SINGLE INJECTION VALVE FOR HPLC COMBINING SAMPLE INTRODUCTION, WASH CYCLES AND DIAGNOSIS

• US 20130067997A1
• Filed: 09/16/2011
• Published: 03/21/2013
• Est. Priority Date: 09/16/2011
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Ebsen, Johnny, Wetzel, Matthias
• Granted Patent: US 9,228,982 B2
• Time in Patent Office: Days
• US Class Current: 73/61.55
• CPC Class Codes: G01N 2030/202 rotary valves
• CPC Class Codes: G01N 2030/207 with metering cavity, e.g. sample loop
• CPC Class Codes: G01N 30/20 using a sampling valve
• CPC Class Codes: G01N 30/24 Automatic injection systems

Abstract

A switchable valve for a sample injector includes a first valve member and a second valve member that can moved with respect to the other. The first valve member includes a plurality of ports, the second valve member includes a plurality of fluid paths. The plurality of ports include eight circumferential ports distributed along a circumference and one central port arranged at a central position of the first valve member. The plurality of fluid paths include three arcuate fluid paths so as to be couplable with at least two of the circumferential ports and one straight fluid path extending between the central position and a circumferential position so as to be couplable with the central port and one of the circumferential ports.

Claims

1. A switchable valve for a sample injector for use in a fluid separation system for separating compounds of a sample fluid in a mobile phase, the switchable valve comprising:

a first valve member and a second valve member, wherein at least one of the first and second valve members is configured to be moved with respect to the other;

the first valve member comprises a plurality of ports,

the second valve member comprises a plurality of fluid paths for fluidly coupling respective ones of the ports in dependency on a relative movement position of the first and second valve members with respect to each other;

wherein the plurality of ports comprise eight circumferential ports distributed along a circumference of the first valve member and comprise one central port arranged at a central position of the first valve member;

wherein one of the circumferential ports has an extension groove;

wherein the plurality of fluid paths comprise three arcuate fluid paths each being arcuate so as to be couplable with at least two of the circumferential ports;

wherein the plurality of fluid paths comprise one straight fluid path extending between the central position and a circumferential position so as to be couplable with the central port and with one of the circumferential ports.

2. The switchable valve of claim 1, comprising at least one of the following features:

the eight circumferential ports are arranged at the same radial distance from the central port;

all but one of the eight circumferential ports are spaced from at least one neighbored circumferential port by about 45°

, and one of the eight circumferential ports is spaced from one of its neighbors by less than about 45°

, particularly by about 22.5°

, and from the other one of its neighbors by more than 45°

, particularly about 67.5°

;

all but one of the eight circumferential ports have a cylindrical input shape, and a near-to-elliptic outlet shape towards a rotor'"'"'s side, and the one of the eight circumferential ports having the extension groove is a cylindrical port with an arcuate extension groove, particularly extending by about 22.5 °

;

the three arcuate fluid paths are arranged at the same radial distance with respect to a central end point of the straight fluid path;

the three arcuate fluid paths are arranged at the same radial distance as a radial end point of the straight fluid path;

two neighbored ones of the three arcuate fluid paths have a radial length of about 67.5°

, and the third one of the three arcuate fluid paths has a radial length of about 45°

;

the switchable valve is configured substantially as shown in FIG. 3;

the valve is a rotary valve, and the first and the second valve members are rotatably movable with respect to each other;

one or more of the ports comprise a through hole having an opening fluidly coupling with a respective one of the fluid paths dependent on the moving position;

the first valve member and the second valve member are configured for fluidly coupling respective ones of the ports in dependency on a relative movement position of the first and second valve members with respect to each other;

the first valve member is a stator and the second valve member is a rotor configured to be moved with respect to the first valve member;

the switchable valve comprises a drive for moving the one of the first and second valve members to be moved;

the switchable valve comprises a valve control unit configured for controlling a movement of the first and second valve members with respect to each other;

the switchable valve is configured to conduct a liquid in at least one of the fluid paths at a high pressure at which compressibility of the liquid becomes noticeable;

the switchable valve is configured to conduct a liquid in at least one of the fluid paths at a high pressure in a range of 20-200 MPa, and particularly 50-120 MPa.

3. A sample injector configured to introduce a sample fluid into a mobile phase, wherein the mobile phase is to be driven by a mobile phase drive through a separation unit for separating compounds of the sample fluid in the mobile phase, the sample injector comprising:

a sample loop for receiving the sample fluid,

a switchable valve of claim 1 for switching the sample loop between the mobile phase drive and the separation unit.

4. A fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising:

a mobile phase drive, particularly a pumping system, configured to drive the mobile phase through the fluid separation system,

a separation unit, particularly a chromatographic column, configured for separating compounds of the sample fluid in the mobile phase, and

a switchable valve of claim 1 being operable for introducing the sample fluid into the mobile phase being conducted between the mobile phase drive and the separation unit.

5. The fluid separation system of claim 4, further comprising at least one of:

a detector configured to detect separated compounds of the sample fluid;

a collection unit configured to collect separated compounds of the sample fluid;

a data processing unit configured to process data received from the fluid separation system;

a degassing apparatus for degassing the mobile phase.

6. A method of operating a switchable valve of claim 1 for a sample injector for use in a fluid separation system for separating compounds of a sample fluid in a mobile phase, wherein the method comprises:

moving the first valve member and the second valve member with respect to one another for fluidically coupling respective ones of the ports in dependency on a relative movement position of the first and second valve members with respect to each other.

12. The sample injector of claim 7, comprising at least one of the following features:

the sample injector further comprises a metering device in fluid communication with two ports of the valve and configured for introducing a metered amount of the sample fluid on the sample loop, wherein the valve is configured to be switchable so that in the block mode the valve fluidically decouples also the metering device from the mobile phase drive and from ambient pressure;

the valve is configured to be switchable so that the valve enables back flushing of the seat in the flush mode;

the sample injector further comprises a flush pump, particularly exactly one flush pump, in fluid communication with a port of the valve and configured for flushing of at least one of the group consisting of the needle and the seat;

the sample injector further comprises a wash port in fluid communication with a port of the valve and configured for washing the needle, particularly for washing selectively an exterior surface of the needle or an interior surface of the needle;

the valve is configured according to claim 1.

18. The sample injector of claim 15, wherein the valve is configured according to claim 1.

7. A sample injector for use in a fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising a mobile phase drive to drive the mobile phase and comprising a separation unit for separating compounds of the sample fluid in the mobile phase, the sample injector comprising:

exactly one switchable valve;

a sample loop in fluid communication with a port of the valve and configured for receiving the sample fluid;

a needle in fluid communication with the sample loop;

a seat for receiving the needle;

a seat capillary in fluid communication with the seat and with a port of the valve;

wherein the valve is configured to be switchable so as to activate at least one selected of the following operation modes;

a) a bypass mode in which the valve fluidically couples the mobile phase drive with the separation unit via the valve;

b) a flush mode in which the valve enables flushing of at least one of the group consisting of the needle and the seat;

c) a block mode in which the valve fluidically couples at least the sample loop, the needle, the seat and the seat capillary to one another and fluidically decouples at least the sample loop, the needle, the seat and the seat capillary from the mobile phase drive and from ambient pressure.

8. The sample injector of claim 7, wherein the valve is configured to be switchable in a wash mode in which an exterior of the needle is washed.

9. The sample injector of claim 7, wherein the valve is configured to be switchable in a sample fluid intake mode in which the sample fluid is intaken into the sample loop via the needle by a metering device.

10. The sample injector of claim 7, wherein the valve is configured to be switchable in a diagnosis mode in which a selectable fluidic part of the fluid separation system is diagnosable, particularly with respect to at least one of the group consisting of blockage of the fluidic part and leakage in the fluidic part.

11. The sample injector of claim 7, wherein the valve is configured to be switchable in a sample fluid injection mode in which the sample fluid is injected into a fluidic channel between the mobile phase drive and the separation unit.

13. A fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising:

a mobile phase drive, particularly a pumping system, configured to drive the mobile phase through the fluid separation system,

a separation unit, particularly a chromatographic column, configured for separating compounds of the sample fluid in the mobile phase, and

a sample injector of claim 7 being operable for introducing the sample fluid into the mobile phase being conducted between the mobile phase drive and the separation unit.

14. A method of operating a sample injector for use in a fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising a mobile phase drive to drive the mobile phase and comprising a separation unit for separating compounds of the sample fluid in the mobile phase, the sample injector comprising exactly one switchable valve, a sample loop in fluid communication with a port of the valve and configured for receiving the sample fluid;

a needle in fluid communication with the sample loop, a seat for receiving the needle, and a seat capillary in fluid communication with the seat and a port of the valve,

wherein the method comprises switching the valve for selectively performing at least one of the following procedures;

a) fluidically coupling the mobile phase drive with the separation unit via the valve;

b) flushing at least one of the group consisting of the needle and the seat;

c) fluidically coupling at least the sample loop, the needle, the seat and the seat capillary to one another and fluidically decoupling at least the sample loop, the needle, the seat and the seat capillary from the mobile phase drive and from ambient pressure.

15. A sample injector for use in a fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising a mobile phase drive to drive the mobile phase and comprising a separation unit for separating compounds of the sample fluid in the mobile phase, the sample injector comprising:

exactly one switchable valve;

a sample loop in fluid communication with a port of the valve and configured for receiving the sample fluid;

a needle in fluid communication with the sample loop;

a seat for receiving the needle;

a seat capillary in fluid communication with the seat and a port of the valve;

exactly one flush pump in fluid communication with a port of the valve and configured for flushing of at least one of the group consisting of the needle and the seat;

a wash port in fluid communication with a port of the valve;

wherein the valve is configured to be switchable so as to activate at least one selected of the following operation modes;

a) a sample path flush mode in which at least the sample loop, the needle, the seat and the seat capillary are flushed by the flush pump;

b) a seat back flush mode in which the seat is back flushed by the flush pump;

c) a needle wash mode in which the needle is washed in the wash port.

16. The sample injector of claim 15, wherein the needle wash mode comprises at least one of the group consisting of an external needle wash mode in which an external surface of the needle is washed in the wash port, and an internal needle wash mode in which an internal surface of the needle is washed in the wash port.

17. The sample injector of claim 15, wherein the valve is configured to be switchable so as to activate at least one selected of the following operation modes:

a) a bypass mode in which the valve fluidically couples the mobile phase drive with the separation unit via the valve;

b) a block mode in which the valve fluidically decouples at least the sample loop, the needle, the seat and the seat capillary from the mobile phase drive and ambient pressure;

c) a sample fluid intake mode in which the sample fluid is intaken into the sample loop via the needle driven by a metering device in fluid communication with two ports of the valve and configured for introducing a metered amount of the sample fluid on the sample loop;

d) a diagnosis mode in which a selectable fluidic part of the fluid separation system is diagnosable, particularly with respect to at least one of the group consisting of blockage of the fluidic part and leakage in the fluidic part;

e) a sample fluid injection mode in which the sample fluid is injected into a fluidic channel between the mobile phase drive and the separation unit.

19. A fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising:

a mobile phase drive, particularly a pumping system, configured to drive the mobile phase through the fluid separation system,

a separation unit, particularly a chromatographic column, configured for separating compounds of the sample fluid in the mobile phase, and

a sample injector of claim 15 being operable for introducing the sample fluid into the mobile phase being conducted between the mobile phase drive and the separation unit.

20. A method of operating a sample injector for use in a fluid separation system for separating compounds of a sample fluid in a mobile phase, the fluid separation system comprising a mobile phase drive to drive the mobile phase and comprising a separation unit for separating compounds of the sample fluid in the mobile phase, the sample injector comprising exactly one switchable valve, a sample loop in fluid communication with a port of the valve and configured for receiving the sample fluid, a needle in fluid communication with the sample loop, a seat for receiving the needle, a seat capillary in fluid communication with the seat and a port of the valve, exactly one flush pump in fluid communication with a port of the valve and configured for flushing of at least one of the group consisting of the needle and the seat, and a wash port in fluid communication with a port of the valve;

wherein the method comprises switching the valve for selectively performing at least one of the following procedures;

a) flushing at least the sample loop, the needle, the seat and the seat capillary by the flush pump;

b) back flushing the seat by the flush pump;

c) washing the needle in the wash port.