Materials and methods for trap-elute mixed mode chromatography

Patent metadata

Field	Value
Publication number	US-11173418-B2
Application number	US-201916506801-A
Country	US
Kind code	B2
Filing date	Jul 9, 2019
Priority date	Jul 11, 2018
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

In various aspects, the present disclosure pertains to materials (e.g., kits, column assemblies, liquid chromatography systems, etc.) methods for performing liquid chromatography that employ a first column (e.g., a trapping column) and a second column (e.g., an analytical column). The first column comprises a first chromatographic material having a first chromatographic surface that comprises first hydrophobic surface groups and first ionizable surface groups having a first pKa value. The second column comprises a second chromatographic material having a second chromatographic surface that comprises second hydrophobic surface groups and (a) permanently ionized surface groups or (b) second ionizable surface groups having a second pKa value. The first hydrophobic surface groups have a hydrophobicity that is less than a hydrophobicity of the second hydrophobic surface groups. Moreover, where the second chromatographic surface comprises second ionizable surface groups, the first pKa value may differ from the second pKa value by 1-12 units.

First claim

The invention claimed is:

1. A liquid chromatography system comprising:
(a) a trapping column comprising a first chromatographic material having a first chromatographic surface that comprises first hydrophobic surface groups and first ionizable surface groups having a first pKa value,
(b) an analytical column comprising a second chromatographic material having a second chromatographic surface that comprises second hydrophobic surface groups having a hydrophobicity that is greater than a hydrophobicity of the first hydrophobic surface groups and (i) permanently ionized surface groups or (ii) second ionizable surface groups having a second pKa value that differs from the first pKa value by 1-12 units,
(c) an injector for introducing a liquid sample into the system,
(d) a detector capable of detecting a property of the components,
(e) a first flow path including the injector and the trapping column but not the analytical column,
(f) a second flow path including the trapping column and the analytical column, and
(g) one or more mobile phase delivery sources configured to pump a first mobile phase along the first flow path and to pump a second mobile phase along the second flow path.

2. The liquid chromatography system of claim 1 , wherein the one or more mobile phase delivery sources comprise a first pump that is configured to pump the first mobile phase along the first flow path, and a second pump, which may be the same as or different from the first pump, that is configured to pump the second mobile phase along the second flow path.

3. The liquid chromatography system of claim 1 , wherein the first chromatographic material is in the form of first particles and wherein the second chromatographic material is in the form of second particles.

4. The liquid chromatography system of claim 3 , wherein a first diameter of the first particles is greater than or equal to a second diameter of the second particles.

5. The liquid chromatography system of claim 4 , wherein a ratio of the first particle diameter to the second particle diameter ranges from 1 to 10.

6. The liquid chromatography system of claim 4 , wherein the first diameter ranges from 2 to 10 microns.

7. The liquid chromatography system of claim 1 , wherein the trapping column has an internal diameter that is greater than or equal to an internal diameter of the analytical column and wherein the trapping column has a length that is shorter than a length of the analytical column.

8. The liquid chromatography system of claim 1 , wherein the trapping column has an internal diameter that is 1.5-5 times greater than an internal diameter of the analytical column.

9. The liquid chromatography system of claim 1 , wherein a volume of the trapping column ranges from 0.05-0.5 times a volume of the analytical column.

10. The liquid chromatography system of claim 1 , wherein the first and second hydrophobic surface groups are hydrocarbon groups, and wherein the second hydrophobic surface groups contain more carbon atoms than the first hydrophobic surface groups.

11. The liquid chromatography system of claim 10 , wherein the second hydrocarbon groups contain 2-20 more carbon atoms than the first hydrocarbon groups.

12. The liquid chromatography system of claim 10 , wherein the first hydrocarbon groups are first alky groups that contain from 3 to 8 carbon atoms and wherein the second hydrocarbon groups are second alkyl groups that contain from 10 to 24 carbon atoms.

13. The liquid chromatography system of claim 12 , wherein the first alky groups contain 4 carbon atoms and wherein the second groups contain 18 carbon atoms.

14. The liquid chromatography system of claim 1 , wherein the first ionizable groups are present in a surface concentration that is less than or equal to a surface concentration of the permanently ionized or second ionizable groups.

15. The liquid chromatography system of claim 1 , wherein the first ionizable groups are present in a surface concentration ranging from 0.03 to 0.3 micromoles per square meter.

16. The liquid chromatography system of claim 1 , wherein the first ionizable groups and the permanently ionized or second ionizable groups are positively charged when ionized.

17. The liquid chromatography system of claim 16 , wherein the second chromatographic surface comprises the second ionizable surface groups, wherein the first and second pKa values are greater than 3, and wherein the second pKa value is 1-7 units greater than the first pKa value.

18. The liquid chromatography system of claim 1 , wherein (a) the first ionizable groups and (b) the permanently ionized or second ionizable groups comprise amine groups.

19. The liquid chromatography system of claim 18 , wherein the first ionizable groups are selected from primary, secondary and tertiary amine groups and the permanently ionized or second ionizable groups are selected from secondary, tertiary and quaternary amine groups.

20. The liquid chromatography system of claim 1 , wherein the first ionizable groups are selected from 4-pyridylethyl, 2-pyridylethyl, 2 imidazolinylpropropyl, 3-propylaniline and imidazole groups.

21. The liquid chromatography system of claim 1 , wherein the second ionizable groups are selected from diethylaminopropyl, ethylaminopropyl, dimethylaminopropyl, methylaminopropyl, aminopropyl, diethylaminomethyl, 3-[Bis(2-hydroxyethyl)amino]propyl, n-butyl-aza-silacyclopentane, n-methyl-aza-silacyclopentane, and bis-3-methylaminopropyl silyl groups.

22. The liquid chromatography system of claim 1 wherein the molar ratio of the first hydrophobic surface groups to the first ionizable groups ranges from 5:1 to 200:1.

23. The liquid chromatography system of claim 1 , wherein the first and second ionizable groups are negatively charged when ionized.

24. The liquid chromatography system of claim 23 , wherein the first ionizable groups are carboxylic acid groups and wherein the second ionizable groups are selected from sulfonic acid groups and carboxylic acid groups.

25. The liquid chromatography system of claim 23 , wherein the second pKa value is 1-4 units less than the first pKa value.

26. The liquid chromatography system of claim 1 , wherein the first chromatographic material is in the form of first particles having a core of a first material, and wherein the second chromatographic material is in the form of second particles having a core of a second material.

27. The liquid chromatography system of claim 1 , wherein the injector comprises a sample loop or a flow through needle.

28. A method for performing liquid chromatography on a liquid sample including a plurality of components using the liquid chromatography system of claim 1 , the method comprising:
introducing the liquid sample into the system via the injector;
flowing the first mobile phase through the first flow path using the one or more mobile phase delivery sources such that the liquid sample is guided through the trapping column and such that the trapping column traps at least a portion of the components of the liquid sample as trapped components;
flowing the second mobile phase through the second flow path using the one or more mobile phase delivery sources, wherein flowing through the second flow path includes flowing the second mobile phase (a) through the trapping column such that at least some of the trapped components are eluted from the trapping column as elu

Assignees

• Waters Technologies Corp

Inventors

• Lauber Matthew A
• Okandeji Babajide O

Classifications

• B01D15/14

  relating to the introduction of the feed to the apparatus · CPC title

• G01N2030/085

  using absorbing precolumn · CPC title

• B01D15/363

  Anion-exchange · CPC title

• G01N30/462 Primary

  with different eluents or with eluents in different states (G01N30/463 takes precedence) · CPC title

• B01D15/1871 Primary

  placed in series · CPC title