Valve and splitting system for multi-dimensional liquid analysis

Patent metadata

Field	Value
Publication number	US-10429361-B2
Application number	US-201614996784-A
Country	US
Kind code	B2
Filing date	Jan 15, 2016
Priority date	Mar 23, 2011
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

A multi-dimensional liquid analysis system includes a flow splitter for separating mobile phase outflow from a first dimension liquid analysis system into first and second liquid split outlet flows. Volumetric flow rate control of the split outlet flows is provided by a flow control pump which withdraws one of the split outlet flows from the flow splitter at a controlled withdrawal flow rate to define the other split outlet flow rate as the difference between the outflow rate from the first dimension system and the withdrawal flow rate. In this manner, accurate and consistent flow division can be accomplished, which is particularly useful for multi-dimensional liquid analysis.

First claim

What is claimed is:

1. A multi-dimensional liquid analysis system, comprising:
a first separation system including a first separation column, the first separation column configured to chromatographically separate a sample within a liquid mobile phase and to provide a first dimension outflow having a first outflow rate;
a flow splitter fluidly coupled to the first dimension outflow, the flow splitter configured to split the first dimension outflow into a first split outlet flow and a second split outlet flow;
a second separation system including a sample loop and a second separation column, wherein the second separation system is configured that the sample loop receives a sample volume from the second split outlet flow, and wherein the second separation column is configured to chromatographically separate the sample volume from the second split outlet flow; and
a flow control pump fluidly coupled to and located downstream of one of the first split outlet flow and the second split outlet flow, the flow control pump configured to withdraw the one of the first split outlet flow and the second split outlet flow from the flow splitter at a controlled withdrawal flow rate to obtain, in the sample volume from the second split outlet flow, a representative sampling of compounds in the first dimension outflow for separation in the second separation system.

2. The multi-dimensional liquid analysis system of claim 1 , further comprising:
a flow restrictor restricting the first split outlet flow to create a fluid pressure at the flow splitter of 1-1000 kilopascals.

3. The multi-dimensional liquid analysis system of claim 1 ,
wherein the flow control pump is a positive displacement pump configured to withdraw the one of the first split outlet flow and the second split outlet flow from the flow splitter at the controlled withdrawal flow rate while operating in a negative displacement mode.

4. The multi-dimensional liquid analysis system of claim 1 , wherein the controlled withdrawal flow rate is controlled according to:

F
c

≤

V
s

(

T

2
⁢
a

+

T

2
⁢
e

)

,

wherein:
F c is the flow rate for the second split outlet flow,
V s ≥V d ,

V d is a volume of the second split outlet flow to be analyzed by the second separation column,
T 2a is an analysis time of the second separation column, and
T 2e is an equilibration time of the second separation column.

5. The multi-dimensional liquid analysis system of claim 1 , further comprising:
a multiple-port injection valve configured to inject the sample volume from the second split outlet flow into the second separation column.

6. The multi-dimensional liquid analysis system of claim 5 , wherein to control the flow rate of the one of the first split outlet flow and the second split outlet flow from the flow splitter, the flow control pump is configured to produce a flow rate for the second split outlet flow that is controlled according to:

F
c

≤

V
L

(

T

2
⁢
a

+

T

2
⁢
e

)

,

wherein:
F c is the flow rate for the second split outlet flow,
V L is a volume of the sample loop,
T 2a is an analysis time of the second separation column, and
T 2e is an equilibration time of the second separation column.

7. A multi-dimensional liquid analysis system, comprising:
a first separation system including a first separation column, the first separation column configured to chromatographically separate a sample within a liquid mobile phase and to provide a liquid mobile phase into a first dimension outflow having a first outflow rate;
a flow splitter fluidly coupled to the first dimension outflow, the flow splitter configured to split the first dimension outflow into a first split outlet flow and a second split outlet flow;
a second separation system including a multiple-port injection valve comprising a sample loop, the second separation system also including a second separation column, wherein the multiple-port injection valve is configured to receive, at a port, the second split outlet flow such that the sample loop receives a sample volume from the second split outlet flow, and wherein the second separation column is configured to chromatographically separate the sample volume from the second split outlet flow; and
a flow control pump fluidly coupled to and located downstream of one of the first split outlet flow and the second split outlet flow, the flow control pump configured to withdraw the one of the first split outlet flow and the second split outlet flow from the flow splitter at a controlled withdrawal flow rate to obtain, in the sample volume from the second split outlet flow, a representative sampling of compounds in the first dimension outflow for separation in the second separation system.

8. The multi-dimensional liquid analysis system of claim 7 , further comprising:
a flow restrictor restricting the first split outlet low to create a fluid pressure at the flow splitter of 1-1000 kilopascals.

9. The multi-dimensional liquid analysis system of claim 7 , wherein the flow control pump comprises a positive displacement pump configured to withdraw the one of the first split outlet flow and the second split outlet flow from the flow splitter while operating in a negative displacement mode.

10. The multi-dimensional liquid analysis system of claim 7 , wherein the controlled withdrawal flow rate is controlled according to:

F
c

≤

V
s

(

T

2
⁢
a

Assignees

• Univ Minnesota

Inventors

• Sims Carl W
• Carr Peter W
• Filgueira Marcelo Roberto
• Witt Klaus

Classifications

• G01N2030/324

  speed, flow rate · CPC title

• G01N30/10

  using a splitter · CPC title

• G01N30/463 Primary

  for multidimensional chromatography · CPC title

• G01N30/7233

  interfaced to liquid or supercritical fluid chromatograph (interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04) · CPC title

• G01N30/32

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