CA1287442C - High performance anion-exchange chromatographic packing composition - Google Patents
High performance anion-exchange chromatographic packing compositionInfo
- Publication number
- CA1287442C CA1287442C CA000518912A CA518912A CA1287442C CA 1287442 C CA1287442 C CA 1287442C CA 000518912 A CA000518912 A CA 000518912A CA 518912 A CA518912 A CA 518912A CA 1287442 C CA1287442 C CA 1287442C
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- CA
- Canada
- Prior art keywords
- particles
- anion
- exchange
- liquid coating
- sites
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Treatment Of Liquids With Adsorbents In General (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
ABSTRACT
A anion-exchange chromatographic packing composition which comprises;
a substrate which comprises insoluble synthetic resinous particles of a low porosity gel type having cation-exchanging sites at least on their available surfaces, the particles having a diameter of from 1 to 75 microns; and a liquid coating which comprises a hydrophilic, water soluble, film forming aminated resin having anion-exchanging sites which attract available cation-exchanging sites of the substrate, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the substrate particles. The invention further includes a chromatographic column and process using the described packing composition.
A anion-exchange chromatographic packing composition which comprises;
a substrate which comprises insoluble synthetic resinous particles of a low porosity gel type having cation-exchanging sites at least on their available surfaces, the particles having a diameter of from 1 to 75 microns; and a liquid coating which comprises a hydrophilic, water soluble, film forming aminated resin having anion-exchanging sites which attract available cation-exchanging sites of the substrate, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the substrate particles. The invention further includes a chromatographic column and process using the described packing composition.
Description
1287~'iZ
HI GH PERFORMANOE: ANION--EXCHANGE - - -CHROMATOGRAPHIC PACKING COMPOSITION
The invention relates to a high performance anion-exchange chromatographic packing composition.
More particularly, the invention resides in an anion-exchanging packing composition comprising a hydro-philic, water soluble, film forming resin. The resinhas anion-exchanging sites which attract the available sites of its substrate particles and thereby form a liquid coating on the available surfaces of the particles.
Since the inception of ion chromatography (U.S. Patent 3,920,397), the basic technology for the anion-exchanger used in the analytical column for .anion determination has not changed. Solid microparticles of anion-exchanger are agglomerated with macroparticles of surface sulfonated or fully sulfonated styrene divinyl-benzene copolymer to produce a low capacity "pellicular type" anion-exchanger (U.S. Patent 4,101,460).
Improvements within this basic technology came with the use of monodisperse anion-exchange latex rather 29,607-F -l-.
- ...
.
12l~ 2 than the previously used ground anion-exchange resins (as described in the '460 patent), and by performing an agglomeration step in a polyvalent salt solution (U.S.
Patent 4,119,580). The use of monodisperse anion--exchange latex eliminated the problem of refining ground ion-exchange resin to obtain the desired size range, while agglomerating in a polyvalent salt solution resulted in a reproducible and dense deposition of microparticles due to the resulting suppression of the anionic repulsion forces between the microparticles.
A further improvement is disclosed in U.S.
Patent 4,383,047 wherein the use of smaller diameter latex microparticles is described. Anion-exchangers of this type achieve a performance level in which baseline separation of fluoride, chloride, nitrite, phosphate, bromide, nitrate, and sulfa~e ions is completed in about 6 minutes (illustrated by the chromatogram in Fi~ure 3 of the '047 patent).
Throughout these developments in the technology the packing compositions have been limited to eluent insoluble resins for both the agglomerated and substrate components. There has not been any suggestion that other types of components could be useful or practicable.
The invention particularly resides in a chromatographic analytical column containing an anion--exchange chromatographic packing comprising:
3o a substrate of insoluble synthetic resinous particles of a low porosity gel type having cation--exchange sites at least on their available surfaces, 29,607-F -2-,. . .
3L28~ 2 the particles having a diameter of from l to 75 microns, and a chromatographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the liquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion-exchange sites which attract available cation-exchange sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles.
The invention also resides in a process for chromatographic separation of diverse anions comprising the steps of:
passing a liquid solution comprising the anions through a bed of insoluble synthetic resin particles of a low porosity gel type having cation-exchanging sites at least on their available surfaces, the particles having a diameter of from l to 75 microns, and a chromatographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the llquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion--exchanging sites which attract available cation--exchanging sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles, and wherein anion--exchanging sites at least on the surface of the liquid coating attract at least one o said anions; and eluting the bed with an eluent which differen-tially removes the attracted anions from the bed.
29,607-F -3----` 12~74~
-3a-Figure 1 reproduces an actual chromatogram developed by the high performance packing composition of one embodiment of this invention.
According to the present invention substrate particles, typically resin beads, serve to firmly retain a liquid coating which includes active anion-exchange 29,607-F -3a-sites used for chromatographic separation. Each substrate particle is insoluble in the solvent systems used for separation~ They are s~itably formed of resin beads, preferably substantially spherical in shape, of from 1 to 7~ microns in diameter, preferably from 3 to 20 microns. Highly preferred for use in the invention are particles having a~diam-eter from 4 to 10 microns.
Suitable compositions for the substrate particles are well kno~m in the a:rt and are discussed in detail in U. S. Patent 4,351,909 and in U. S. Patent 4,383,047. In the present invention, the particles may be `'macroporous" as described in the '909 patent, resulting in chromatographic columns having higher capacities but longer analysis times r or the particles preferably may be of low porosity, as described in the '047 patent, to yield columns having shorter analysis times. Particles having low porosity are known in the art as gel type resins and are exemplified by the DOWEX~
50W ion-exchange resins. As in both of the references cited, the substrate particles preferably are mono-disperse with respect to their diameters.
Due to the nature of the electro-static bonds which form with the liquid coating, the available surfaces of the substrate particles preferably are relatively "hard" rather than swollen. This means that substrate particles of the gel type resins should have a relatively high degree of crosslinking. Good results have been achieved with crosslinking of about 35 percen~ wi-thin the particles.
Glass or silica beads, also known in the art as suitable substrate particles, provide the "hard"
surfaces of the preferred particles. Basic eluents, 29,607-F -4-~ 2 ~3 7 ~ ~ 2 . .
however, have been found to remQve the liquid coating on glass beads. In practicing the invention, therefore, glass beads may be used for the substrate except where a basic eluent, having a pH of about 8 or more, will be used with the packing composition, in which case a synthetic resin is preferred.
Among suitable materials for the anion-exchange - liquid coating are the well known water sol~ble-aminated poly(vinylaromatic) resins such as the quaternary ammonium electroconductive resins discussed in detail in U.S.
Patent 3,887,496 (in particular, at column 2, lines 34-47). Preferred for use are poly(vinylaromatic) resins having anion-exchanging sites substantially throughout the entirety of a majority of the polymer chains. The anion-exchanging sites may be either strong base, generally quaternary ammonium unctional groups, or weak base, general}y tertiary, secondary and primary amine functional groups.
Column Preparation ~0 Columns usin~ the packing compositions of the invention are desirably prepared by first efficiently packing the column with the substrate particles, and then adding a solution of the liquid coating resin using an in situ coating method. The amount of resin which coats onto the substrate particles b~ electrostatic attraction is self-limiting and the excess resin will wash out of the column.
To assure a proper bonding between the substrate and the liquid coating, the substrate particles should not contact any surfactants or other agents which could interfere with the electrostatic attraction between the coating and substrate particles. The particles should 29,607-F -5-~2~3~4 ~2 be thoroughly cleansed of any such surfactant or agent if contact cannot be avoided.
The invention, in its broadest sense, additionally embrac~s alternative methods for preparing the packed column or packing composition described.
- Such alternate methoGs are disclosed in U.S. Patent 4,119,580 and U.S. Patent 4,101,460 wherein the substrate particles are added to a solution of the liquid coating resin in an aqueous solution of a polyvalent salt, followed by a conventional column packing procedure using the precoated packing resulting from this preparation.
The anion-exchange compositions o~ the present invention have been found to be stable. The liquid coating is irreversibly attached to the available surfaces of the substrate particles such that a substantial amount o the coating will not be displaced by eluents normally used in the art, such as electrolyte solutions of 0.1 M or less. Shearing forces, such as those encountered when a liquid passes through an ion-exchange bed at elevated flow rates, also will not displace a substantial amount of the li~uid coating.
Chromatoqraphic Conditions The following chromatographic conditions were used to evaluate the packed chromatographic column described in the example, below.
Column: 9 x 2~2 mm, 10-20~l DOWEX~
50W X 35 treated with guaternized polystyrene Eluent: 0.0024 molar Na CO3 0.003 molar NaH~O3 29,607-F -6-.
~28~
-~ 7 Flow Rate: 138 ml/hour Stripper Column: 2.8 x 300 mm DOWEX~ 50W X 16, H form resin 200-40~ mesh Injection Volume: 50 microliter loop Detection: conductivity at 7.5~ Mho cm 1 full scale deflection Sample Standard The following seven ion standards were used as a 4X dilution:
F 3.3 ppm Cl- 4 ppm NO2_ 10 ppm P04~3 54 ppm Br 10 ppm N03- 34 ppm so4 50 ppm The above conditions and standard solutions are widely used for the evaluation of ion chromatographic an~ytical columns (see U.S. Patent 4,119,580).
Example To compare the performance of one embodiment of the present invention to that of columns already known in the art, a "suction packed" column was prepared 29,607-F -7-7~2 with the substrate as described above on which a water soluble aminated polystyrene resin was coated. The packins method used is described in det~il in U. S.
Patent 4,383,047.
An actual chromatogram which resulted from the use of tne column of this example is reproduced in -' Figure 1. This Figure clearly indicates that the column achieved good separation of the components of the seven ion standard solutions within approximately seven minutes.
29,607-F -8-
HI GH PERFORMANOE: ANION--EXCHANGE - - -CHROMATOGRAPHIC PACKING COMPOSITION
The invention relates to a high performance anion-exchange chromatographic packing composition.
More particularly, the invention resides in an anion-exchanging packing composition comprising a hydro-philic, water soluble, film forming resin. The resinhas anion-exchanging sites which attract the available sites of its substrate particles and thereby form a liquid coating on the available surfaces of the particles.
Since the inception of ion chromatography (U.S. Patent 3,920,397), the basic technology for the anion-exchanger used in the analytical column for .anion determination has not changed. Solid microparticles of anion-exchanger are agglomerated with macroparticles of surface sulfonated or fully sulfonated styrene divinyl-benzene copolymer to produce a low capacity "pellicular type" anion-exchanger (U.S. Patent 4,101,460).
Improvements within this basic technology came with the use of monodisperse anion-exchange latex rather 29,607-F -l-.
- ...
.
12l~ 2 than the previously used ground anion-exchange resins (as described in the '460 patent), and by performing an agglomeration step in a polyvalent salt solution (U.S.
Patent 4,119,580). The use of monodisperse anion--exchange latex eliminated the problem of refining ground ion-exchange resin to obtain the desired size range, while agglomerating in a polyvalent salt solution resulted in a reproducible and dense deposition of microparticles due to the resulting suppression of the anionic repulsion forces between the microparticles.
A further improvement is disclosed in U.S.
Patent 4,383,047 wherein the use of smaller diameter latex microparticles is described. Anion-exchangers of this type achieve a performance level in which baseline separation of fluoride, chloride, nitrite, phosphate, bromide, nitrate, and sulfa~e ions is completed in about 6 minutes (illustrated by the chromatogram in Fi~ure 3 of the '047 patent).
Throughout these developments in the technology the packing compositions have been limited to eluent insoluble resins for both the agglomerated and substrate components. There has not been any suggestion that other types of components could be useful or practicable.
The invention particularly resides in a chromatographic analytical column containing an anion--exchange chromatographic packing comprising:
3o a substrate of insoluble synthetic resinous particles of a low porosity gel type having cation--exchange sites at least on their available surfaces, 29,607-F -2-,. . .
3L28~ 2 the particles having a diameter of from l to 75 microns, and a chromatographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the liquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion-exchange sites which attract available cation-exchange sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles.
The invention also resides in a process for chromatographic separation of diverse anions comprising the steps of:
passing a liquid solution comprising the anions through a bed of insoluble synthetic resin particles of a low porosity gel type having cation-exchanging sites at least on their available surfaces, the particles having a diameter of from l to 75 microns, and a chromatographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the llquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion--exchanging sites which attract available cation--exchanging sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles, and wherein anion--exchanging sites at least on the surface of the liquid coating attract at least one o said anions; and eluting the bed with an eluent which differen-tially removes the attracted anions from the bed.
29,607-F -3----` 12~74~
-3a-Figure 1 reproduces an actual chromatogram developed by the high performance packing composition of one embodiment of this invention.
According to the present invention substrate particles, typically resin beads, serve to firmly retain a liquid coating which includes active anion-exchange 29,607-F -3a-sites used for chromatographic separation. Each substrate particle is insoluble in the solvent systems used for separation~ They are s~itably formed of resin beads, preferably substantially spherical in shape, of from 1 to 7~ microns in diameter, preferably from 3 to 20 microns. Highly preferred for use in the invention are particles having a~diam-eter from 4 to 10 microns.
Suitable compositions for the substrate particles are well kno~m in the a:rt and are discussed in detail in U. S. Patent 4,351,909 and in U. S. Patent 4,383,047. In the present invention, the particles may be `'macroporous" as described in the '909 patent, resulting in chromatographic columns having higher capacities but longer analysis times r or the particles preferably may be of low porosity, as described in the '047 patent, to yield columns having shorter analysis times. Particles having low porosity are known in the art as gel type resins and are exemplified by the DOWEX~
50W ion-exchange resins. As in both of the references cited, the substrate particles preferably are mono-disperse with respect to their diameters.
Due to the nature of the electro-static bonds which form with the liquid coating, the available surfaces of the substrate particles preferably are relatively "hard" rather than swollen. This means that substrate particles of the gel type resins should have a relatively high degree of crosslinking. Good results have been achieved with crosslinking of about 35 percen~ wi-thin the particles.
Glass or silica beads, also known in the art as suitable substrate particles, provide the "hard"
surfaces of the preferred particles. Basic eluents, 29,607-F -4-~ 2 ~3 7 ~ ~ 2 . .
however, have been found to remQve the liquid coating on glass beads. In practicing the invention, therefore, glass beads may be used for the substrate except where a basic eluent, having a pH of about 8 or more, will be used with the packing composition, in which case a synthetic resin is preferred.
Among suitable materials for the anion-exchange - liquid coating are the well known water sol~ble-aminated poly(vinylaromatic) resins such as the quaternary ammonium electroconductive resins discussed in detail in U.S.
Patent 3,887,496 (in particular, at column 2, lines 34-47). Preferred for use are poly(vinylaromatic) resins having anion-exchanging sites substantially throughout the entirety of a majority of the polymer chains. The anion-exchanging sites may be either strong base, generally quaternary ammonium unctional groups, or weak base, general}y tertiary, secondary and primary amine functional groups.
Column Preparation ~0 Columns usin~ the packing compositions of the invention are desirably prepared by first efficiently packing the column with the substrate particles, and then adding a solution of the liquid coating resin using an in situ coating method. The amount of resin which coats onto the substrate particles b~ electrostatic attraction is self-limiting and the excess resin will wash out of the column.
To assure a proper bonding between the substrate and the liquid coating, the substrate particles should not contact any surfactants or other agents which could interfere with the electrostatic attraction between the coating and substrate particles. The particles should 29,607-F -5-~2~3~4 ~2 be thoroughly cleansed of any such surfactant or agent if contact cannot be avoided.
The invention, in its broadest sense, additionally embrac~s alternative methods for preparing the packed column or packing composition described.
- Such alternate methoGs are disclosed in U.S. Patent 4,119,580 and U.S. Patent 4,101,460 wherein the substrate particles are added to a solution of the liquid coating resin in an aqueous solution of a polyvalent salt, followed by a conventional column packing procedure using the precoated packing resulting from this preparation.
The anion-exchange compositions o~ the present invention have been found to be stable. The liquid coating is irreversibly attached to the available surfaces of the substrate particles such that a substantial amount o the coating will not be displaced by eluents normally used in the art, such as electrolyte solutions of 0.1 M or less. Shearing forces, such as those encountered when a liquid passes through an ion-exchange bed at elevated flow rates, also will not displace a substantial amount of the li~uid coating.
Chromatoqraphic Conditions The following chromatographic conditions were used to evaluate the packed chromatographic column described in the example, below.
Column: 9 x 2~2 mm, 10-20~l DOWEX~
50W X 35 treated with guaternized polystyrene Eluent: 0.0024 molar Na CO3 0.003 molar NaH~O3 29,607-F -6-.
~28~
-~ 7 Flow Rate: 138 ml/hour Stripper Column: 2.8 x 300 mm DOWEX~ 50W X 16, H form resin 200-40~ mesh Injection Volume: 50 microliter loop Detection: conductivity at 7.5~ Mho cm 1 full scale deflection Sample Standard The following seven ion standards were used as a 4X dilution:
F 3.3 ppm Cl- 4 ppm NO2_ 10 ppm P04~3 54 ppm Br 10 ppm N03- 34 ppm so4 50 ppm The above conditions and standard solutions are widely used for the evaluation of ion chromatographic an~ytical columns (see U.S. Patent 4,119,580).
Example To compare the performance of one embodiment of the present invention to that of columns already known in the art, a "suction packed" column was prepared 29,607-F -7-7~2 with the substrate as described above on which a water soluble aminated polystyrene resin was coated. The packins method used is described in det~il in U. S.
Patent 4,383,047.
An actual chromatogram which resulted from the use of tne column of this example is reproduced in -' Figure 1. This Figure clearly indicates that the column achieved good separation of the components of the seven ion standard solutions within approximately seven minutes.
29,607-F -8-
Claims (8)
1. A chromatographic analytical column containing an anion-exchange chromatographic packing comprising:
a substrate of insoluble synthetic resinous particles of a low porosity gel type having cation--exchange sites at least on their available surfaces, the particles having a diameter of from 1 to 75 microns, and a chromatographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the liquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion-exchange sites which attract avail-able cation-exchange sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles.
a substrate of insoluble synthetic resinous particles of a low porosity gel type having cation--exchange sites at least on their available surfaces, the particles having a diameter of from 1 to 75 microns, and a chromatographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the liquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion-exchange sites which attract avail-able cation-exchange sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles.
2. The packed column of Claim 1, wherein said particles have a diameter from 3 to 20 microns.
3. The packed column of Claim 1, wherein said particles have a diameter of from 4 to 10 microns.
29,607-F -9-
29,607-F -9-
4. The packed column of Claim 1, 2 or 3, wherein the particles are monodisperse.
5. The packed column of Claim 1, wherein said liquid coating is a aminated poly(vinylaromatic) resin.
6. A process for chromatographic separation of diverse anions comprising the steps of:
passing a liquid solution comprising the anions through a bed of insoluble synthetic resin particles of a low porosity gel type having cation-exchanging sites at least on their available surfaces, the particles having a diameter of from 1 to 75 microns, and a chroma-tographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the liquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion--exchanging sites which attract available cation--exchanging sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles, and wherein anion--exchanging sites at least on the surface of the liquid coating attract at least one of said anions; and eluting the bed with an eluent which differentially removes the attracted anions from the bed.
passing a liquid solution comprising the anions through a bed of insoluble synthetic resin particles of a low porosity gel type having cation-exchanging sites at least on their available surfaces, the particles having a diameter of from 1 to 75 microns, and a chroma-tographically active anion-exchange liquid coating irreversibly attached to the available surfaces of the particles, the liquid coating comprising a hydrophilic, water soluble, film forming aminated resin having anion--exchanging sites which attract available cation--exchanging sites on the particles, wherein the liquid coating is retained by electrostatic bonds on the available surfaces of the particles, and wherein anion--exchanging sites at least on the surface of the liquid coating attract at least one of said anions; and eluting the bed with an eluent which differentially removes the attracted anions from the bed.
7. The process of Claim 6, wherein the pH of the eluent is less than 8.
9,607-F -10-
9,607-F -10-
8. An ion-exchange process comprising the use of a hydrophilic, water soluble, film forming aminated resin having anion-exchange functional groups and an ion-exchange functional substrate which is an insoluble synthetic resinous particle of a low porosity gel type.
29,607-F -11-
29,607-F -11-
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000518912A CA1287442C (en) | 1983-05-02 | 1986-09-24 | High performance anion-exchange chromatographic packing composition |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US49026883A | 1983-05-02 | 1983-05-02 | |
| CA000518912A CA1287442C (en) | 1983-05-02 | 1986-09-24 | High performance anion-exchange chromatographic packing composition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1287442C true CA1287442C (en) | 1991-08-06 |
Family
ID=25671099
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000518912A Expired - Fee Related CA1287442C (en) | 1983-05-02 | 1986-09-24 | High performance anion-exchange chromatographic packing composition |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1287442C (en) |
-
1986
- 1986-09-24 CA CA000518912A patent/CA1287442C/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |