Glycidol functionalized anion exchange stationary phases
Treatment of anion exchange materials containing hydroxyl containing moieties in the beta position relative to the quaternary center in the hydroxide form with glycidol substantially alters the selectivity of the anion exchange material. Furthermore, sequential treatments of first a hydroxide containing solution to put the anion exchange material in the hydroxide form followed by treatment with glycidol in an alternating sequence progressively changes selectivity in a predictable manner allowing facile manipulation of selectivity. Unique to the selectivities achievable with this chemistry is the ability to reverse the elution order of sulfate and carbonate. With all other known systems, carbonate elutes ahead of sulfate and sometimes compromises the ability to quantitate sulfate. With glycidol treatment, carbonate can be moved after sulfate which eliminates interference issues for samples containing significantly more carbonate than sulfate. This modification is useful for columns operated with a hydroxide or carbonate eluent system.
1. An anion exchange chromatographic medium comprising a solid support having attached thereto an anion exchange moiety comprising a glycidol-derived ether having the formula:
wherein
R 1 is selected from substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl;
R 2 and R 3 are selected from H, substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl;
R 10 , R 11 and R 12 are members independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl and substituted or unsubstituted heterocylcoaryl, wherein at least one member selected from R 10 , R 11 and R 12 is or comprises a covalent bond to said solid support; and
X − is an organic or inorganic anion.
2. The anion exchange chromatographic medium according to claim 1 , wherein R 2 and R 3 are independently selected from H and
wherein R 4 and R 5 are independently selected from H, substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl.
3. The anion exchange chromatographic medium according to claim 2 , wherein R 4 and R 5 are independently selected from H and
wherein R 6 and R 7 are independently selected from H, substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl.
4. The anion exchange chromatographic medium according to claim 3 , wherein R 6 and R 7 are independently selected from H and
5. The anion exchange chromatographic medium according to claim 1 , wherein R 1 is:
wherein
m is 2, 3, 4, 5 or 6.
6. The anion exchange chromatographic medium according to claim 1 , wherein said support comprises a polymerized synthetic organic polymer.
7. The anion exchange chromatographic medium according to claim 6 , wherein said solid support is a resin.
8. An anion exchange chromatographic medium comprising a solid support having attached thereto an anion exchange moiety comprising a glycidol-derived ether having the formula:
wherein
R 1 is selected from substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl,
R 2 and R 3 are selected from H, substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl,
R 10 , R 11 and R 12 are members independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl and substituted or unsubstituted heterocylcoaryl, and
X − is an organic or inorganic anion, and
wherein at least one of R 10 , R 11 and R 12 comprises a moiety according to Formula VI:
wherein R 20 , R 21 , R 22 , R 23 and R 24 are independently selected from H and a glycidol-derived ether, with the proviso that at least one of R 20 , R 21 , R 22 , R 23 and R 24 is said glycidol-derived ether.
9. The anion exchange chromatographic medium according to claim 1 , wherein said solid support is a product of condensation polymerization.
10. The anion exchange chromatographic medium according to claim 9 , wherein said condensation polymerization is between an amine and a diepoxide.
11. The anion exchange chromatographic medium according to claim 1 in a flow-through bed suitable for use as a chromatographic device.
12. A chromatography column packed with the anion exchange chromatographic medium according to claim 1 .
13. A chromatographic method comprising flowing a liquid through a bed of separation medium comprising the composition of claim 1 .
14. The chromatographic method of claim 13 , wherein said liquid comprises anions, cations and uncharged molecules.
15. A method of separating analytes in a liquid sample comprising flowing said liquid sample through an anion exchange chromatographic medium comprising a solid support having attached thereto an anion exchange moiety comprising a glycidol-derived ether having the formula:
wherein
R 1 is selected from substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl,
R 2 and R 3 are selected from H, substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl,
R 10 , R 11 and R 12 are members independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl and substituted or unsubstituted heterocylcoaryl, and
X − is an organic or inorganic anion,
wherein said sample includes both carbonate and sulfate and sulfate elutes before carbonate during said separating.
16. A chromatographic system comprising the flow through bed of claim 11 in fluidic communication with one or more of:
a) a suppressor;
b) an injection valve;
c) a source of eluent; and
d) a detector.
17. The chromatographic system according to claim 16 , wherein said flow through bed is a column.