JP2012026893A - Liquid chromatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high performance liquid chromatograph (called as HPLC hereafter) with a recycle separation function.SOLUTION: The liquid chromatograph is connected to a supply flow channel of a moving phase and a recycle flow channel in which a liquid feed pump 42, a separation column 48, and a detector 47 are interposed, and an introduced sample is made recyclable, has a single switching valve 4 which makes the supply flow channel of the moving phase and the recycle flow channel switchable, one end parts of the respective connection conduct tubes 22, 23 to be connected to the suction side and the discharge side of the liquid feed pump 42 is connected to the switching valve 4, one end part of the introduction side of the separation column 48 is connected to the switching valve 4, an inner diameter of the connection conduct tube 22 for connecting the suction side of the liquid feed pump 42 to the switching valve 4 is formed to the maximum in piping to the switching valve 4, length of the connection conduct tube 22 is formed to be short as much as possible, and an inner diameter of a connection conduct tube 26 for connecting an exit side end of the detector 47 to the switching valve 4 is formed in the middle in piping to the switching valve 4.

Description

The present invention is, for example, a high performance liquid chromatograph (hereinafter, HPL) having a recycling separation function.
The recycle switching valve and the switching valve inserted in the recycle flow path are composed of a single valve, reducing the number of parts and simplifying the structure, thereby reducing the size, weight and cost. At the same time, the complexity of valve operation can be eliminated, and this can be done easily and accurately, the dimensions of each connecting conduit are rationally configured, and the dead volume is reduced to prevent sample diffusion during separation, In addition to improving the accuracy of normal and recycle separation, the orifice and rotor rotor grooves provided in the switching valve are rationally configured to allow smooth and safe fluid movement during sample introduction and recycle separation. The present invention relates to a liquid chromatograph.

  A liquid chromatograph equipped with a recycle separation function (hereinafter referred to as LC) is equipped with a recycle valve and a switching valve. The sample is introduced into the eluent, and when the target component of the sample is eluted, the recycle valve is switched. At the same time, there is one in which the switching valve is switched so that the eluent and the sample are circulated through the recycling flow path for recycling separation (for example, see Patent Document 1).

  However, the LC requires a recycle valve and a switching valve, which increases the number of parts, makes the configuration complicated and expensive, and requires switching them, resulting in complicated operation.

  As a solution to the above problem, there is one in which the recycling valve and the switching valve are constituted by a single 8-port switching valve, the number of valves is reduced, and the complicated switching operation of the valve is eliminated ( For example, see Patent Document 2).

  However, since the LC has a buffer flow path connected to the 8-port switching valve and a sample injection device is inserted in the recycle flow path, the dead volume of the recycle flow path increases and the sample diffuses. The recycling separation accuracy was not sufficient.

  By the way, this type of switching valve includes a stator in which an orifice communicating with a port opened to the outside and a rotor in which a plurality of rotor grooves capable of communicating with the orifice are formed, The rotor is configured to be liquid-tight and rotatable with respect to the stator (for example, see Patent Document 3).

However, when the number of ports is increased, the length of the rotor groove and the orifice diameter of the switching valve are restricted, and the supply and discharge of the moving fluid is not performed smoothly and efficiently, affecting the separation accuracy and separation time. In addition, the seal function between the stator and the rotor is lowered, and there is a problem of causing liquid leakage.
In this case, if the length of the rotor groove and the diameter of the orifice are made the same, the correspondence with the device connected to the switching valve becomes uniform, for example, the elution of the eluent or sample by the liquid feed pump is unstable. As a result, the amount of movement of the eluent and sample fluctuated, and the cell was damaged due to an increase in detector pressure.

Japanese Patent No. 2557384 JP 2006-138699 A JP-A-1-307575

  The present invention solves such a problem, and is suitable for, for example, HPLC having a recycling separation function. The recycling switching valve and the switching valve inserted in the recycling flow path are constituted by a single valve, and the number of parts is reduced. Reduced and simplified configuration to reduce size, weight and cost, eliminate the complexity of valve operation, easily and accurately do this, and rationally configure the dimensions of each connecting conduit, and its dead volume In addition to improving the accuracy of normal and recycle separation, the orifice of the switching valve and the rotor groove of the rotor are rationally configured for sample introduction. It is an object of the present invention to provide a liquid chromatograph that can smoothly and safely move fluid during separation and recycling.

  The invention according to claim 1 is connected to a supply flow path for the mobile phase, a recycle flow path that allows the introduced sample to be circulated through the liquid feed pump, the separation column, and the detector. In a liquid chromatograph having a single switching valve capable of switching between a recycle flow path and a recycle flow path, a plurality of connection conduits for connecting a connection conduit connecting the suction side of the liquid feeding pump and the switching valve to the switching valve A plurality of pipes connected to the switching valve for connecting the outlet end of the detector and the switching valve. Inner diameters of the connection conduit formed between the inlet side end of the detector and the switching valve, and the connection conduit connecting the discharge side of the liquid feed pump and the switching valve, formed at an intermediate inner diameter in the connection conduit. To the switching valve It is formed to the minimum among the plurality of connecting conduits to prevent an increase in dead volume when a device such as a sample injection device is inserted between the connecting conduits connected to the suction side and the discharge side of the liquid feeding pump. In addition, the internal diameter of each connection conduit that connects a device such as a liquid feed pump and a detector and the switching valve is rationally configured to reduce the dead volume of each connection conduit, and the suction side of the liquid feed pump The inner diameter of the connecting conduit that connects the switching valve is maximized in the switching valve piping so that the suction operation by the liquid feed pump is performed smoothly and efficiently, and the outlet end of the detector is connected to the switching valve. The inner diameter of the connecting conduit is formed in the middle of the switching valve piping to prevent a high pressure load on the detector cell and to prevent damage to the cell.

In the invention of claim 2, eight or more ports are provided on the surface of the valve head of the switching valve, and eight or more orifices communicating with the port are formed on the seal surface of the valve head. The number of ports formed on the valve head and the number of orifices formed on the seal surface are both reduced as compared to the prior art, thereby simplifying the configuration and facilitating manufacturing, and reducing the size and weight of the switching valve. I have to.
According to a third aspect of the present invention, a plurality of orifices having large and small diameters are formed on a seal surface provided on an inner end surface of the valve head of the switching valve, and the seal surface is liquid-tightly rotated and slid. A plurality of rotor grooves having different groove widths are formed on the seal surface of the rotor that can be provided, and the diameter of the orifice and the width of the rotor groove are set to a device such as a liquid feed pump or a detector. Therefore, the mobile fluid can be supplied and discharged rationally and smoothly.

According to a fourth aspect of the present invention, a plurality of orifices having different diameters and a plurality of rotor grooves having different groove widths are formed at inner and outer positions in the radial direction of the respective seal surfaces. The surface is rationally configured to reduce the size and weight of the switching valve.
According to the fifth aspect of the present invention, an orifice and a rotor groove in the switching valve communicating with the suction side of the liquid feeding pump are formed to have a maximum diameter and a maximum width, and the switching valve communicating with the outlet side end of the detector is provided. An orifice and a rotor groove are formed with an intermediate diameter and an intermediate width, and communicated with an orifice and a rotor groove in a switching valve that communicates with the inlet side end of the detector and with a discharge side end of the liquid feed pump. The orifice and rotor groove in the switching valve are formed to the minimum diameter and width, and the orifice and rotor groove in the switching valve are rationally configured according to the connected equipment to smoothly supply and discharge moving fluid. And I try to do it efficiently.

According to the invention of claim 6, the maximum inner diameter and the minimum inner diameter ratio of the connecting conduits are formed to be about 1: 0.5: 0.3, and each connecting conduit is rationally set according to the corresponding equipment. The mobile fluid is smoothly and efficiently supplied and discharged, and the dead volume of each connecting conduit is reduced.
According to the seventh aspect of the present invention, the ratio of the maximum diameter and the intermediate diameter to the minimum diameter of the orifice is about 1: 0.8:
It is formed to 0.5, and each orifice is rationally configured according to the corresponding equipment so that the moving fluid can be smoothly and efficiently supplied and discharged.
According to an eighth aspect of the present invention, the ratio of the maximum width of the rotor groove to the intermediate width and the minimum width is formed to be about 1: 0.8: 0.5, and each rotor is formed according to the corresponding equipment. The groove is rationally configured so that the moving fluid can be supplied and discharged smoothly and efficiently.

  In the first aspect of the present invention, the connection conduit connecting the suction side of the liquid feeding pump and the switching valve is formed to have the maximum inner diameter among the plurality of connection conduits piped to the switching valve, and the length thereof is set. A connecting conduit that connects the outlet end of the detector and the switching valve is formed to have an inner diameter that is intermediate among the plurality of connecting conduits that are connected to the switching valve. The inner diameters of the connecting conduit connecting the inlet end and the switching valve and the connecting conduit connecting the discharge side of the liquid feeding pump and the switching valve are minimized among the plurality of connecting conduits piping to the switching valve. Since it has been formed, it prevents the increase in dead volume when a device such as a sample injection device is inserted between the connection conduits connected to the suction side and the discharge side of the liquid feed pump, and the liquid feed pump, detector, etc. Connecting each device to the switching valve The inside diameter of the connection conduit is reduced, the dead volume of each connection conduit is reduced, and the inside diameter of the connection conduit connecting the suction side of the liquid feeding pump and the switching valve is formed to the maximum in the piping of the switching valve, The suction operation by the liquid feed pump can be performed smoothly and efficiently, and the inner diameter of the connection conduit connecting the outlet end of the detector and the switching valve is formed in the middle of the switching valve piping. A high-pressure load on the cell can be prevented, and damage to the cell can be prevented.

In the invention of claim 2, eight or more ports are provided on the surface of the valve head of the switching valve, and eight or more orifices communicating with the port are formed on the seal surface of the valve head. Therefore, the number of ports formed on the valve head and the number of orifices formed on the seal surface are both reduced as compared with the prior art, thereby simplifying the configuration and facilitating manufacturing, and reducing the size and weight of the switching valve. be able to.
According to a third aspect of the present invention, a plurality of orifices having large and small diameters are formed on a seal surface provided on an inner end surface of the valve head of the switching valve, and the seal surface is liquid-tightly rotated and slid. Since a plurality of rotor grooves having different groove widths are formed on the seal surface of the rotor that can be provided, the diameter of the orifice and the width of the rotor groove are determined by a liquid feed pump, a detector, etc. It can be rationally formed according to the device, and the moving fluid can be supplied and discharged rationally and smoothly.

In the invention of claim 4, since the plurality of orifices having different diameters and the plurality of rotor grooves having different groove widths are formed in the inner and outer positions in the radial direction of the respective seal surfaces. The switch surface can be rationally configured, and the switching valve can be reduced in size and weight.
According to the fifth aspect of the present invention, an orifice and a rotor groove in the switching valve communicating with the suction side of the liquid feeding pump are formed to have a maximum diameter and a maximum width, and the switching valve communicating with the outlet side end of the detector is provided. An orifice and a rotor groove are formed with an intermediate diameter and an intermediate width, and communicated with an orifice and a rotor groove in a switching valve that communicates with the inlet side end of the detector and with a discharge side end of the liquid feed pump. Since the orifice and rotor groove in the switching valve have the minimum diameter and minimum width, the orifice and rotor groove in the switching valve are rationally configured according to the connected equipment to supply and discharge moving fluid. Smooth and efficient.

In the invention of claim 6, since the maximum inside diameter and the minimum inside diameter ratio of the connecting conduits are formed to be about 1: 0.5: 0.3, each connecting conduit is rationalized according to the corresponding equipment. Thus, the moving fluid can be smoothly and efficiently supplied and discharged, and the dead volume of each connecting conduit can be reduced.
According to the seventh aspect of the present invention, the ratio of the maximum diameter and the intermediate diameter to the minimum diameter of the orifice is about 1: 0.8:
Since it is formed to 0.5, each orifice can be rationally configured according to the corresponding device, and the moving fluid can be supplied and discharged smoothly and efficiently.
In the invention of claim 8, since the ratio of the maximum width and the intermediate width to the minimum width of the rotor groove is set to about 1: 0.8: 0.5, each rotor has a ratio corresponding to the corresponding equipment. It is possible to rationally configure the groove and supply and discharge the moving fluid smoothly and efficiently.

It is a front view which shows the use condition of the switching valve applied to this invention. It is a perspective view which shows the seal surface of the inner end surface of the switching valve applied to this invention, and it has played the function of a stator. It is a perspective view which shows the rotor of the switching valve applied to this invention, and its sealing surface. It is explanatory drawing which shows the normal time (at the time of sample introduction and the time of fractionation) of the switching valve applied to this invention. It is explanatory drawing which shows the time of recycling of the switching valve applied to this invention.

It is explanatory drawing which shows the normal time of the switching valve applied to the 2nd Embodiment of this invention. It is explanatory drawing which shows the time of recycling of the switching valve applied to the 2nd Embodiment of this invention. It is explanatory drawing which shows the normal time of the switching valve applied to the 3rd Embodiment of this invention.

  Hereinafter, the illustrated embodiment in which the present invention is applied to an HPLC having a recycle separation function will be described. In FIGS. 1 to 5, reference numeral 1 denotes an HPLC casing installed on a work table 2, and the proximity position of the casing 1. The valve box 3 is installed in the front.

The valve box 3 is provided with a switching valve 4 having the functions of a HPLC switching valve and a recycling channel.
As the switching valve 4, a multi-port valve of 8 ports or more is used. In the embodiment, an 8-port switching valve is used, and the front portion of the valve head 5 projects from the front portion of the valve box 3. Has been.

  The switching valve 4 has a valve head 5 having a function of a stator in order to reduce an internal dead volume, and the valve head 5 is a cylindrical valve housing via a bolt (not shown). (Not shown).

The outside of the valve head 5 is formed in a substantially truncated cone shape, and a pair of ports 6 to 13 are formed at the concentric positions of the conical surface 5a as openings of a small hole passage which will be described later.
Ports 6 to 9 are arranged on the outer circle part of the concentric circles, ports 10 to 13 are arranged on the inner circle part, and the diameters are formed in the order of the ports 6 to 13 in the order of the smallest diameter. Ports 10 to 13 are formed with the same diameter.

Fittings 14 to 21 are screwed into the ports 6 to 13, of which connecting conduits 22 and 23 having different diameters are connected between the fittings 14 and 19, and a connecting conduit 24 is connected to the fitting 15.
Further, a connecting conduit 25 is connected to the fitting 16, connecting conduits 26 and 27 having different diameters are connected between the fittings 17 and 20, and a connecting conduit 28 is connected between the fittings 18 and 21.

The connecting conduits 22 to 28 are made of PEEK (registered trademark), stainless steel, or Teflon (registered trademark), and the inner diameters thereof are different from each other. In the embodiment, the inner diameter is 0.1 to 2.0 mm. Are appropriately selected and used.
Among these, the inner diameters of the connection conduits 22 and 24 are formed to the maximum diameter in the piping of the switching valve 4, the inner diameters of the connection conduits 25 and 26 are formed to the next largest intermediate diameter, and the inner diameters of the connection conduits 27 and 28 are formed. Is formed to have a minimum diameter, and the inner diameter of the connecting conduit 23 is formed to be approximately ½ of the connecting conduit 22 or 24.

  The inner diameters of the connection conduits 22 to 28 in the embodiment are as follows. When the inner diameter of the connection conduits 22 and 24 is 1, the inner diameter ratio of the connection conduits 25 and 26 to the connection conduits 27 and 28 is about 1: 0.5: 0. More specifically, it is formed in the range of 1: 0.3 to 0.7: 0.1 to 0.5 depending on the analysis conditions and the flow rate.

  Inside the valve head 5, small and small diameter passages (not shown) communicating with the ports 6 to 13 are formed in an oblique shape, and the end of the passage projects into the inner end surface of the valve head 5. On the provided seal surface 5a, orifices 29 to 32 having different diameters are formed as ejection holes.

  The orifices 29 to 32 are concentrically arranged on the seal surface 5a as shown in FIG. 2, the orifices 29 to 32 are arranged on the outer circle portion thereof, and the orifices 33 to 36 are arranged on the inner circle portion thereof. Are formed in the order of the smaller diameters of the orifices 29 to 36, and the smallest diameter orifices 33 to 36 are formed to have the same diameter.

  Of the orifices 29 to 36 of the embodiment, the orifices 29 and 30 are formed to have the largest diameter, the orifices 31 and 32 are formed to the next largest intermediate diameter, and the orifices 33 to 36 are formed to the smallest diameter, When the orifices 29 and 30 are 1, the diameter is about 1: 0.8: 0.5. More strictly, depending on the analysis conditions and flow rate, 1: 0.7 to 1.0: 0.4. To 0.6.

The seal surface 37a of the rotor 37 is disposed on the seal surface 5a of the valve head 5 so as to be liquid-tight and rotatable and slidable.
The rotor 37 is formed to have a smaller diameter than the valve head 5, and the seal surface 37 a projects from the end surface of the rotor 37 in a disk shape. The seal surface 37a is formed as a flat surface having the same diameter as the seal surface 5a, and a plurality of substantially arc-shaped rotor grooves 38 to 41 are concentrically formed on the seal surface 37a as shown in FIG. The rotor grooves 38 and 39 are arranged in the outer circle portion, and the rotor grooves 40 and 41 are arranged in the inner circle portion.

The length of the rotor groove 38 is approximately twice that of the rotor grooves 39 to 41, and the length of the rotor grooves 39 to 41 is formed to be substantially the same.
The width of the rotor grooves 38 to 41 is formed to be substantially equal to the diameter of the corresponding orifices 29 to 36, of which the rotor groove 38 is formed to the maximum width, and the rotor groove 39 is the next. The rotor grooves 40 and 41 are formed to have a minimum width, and the rotor grooves 40 and 41 are formed to have the same width.

  The groove width ratio of the rotor grooves 38 to 41 is formed to be about 1: 0.8: 0.5 when the width of the rotor groove 38 is 1, similarly to the orifice ratio described above. Is formed in the range of 1: 0.7 to 1.0: 0.4 to 0.6 depending on the analysis conditions and flow rate.

The rotor 37 of the embodiment is linked to a motor (not shown) as a rotating means, but can be manually rotated instead of the motor.
The rotor 37 is rotatably supported via a bearing (not shown), and an urging means such as a disc spring is disposed behind the rotor 37, and the rotor is interposed via the urging means. 37 is urged forward, and its seal surface 37a is disposed in a liquid-tight manner on the seal surface 5a so as to be rotatable and slidable.

One end of the connection pipe 22 having the maximum inner diameter is connected to the fitting 14 communicating with the port 6, and the other end is connected to the suction side end of the liquid feed pump 42. It is possible to execute smoothly and efficiently.
The length of the connecting conduit 22 is formed as short as possible. In the embodiment, the connecting conduit 22 is formed to be approximately 10% of the pipe length of the connecting conduits 22 and 23 between the ports 6 and 11, and the dead volume of the portion is formed. We are trying to reduce it.

A connection conduit 23 is connected between the discharge side end of the liquid feed pump 42 and the fitting 19, and the inner diameter of the connection conduit 23 is formed to be approximately ½ of the connection conduit 22, in other words, the port. 11 is formed to have the same diameter or a slightly larger diameter than the orifice 34 having the smallest diameter communicating with 11.
The length of the connecting conduit 23 is formed to be approximately 90% of the pipe length of the connecting conduits 22 and 23 between the ports 6 and 11, so as to reduce the dead volume of the portion.

  The other connecting conduit 24 having the maximum inner diameter is connected to a fitting 15 having one end communicating with the port 7, and the other end is piped into an eluent storage container 43, and is an elution which is a mobile phase stored in the container 43. The liquid 44 can be supplied smoothly and efficiently.

One of the intermediate connection conduits 25 is connected to the fitting 16 having one end communicating with the port 8 and the other end connected to the sorting device 45, and has an inner diameter in the middle to suppress an increase in pressure. Thus, failure or breakage of the detector cell described later is prevented.
The other middle connecting conduit 26 is connected to a fitting 17 having one end communicating with the port 9, and the other end connected to an outlet side end portion of a detector 47 having a cell 46, through the pipe diameter. A high-pressure load on the cell 46 is prevented, and a failure of the cell 46 can be prevented beforehand.

  A connecting conduit 27 having a minimum inner diameter or a slightly larger diameter is connected to the inlet end of the detector 47 and the fitting 20 communicating with the port 12, and a separation column 48 is inserted into the conduit 27, The dead volume of the part is reduced. It is also possible to arrange a guard column in the connection conduit 28 on the upstream side of the separation column 48 and on the downstream side of the autosampler 50.

A connecting conduit 28 having a minimum inner diameter is connected between the fitting 18 and a fitting 21 communicating with the port 13, and a preheat tube 49 is inserted upstream of the conduit 28. An autosampler 50 is inserted downstream of 49.
The preheat tube 49 is supplied with the eluent 44 until the recycle target component is eluted, and the eluent 44 can be heated by a heater (not shown) attached to the tube 49. Yes.

In the embodiment, the autosampler 50 is disposed in the connection conduit 28, but may be disposed in the connection conduit 27 upstream of the separation column 48.
However, in the latter case, since the autosampler 50 becomes a dead volume of the recycle channel, the former is preferable in terms of accuracy of recycle separation.
The separation column 48 and the preheat tube 49 are arranged in an oven (not shown), and the autosampler 50 is arranged in the oven in the case of manual operation.

  In addition, in the drawing, 52 is a push button switch for driving a motor provided in the valve box 3, and 53 and 54 are operation mode display portions of the switching valve 4, which are usually used at the time of sample introduction or sorting. It is possible to display the time of operation and the time of recycle operation.

The HPLC having the recycling function configured as described above requires a new switching valve 4 and piping.
The switching valve 4 requires production of a valve head 5 having a stator and a new rotor 37. Among these, the valve head 5 has eight ports 6 to 6 on a conical surface 5a on the surface. 13 are formed on inner and outer concentric circles, ports 6 and 7 and ports 8 and 9 are formed on the outer circle, and four ports 10 to 13 are formed on the inner circle. To do. This situation is as shown in FIG.

Each of the ports 6 to 13 is arranged with a sufficient space that can be sealed in the circumferential direction and the inside and outside directions thereof, and makes it possible to avoid contact of the fittings 14 to 21 attached to them.
Each of the ports 6 to 13 is formed at an equiangular position where each circumference is basically divided into eight, and the ports 6 and 7, the ports 8 and 9, the ports 10 and 11, and the ports are formed. -G and 12 are formed in pairs, and the pairs are formed to have the same diameter.

  Each of the ports 6 to 13 is formed to have a large and a small diameter, among which the ports 6 and 7 are formed to the maximum diameter, and the ports 8 and 9 are then formed in the middle of the large diameter. 10 to 13 are formed to the minimum diameter, and the port diameter ratio is set to about 1: 0.8: 0.5 with Ports 6 and 7 being 1, and more strictly according to analysis conditions and flow rate. And 1: 0.7 to 1.0: 0.4 to 0.6.

Then, screw portions for screwing the fittings 14 to 21 are formed on the inner surfaces of the ports 6 to 13, and communicated with the ports 6 to 13 and the orifices 29 to 36 inside the valve head 5. A small hole passage (not shown) is formed.
In this case, since the ports 6 to 13 are formed on the inner and outer concentric circles, it is possible to secure a wide space for each small hole passage, and to reliably and easily form a space between them.

  Next, eight orifices 29 to 36 are opened at inner and outer concentric positions on the seal surface 5a functioning as a stator on the inner end surface of the valve head 5, and the orifices 29, 30 and the orifice 31, 32 are spaced apart and four orifices 33-36 are spaced apart on the inner circle.

  Each of the orifices 29 to 36 is arranged with a sufficient interval so that it can be sealed in the circumferential direction and the inner and outer directions, and they are formed at equiangular positions where each circumference is basically divided into eight parts. 29, 30, orifices 31, 32, orifices 33, 34, and orifices 35, 36 are formed in pairs, and the pairs are formed in the same diameter.

Each of the orifices 29 to 36 is formed to have the same diameter as that of the corresponding small hole passage, the orifices 29 and 30 are formed to the maximum diameter, and the orifices 31 and 32 are formed to the next intermediate diameter. The orifices 33 to 36 are formed to have a minimum diameter, and the aperture ratio is set to about 1: 0.8: 0.5 with the orifices 29 and 30 being 1, and more strictly, depending on the analysis conditions and flow rate, 1: 0.7 to 1.0: 0.4 to 0.6. This situation is as shown in FIGS.
In this case, since the orifices 29 to 36 are formed on the inner and outer concentric circles, it is possible to secure a wide space for each orifice, to avoid the polymerization of these orifices, and to form them reliably and easily, and to improve the seal surface. There is an advantage that eight orifices can be used without forming nine orifices on the same circle.

Further, on the convex disc-shaped seal surface 37a of the rotor 37, four substantially arc-shaped rotor grooves 38 to 41 are formed at inner and outer concentric positions, and the rotor is formed on the outer circle. The grooves 38 and 39 are formed apart from each other, and the two rotor grooves 40 and 41 are formed separately on the inner circle.
Each of the rotor grooves 38 to 41 is arranged with a sufficient interval that can be sealed in the circumferential direction and the inner and outer directions, and they are formed at equiangular positions that basically divide each circumference into eight equal parts. Of these, the rotor groove 38 is formed to be the longest over two equiangular regions, and the other rotor grooves 39, 40, 41 are formed to have the same length in each equiangular region.

  The groove widths of the rotor grooves 38 to 41 are formed in three ways. Among these, the groove width of the rotor groove 38 is formed to the maximum width having the same diameter as the corresponding orifices 29 and 30, and the rotor groove 39 is formed. The groove widths of the rotor grooves 40 and 41 are formed to have a minimum width of the same diameter as that of the corresponding orifices 33 to 36.

The groove widths of the rotor grooves 38 to 41 are such that the rotor groove 38, the rotor groove 39, and the rotor grooves 40 and 41 are formed of the above-mentioned orifice. Similar to the aperture ratio, it is formed at about 1: 0.8: 0.5, more strictly, 1: 0.7 to 1.0: 0.4 to 0.6 depending on the analysis conditions and flow rate. Form. This situation is as shown in FIGS.
In this case, since the rotor grooves 38 to 41 are formed on the inner and outer concentric circles, a wide space for the rotor grooves 38 to 41 can be secured, and polymerization thereof is avoided reliably and easily. It can be formed and a reliable seal effect can be obtained.

The assembly of the valve head 5 having the stator thus manufactured and the switching valve 4 using the rotor 37 is the same as in the prior art.
That is, the rotor 37 is rotatably assembled to the inner end surface of the valve head 5, and the outer periphery of the valve head 5 is connected to a valve housing (not shown).

Next, a bearing is mounted inside the valve housing, and a rotating shaft (not shown) is supported on the bearing via a biasing means such as a disc spring, and a rotor 37 is integrally attached to the rotating shaft. To do.
Then, the seal surface 37a of the rotor 37 is brought into close contact with the seal surface 5a of the valve head 5 in a liquid-tight manner so as to be rotatable and slidable, and the valve head 5 is integrally connected to the valve housing. .
At that time, the orifices 29 to 36 are positioned in the corresponding rotor grooves 38 to 41, and they are arranged so as to communicate with each other as shown in FIG.

  Thereafter, the assembled switching valve 4 is accommodated in the valve box 3, and fittings 14 to 21 are attached to the ports 6 to 13 of the valve head 5 protruding from the front portion of the box 3. The connecting conduits 22 to 28 are piped.

The pipe has one end of a connecting pipe 22 having a shortest maximum inner diameter attached to the fitting 14, and the other end is connected to the suction side end of the liquid feed pump 42 disposed in the HPLC 1, and the discharge side end of the pump 42 is connected. One end of the connecting conduit 23 having a minimum inner diameter or a slightly larger diameter is connected to the portion, and the other end is attached to the fitting 19.
Further, one end of the connection conduit 24 having the maximum inner diameter is attached to the fitting 15, and the other end is inserted into the eluent 44 in the eluent storage container 43 disposed in the HPLC 1.

Further, one end of a connecting conduit 25 having an intermediate inner diameter is attached to the fitting 16, and the other end is connected to an inlet of a sorting device 45 disposed outside the HPLC 1.
Further, one end of a connecting conduit 26 having an intermediate inner diameter is attached to the fitting 17, and the other end is connected to an outlet side end portion of a detector 47 disposed inside the HPLC 1.
One end of a connecting conduit 27 having a minimum inner diameter or a slightly larger diameter is connected to the introduction end of the detector 47, and the other end is attached to the fitting 20. A separation column 48 arranged in an oven (not shown) is inserted.

  Furthermore, one end of the connecting conduit 28 is attached to the fitting 18, the other end is attached to the fitting 21, and a heat tube 49 disposed in the oven is inserted upstream of the connecting conduit 28, An autosampler 50 is inserted on the downstream side of 28.

  Thus, according to the present invention, various connection conduits 22 to 28 having different inner diameters and lengths are prepared according to the devices such as the ports 6 to 21 and the detector 47, and these are connected to the piping. In addition to smooth and efficient supply and discharge of the moving fluid, the dead volume of each conduit 22 to 28 is reduced to improve the separation accuracy.

  Further, since the valve head 5 has a function of a stator and the seal surface 37a of the rotor 37 is disposed in close contact with the seal surface 5a of the inner end surface thereof, the valve head 5 and the rotor 37 are arranged. It is possible to reduce the number of components interposed between the two and reduce the dead volume by omitting the formation of small hole passages for the components.

Thus, after connecting pipes 22 to 28 are piped, separation by HPLC 1 is started.
That is, at the normal time of sample introduction and sorting, the switching valve 4 is set to the normal operation mode, the ports 6 to 13 and the orifices 29 to 36 are communicated, and the liquid feed pump 42 is connected. Drive

In this way, the eluent 44 in the eluent container 43 is guided to the connection conduit 24 and flows into the rotor groove 38 from the orifice 30, and from the orifice 29 of the rotor groove 38 to the connection conduit 22. It flows out and is sucked into the liquid feed pump 42.
After the eluent 44 is discharged from the liquid feed pump 42, it flows out into the connecting conduit 23, moves through the conduit 23, and flows into the rotor groove 40 from the orifice 34.

At this time, since the connecting conduits 22 and 24 are formed to have a maximum inner diameter, the supply of the eluent 44 from the eluent container 43 to the rotor groove 38 and the supply from the rotor groove 38 to the liquid feed pump 42 are performed. The eluent 44 is sucked smoothly and efficiently.
Moreover, since the connecting conduit 22 is formed as short as possible, the dead volume of the part can be suppressed as small as possible.

  In addition, since the liquid feed pump 42 to the port 11 are connected by the connecting conduit 23 having a minimum inner diameter or slightly larger than that, the dead volume of the part is reduced, which is combined with the above. Thus, the dead volume of the connection conduits 22 and 23, which are the flow paths for the eluent 44, can be kept small.

Thereafter, the eluent 44 flows out from the orifice 33 of the rotor groove 40 and moves to the connection conduit 28, where it is guided to a heat tube 49 inserted in the conduit 28 and heated. A sample is introduced when the autosampler 50 is moved, and flows into the rotor groove 41 from the orifice 36.
At that time, since the connecting conduit 28 is formed to have a minimum inner diameter, the dead volume of the part can be kept small.

Thereafter, the eluent 44 flows out of the orifice 35 together with the sample into the connection conduit 27, the target component is separated by the separation column 48 inserted in the conduit 27, moves through the connection conduit 27, and flows to the downstream detector 47. Led.
At that time, since the fitting 20 to the detector 47 are connected by the connecting conduit 27 having the smallest inner diameter, the dead volume of the part can be suppressed to be small, the sample diffusion is suppressed, and the separation by the separation column 48 is performed. Can be performed with high accuracy.
Moreover, the separation column 48 is heated by an oven (not shown), and the eluent 44 heated by the heater tube 49 is moved, so that the temperature difference between the inside and outside is eliminated, and the separation accuracy is improved.

Then, the target component of the sample is detected in the cell 46 of the detector 47, flows out to the connection conduit 26, is guided to the rotor groove 39 from the orifice 32, and is connected to the connection conduit 25 from the orifice 31 of the rotor groove 39. To the sorting device 45, and the sorting device 45 sorts each target component.
At this time, since the inner diameters of the connecting conduits 25 and 26 are formed in the middle, the pressure increase of the conduits 25 and 26 can be suppressed, and the high-pressure load on the cell 46 caused by them can be avoided, and the failure of the cell 46 can be prevented. .

Thus, when the target component of the sample is eluted and confirmed by the detector 47, the rotor driving motor (not shown) is driven, and the rotor 37 is rotated by a predetermined angle (about 45 °). The rotor grooves 38 to 41 are moved in the same manner to switch the switching valve 4 to the recycling mode.
This situation is as shown in FIG. 5. The orifices 29 to 30 and 32 communicate with the rotor groove 38, the orifice 31 communicates with the rotor groove 39, the orifice 33 communicates with the rotor groove 40, and the orifice 34 and 35 communicate with the rotor groove 41.

That is, one end of the connection conduit 22 communicates with the rotor groove 38 via the orifice 29, the other end of the connection conduit 23 communicates with the rotor groove 41 via the orifice 34, and one end of the connection conduit 27 communicates with the orifice. 35 is connected to the rotor groove 41, and one end of the connecting conduit 26 is connected to the rotor groove 38 via the orifice 32, thereby forming a closed loop recycle flow path.
At that time, the connecting conduit 28 communicating with the orifices 33 and 36 is disconnected from the recycling passage, and the dead volume by the heater tube 49 and the autosampler 50 inserted into the connecting conduit 28 is recycled. Removed from.

In addition, the orifice 31 is closed by the seal surface 37a of the rotor 37, the connection conduit 25 communicating with the orifice 31 is disconnected from the recycling flow path, and the sorting by the sorting device 45 is stopped.
In this case, one end of the connection conduit 24 communicates with the rotor groove 38 via the orifice 30, and the connection conduit 24 functions as a kind of buffer for the recycle flow path.

  Then, the eluent 44 and the sample moving fluid circulate through the recycling flow path via the liquid feed pump 42, and the target component in the sample is separated by the separation column 48, which is detected by the detector 47.

During such recycle separation, the moving conduit 42 sucks the moving fluid from the rotor groove 38 smoothly and efficiently by the connection pipe 22 having the maximum inner diameter.
Further, since the connecting conduit 22 is formed as short as possible, and the connecting conduits 23 and 27 on the discharge side have the minimum inner diameter, the dead volume of the flow path is reduced, and the diffusion of the sample is suppressed, The separation accuracy by the separation column 48 is improved.
In addition, since the outlet side of the detector 47 and the rotor groove 38 communicate with each other through the intermediate connection conduit 26 to suppress the pressure increase in the relevant portion, a high-pressure load on the cell 46 is avoided, and the cell 46 fails. To prevent.

Thus, in the present invention, the recycle valve and the flow path switching valve interposed in the recycle flow path are configured by a single switching valve 4, so that two valves are not required as in the prior art, and the number of parts accordingly. This makes it possible to reduce the size and weight of the HPLC and to manufacture it at low cost.
In addition, since it is sufficient to switch the single switching valve 4 at the normal time of sample introduction or sorting, or at the time of recycling, the trouble of switching between the two valves as in the conventional case can be eliminated.

Further, according to the present invention, the seal surface 5a of the inner end surface of the valve head 5 has the function of a stator, and the seal surface 37a of the rotor 37 is arranged in direct contact with the seal surface 5a. Therefore, the number of parts interposed between them is reduced, and the manufacturing labor for forming the small hole passages in them is eliminated, and an increase in dead volume due to the small hole passages is prevented.
Further, orifices 29 to 32 and 33 to 36 and rotor grooves 38, 39, 40 and 41 are formed at the inner and outer positions on the concentric circles of the seal surfaces 5a and 37a of the valve head 5 and the rotor 37, respectively. Since these are rationally arranged, it is possible to reduce the size and weight of the valve head 5 and the rotor 37, and their seal surfaces 5a and 37a. There is an advantage that can be handled at the port.

Moreover, since the diameters of the orifices 29 to 36 and the width of the rotor grooves 38 to 41 are rationally formed according to the connecting conduit or connecting device, the analysis conditions and the flow rate, the dead volume of each flow path is rationalized. Can be reduced.
Further, according to the present invention, the ports 6 to 9 and 10 to 13 having large and small diameters are rationally arranged at the inner and outer positions on the concentric circles on the surface of the valve head 5, so that the valve head 5 can be reduced in size and weight. .

  Then, large and small fittings 14 to 21 are arranged on the ports 6 to 13, and the fittings 14 to 21 are connected to the fittings 14 to 21 with different diameters and different lengths according to the connecting device, analysis conditions, and flow rate. By connecting the conduits 22 to 28, the dead volume of the connection conduits 22 to 28 is reasonably reduced, and by connecting the connection conduits 22 to 28 from the inner and outer circles of the valve head 5, the piping space thereof is obtained. Can be made compact.

6 to 8 show other embodiments of the present invention, and the same reference numerals are used for portions corresponding to the above-described configuration.
Of these, FIGS. 6 and 7 show a second embodiment of the present invention, in which the present invention is applied to a 10-port switching valve 4a of 9 ports or more, and its status is shown. Ten orifices 29a to 36a, 55, 56 are formed at equiangular (36 °) positions on the circumference of the seal surface 5a of the valve head 5 functioning as a seal. Four rotor grooves 38a to 41a are formed on the circumference of the surface 37a. In the drawing, reference numeral 56 a denotes a blind plug that closes the orifice 56.

  The orifices 29a to 36a, 55 and 56 are formed to have the same diameter, and the groove widths of the rotor grooves 38a to 41a are formed to the same width as the orifice 29a, and the length thereof is basically the rotor. The grooves 38a to 41a are formed to have a length equal to 10 times the circumference of the grooves. Among these, the rotor groove 38a is formed approximately twice as long as that, and the orifices 29a to 36a, 55, and 56 are arranged at the respective times during normal operation or recycling. -Communication with the groove 38a-41a is enabled.

On the circumference of the surface of the valve head 5, ten ports having the same diameter are formed at equiangular (36 °) positions, and the same fitting is screwed into the port, and the fitting is the same as described above. Connecting conduits 22a to 28a having different inner diameters are connected. In the drawing, reference numeral 56 a denotes a blind plug that closes the orifice 56.
The operation method of the switching valve 4a at the normal time and at the time of recycling in this embodiment is substantially the same as the above-described embodiment.

Thus, in this embodiment, ten orifices 29a to 36a, 55, 56 having the same diameter are formed on the circumference of the seal surface of the inner end face of the valve head 5 having the function of a stator. Since four rotor grooves 38a to 41a having the same width are formed on the circumference of the seal surface 37a of the rotor 37, the orifices 29a to 36a, 55, 56 and the rotor groove are formed. The structure of 38a-41a becomes simple and can be manufactured easily and inexpensively.
Moreover, since the length of the rotor grooves 39a to 41a is formed to be equal to the circumference of the circumference, the length is shorter than that of the rotor groove of the 8-port switching valve 4 of the above-described embodiment. Therefore, the dead volume can be reduced accordingly.

  Further, ten ports having the same diameter are formed on the circumference of the valve head 5, the same fitting is screwed into the port, and the same connection as described above having inner diameters of large and small diameters is attached to the fitting. Since the conduits 22a to 28a are connected, the configuration is simple, the fitting and the connecting conduits 22a to 28a can be easily and inexpensively manufactured, and they can be easily attached.

  FIG. 8 shows a third embodiment of the present invention. This embodiment applies the present invention to a 12-port switching valve 4b, and seals the inner end face of the valve head 5 functioning as a stator. Twelve orifices 29b to 36b, 55b, 56b, 57, 58 are formed at equiangular (30 °) positions on the circumference of the surface 5b, and on the circumference of the seal surface 37b of the rotor 37. The four rotor grooves 38b to 41b are formed in each of them.

The orifices 29b to 36b, 55b, 56b, 57 and 58 are formed to have the same diameter, and the groove widths of the rotor grooves 38b to 41b are formed to the same width as the orifice 29b, and the rotor grooves 38b to The length of 41b is basically formed to be equal to 12 times the circumference of the circumference, and the rotor groove 38b is approximately twice as long as that of the orifices 29b to 36b, 55b, 56b, 57, and 58 can communicate with the rotor grooves 38b to 41b.
On the circumference of the surface of the valve head 5, twelve ports having the same diameter are formed at equiangular (30 °) positions, and the same fitting is screwed into the port. Connecting conduits 22b to 28b having the same inner diameter as described above are connected. In the figure, 57b and 58b are blind plugs for closing the orifices 57 and 58.

  The operation method and the effect of the switching valve 4b at the normal time and at the time of recycling are substantially the same as those of the second embodiment described above, and the length of the rotor grooves 38b to 41b is shortened. The dead volume of the part is further reduced.

  In the liquid chromatograph of the present invention, the recycle switching valve and the switching valve inserted in the recycle flow path are configured as a single valve, the number of parts is reduced, the configuration is simplified, and the size, weight, and cost are reduced. At the same time, the complexity of valve operation can be eliminated, and this can be done easily and accurately, the dimensions of each connecting conduit are rationally configured, and the dead volume is reduced to prevent sample diffusion during separation, In addition to improving the accuracy of normal and recycle separation, the orifice and rotor rotor grooves provided in the switching valve are rationally configured to allow smooth and safe fluid movement during sample introduction and recycle separation. Therefore, for example, it is suitable for HPLC having a recycle separation function.

1 HPLC
4, 4a, 4b Switching valve 5 Valve head 22-28 Connection conduit 22a-28a Connection conduit 22b-28b Connection conduit 5a, 37a Seal surface 29-36 Orifice 29a-36a, 55, 56 Orifice 29b-36b, 55b, 56b, 57, 58 Orifice

37 rotor 37a, 37b seal surface 38-41 rotor groove 38a-41a rotor groove 38b-41b rotor groove 42 liquid feed pump 46 cell 47 detector 48 separation column

Claims (8)

  Connected to the supply flow path of the mobile phase and the recycle flow path through which the introduced sample can be circulated, and the supply flow path and the recycle flow path are switched. In a liquid chromatograph having a single switching valve enabled, a connecting conduit connecting the suction side of the liquid feeding pump and the switching valve has a maximum inner diameter among a plurality of connecting conduits piped to the switching valve. And a connecting conduit that connects the outlet end of the detector and the switching valve is intermediate among the plurality of connecting conduits that are connected to the switching valve. A plurality of pipes each having an inner diameter of a connection conduit formed on the inner diameter and connecting the inlet side end of the detector and the switching valve and a connection conduit connecting the discharge side of the liquid feed pump and the switching valve to the switching valve Connecting conduit Liquid chromatograph, characterized in in that the minimum formation   2. The liquid chromatograph according to claim 1, wherein eight or more ports are provided on a surface of the valve head of the switching valve, and eight or more orifices communicating with the port are formed on a seal surface of the valve head. Graph.   A plurality of orifices having large and small diameters are formed on a seal surface provided on the inner end surface of the valve head of the switching valve, and a rotor provided on the seal surface so as to be liquid-tight and rotatable and slidable. The liquid chromatograph according to claim 1, wherein a plurality of rotor grooves having different groove widths are formed on the seal surface.   The liquid chromatograph according to claim 3, wherein a plurality of orifices having different diameters and a plurality of rotor grooves having different groove widths are formed at inner and outer positions in the radial direction of each seal surface.   The orifice and rotor groove in the switching valve that communicates with the suction side of the liquid feed pump are formed to the maximum diameter and width, and the orifice and rotor groove in the switching valve that communicates with the outlet side end of the detector. An orifice and a rotor groove in the switching valve that are formed in an intermediate diameter and an intermediate width and communicate with the inlet side end of the detector, and an orifice and a rotor in the switching valve that communicate with the discharge side end of the liquid feed pump. 5. The liquid chromatograph according to claim 4, wherein the groove is formed with a minimum diameter and a minimum width.   2. The liquid chromatograph according to claim 1, wherein a maximum inner diameter and a minimum inner diameter ratio of the connection conduit are formed to be about 1: 0.5: 0.3.   The liquid chromatograph according to claim 3, wherein a ratio of the maximum diameter of the orifice and the ratio between the intermediate diameter and the minimum diameter is set to about 1: 0.8: 0.5.   4. The liquid chromatograph according to claim 3, wherein a ratio of the maximum width of the rotor groove and the ratio between the intermediate width and the minimum width is about 1: 0.8: 0.5.

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