Apparatus and method for introducing a sample into a separation unit of a chromatography system

Patent metadata

Field	Value
Publication number	US-10478749-B2
Application number	US-201415314717-A
Country	US
Kind code	B2
Filing date	May 29, 2014
Priority date	May 29, 2014
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

An apparatus introduces a sample into a separation unit of a chromatography system with a mobile phase, including first and second mobile phase components. The apparatus includes first and second pump systems, and an injection unit. The first pump system provides the first mobile phase component, first and second portions of the first mobile phase component flowing through first and second branches, respectively. The second pump system provides the second mobile phase component, a first portion of the second mobile phase component flowing through a third branch. The injection unit receives a combined stream of the first portions of the first and second mobile phase components provided via the first and third branches, respectively, and injects the sample into the combined stream to form a sample-containing stream, which is subsequently combined with the second portion of the first mobile phase component to form a diluted sample-containing stream.

First claim

What is claimed:

1. An apparatus for introducing a sample into a separation unit of a chromatography system with a mobile phase, the mobile phase comprising a first mobile phase component and a second mobile phase component, the apparatus comprising:
an injection unit;
a first pump system configured to provide the first mobile phase component, a first portion of the first mobile phase component flowing from the first pump system through a first branch to the injection unit, and a second portion of the first mobile phase component flowing through a second branch;
a second pump system configured to provide the second mobile phase component, at least a first portion of the second mobile phase component flowing from the second pump system through a third branch to the injection unit; and
an input junction configured to provide a combined stream, comprising the first portion of the first mobile phase component provided via the first branch and the first portion of the second mobile phase component provided via the third branch, wherein:
the injection unit is configured to receive the combined stream from the input junction and to inject the sample into the combined stream to form a sample-containing stream; and
the sample-containing stream is subsequently combined with the second portion of the first mobile phase component provided via the second branch to form a diluted sample-containing stream, which flows to the separation unit of the chromatography system for separating sample constituents.

2. The apparatus of claim 1 , wherein a second portion of the second mobile phase component flows through a fourth branch.

3. The apparatus of claim 2 , wherein:
the first branch comprises a first restrictor configured to restrict flow of the first mobile phase component to provide the first portion of the first mobile phase component;
the second branch comprises a second restrictor configured to restrict flow of the first mobile phase component to provide the second portion of the first mobile phase component;
the third branch comprises a third restrictor configured to restrict flow of the second mobile phase component to provide the first portion of the second mobile phase component; and
the fourth branch comprises a fourth restrictor configured to restrict flow of the second mobile phase component to provide the second portion of the second mobile phase component.

4. The apparatus of claim 3 , wherein a restriction of at least one of the first through fourth restrictors is variable.

5. The apparatus of claim 3 , wherein a restriction of at least one of the first through fourth restrictors is selectable, and
wherein the at least one of the first through fourth restrictors that is selectable comprises a valve for selecting one of a plurality of restrictors having different corresponding restrictions.

6. The apparatus of claim 4 , wherein varying the restriction of the at least one of the first through fourth restrictors adjusts at least one of an amount of dilution of the diluted sample-containing stream and a flow rate of the combined stream.

7. The apparatus of claim 6 , wherein increasing the flow of the second portion of the first mobile phase component through the second branch by varying relative restrictions of the first and second restrictors increases an amount of dilution of the diluted sample-containing stream, thereby increasing loading capacity of the separation unit of the chromatography system.

8. The apparatus of claim 1 , wherein:
the first branch comprises a first restrictor configured to restrict flow of the first mobile phase component to provide the first portion of the first mobile phase component;
the second branch comprises a second restrictor configured to restrict flow of the first mobile phase component to provide the second portion of the first mobile phase component; and
the third branch comprises a third restrictor configured to restrict flow of the second mobile phase component to provide the first portion of the second mobile phase component;
wherein a restriction of at least one of the first through third restrictors is selectable, and
wherein the at least one of the first through third restrictors that is selectable comprises a valve for selecting one of a restriction or an alternative path.

9. The apparatus of claim 1 , wherein respective amounts of the first portion of the first mobile phase component and the first portion of the second mobile phase component of the combined stream are selected to provide an increased flow rate of the combined stream through the injection unit.

10. The apparatus of claim 1 , wherein the first mobile phase component comprises water, and the second mobile phase component comprises acetonitrile or other organic solvent.

11. The apparatus of claim 1 , wherein the first mobile phase component comprises hexane or other relatively non-polar solvent, and the second mobile phase component comprises isopropanol or other relatively polar solvent.

12. The apparatus of claim 1 , wherein the first mobile phase component comprises carbon dioxide, and the second mobile phase component comprises methanol or other organic solvent.

13. A method of injecting a sample in a chromatography system with a mobile phase comprising a first mobile phase component and a second mobile phase component, the method comprising:
proportioning the first mobile phase component into corresponding first and second portions of the first mobile phase component;
proportioning the second mobile phase component into corresponding first and second portions of the second mobile phase component;
combining the first portion of the first mobile phase component and the first portion of the second mobile phase component to form a combined stream;
injecting a sample solution into the combined stream to form a sample-containing stream comprising the sample solution and the first portion of the first mobile phase component and the first portion of the second mobile phase component;
after the injecting, combining the sample-containing stream with at least one of the second portion of the first mobile phase component and the second portion of the second mobile phase component to form a diluted sample-containing stream; and
passing the diluted sample-containing stream to a chromatographic column.

14. The method of claim 13 , further comprising:
varying the second portion of the first mobile phase component to adjust an amount of dilution of the diluted sample-containing stream.

15. The method of claim 13 , wherein:
the first portion of the first mobile phase component is between about 5 percent and about 35 percent of a first mobile phase component flow;
the first portion of the second mobile phase component is between about 65 percent and about 95 percent of a first mobile phase component flow;
the second portion of the first mobile phase component is between about 65 percent and about 95 percent of the first mobile phase component flow; and
the second portion of the second mobile phase is component between about 5 percent and about 35 percent of the second mobile phase component flow.

Assignees

• Agilent Technologies Inc

Inventors

• Wikfors Edwin E

Classifications

• B01D15/325

  Reversed phase · CPC title

• B01D15/18

  relating to flow patterns · CPC title

• B01D15/14 Primary

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

• G01N30/32

  of pressure or speed (G01N30/36 takes precedence) · CPC title

• G01N2030/342

  fluid composition fixed during analysis · CPC title