JPH0552749U - Differential refractometer - Google Patents

Abstract

(57) [Summary] [Purpose] To enable measurement by appropriately switching between encapsulation mode and parallel flow mode. [Structure] In the filling mode, the ports H3 and H5 of the 6-way valve are connected by the 4-way valve 13 or the pipe 22.
The outflow port H1 of the sample cell S and the inflow port H2 of the reference cell R are connected, and then H1 is connected to the drain H6 to enclose the reference cell R. In the parallel flow mode, H3 and H5 are connected to the reference liquid source 19 and the drain, respectively, and the outlet H of the sample cell S is
1 to H6, reference cell R inlet H2 to H3, outlet H4
To H5.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a differential refractometer used for a liquid chromatograph or the like.

[0002]

[Prior Art]

 A differential refractometer is a device that puts a sample solution and a reference solution in each cell of a detection cell divided into a sample cell and a reference cell, and passes light through both cells to detect the difference in refractive index between the two solutions. Therefore, the differential refractometer is provided with a flow path system for supplying the sample liquid and the reference liquid to each cell of the detection cell.

Two types of flow path systems are used in the conventional differential refractometer. One is a type in which the reference liquid does not flow in the reference cell and is sealed in the cell when the sample is measured. Usually, the piping configuration is as shown in FIG. In this method, the reference liquid (mobile phase), which first passed through the column 15 of the liquid chromatograph, enters the sample cell S 1 of the detection cell 11, exits there, and then passes through the three-way valve 22 to refer to the detection cell 11 again. Enter cell R. The reference liquid that has left the reference cell R is discharged from the drain. When measuring the sample, the three-way valve 22 is switched to seal the reference liquid in the reference cell R, and the sample liquid from the column 15 is discharged to the drain immediately after passing through the sample cell S. Hereinafter, this is referred to as an encapsulation mode.

The other is a method of providing independent channels for the sample cell S and the reference cell R, as shown in FIG. With this method, the conditions for both solutions during measurement can be made uniform, so the baseline during measurement is stable, and high-sensitivity analysis can be performed. Hereinafter, this is called a parallel flow mode. The reference liquid side flow passage is usually provided with a flow passage resistance 18 having a value similar to that of the sample liquid side column 15.

[0005]

[Problems to be solved by the device]

 In the differential refractometer using the method shown in Fig. 4, since the reference liquid is enclosed during measurement, it is difficult to match the conditions such as the temperature of both liquids, and it is difficult to perform highly sensitive analysis because the baseline is not stable. Is. On the other hand, although the differential refractometer according to the method of FIG. 5 can perform high-sensitivity measurement, it has drawbacks such as the need for two pumps and the large amount of mobile phase used. Traditionally, these two types of differential benders have been manufactured separately.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a differential refractometer capable of performing measurement by arbitrarily switching these two methods. It is in.

[0007]

[Means for Solving the Problems]

 The present invention, which was made to solve the above problems, divides a transparent detection cell into a sample cell and a reference cell, and puts a sample solution and a reference solution in each cell to measure the difference in refractive index between the cells. In the differential refractometer, port H1 connected to the outlet of the sample cell, port H6 connected to the drain, port H2 connected to the inlet of the reference cell, and port connected to the outlet of the reference cell A 6-way switching valve that connects 3 ports each of 6 ports of H4 and 2 ports H3 and H5 that can be switched to each individual connection or interconnection to the reference liquid supply port and drain. It is characterized by being provided.

[0008]

[Action]

 In the sealed mode, ports H3 and H5 of the 6-way switching valve are interconnected. Then, first, the outlet H1 of the sample cell is connected to the inlet H2 of the reference cell, the outlet H4 of the reference cell is connected to H3, and H5 is connected to the drain H6. As a result, the reference liquid flows through the sample cell and the reference cell. Next, H1 is connected to the drain H6 to allow the sample solution to flow into the sample cell, the ports H2 and H3, H4 and H5 are connected, and the reference cell R is sealed. In the parallel flow mode, H3 and H5 are connected to the reference liquid supply port and the drain, respectively. Then, the outlet H1 of the sample cell is connected to the drain H6, the inlet H2 of the reference cell is connected to the reference liquid supply port H3, and the outlet H4 is connected to the drain H5.

[0009]

【Example】

 The construction and operation of the differential refractometer for a liquid chromatograph, which is an embodiment of the present invention, will be described with reference to FIGS. As shown in FIGS. 1 and 2, in addition to the detection cell 11 having the sample cell S and the reference cell R, the differential refractometer 10 of the present embodiment has two rotary valves 12 of a 6-way valve and a 4-way valve, Equipped with 13. Of these, the six ports H1 to H6 of the 6-way rotary valve 12 are connected as follows. H1: sample cell S outlet H2: reference cell R inlet H3: third port Q3 of the four-way rotary valve 13 H4: reference cell R outlet H5: four-way rotary valve 13 second port Q2 H6: drain

The four ports Q1 to Q4 of the four-way rotary valve 13 are connected as follows. Q1: Drain Q2: 5th port H5 of 6-way rotary valve 12 Q3: 3rd port H3 of 6-way rotary valve 12 Q3: Reference liquid supply source (pump 19) The sample cell S inlet is a liquid chromatograph. It is connected to the column 15.

A. When the differential refractometer of this embodiment is used in the enclosed mode, the procedure is as follows.

A-1: First, the 6-way rotary valve 12 and the 4-way rotary valve 13 are placed at the positions shown in FIG. 1 (a). Then, only the mobile phase (reference liquid) is supplied to the differential refractometer 10 through the column 15 by the pump 17 without inserting the sample from the injector 16. At this time, the mobile phase sequentially passes through the sample cell S and the reference cell R in the differential refractometer 10 by the following route. Sample cell S → 6 way rotary valve [H1 → H2] → Reference cell R → 6 way rotary valve [H4 → H3] → 4 way rotary valve [Q3 → Q4] → Drain

A-2: Next, the 4-way rotary valve 13 is left as it is, the 6-way rotary valve 12 is turned to the position shown in FIG. 1B, and the sample is introduced into the column 15 from the injector 16. At this time, the sample liquid is discharged to the drain without flowing through the reference cell R as follows. Sample cell S → 6-way rotary valve [H1 → H6] → drain On the other hand, the path passing through the reference cell R is closed as follows. Reference cell R → 6 way rotary valve [H4 → H5] → 4 way rotary valve [Q2 → Q3] → 6 way rotary valve [H3 → H2] → Reference cell R

B. When the differential refractometer of this embodiment is used in the parallel flow mode, the procedure is as follows. The 6-way rotary valve 12 and the 4-way rotary valve 13 are placed in the positions shown in FIG. As a result, the sample liquid from the column 15 passes only the sample cell S as follows. Sample cell S → 6-way rotary valve [H1 → H6] → drain On the other hand, the reference liquid supplied by the pump 19 passes only the reference cell R in the following route. 4-way rotary valve [Q4 → Q3] → 6 way rotary valve [H3 → H2] → Reference cell R → 6 way rotary valve [H4 → H5] → 4 way rotary valve [Q2 → Q1] → Drain The reference liquid (mobile phase) flows in each cell S, R completely independently.

The rotation of the 6-way rotary valve 12 and the 4-way rotary valve 13 when switching between the above modes may be performed manually or by a motor. When using a motor, it is desirable to provide a control device so that the rotary valves 12 and 13 are automatically switched by switching the button for each mode.

In the above embodiment, the reference liquid passage was switched using the 4-way rotary valve 13 when switching from the sealed mode to the parallel flow mode. However, the switching of the flow path for this side should be performed manually. Good. That is, as shown in FIG. 3, the 4-way rotary valve is discharged, and in the filling mode (A), the fifth port H5 of the 6-way rotary valve 12 and the third port H3 are connected by the pipe 20. In the parallel flow mode (B), the third port H3 of the 6-way rotary valve 12 is connected to the reference liquid supply source (pump 19) and the fifth port H5 is connected to the drain.

[0017]

[Effect of the device]

 In the differential refractometer according to the present invention, the enclosing mode and the parallel flow mode can be appropriately switched by switching the 6-way valve. As a result, the consumption of mobile phase can be suppressed by using the parallel flow mode when it is necessary to perform highly accurate measurement and by using the confinement mode when high measurement accuracy is not required.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a differential refractometer according to an embodiment of the present invention in a sealed mode.

FIG. 2 is a circuit diagram of the above embodiment in a parallel flow mode.

FIG. 3 is a circuit diagram of a differential refractometer which is another embodiment of the present invention.

FIG. 4 is a circuit diagram of a conventional differential refractometer dedicated to a sealed mode.

FIG. 5 is a circuit diagram of a conventional differential refractometer for parallel flow mode only.

[Explanation of symbols]

10 ... Differential refractometer 11 ... Detection cell 12 ... 6-way rotary valve 13 ... 4-way rotary valve 15 ... Liquid chroma and graph column 16 ... Injector 20 ... Interconnection pipe 22 ... Three-way valve

Claims (1)

[Scope of utility model registration request] 1. A differential refractometer in which a transparent detection cell is divided into a sample cell and a reference cell, and a sample solution and a reference solution are put in each cell to measure the difference in refractive index between the sample cell and the reference cell. Connected ports, ports connected to the drain, ports connected to the inlet of the reference cell, ports connected to the outlet of the reference cell, and individual connections to the reference liquid supply port and the drain or to each other. A differential refractometer, which is provided with a two-way switchable connection and a six-way switching valve that connects three six ports each of two ports.