JPH04301563A - Minute sample injector - Google Patents

Abstract

PURPOSE:To obtain a minute sample injector which can inject a very minute amount of sample to be measured, with excellent reproducibility. CONSTITUTION:A disk-shaped rotor 7, a shaft rotating integrally with the rotor 7, a handle 13 for rotating the rotor 7 through the intermediary of the shaft, and a first disk-shaped stator 8 disposed oppositely to the rotor 7, are provided. A second disk-shaped stator 10 disposed oppositely to the rotor 7 with the first stator 8 interposed, and first to sixth holes are made at equal intervals along the circumference of the second stator 10. In the rotor 7, first and second grooves are formed in the shapes of circular arcs on the side being in contact with the first stator 8, and in the second stator 10, a third groove is formed to be long in the central part of the side being in contact with the first stator 8. switching of internal flow passages is made with the rotor 7 rotated by 60 deg..

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample injector that is attached to a liquid chromatograph or ion chromatograph and is capable of stably injecting a very small amount of sample.

0002

2. Description of the Related Art FIG. 3 is an explanatory diagram of the configuration of an ion chromatograph equipped with such a sample injector. In this figure, 1a is a tank in which a mobile phase made of, for example, a carbonate solvent is stored, 1b is a tank in which a scavenger liquid is stored, and 1
c and 1d are waste liquid tanks, 2a and 2b are liquid pumps, 3 is a sample injector, 4 is a separation column filled with, for example, an anion exchange resin with a low ion exchange capacity, and 5 is, for example, an ion exchange membrane 5.
The suppressor is divided into an inner chamber 5b and an outer chamber 5c by a, and 6 is a detector, for example, a conductivity detector.

In the ion chromatograph having such a configuration, initially, the sample injector 3 is off and its internal flow path is in a solid line connection state. When the pump 2a is driven, the mobile phase in the tank 1a is transferred from the first port 3a of the sample injector 3 to the groove n to the second port 3b to the separation column 4 to the inner chamber 5b of the suppressor 5 to detection. The liquid is discharged to the waste liquid tank 1c through the vessel 6. Furthermore, when the pump 2b is driven, the scavenger liquid in the tank 1b is discharged into the waste liquid tank 1d via the outer chamber 5b of the suppressor 5. Therefore, the cations contained in the mobile phase flowing in the inner chamber 5b are ion-exchanged via the ion exchange membrane 5a, and the conductivity background of the eluent is reduced.

On the other hand, using the syringe 3h, the sample injector 3
When the sample to be measured is injected from the third port 3c of the sample injector 3, the sample is transferred from the third port 3c of the sample injector 3 to the measuring tube 3g to the sixth
It flows through port 3f → groove 3m → fifth port 3e, filling the inside of metering tube 3g. In this state, when the sample injector 3 is turned on and its internal flow path is switched to the broken line connection state, the sample to be measured in the measuring tube 3g is transported to the separation column 4 by the mobile phase, and the sample to be measured is transferred to the separation column 4 by the mobile phase. The ionic species in the sample to be measured are separated chromatographically. The sample to be measured separated in this way is stored in the inner chamber 5 of the suppressor 5.
It is detected by the detector 6 via b.

[0005]

However, in the conventional example described above, the amount of sample injected by the sample injector 3 is determined by the amount of the sample to be measured, the size of the separation column 4, etc. Ta. Further, the sample injection amount may also change depending on whether the measurement conditions (for example, the pH concentration of the mobile phase, etc.) are easily influenced by the properties of the sample to be measured or the solvent. Therefore, in order to introduce a minute amount of the sample to be measured into the separation column 4 using the sample injector 3, the measuring tube 3 must be
The methods used have been to reduce the internal volume by reducing the inner diameter and length of tube 3g, or to partially inject the sample to be measured into measuring tube 3g using syringe 3h.

However, the method of reducing the internal volume by reducing the inner diameter and length of the measuring tube 3g has the disadvantage that it is difficult to produce a measuring tube with an internal volume of 5 μl or less with good reproducibility. In addition, when partially injecting the sample to be measured into the measuring tube 3g using the syringe 3h, it is possible to inject up to about 0.5 μl using the small-capacity syringe 3h, but the reproducibility is poor. The disadvantage was that it was difficult to inject.

The present invention has been made in view of the above circumstances, and its object is to provide a microsample injector capable of injecting a microscopic amount of a sample to be measured with good reproducibility.

[0008]

[Means for Solving the Problems] The present invention provides a micro sample injector that includes a disk-shaped rotor, a shaft that rotates integrally with the rotor, and a rotor that rotates through the shaft. a handle for rotating the rotor; a disk-shaped first stator disposed opposite to the rotor;
a disk-shaped second stator disposed opposite to the rotor via the rotor; and first to sixth holes bored at equal intervals along the circumference of the second stator. and a first arc-shaped surface of the rotor that is in contact with the first stator.
and a third groove formed in an elongated shape in the center of the surface of the second stator that contacts the first stator; 1st to 6th
seventh to twelfth holes drilled at positions corresponding to the holes, a mobile phase introduction channel connected to the first hole, and the second
A mobile phase lead-out flow path connected to the hole, a test liquid introduction flow path connected to the fourth hole, and a test liquid lead-out flow path connected to the fifth hole are provided, and the rotor The above-mentioned problem has been solved by adopting a configuration in which the internal flow path is switched by rotating the internal flow path by 60 degrees.

[0009]

[Operation] The present invention operates as follows. That is, at first, the sample introducer of the embodiment of the present invention is turned off, and the mobile phase introduced from the mobile phase introduction channel flows from the first hole of the second stator to the first hole of the first stator. → the first groove of the rotor → the second hole of the first stator → the second hole of the second stator, and is discharged from the mobile phase outlet channel. The liquid to be measured introduced into the rotor hole with the syringe is transferred from the first hole to the first stator hole to the second stator groove to the first stator hole to the rotor. -> the second groove of the first stator → the hole of the second stator, and is discharged from the outlet flow path of the liquid to be measured. In this way, the groove of the second stator is filled with the liquid to be measured. Next, the sample introducer of the embodiment of the present invention is turned on, and the mobile phase introduction channel Q1
The mobile phase introduced from the first hole of the second stator → first hole of the first stator → first groove of the rotor → hole of the first stator → hole of the second stator The mobile phase passes through the groove → the hole in the first stator → the second groove in the rotor → the hole in the first stator → the second stator, and is discharged from the mobile phase outlet flow path. In addition, the liquid to be measured introduced into the hole of the rotor with the syringe passes through the first hole → the hole of the first stator → the hole of the second stator, and is discharged from the extraction flow path of the liquid to be measured. Ru.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of the present invention, and in the figure, 7 is a disk-shaped rotor made of ceramic, for example, and 8 is a rotor 7 disposed opposite to it. a disc-shaped first stator, 9 a spacer, 10
11 is a shaft (or bearing unit); 12 is a housing; The handle that rotates the rotor 7 is shown.

FIG. 2 is an explanatory diagram showing the main part of the embodiment of the present invention. In the figure, (A) shows the rotor, and (B) shows the first stator. , (c) shows the surface of the second stator facing the first stator, and (d) shows the surface of the second stator facing the first stator.
The outside of the stator is shown. Also, in Figure 2,
7a is a hole provided so as to pass through the rotor 7, and 7b and 7c are first holes provided in a surface of the rotor 7 in contact with the first stator 8 and formed in an arc shape. , second
grooves, 71 to 73 are screw holes, 8a to 8f are first to sixth holes provided to penetrate the first stator 8, and 10a to 10d are holes that penetrate the second stator 10. The seventh to tenth holes 10e provided in this manner are connected to the first stator 8 through the spacer 9 in the second stator 10.
Q1 is a mobile phase introduction channel, Q2 is a mobile phase outlet channel, Q3 is a measurement liquid introduction channel, and Q4 is a third groove formed in an elongated shape in the center of the surface in contact with the This is the outlet flow path for the liquid to be measured.

The operation of the embodiment of the present invention will be explained below with reference to FIGS. 1 and 2. Initially, the sample introducer of the embodiment of the present invention is turned off and is in the state shown in FIGS. 1 and 2. In this state, the mobile phase introduction channel Q1
The mobile phase introduced from the first hole 10a of the second stator 10→the first hole 8a of the first stator 8→the first hole of the rotor
Groove 7b → second hole 8b of first stator 8 → second stator 1
The mobile phase is discharged from the mobile phase outlet channel Q2 through the second hole 10b. Also, with syringe 3h, hole 7a of rotor 7
The liquid to be measured introduced into the first hole 7a → the first stator 8
hole 8f → groove 10e of second stator 10 → hole 8c of first stator 8 → second groove 7c of rotor 7 → first stator 8
The measured liquid passes through the hole 8d of the second stator 10 and then the hole 10c of the second stator 10, and is discharged from the outlet channel Q3 of the liquid to be measured. In this way,
The groove 10e of the second stator 10 is filled with the liquid to be measured.

Next, the sample introducer of the present invention is turned on and the handle 13 is rotated 60 degrees in the direction of the arrow in FIG. As a result, the rotor 7 is also rotated by 60 degrees in the direction of the arrow in FIG. 2(a). In this state, the mobile phase introduced from the mobile phase introduction channel Q1 is transferred from the first hole 10a of the second stator 10 to the first hole 8a of the first stator 8.
→ First groove 7b of rotor → Hole 8f of first stator 8 → Second groove
Groove 10e of stator 10 → hole 8c of first stator 8 → second groove 7c of rotor 7 → hole 8b of first stator 8 → second
It passes through the stator 10b and is discharged from the mobile phase outlet channel Q2. This outlet channel Q2 is connected to the separation column 4 in FIG.
It is connected to the. Therefore, the groove 10 of the second stator 10
The sample to be measured transported from e is chromatographically separated in a separation column. Further, the liquid to be measured introduced into the hole 7a of the rotor 7 with the syringe 3h is transferred from the first hole 7a to the hole 8e of the first stator 8 to the second stator 10.
The liquid to be measured is discharged from the outlet channel Q3 through the hole 10d.

By repeating the on-off operation of the sample introducer according to the embodiment of the present invention in this way, it becomes possible to inject a very small amount of the sample to be measured into an analyzer such as an ion chromatograph with good reproducibility. Note that the present invention is not limited to the above-described embodiments, and can be modified in various ways.

[0015]

According to the present invention as described in detail above, the stator of a conventional sample injector can be replaced with a second stator having a groove serving as a sample loop, thereby simplifying the structure. A micro sample injector with excellent injection reproducibility can be realized. Further, according to the present invention, even when the retention time of each component in the separation column is likely to fluctuate depending on the pH of the sample solvent or sample solution, there is also the advantage that measurement can be performed with good reproducibility. Furthermore, compared to the conventional example of sample injection using a microsyringe, this method has the advantage that there is no variation in the sampling of the sample to be measured by the measuring person, and measurements can be performed with good reproducibility.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of main parts of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a usage example of a conventional example. 1a, 1b tank 2a, 2b Liquid pump 3 Sample injector 4 Separation column 5 Suppressor 6 Detector 7 Rotor 8 First stator 10 Second stator

Claims (1)

[Claims] Claim 1: A disc-shaped rotor, a shaft that rotates integrally with the rotor, a handle that rotates the rotor via the shaft, and a handle that rotates the rotor via the shaft. disc-shaped first stators disposed opposite to each other;
a disk-shaped second stator disposed opposite to the rotor via a rotor and a spacer; a sixth hole; first and second grooves formed in an arc shape on a surface of the rotor in contact with the first stator; a third groove formed in an elongated shape in the center of the surface in contact with the first stator, and bored at positions corresponding to the first, second, fourth, and fifth holes, respectively, in the first stator; 7th to 10th holes, a mobile phase introduction channel connected to the first hole, a mobile phase outlet channel connected to the seventh hole, and a cover connected to the eighth hole. A sample comprising a measurement liquid introduction flow path and a measurement liquid output flow path connected to the ninth hole, and wherein the rotor is rotated by 60 degrees to switch the internal flow path. syringe.