Injector sample dilution for a liquid chromatography system

Patent metadata

Field	Value
Publication number	US-9823225-B2
Application number	US-201514824431-A
Country	US
Kind code	B2
Filing date	Aug 12, 2015
Priority date	Aug 25, 2014
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

Described are a method and a system for diluting a sample at a location of injection in a liquid chromatography system. The method includes loading a sample into a first fluid channel, separating a flow of a mobile phase into a first flow in the first fluid channel and a second flow in a second fluid channel, and combining the sample that is displaced from the first fluid channel and the mobile phase exiting the second fluid channel at the location of injection into the system flow to thereby generate a diluted sample in the system flow. The dilution ratio of the diluted sample is responsive to the flow rates of the first and second flows. Advantageously, the flow rates can be changed by changing the flow restriction of one of the fluid channels. Thus providing the proper flow restriction enables a user to obtain a desired dilution ratio.

First claim

What is claimed is:

1. A method of diluting a sample in a liquid chromatography system, the method comprising:
loading a sample into a first fluid channel;
separating a flow of a mobile phase of a liquid chromatography system at a valve into a first flow in the first fluid channel and a second flow in a second fluid channel, the first flow and the second flow having a first flow rate and a second flow rate, respectively, wherein the flow of mobile phase in the first fluid channel displaces the sample in the first fluid channel; and
combining the sample exiting the first fluid channel and the mobile phase exiting the second fluid channel at a location of injection into the system flow to thereby generate a diluted sample in the system flow, wherein a dilution ratio of the diluted sample is responsive to the first flow rate and the second flow rate.

2. The method of claim 1 wherein loading a sample comprises drawing the sample from a sample source into the first fluid channel with a sample syringe.

3. The method of claim 1 wherein the sample loaded into the first fluid channel includes a sample in a diluent.

4. The method of claim 1 wherein the sample exiting the first fluid channel and the mobile phase exiting the second fluid channel are combined for a predetermined duration.

5. The method of claim 1 wherein only a portion of a volume of the sample loaded into the first fluid channel is combined with the mobile phase exiting the second fluid channel to generate the diluted sample.

6. A system for injecting a diluted sample in a liquid chromatography system, comprising:
a first fluid channel having a first end and a second end;
a second fluid channel having a first end and a second end;
an injection valve having a first node and a second node in communication with the first end and the second end, respectively, of the second fluid channel, and having a third node configured for communication with a sample syringe, the first node configured to receive a mobile phase of a liquid chromatography system; and
a control module in communication with the injection valve to control a state of the injection valve,
wherein, when the injection valve is in a first state, the third node is in communication with the first end of the first fluid channel to thereby enable a sample in a sample source in communication with the second end of the first fluid channel to be loaded into the first fluid channel,
wherein, when the injection valve is in a second state, the first node is in further communication with the first end of the first fluid channel and the second node is in further communication with the second end of the first fluid channel so that the mobile phase flows into the first fluid channel and the second fluid channel, at a first flow rate and a second flow rate, respectively, and
wherein the sample displaced out from the second end of the first fluid channel and the mobile phase exiting the second end of the second fluid channel are combined at the second node to generate a flow of a diluted sample having a dilution ratio that is responsive to the first flow rate and the second flow rate.

7. The system of claim 6 further comprising a sample source in communication with the second end of the first fluid channel.

8. The system of claim 6 further comprising a sample syringe in communication with the third node of the injection valve.

9. The system of claim 6 wherein each of the nodes comprises at least one injector port.

10. The system of claim 6 wherein at least one of the nodes of the injector ports comprises a plurality of ports in communication with each other through at least one fluid channel in the injection valve.

11. The system of claim 6 wherein the injection valve is a rotary shear seal valve.

12. The system of claim 11 wherein at least one of the nodes of the injector ports comprises a plurality of ports in communication with each other through at least one fluid channel in the rotary shear seal valve.

13. The system of claim 12 wherein the at least one fluid channel in the rotary shear seal valve includes a groove in a rotor or a stator.

14. The system of claim 12 wherein the sample in the sample source includes a sample in a diluent.

Assignees

• Waters Technologies Corp

Inventors

• Cormier Sylvain
• Moeller Mark W
• Beals Peyton C

Classifications

• G01N30/24

  Automatic injection systems · CPC title

• G01N2030/207

  with metering cavity, e.g. sample loop · CPC title

• G01N2030/027

  Liquid chromatography · CPC title

• G01N30/06

  Preparation · CPC title

• G01N2030/201

  multiport valves, i.e. having more than two ports · CPC title