JPS62272155A - Sample introducing device for liquid chromatograph - Google Patents

Abstract

PURPOSE:To prevent the leaking-out and splashing of a liquid in a sample loop from a sample injecting port by providing a 6-way valve, etc., on a flow passage between a pump and sepn. column. CONSTITUTION:The moving phase solvent in a storage tank 2 is conducted by the pumping operation of a pump 4 into the sepn. column 8 through the flow passage 6. A sample introducing device is constituted of the 6-way valve 14 and the sample loop 16. The loop 16 is connected to the sample injecting port 20d in order to hold the prescribed sample by the turning of a rotor 18 of the valve 14. The loop is connected to the flow passage 20f on the column 8 side prior thereto. The loop 16 is connected to a drain port 20c and/or moving phase inlet port 20a in the 1st auxiliary connecting path 22 and/or 2nd auxiliary connecting path 24 further prior thereto. The leaking-out and splashing of the liquid in the loop 16 from the port 20a are thus prevented.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Technical Field) The present invention relates to a sample introduction device for a liquid chromatograph, and particularly to a problem when switching channels in a six-way valve equipped with a sample loop, a so-called loop injector. The present invention relates to an improved structure that can advantageously eliminate the problem.

(Prior art) Liquid chromatography, especially high performance liquid chromatography (HP LC) has been widely adopted as one of the separation analysis techniques and preparative techniques. In a device for performing liquid chromatography, a so-called liquid chromatograph, a loop injector using a sample loop method is generally used as the sample introduction device to introduce a predetermined amount of sample into the system. It is used.

By the way, such a loop injector uses a six-way valve as a flow path switching section provided on a flow path between a mobile phase pump and a separation column of a liquid chromatograph, and a sample injection port (inlet) of the six-way valve. It consists of a sample loop section that holds a predetermined sample injected with a sample injector, and by switching the hexagonal pulp, both ends of the sample loop are connected to the flow path on the mobile phase pump side and the separation column side. The sample in the sample loop is guided to the separation column together with the mobile phase solvent discharged from the mobile phase pump, and by changing the volume of the sample loop, the sample can be connected to It is possible to inject samples of about several tens of millimeters, and is known to have excellent performance in terms of operability and simplicity during injection.

(Problem) However, in such a sample introduction device, a high-pressure mobile phase solvent is pumped into the sample loop from a mobile phase pump in order to push out the sample contained and held there and guide it to the separation column side. As the sample loop is guided and allowed to flow, the pressure inside the sample loop becomes high, and in this state, the flow path of the six-way valve is switched and connected to the sample injection port under normal pressure. The liquid (mobile phase solvent) in such sample loop
There was a problem that the sample would flow backwards and leak from the sample injection port, and in severe cases, it would scatter. In particular, when the sample loop has a large capacity, this phenomenon of liquid scattering becomes noticeable, especially in high-performance liquid chromatography analysis that frequently uses Ni8-containing media such as methanol, acetonitrile, and chloroform as the mobile phase. It is considered to be an extremely dangerous phenomenon, causing fire, toxicity to the human body, and contamination around equipment.

Furthermore, even when the sample (liquid) at normal pressure held in the sample loop is guided to the separation column by connecting the sample loop to the flow path on the separation column side by switching the six-way valve, A pressure much higher than normal pressure is acting on the separation column side, for example, 100 kg/cr in high performance liquid chromatography analysis.
s” or more is applied, and this causes large pressure fluctuations on the separation column side when switching channels with a six-way valve, which poses the problem of deterioration of the separation column. -ing

In particular, when the amount of sample held in the sample loop increases, and the volume of the sample loop reaches several IQml,
The pressure change on the separation column side becomes significant, accelerating deterioration of the separation column.

(Solution Means) Here, the present invention has been made to solve the problems in the conventional loop injector type sample introduction device, and is characterized by a mobile phase pump for a liquid chromatograph. A six-way valve that switches the flow path by rotation of the rotor relative to the stator is disposed on the flow path between the mobile phase pump and the separation column, and its mobile phase inlet port is connected to the flow path on the mobile phase pump side. The mobile phase outlet port is connected to the flow path on the separation column side, while the remaining four ports of the six-way valve are configured as a sample loop outlet port, a drain port, a sample injection port and a sample loop population port, and the sample A sample introduction device comprising a sample loop for holding a predetermined sample injected through the sample injection port between a loop outlet port and the sample loop inlet port, wherein the sample loop provided in the rotor of the six-way valve In addition to a plurality of main connections for connecting two ports in predetermined combinations, rotation of the rotor of the six-way valve connects the sample loop inlet port to the sample injection port. a first sub-connection connecting an outlet port to said drain port in cooperation with one of said main connections; and/or rotation of a rotor of said six-way valve connects said sample loop inlet port to said mobile phase outlet port; a second sub-connection path is provided on the rotor and/or the stator, cooperating with one of the main connections, connecting the sample loop outlet port to the mobile phase inlet port prior to being connected to the mobile phase inlet port; There is a particular thing.

In the sample introduction device according to the present invention, the sample loop connected between the sample loop inlet port and the sample loop outlet port of the six-way valve is preferably configured with pipes of different diameters, and The predetermined length portion of the sample loop on the side connected to the sample loop inlet port is a pipe having a smaller diameter (inner diameter) than the portion on the side connected to the sample loop outlet port.

(Operation/Effect) Therefore, in the sample introduction device according to the invention having such a configuration, the sample loop is connected to the sample injection port for holding a predetermined sample by rotation of the rotor of the six-way valve. in advance and/or on the side of the separation column (
prior to being connected to the mobile phase outlet port), such sample loop is connected to the drain port and/or the mobile phase inlet port via the first subconnection and/or the second subconnection; Therefore, the problem caused by the pressure inside the sample loop when switching channels using a six-way valve can be effectively solved.

That is, to inject the sample into the sample loop,
When connecting the sample loop population port and the sample injection port, the sample loop outlet port and the drain port are connected by one main connection path and the first sub connection path prior to the connection. To,
The high-pressure liquid (mobile phase solvent) present in the sample loop is discharged out of the system through the drain port, and as a result, the pressure inside the sample loop is at or near normal pressure. Even if the sample injection port and the sample loop inlet port are connected after that, the liquid in the sample loop will not leak or scatter from the sample injection port.

Furthermore, even if the flow path is switched by rotating the rotor of a six-way valve in order to send the sample at normal pressure held in the sample loop to the separation column, the sample loop Prior to being connected to the flow path on the column side, it is connected to the flow path on the mobile phase pump side, specifically the mobile phase inlet port, via one main connection path and a second sub connection path, After the mobile phase solvent sent by the mobile phase pump is introduced and the pressure within the sample loop is increased, it is led to the separation column side, and the pressure fluctuations are effectively suppressed. Therefore, deterioration of the column can be advantageously avoided.

In addition, in the sample introduction device according to the present invention, if the sample loop is configured by connecting pipes of different diameters (inner diameters), the amount of sample held in the pipe portion of the large diameter increases, and the pipe There is also the advantage that the sample injection amount range is widened without increasing the length so much, and the troublesome work or labor of replacing the sample loop according to the sample amount can be advantageously eliminated.

Moreover, the sample loop has a small aperture in a predetermined length portion on the side connected to the separation column side flow path, in other words, in a predetermined length portion on the sample injection port side into which a predetermined sample is injected by the sample injector. By configuring the tube with a pipe, even if a small amount of sample, for example a few microliters, is injected, such a small amount of sample will be retained in the sample loop portion with a small diameter. Therefore, the diffusion phenomenon of the sample in the sample loop can be effectively suppressed or prevented, and thereby problems such as a decrease in the number of theoretical plates during separation in a separation column can be advantageously solved. be.

(Examples) Hereinafter, in order to clarify the present invention more specifically, some examples of the present invention will be described in detail based on the drawings.

First, FIG. 1 shows a high performance liquid chromatograph (H) as a liquid chromatograph equipped with a sample introduction device according to the present invention.
2 is a system diagram according to an example of PLC'), in which 2 is a storage tank for storing a predetermined mobile phase solvent, and the mobile phase solvent in this storage tank 2 is used for the pump operation of the pump 4. is led to a known separation column 8 through a flow path 6. Further, a sample introduction device 10 according to the present invention is provided on the flow path 6 between the pump 4 and the separation column 8, and a predetermined amount of sample introduced by the sample introduction device 10 is transferred to the pump 4. It is guided into the separation column 8 together with the mobile phase solvent sent from the separation column 8.
Within this system, the respective sample components are separated in a known manner and eluted together with a mobile phase.

Although not shown, a detector or the like for detecting the sample components separated and eluted by the separation column 8 is provided on the flow path downstream of the separation column 8, as necessary. ing.

By the way, the sample introduction device 10 is composed of a six-way valve 14, which is a well-known flow path switching pulp, and a sample loop 16 attached to the six-way valve 14. As is well known, the six-way valve 14 is
The flow path is switched by the rotation of the rotor relative to the stator, and as shown in the figure, there are six ports in which the flow path is connected or disconnected by the rotation of the rotor 18, namely, the mobile phase artificial port 20a, the sample loop outlet port 20b,
Drain port 20c, sample injection port 20d, sample loop inlet port 20e, and mobile phase outlet port 2
0r, and among these, the flow path 6 of the four pumps is connected to the mobile phase inlet port 20a, while the flow path 6 portion on the separation column 8 side is connected to the mobile phase outlet port 20f. ing. Further, a predetermined sample is injected from the sample injection port 20d using a sample injector such as a syringe, and excess liquid is discharged from the drain port 20c.

A sample loop 1 for holding the sample to be injected is located between the sample loop inlet port 20e and the sample loop outlet port 20b of the six-way valve 14.
6 is connected. This sample loop 16 is composed of a first pipe 22 with a small diameter (inner diameter) and a second pipe 24 with a large diameter (inner diameter), and the first pipe 22 is connected to the sample loop inlet port 20e. A second pipe 24 is connected to the sample loop outlet port 20b and can be connected to the flow path 6 section on the pump 4 side. I'm starting to get it.

More specifically, such a six-way valve 14 is shown in FIG.
) and (b), it has a stator 28 fixed to the valve body 26 and a rotor 18 rotatably housed within the valve body 26, and the rotor 18 is rotated within a predetermined angle, that is, within a 60° angle range, by a rotary knob 30 provided externally to switch the flow path. In addition, the stator 28 is provided with six holes drilled out with a phase difference of 60°, and six ports 20a to 20a are provided in the stator 28.
It is said to be 2Of.

Further, on the sliding surface of the rotor 18 with respect to the stator 28, there are six ports 20a to 20 provided on the stator 28 side.
Three circular arc grooves 32a, 32b, and 32c extending in a range of 60° are located on the same circumference as Of.
They are provided independently with a phase difference of 0°, and the circular arc grooves 32a to 32c connect the ports 20a to 20a to 32c.
20'' in a predetermined combination.
A predetermined length in the circumferential direction so that both ends of the arcuate groove 32a that selectively connects the sample loop outlet port 20b to the drain port 20c or the mobile phase inlet port 20a approach the adjacent arcuate grooves 32b and 32c, respectively. are extended to form a first extension groove 34a and a second extension groove 34b, respectively, thereby forming first and second sub-connection paths.

Therefore, in the sample introduction device 10 having such a structure,
When holding a predetermined sample in the sample loop 16, the rotor 18 is rotated counterclockwise as shown by the arrow in the A state of the six-way valve 14 schematically shown in FIG. Before the movement angle reaches 60', in other words, before the sample loop inlet port 20e is connected to the sample injection bow 1-20d via the arcuate groove 32b, the arcuate groove 32a is formed at one end. The first extension? R (shown with diagonal lines for ease of understanding) 34a is connected to the drain port 20c and is connected to the sample loop outlet port 20b via one arcuate groove 32a and a first extension groove 34a. drain port 20c
are connected to form the B state in FIG. The sample loop 16 is discharged from the system through the sample loop 20c, and the pressure inside the sample loop 16 is at or near normal pressure.

Then, when the rotor 18 is further rotated from the B state and the rotation angle reaches 60 degrees, it becomes the C state in FIG. g32b, and under such a connected state, a predetermined amount of sample is injected from the sample injection board 20d by a predetermined sample injector such as a syringe, thereby forming the sample loop. A predetermined sample is introduced into the 16 first pipes 22 and further into the second pipe 24. The liquid present in the sample loop 16 is forced out of the sample loop 16 as the sample is injected, and is discharged to the outside of the system through the sample loop outlet port 20b1 and further through the drain port 20c. In addition, at the time of sample injection, the mobile phase inlet port 20a and the mobile phase outlet port 20 are connected through another circular groove 32c, and the mobile phase solvent constantly fed from the pump 4 flows. The separation column 8 is supplied through the line 6.

In addition, after a predetermined amount of sample is injected and held in the sample loop 16 at normal pressure in this way,
When introducing such a sample to the separation column 8 side together with the mobile phase solvent, when the rotor 18 is rotated clockwise as shown by the arrow in state C in FIG. 3, the sample loop inlet port 20e and the mobile phase outlet Before the ports 20 and 32c are connected to each other through an arc 32c, a second extension groove (shaded portion )34b
is connected to the mobile phase input port 20a, so that the second extension groove 34b and the arcuate groove 32a cooperate to connect the mobile phase input port 20a and the sample loop exit port 20b. From here, sample loop 1
The liquid in 6, in particular the sample held therein, is pumped by pump 4.
It will be pressurized by the mobile phase solvent sent from.

Then, while the liquid in the sample loop 16 is pressurized by the mobile phase solvent sent from the pump 4, the rotor 18 is further rotated, and when the amount of rotation reaches 60'', it is again shown in FIG. In state A, the arcuate groove 32c
The mobile phase outlet port 20f and the sample loop inlet port 20e are connected, whereby the mobile phase solvent sent from the pump 4 pushes out the sample held in the sample loop 16, and through the flow path 6, both Separation column 8
Then, a predetermined separation operation proceeds within the separation column 8, and the target sample components are separated.

In this way, in this sample introduction device 10, the third
As shown in the figure as state B and state D, the sample loop 16 is A sample loop connected to the other end of the sample loop 16 is connected to the sample loop inlet port 20e at the other end of the sample loop 16 before the sample loop inlet port 20e connected to one end is selectively connected to the sample injection port 20d and the mobile phase outlet port 20f. Since the loop exit port 20b will be connected to the drain port 20c or the moving/sliding port 20a, the sample loop 1
6 can be effectively depressurized or pressurized,
Therefore, there are problems when injecting a sample or when sending a sample to the separation column 8 side, in other words, problems with backflow of the sample from the sample injection bow 1-20d, or when introducing a sample from the sample loop 16 to the column 8. The problem of pressure fluctuations acting on the upper part of the column 8 has been effectively solved, and thus the deterioration of the column can be advantageously solved.

In the sample introduction device 10 of this embodiment, a predetermined sample injected from the sample injection port 20d of the hexagonal pulp 14 first passes through the sample loop inlet port 20e to the first sample loop 16 having a small diameter. pipe 2
In separation and analysis operations that target up to several tens of microliters of sample, such a small amount of sample is held in the first pipe 22. By doing so, the degree of diffusion of the sample can be effectively suppressed depending on the diameter of the first pipe 22, thereby advantageously suppressing or preventing a decrease in the number of theoretical plates in the separation column 8. This is possible. Therefore, regarding the size of the first pipe 22, the length and diameter are appropriate to accommodate the amount of sample for purposes such as analysis where diffusion inside the sample loop 16 is a problem. The decision will be made accordingly.

In addition, when a sample amount up to several tens of millimeters is targeted for the purpose of preparative separation, etc., when such a large amount of sample is injected, the first pipe 22 of the sample loop 16
After the inside is filled with the sample, the sample is guided into the pipe 24 with a larger diameter (inner diameter) and a large amount can be held there. Therefore, when holding a large amount of sample, the length of the sample loop 16 is There is no need to make it that long,
This makes it possible to advantageously retain a target amount of sample. Note that the length and diameter of the second pipe 24 will be determined as appropriate depending on the large amount of sample to be held.

In this way, the sample loop 16 is constructed from pipes of different diameters, and the sample loop 16 is several tens of meters long! By having a capacity of Therefore, it is possible to inject and hold a sample of several μβ to several tens of ml in one sample loop 16 without having to replace the sample loop, and the troublesome work and effort of replacing the sample loop according to the sample amount is eliminated. It's not necessary at all.

Although one embodiment of the present invention has been described in detail above, it goes without saying that the present invention is not to be construed as being limited only to such illustrative specific example, and the present invention may deviate from its spirit. It should be understood that various changes, modifications, improvements, etc. can be made and implemented based on the knowledge of those skilled in the art.

For example, the first and second extension grooves 34a, 3 in the previous example
Regarding 4b, in addition to cases in which they are provided at the same time, in cases where only one of the functions of pressurizing or depressurizing the liquid inside the sample loop 16 is required, an extension groove for one of them may be provided. Even if the extension grooves 34a and 34b are arranged in such a manner, the hexagonal valve 14
When the rotating direction of the rotor 18 is reversed from the previous example,
They are connected to adjacent arcuate grooves 3 as shown in FIG.
They are provided as extensions extending a predetermined length from the opposing ends of 2a and 32b in a direction toward each other.

In FIG. 4, a predetermined sample is placed in the sample loop 16.
When introducing the sample into the sample, by rotating the rotor 18 in the direction of the arrow in the A state, the sample loop outlet port 20b of the sample loop 16 connects to the drain port 20 via the first extension groove 34a and the circular arc groove 32b.
C, the pressure inside the sample loop 16 is reduced, and the sample inside the sample loop 16 is transferred to the separation column 8.
When introducing the rotor 18 in the direction of the arrow in state B in FIG.
A second extension groove 34b provided at one end of the sample loop 16 is connected to the sample loop outlet port 20b, thereby connecting the sample loop 16 to the mobile phase inlet port 20a. The liquid (sample) becomes pressurized.

Further, as the six-way valve constituting the sample introduction device of the present invention, in addition to the usual type in which the stator 28 is provided with six ports 20a to 20f as shown in the example, improved types thereof, such as the one shown in FIG. As shown, the sample injection port is composed of a needle port 36 provided on the rotor 1, and a predetermined sample is injected with a syringe through this needle port 36. However, it is possible to enjoy the effect of effectively shifting the liquid inside the sample loop 16 from a normal pressure state to a pressurized state or from a pressurized state to a normal pressure state.

In the rheodyne type valve shown in FIG. 5, unlike the previous example, the rotor 18 is provided with two arcuate grooves 32a and 32c extending over an angular range of 60°, and one of the arcuate grooves 32a First and second extension grooves 34a and 34b of a predetermined length are provided at both ends of the groove.

Then, as the rotor 18 rotates, these two extension grooves 34a and 34b are rotated in the direction of the arrow from the state A when introducing a sample into the sample loop 16, for example, so that the first extension groove 34a is drain port 20
In addition, when the four samples in the sample loop 16 are connected to the separation column 8, the rotor 18 is rotated in the direction of the arrow in the state shown in B to connect the second extension. Groove 34b is now connected to mobile phase artificial port 20a.

Further, the first and second sub-connection paths according to the present invention are provided in the circumferential direction of the rotor 18 as extension grooves of the arcuate grooves 32a to 32c, which are the main connection paths, in the previous example. It is also possible to provide it on the 28 side, examples of which are shown in FIGS. 6 to 8, respectively.

First, FIGS. 6 and 7 show different examples applied to a normal six-way valve. In FIG. 6, the first sub-connection path is connected to the extension 38a of the drain port 20c.
As shown in FIG.
The extension portion 38a of the stator 28 is provided at the sliding contact portion of the stator 28 with respect to the rotor 18 so as to extend toward the sample loop outlet port 2Ob side by a predetermined length. Therefore, when the rotor 18 is rotated in the direction of the arrow in state A in FIG. 6, the sample loop outlet port 20e and sample injection port 20d are 20b and the drain port 20c are connected by the arcuate groove 32a and the first extension (port) 38a, and when the rotor 18 is rotated in the direction of the arrow in state B in FIG. Before the sample loop inlet port 20e is connected to the mobile phase outlet port 20f via the circular arc groove 32C, the sample loop outlet port 20b is connected to the mobile phase outlet port 20f.
is the second extension (port) 38b and one circular arc groove 32a.
The mobile phase inlet port 20a can then be connected to the mobile phase inlet port 20a.

In the example shown in FIG. 7, the first and second sub-connection paths extend from the sample loop outlet port 20b to the drain port 20c side at the sliding contact portion of the stator 28 with the rotor 18. First and second extensions 38a each extend a predetermined length toward the phase inlet port 20'a side.
, 38b, and as in the case of FIG. 6, the sample loop 16 is connected to the drain port 20C or the mobile phase inlet port 20a due to the presence of the first and second extensions 38a and 38b. The connection will be made in advance.

Furthermore, FIG. 8 shows an example in which first and second sub-connection paths are provided at the sliding contact portion of the stator 28 with respect to the rotor 18 in a rheodyne type valve, and in the case of FIG. Similarly, a first extension 38a extending a predetermined length from the drain port 20c to the sample loop outlet port 20b serves as a first sub-connection path, and a predetermined length extends from the mobile phase inlet port 20a to the sample loop outlet port 20b. A second extension 38b extending in length is provided in each case as a second sub-connection path. The connection of each port in this type of valve is the same as the example shown in FIG. 6, so a detailed explanation will be omitted.

Additionally, extension grooves 34a, 34b and extension portions 38a, 3
8b may be combined to form the first sub-connection path and the second sub-connection path.

In addition, in the present invention, the effect of pressurizing or depressurizing the liquid inside the sample loop 16 is achieved by the extension grooves 34a, 34b and the port extension 38 when the rotational speed of the rotor 18 is constant.
a, 38b (length on the circumference), and the effect becomes more pronounced as their lengths become longer. In order to make one of the effects of pressurizing or depressurizing the liquid inside the loop more effective, it is desirable to make the extension groove or port extension that is expected to have that effect relatively long. However, it goes without saying that the length must be determined so that the connection path formed by adding one arcuate groove and an extension groove or port extension does not connect three ports at the same time. be.

Furthermore, in the example shown in FIG.
Although it is made up of two pipes (No. 4), it is also possible to make up a larger number of pipes with different inner diameters, thereby avoiding the need to make the pipe length too long to reach a larger sample capacity range. It can be introduced without reducing the number of theoretical plates, and the aperture (inner diameter)
There is no problem in constructing the sample loop 16 with a pipe whose value gradually changes. In that case, the smallest diameter portion of the pipe will be connected to the sample loop inlet port 20e of the hexagonal valve 14.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an example of a liquid chromatograph equipped with a sample introduction device according to the present invention, and FIGS. FIG. 3 is an explanatory diagram showing each operating state of the rotor in the hexagonal valve, and FIGS. 4 to 8 are diagrams showing the hexagonal valve having different sub-connection passages. It is an explanatory diagram showing an operation mode. 2: Storage tank 4: Pump 6: Channel 8: Separation column 10: Sample introduction device 14: Six-way valve 16: Sample loop °18: Rotor 20a: Mobile phase inlet port 20b; Sample loop outlet port 20C Ni drain port 20d: Sample Injection port 20e: Sample loop inlet port 20f: Mobile phase outlet port 22: First pipe 24: Second pipe 26: Valve body 28: Stator 30: Rotation knobs 32a to 32c: Arc groove 34a: First extension? R34b: Second extension groove 36: Needle port 38a: First extension 38b: Second extension Applicant
Hani Chemical Co., Ltd. Figure 1 Figure 2 (b)

Claims (7)

[Claims] (1) A six-way valve that switches the flow path by rotation of the rotor relative to the stator is arranged on the flow path between the mobile phase pump and the separation column of the liquid chromatograph, and the mobile phase inlet port is connected to the mobile phase pump. The remaining four ports of the six-way valve are connected to the sample loop outlet port, the drain port, the sample injection port, and the sample injection port. A sample introduction device configured as a loop inlet port and provided with a sample loop for holding a predetermined sample injected through the sample injection port between the sample loop outlet port and the sample loop inlet port, In addition to a plurality of main connection paths provided in the rotor of the six-way valve for connecting the six ports in a predetermined combination, rotation of the rotor of the six-way valve causes the sample loop inlet port to connect to the sample injection port. a first sub-connection connecting said sample loop outlet port to said drain port in cooperation with one of said main connections prior to being connected to said one of said main connections; a second sub-connection path cooperating with one of the main connection paths to connect the sample loop outlet port to the mobile phase inlet port prior to the sample loop inlet port being connected to the mobile phase outlet port; A sample introduction device in a liquid chromatograph, characterized in that it is provided on the rotor and/or the stator. (2) The sample introduction device according to claim 1, wherein the first or second sub-connection path is provided on the rotor with a predetermined length in the circumferential direction of the rotor as an extension of the connection path. . (3) The first and second sub-connection paths are provided in the rotor as extensions at both ends of one of the main connection paths, each having a predetermined length in the circumferential direction of the rotor. Sample introduction device as described in section. (4) The first and second sub-connection paths are provided as extensions extending in a direction approaching each other from opposite ends of two adjacent main connection paths, each extending a predetermined length in the circumferential direction of the rotor. Claim No. 1 provided in
Sample introduction device as described in section. (5) The first or second sub-connection path is connected to a sliding contact portion of the stator with respect to the rotor, to the sample loop exit port side as an extension of the drain port, or as an extension of the mobile phase inlet port. The sample introduction device according to claim 1, wherein the sample introduction device is provided so as to extend for a predetermined length on the sample loop exit port side. (6) The first and second sub-connection paths are provided with predetermined lengths from the sample loop outlet port to the drain port side and to the mobile phase inlet port side, respectively, at the sliding contact portion of the stator with respect to the rotor. The sample introduction device according to claim 1, which is provided as an extending portion. (7) The sample loop is composed of pipes of different diameters, and a predetermined length portion of the sample loop on the side connected to the separation column side flow path is connected to the mobile phase pump side flow path. 7. The sample introduction device according to any one of claims 1 to 6, wherein the pipe has a diameter smaller than that of the portion on which the sample is introduced.