed on the surface layer of the filler, the ions diffuse into the filler while repeatedly bonding and dissociating with the ion exchange group. The degree of diffusion of these ions into the packing material is not controlled at all in ion chromatography, and even if ions of the same type are present, a distribution occurs during the time that they are held in a fixed packing stationary phase, This causes a reduction in chromatographic separation performance (that is, resolution).

In the conventional column packing for ion chromatography, the ion exchange groups are not densely arranged at the molecular level. That is, in a conventional filler, as represented by an acrylic resin, an acrylic monomer having an ion exchange group at a specific site thereof and a monomer such as DVB having no ion exchange group are copolymerized, or Then, as typified by a styrene resin, styrene having no ion exchange group and a monomer such as DVB are copolymerized to obtain a polymer matrix, and then an ion exchange group is introduced into a specific portion of the polymer matrix. Since there is a certain distance between the ion exchange groups due to the structure of the monomer or the base polymer, it is not possible to take a structure in which the ion exchange groups are densely packed at the molecular level.

[0010] For this reason, in the conventional packing, when the ions develop in the stationary phase, they migrate between ion exchange groups existing at a certain distance or more while being solvated by the solvent molecules of the eluent. The rate at which ions develop in the stationary phase is not only dependent on the formation / dissociation of ionic bonds, which are governed by the affinity of the ions with the ion exchange groups, but also on the uncertainty of the solvent. It depends on the migration distance between the ion-exchange groups of the sum ion and the migration speed, which also causes a reduction in the separation performance of ion chromatography.

That is, an object of the present invention is to substantially eliminate the diffusion of the ions to be treated into the inside of the filler, and to improve the separation performance caused by the diffusion of the ions to be treated into the inside of the filler and the migration between ion exchange groups. An object of the present invention is to provide a column packing material for ion chromatography, which reduces the decrease and realizes high-resolution ion chromatography.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems of the conventional column packing for ion chromatography, and as a result, have found that a single molecule comprising an amphipathic chain substance is obtained. If the membrane or bilayer is the outermost layer, there is substantially no diffusion of ions to be treated into the filler, and
The present inventors have found that a novel column packing for ion chromatography in which ion exchange groups are densely and regularly arranged on the surface of the packing can be prepared, and the present invention has been completed.

That is, according to the present invention, an amphiphilic chain organic molecule having an ion-exchange group at at least one end and having a hydrophobic portion in a portion other than the ion-exchange group is formed by hydrophobic interaction between the hydrophobic portions. An object of the present invention is to provide a column packing for ion chromatography, which has a monomolecular film or a bimolecular film arranged by an action as an outermost layer on a substrate.

The column packing material for ion chromatography of the present invention comprises a monomolecular film or a bimolecular film in which amphiphilic chain organic molecules are arranged in water as the outermost layer of the packing material. Substantially eliminates diffusion into the interior of the filler, and arranges ion exchange groups densely and regularly on the surface of the filler, resulting from diffusion of ions to be treated into the interior of the filler and migration between ion exchange groups. Reduces separation performance and achieves high-resolution ion chromatography.

The amphiphilic substance is a group of compounds consisting of a lyophobic group having a weak interaction with a solvent molecule such as a water molecule and an amphiphilic group having a strong interaction. , Long-chain carboxylic acids, soaps, synthetic detergents, dyes,
Examples include phospholipids. Some amphiphilic substances form a monomolecular film or a bimolecular film by self-assembly when dispersed in an aqueous solvent such as water. An amphiphilic substance forming a monomolecular film or a bimolecular film is generally composed of organic molecules whose molecular shape is a chain, for example, as shown below, a double-stranded amphiphilic compound, a single-stranded Type amphiphilic compounds, multi-chain type amphiphilic compounds, fluorocarbon chain type amphiphilic compounds, amphiphilic chain compounds having hydrophilic groups at both molecular ends, and composite substances thereof.

Examples of the double-stranded amphiphilic compound include compounds represented by formulas (1) to (13), and among these, compounds (1) to (1)
The compounds represented by the formula 1 ”have an ion-exchange group and can be used as an amphiphilic chain organic molecule in the present invention. "M" in the formula
Represents a metal element capable of forming a chelate with N atoms such as Fe and Cu. In the following chemical formulas, * represents an asymmetric carbon atom, and n, m, and x represent positive integers suitable for making the substances of each formula amphiphilic.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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Examples of the single-chain amphiphilic compound include compounds represented by the formulas (Chemical Formula 14) to (Chemical Formula 19), which have an ion-exchange group. In the present invention, it can also be used as an amphiphilic chain organic molecule.

[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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As the polychain amphiphilic compound, for example,
Compounds represented by the formulas (Chemical Formula 20) to (Chemical Formula 22) can be given. These compounds have an ion-exchange group and can be used as an amphiphilic chain organic molecule in the present invention. You can do it.

[0038]

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[0039]

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[0040]

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Examples of the fluorocarbon chain type amphiphilic compound include compounds represented by the formulas (Formula 23) to (Formula 28).
The compounds represented by the formulas (3) to (27) have an ion exchange group and can be used as an amphiphilic chain organic molecule in the present invention.

[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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Examples of the amphiphilic compound having a hydrophilic group at both ends of the molecule include compounds represented by formulas (Chemical Formula 29) to (Chemical Formula 36). A, b, e of “chemical 31” and “chemical 32”
Compounds represented by the formulas f, g, “Formula 33”, “Formula 34”, and “Formula 36” have an ion exchange group, and are also used as amphiphilic chain organic molecules in the present invention. Is what you can do.

[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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As the complex type amphiphile, for example,
Substances represented by the formulas (Chemical Formula 37) and (Chemical Formula 38) can be given. Among them, the substance represented by the formula (Chemical Formula 38) has an ion-exchange group. Can also be used as amphiphilic chain organic molecules. Note that, in the formula of “Chemical Formula 38”, dots arranged in the vertical direction indicate that two kinds of molecules are alternately arranged by hydrogen bonds, and between N and H and between O and H. Form a hydrogen bond.

[0058]

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[0059]

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Among the above amphiphilic substances, those not mentioned as those which can be used as amphiphilic chain organic molecules in the present invention have strong interaction with solvent molecules such as water. The amphiphilic group is not an ion-exchange group, or even if it is an ion-exchange group, forms an intramolecular salt or a salt between two kinds of amphiphilic chain organic molecules. However, when an inner salt or a salt between two kinds of amphiphilic chain organic molecules is formed, it may dissociate and have an ion exchange ability depending on temperature, pH conditions, types of ions to be exchanged, and the like. As such, amphiphilic chain organic molecules forming such salts can also be used in the present invention. Further, when a plurality of kinds of amphiphilic chain organic molecules as exemplified above are mixed and used, a monomolecular film or a bimolecular film can be formed, and a desired ion exchange capacity according to the application is obtained. In the present invention, it is possible to use an ion exchanger produced by mixing a plurality of types of amphiphilic chain organic molecules as long as a column packing material for ion chromatography having the same can be obtained. In addition to the amphiphilic chain organic molecules having a group, amphiphilic chain organic molecules having no ion-exchange group can be mixed and used. When an ion exchanger is produced by mixing amphiphilic chain organic molecules having no ion exchange group in addition to amphiphilic chain organic molecules having an ion exchange group, the outermost layer of the ion exchanger The arrangement due to the hydrophobic interaction between the hydrophobic parts of the amphiphilic chain organic molecules having an ion exchange group existing in the sparse or inexpensive is sparse or indirect, There is no doubt that a monolayer or bilayer formed by arranging amphiphilic chain organic molecules having a hydrophobic portion in the portion by hydrophobic interaction between the hydrophobic portions is formed as the outermost layer.

When a monomolecular film or a bimolecular film is formed in water, the surface thereof has a structure in which hydrophilic groups are arranged at a high density, and the inside of the film has a structure in which hydrophobic parts are arranged by hydrophobic interaction. I take the. At this time, even when the hydrophilic group is an ion dissociable functional group such as a quaternary ammonium group, a phosphoric acid group, or a sulfonic acid group, the counter ion sometimes acts to cancel the charge. Therefore, the hydrophobic interaction overcomes the charge repulsion between ion-dissociative functional groups, enabling high-density arrangement of ion-dissociative hydrophilic groups, and in some cases, the two-dimensional close packing of ion-dissociative hydrophilic groups. It is thought that it also enables high density arrangement with close regularity. Since the ion-dissociative functional group has ion-exchange ability, a monolayer or bilayer consisting of an amphipathic chain organic molecule having an ion-dissociative functional group as a hydrophilic group itself has a molecular level. Is an ion exchanger having ion exchange groups arranged at a high density.

However, monolayers or bilayers of amphiphilic chain organic molecules have heretofore been studied as a model substance of a biological membrane, for example, the phenomena of movement of water, ions, and the like. Due to its low mechanical strength, it was not industrially used as a column packing for ion chromatography.

In the column packing material for ion chromatography of the present invention, the above-mentioned monomolecular film or bimolecular film is formed by coating an organic substance such as an ion-exchange resin or a synthetic organic adsorbent, an inorganic substance such as glass or metal, or an inorganic substance thereof. After being supported on the substrate of the composite, or further, after supporting the monolayer or the bilayer, the amphiphilic chain organic molecules constituting the monolayer or the bilayer are subjected to the hydrophobic interaction. In addition to the above, by having a hydrogen bond and / or covalent bond, to have a physical strength that can withstand industrial use, and,
By making such a monomolecular film or bilayer film the outermost layer, diffusion of ions to be treated into the filler is substantially eliminated, and ion exchange groups are densely and regularly arranged on the surface of the filler. Reduction of separation performance deterioration due to diffusion of treated ions into the packing material and migration between ion exchange groups,
High resolution ion chromatography can be realized.

In the present invention, the amphiphilic chain organic molecule is not particularly limited as long as it self-organizes in water to form a monomolecular film or a bimolecular film. An azobenzene compound having high density and regularity of hydrophobic interaction, as shown in the formula of Chemical formula 39, wherein n = 6 or more and m = 8 or more, and n =
8-16 and m = 10-16 are more preferable, and n = 8 and m = 10 are particularly preferable.].

[0065]

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The ion-exchange group is not particularly limited as long as it is an ion-dissociable functional group and has an ion-exchange ability. As the cation-exchange group, a sulfonic acid group (R-SO ₃ ^- H ⁺ ), carboxylic acid group (R-COO ^- H)
⁺ ), Phosphonic acid groups [RP (O) (O ⁻ H ⁺ ) ₂ ],
Phosphinic acid group [R-PH (O) (O ^- H ⁺ )], arsenite group (R-OAsO ^- H ⁺ ), phenoxide group (RC
₆ H ₄ O ⁻ H ⁺ ), and quaternary ammonium groups (RN ⁺ R ₁ R ₂ R ₃ ) and tertiary sulfonium groups (RS ⁺ R ₁ R ₂ ) as anion exchange groups. And primary to primary tertiary amino groups can be suitably used. These ion exchange groups are bound to at least one end of the amphiphilic chain organic molecule. Generally, an amphipathic chain substance having ion exchange groups at both molecular ends forms a monomolecular film, and an amphipathic chain substance having an ion exchange group at one end of the molecule forms a bilayer film. In the present invention, whether the membrane formed by the amphiphilic chain organic molecule is a monolayer or a bilayer, the ion chromatography in the form of an ion exchanger having a high surface charge density is intended. Column packing material can be obtained.

The substrate for supporting a monomolecular film or a bimolecular film can be selected from materials and shapes depending on the purpose. The substrate is not limited to a specific substrate. An organic substance such as an exchange resin, an organic fiber, or a synthetic organic adsorbent, an inorganic substance such as glass or metal, or a composite thereof can be used.

[0068]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described focusing on a method for producing a column packing for ion chromatography of the present invention, but the present invention is not limited thereto.

One method for supporting a monolayer or bilayer on a substrate as described above is to coat the surface of the substrate with a thin film of a polymer electrolyte and then to support the monolayer or bilayer by ionic bonding. There is a way to make it happen. That is, for example, after coating the surface of the substrate with a thin film of a polymer electrolyte such as polyethyleneimine or polystyrenesulfonic acid alone or alternately, disperse the amphiphilic chain organic molecules in water in which the coated substrate is immersed. A monomolecular film or a bimolecular film is supported on the coated substrate by ionic bonding to obtain a column packing for ion chromatography.

On the other hand, when the substrate itself has an ion-exchange group, the substrate may be coated with the above-mentioned polymer electrolyte thin film, but is not always necessary. That is, amphiphilic chain organic molecules are dispersed in water in which a substrate having an ion-exchange group is immersed, and a monolayer or a bilayer is supported on the substrate by ionic bonding. A method for obtaining an agent can be used. Some examples of such a substrate include general-purpose ion exchange resins such as spherical or particulate ion exchange resin particles, ion exchange membranes and ion exchange fibers.

As a substrate for supporting a monomolecular film or a bimolecular film, it is preferable to use general-purpose ion exchange resins. In this case, the monomolecular film or the bimolecular film is supported on the ion exchange resin by an ionic bond formed between the ion exchange group of the monomolecular film and the ion exchange group of the ion exchange resin serving as the substrate. As described above, the surface of a conventional ion exchange resin does not have a structure in which ion exchange groups are densely arranged at a molecular level. For this reason, all ion exchange groups on the surface of the monomolecular membrane or the bimolecular membrane on the side bound to the ion exchange resin do not participate in ionic bonding.
Some of the ion-exchange groups of the monomolecular or bilayer membrane form ionic bonds with the ion-exchange groups of the ion-exchange resin serving as the substrate, forming an anchor, and the hydrophobic part of the amphiphilic chain organic molecule is hydrophobic. By arranging by a sexual interaction, a monomolecular film or a bimolecular film is formed on the surface of the ion-exchange resin serving as a substrate, and it is possible to obtain an ion chromatography column packing material having physical strength that can withstand industrial use. it can.

As a general-purpose ion exchange resin serving as a substrate
Is the monolayer or bilayer of the monolayer or bilayer to be supported.
Resin having ion-exchange group with polarity opposite to on-exchange group
Is selected. That is, the monolayer or bilayer is a sulfo
Acid groups (R-SO₃ ⁻H⁺), Carboxylic acid group (R-CO
O⁻H⁺), A phosphonic acid group [RP (O) (O⁻H⁺)
₂], A phosphinic acid group [R-PH (O) (O
⁻H⁺)], Arsenite group (R-OAsO)⁻H⁺), Feno
Oxide group (RC₆H₄O⁻H⁺Cation exchange
When it has a group, the ion exchange resin serving as the substrate is
An ion exchange resin is used.
The molecular film is made of a quaternary ammonium group (RN⁺R₁R
₂R ₃), Tertiary sulfonium group (RS⁺R
₁R₂), An anion exchange group such as a primary to primary amino group
If it does, the ion exchange resin used as the substrate should be positive
An on-exchange resin is used. General-purpose ion exchange as a base
The exchange resin is the reverse of the ion exchange groups on the monolayer or bilayer.
If the ion exchange resin has a polar ion exchange group,
The shape and brand are not particularly limited.

In the method using an ion exchange resin as a substrate, the shape may be selected from spherical, particulate, flake, film, fibrous, etc. according to the purpose, and the brand may be appropriately selected according to the purpose. Should be selected. Examples of the anion exchange resin include Amberlite IRA400, IRA402BL and IRA402 manufactured by Rohm and Haas Company.
900 as a cation exchange resin, for example, Amberlite IR120 manufactured by Rohm and Haas
B, IR124, and CT200 can be suitably used.

Further, when an organic substance such as a synthetic organic adsorbent or an organic fiber, an inorganic substance such as glass or metal, or a composite thereof is used as a base, a monomolecular film or a bimolecular film for supporting the monomolecular film or the bimolecular film is used. Is a method in which an amphipathic chain organic molecule is covalently bonded to the substrate surface. For example, a weakly basic ion-exchange resin having a primary amino group (a kind of synthetic organic adsorbent) is reacted with an amphiphilic chain organic molecule having a carboxyl group, and both are reacted via an amide group formed. After the substrate surface is modified with an amphiphilic chain organic molecule by covalent bonding, the amphiphilic chain organic molecule is dispersed in water in which the surface-modified substrate is immersed to form a monomolecular film or a bilayer on the substrate. A method of forming and supporting a molecular membrane, or a method in which a weakly basic ion exchange resin having a tertiary amino group and an amphiphilic chain organic molecule having a halogen atom are covalently bonded by a quaternization reaction to form a substrate. After modifying the surface with an amphiphilic chain organic molecule, disperse the amphiphilic chain organic molecule in water in which the surface-modified substrate is immersed to form and support a monolayer or bilayer on the substrate. Is mentioned.

As still another method for supporting a monomolecular film or a bimolecular film on a substrate, the surface of an organic material such as a synthetic organic adsorbent or an organic fiber or an inorganic material such as glass or metal serving as a substrate may be treated. After coating with gold and / or silver, the sulfur-containing amphiphilic chain organic molecules are dispersed in the water in which the coated substrate is immersed to form a bond between gold and / or silver and sulfur on the coated substrate. There is a method of supporting a monomolecular film or a bimolecular film by the method [for the bond of gold and / or silver and sulfur,
For example, Kuniyoshi Aramaki, "Prevention of Copper Corrosion by Self-Assembled Film", Surface, Vol. 36, no. 5 (1998), and Toshihiro Kondo, Kohei Uozaki, "Utilization of Gold-Sulfur Bond:
Self-Assembled Monolayer (SAM) ", Chemistry and Industry, No. 52
Vol. 7, No. 7 (1999)]. In this method, as a substrate for supporting a monomolecular film or a bimolecular film, its material, shape and the like can be selected according to the purpose, and it is not limited to a specific substrate. 0.
Spherical glass beads having a size of 2 to 1 mm are inexpensive and suitable for packing a column packing material for ion chromatography to be produced, which is preferable. The method of coating such a substrate with gold and / or silver is not particularly limited as long as the manufactured column packing for ion chromatography has a physical strength that can withstand industrial use. Method, a vacuum evaporation method, or the like can be used. The amphiphilic chain organic molecule containing a sulfur atom to be supported on a substrate coated with gold and / or silver is not particularly limited as long as the sulfur atom can easily form a bond with gold and / or silver. However, for example, for example,
A halogen salt of bis (11-trimethylammonioundecanoylaminoethyl) disulfide as shown in the formula of "0" can be suitably used. In addition, although platinum, copper, etc. can be used as a coating material, the above-mentioned gold and / or silver are preferable in terms of cost and oxidation resistance.

[0076]

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Further, a method is employed in which the substrate is irradiated with radiation such as γ-rays or accelerated electron beams to generate radicals, and amphiphilic chain organic molecules are introduced into the surface of the substrate by utilizing a radical reaction. (Japanese Patent Application No. 2000-23407).
In this case, as a substrate that can be used, for example, metal oxides such as silica, alumina, titania, zirconia, and zeolite whose surface is modified with a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, or the like. Surface-modified inorganic compounds having an organic group introduced on the surface thereof, such as clay minerals such as mica, talc, and montmorillonite; and inorganic carbon materials such as activated carbon and carbon fiber; and olefins such as polyethylene and polypropylene. Copolymers, copolymers of olefins, various organic high molecular compounds including olefin polymers such as copolymers of olefins and other polymerizable monomers, and Examples of amphiphilic chain organic molecules that can be used include:
For example, as a functional group having reactivity with a radical, a thiol group, a disulfide group, a dithiocarbamate group, a halogenated carbon group (a group containing at least one halogen-carbon bond), a nitroxyl group, an ethylene group, a styryl group, Groups containing unsaturated double bonds such as α, β-unsaturated carbonyl groups, groups containing conjugated double bonds such as polyene such as butadiene, and groups containing unsaturated triple bonds such as acetylene and diacetylene And the like, and specific examples thereof include “chemical formula 23” to “chemical formula 28” and “chemical formula 36”.
Amphiphiles having a fluorocarbon group represented by the formula: or parents containing a disulfide group such as a halogen salt of bis- (11-trimethylammonioundecanoylaminoethyl) disulfide represented by the formula: Medium substances.

In order to further improve the physical strength of the monolayer or the bilayer supported on the substrate, the amphiphilic chain organic molecules constituting the monolayer or the bilayer are separated by the hydrophobic part by the hydrophobic part. In addition to the interaction, it is preferred that they are further bonded by hydrogen bonds and / or covalent bonds.

As the group or bond capable of forming a hydrogen bond by being contained in an amphiphilic chain organic molecule, an amide group, a urea bond, a urethane bond or the like can be used. The bis (11-trimethylammonioundecanoylaminoethyl) disulfide halogen salt is an example in which an amide group forms a hydrogen bond between molecules to improve the physical strength of a column packing for ion chromatography.

On the other hand, to form a covalent bond, a group containing an unsaturated double bond such as an ethylene group, a styryl group, an α, β-unsaturated carbonyl group or a conjugated double bond such as a polyene such as butadiene is used. A group containing at least one unsaturated triple bond such as acetylene, diacetylene or the like is introduced into a part of the amphiphilic chain organic molecule, and heating and / or irradiation of light or radiation and / or Addition of a radical initiator is performed to form a covalent bond.

The site for introducing the functional group for forming these bonds is not particularly limited, but in order to further increase the physical strength of the monolayer or bilayer, a site as close as possible to the site for bonding to the substrate is used. Preferably it is introduced.

As described above, in a monomolecular film or a bimolecular film formed by amphiphilic chain organic molecules, on the surface thereof, ion-exchange groups have a highly regular high-density arrangement close to two-dimensional close packing. In this case, a hydrophobic layer in which the hydrophobic portions of the amphiphilic chain organic molecules are arranged by hydrophobic interaction is formed. The column packing for ion chromatography according to the present invention has a monolayer or a bilayer formed of an amphipathic chain substance on the surface of the packing, so that the outermost layer is only one-dimensional on a molecular level. It consists of an ion-exchange base layer with a high degree of regularity close to close packing and a highly hydrophobic layer in which the hydrophobic part of the amphiphilic chain organic molecule is arranged by hydrophobic interaction. are doing. Therefore, in the column packing for ion chromatography of the present invention, the ions to be treated are:
It is adsorbed only on the outermost layer of the packing material and does not substantially diffuse into the packing material due to the hydrophobic layer existing immediately below the ion-exchange base layer, so that the separation performance of ion chromatography is not reduced. Furthermore, during the development with the eluent, the ions to be treated move on the two-dimensionally arranged ion exchange base layer with high regularity while repeating generation and dissociation of ionic bonds. High-resolution ion chromatography is achieved by eliminating the migration of ions to be treated between ion-exchange groups that are located at a certain distance apart, which was one of the factors contributing to the reduction in separation performance of column packing for ion chromatography. can do.

[0083]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. L represents liter. Also, in FIG. 1 and FIG.
"-R" indicates the number of liters of the eluent flowing per liter of column packing material, and "normalized concentration" means that the component concentration (C) in the eluate is divided by the component concentration (C0) in the stock solution. This is the standardized concentration.

Production Example 1 In this production example, p- (10- (4
It is a production example of an ion exchanger in which a bimolecular membrane of -sulfophenoxy) decyloxy) -p'-octyloxyazobenzene is supported via ionic bonds. In Example 1 below, this ion exchanger was used as a cation exchanger.

[1] Preparation of sodium salt of p- (10- (4-sulfophenoxy) decyloxy) -p'-octyloxyazobenzene The above compound was prepared in the following four steps 1) to 4). Was.

1) Production of p-octyloxyaniline hydrochloride Potassium hydroxide (purity: 85%) 29 was placed in a 100 L reactor.
After adding 50 mol of ethanol and 50 L of ethanol and dissolving uniformly, 27 mol of p-acetylaminophenol and 27 mol of octyl bromide were added, and the mixture was reacted with heating under reflux for 8 hours. After cooling to room temperature, the precipitated potassium bromide was filtered off.
15 L of 5% concentrated hydrochloric acid was added, and the mixture was reacted for 9 hours under reflux. The resulting solution was concentrated and cooled to room temperature, and the resulting crystals were filtered off and recrystallized from ethyl acetate. The yield is
53%.

2) Production of p- (octyloxy) -p'-hydroxyazobenzene In a 300 L reactor, 14 mol of p-octyloxyaniline hydrochloride, 50 L of acetone, 50 L of water, 35% concentrated hydrochloric acid 3
After 0 mol was added and uniformly dissolved, the mixture was cooled to 5 ° C. or lower. 15 mol of sodium nitrite and 10 L of water are added to this solution.
Aqueous sodium nitrite solution was gradually added. Separately, 15 mol of potassium hydroxide (purity: 85%) and 15 mol of potassium carbonate were made into an aqueous solution, 15 mol of phenol was dissolved, cooled to 5 ° C. or lower, and gradually added to the previously obtained solution. After stirring at 10 ° C. or lower for 4 hours, the pH was adjusted to 3 with concentrated hydrochloric acid, the resulting solid was separated by filtration, washed sufficiently with water, and recrystallized from benzene. The yield was 70%.

3) p- (10-bromodecyloxy)-
Production of p'-octyloxyazobenzene Potassium hydroxide (85% purity) in a 100 L reactor
Then, 40 mol of ethanol and ethanol were added and uniformly dissolved, and then 9 mol of p- (octyloxy) -p'-hydroxyazobenzene and 46 mol of dibromodecane were added, and the mixture was reacted under heating and reflux for 6 hours. After cooling to room temperature, the precipitated solid was separated by filtration, washed with hexane and then with water. In order to purify the obtained solid, it was recrystallized from a benzene-ethanol (1: 1 by volume) mixed solvent. The yield was 70%.

4) Production of a sodium salt of p- (10- (4-sulfophenoxy) decyloxy) -p'-octyloxyazobenzene 600 mmol of potassium hydroxide (purity: 85%) was dissolved in ethanol. 550 mmol of (10-bromodecyloxy) -p'-octyloxyazobenzene and 550 mmol of sodium salt of p-phenolsulfonic acid were added, and the mixture was reacted under heating and refluxing for 8 hours. After cooling to room temperature, the precipitated solid was separated by filtration, washed with hexane, and further recrystallized from a mixed solvent of benzene and ethanol (volume ratio: 1: 1). The yield was 63%.

[2] Production of ion exchanger 200 mmol of the sodium salt of p- (10- (4-sulfophenoxy) decyloxy) -p'-octyloxyazobenzene produced as described above was dispersed in 20 L of water. Next, 100 g (dry weight) of Amberlite IRA402BL, which is a strong basic anion exchange resin, is immersed in this dispersion for 20 minutes, filtered, washed with water, and p- (10-
An ion exchanger having a bilayer formed of (4-sulfophenoxy) decyloxy) -p'-octyloxyazobenzene as the outermost layer was obtained.

Example 1 Separation and purification of a rare earth metal were carried out using a column packing for ion chromatography having a bilayer membrane made of an amphiphilic chain substance as the outermost layer prepared as in Production Example 1. .
A column having an inner diameter of 20 mmφ was packed with the ion exchanger prepared in Production Example 1 at a bed height of 478 mm (filler wet volume 150 ml) as a column filler. 1N hydrochloric acid was passed through to make the filler H-form.
Converted to ²⁺ form. Subsequently, pH was adjusted with hydrochloric acid containing rare earth metals gadolinium and samarium (molar ratio 1: 1).
1.5% 1% (total weight% of gadolinium + samarium)
After passing 15 ml of the aqueous solution to adsorb the rare earth metal ions, the eluent [pH
8.5 of 0.5% aqueous solution of ethylenediaminetetraacetic acid (EDTA) ammonium salt] was passed through at SV = 1 to separate and purify gadolinium and samarium to obtain an elution diagram showing the elution curve of FIG. FIG. 1 demonstrates that rare earth metals (gadolinium and samarium) can be well separated and purified by the column packing for ion chromatography of the present invention.

Comparative Example 1 For comparison with Example 1, a rare earth metal (gadolinium and samarium) was prepared under the same conditions as in Example 1 except that Amberlite IR120B was used as a column packing for ion chromatography. Separation and purification were performed to obtain an elution diagram showing the elution curve of FIG. When the elution diagram of FIG. 2 is compared with the elution diagram of Example 1 shown in FIG. 1, it can be seen that only low separation performance was obtained in this comparative example.

[0093]

According to the present invention, there is provided a column packing for ion chromatography having a monolayer or a bilayer having an array of amphiphilic chain organic molecules as the outermost layer.
If this column packing is used, the monolayer or bilayer is made the outermost layer to substantially eliminate the diffusion of ions to be treated into the packing and to arrange ion exchange groups densely and regularly. The reduced surface of the filler can reduce the degradation of separation performance due to the diffusion of ions to be treated into the interior of the filler and migration between ion-exchange groups, thereby realizing high-resolution ion chromatography.

The column packing material for ion chromatography of the present invention includes a simulated moving bed chromatograph having three or more components having an ion chromatography analyzer, a batch type preparative chromatographic separator, a simulated moving bed chromatograph, and a shut-off valve. It can be used by filling it into columns of various chromatographic devices such as a separation device.

[Brief description of the drawings]

FIG. 1 is an elution diagram showing an elution curve in Example 1 of the present invention.

FIG. 2 is an elution diagram showing an elution curve in Comparative Example 1.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kohei Sato 1-2-8 Shinsuna, Koto-ku, Tokyo Organo Corporation F-term (reference) 4D017 AA01 AA03 AA11 AA13 BA03 BA13 CA14 CA17 CB01 DA03 DB02 4F071 AA69 AH02 FA03 FC01 FC02 4G066 AB05B AB09B AB15B AB19B AB21B AE04B AE05B AE10B AE19C BA50 DA07 EA01 FA12

Claims (1)

[Claims] Claims 1. At least one end has an ion exchange group,
In addition, a monomolecular film or a bimolecular film, in which amphiphilic chain organic molecules having a hydrophobic portion in a portion other than the ion exchange group are arranged by hydrophobic interaction between the hydrophobic portions, is formed on the substrate as a top layer. A column packing for ion chromatography, characterized in that it has: