JPH05215737A - Flow cell for liquid chromatograph - Google Patents

Abstract

PURPOSE:To widen the flow velocity range for flow cell application and reduce the time and man power for exchanging the flow cell and pipings by providing a flow cell pipes for detector with a bypass capable of flowing excess elution liquid. CONSTITUTION:The elution liquid in an elution liquid vessel 1 is sent to a connection pipe 2 with a pump 3, flows in a column 5 accompanying sample injected from an injector 4 and the dissociated elution liquid is guided to a flow cell 7 of a detector 6. At this moment, the elution liquid coming out of the column 5 is lead partly to the flow cell using a three-way joint 9 and the rest to a bypass 11. As the flowrate ratio is determined by the pipe diameters of the inlet side 81 of the pipe 8 of the flow cell 7 and the bypass 11, a supplimentary piping is prepared. If such a flow regulator as a needle pipe and the like is provided to the bypass 11, a desired flow ratio of elution liquid is controlled without changing the piping and thus the flowrate range applied to the flow cell 7 can be widened.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flow cell for a liquid chromatograph.

[0002]

2. Description of the Related Art Conventionally, a flow cell for a liquid chromatograph is connected to a flow cell installed in a detector with a column by a connecting path, and the other is provided with a draining path to a drain. Is configured to be discharged to the drain through the flow cell.

With such a structure, all the eluent that has passed through the column passes through the flow cell.

Further, the flow cell of the detector is selected and used according to the size of the column to be used, depending on the purpose of use such as analysis, fractionation, and large-scale fractionation.

Further, as the column size increases,
Since the flow velocity becomes faster, it was necessary to change the pipe diameter of the flow cell to a thick one according to the column size.

[0006]

As a result, the flow velocity to be adapted is determined depending on the type of flow cell, and if the flow velocity is higher than that, the pressure rises due to the pipe diameter, and the flow cell must be of that type. It is necessary to change the pipe diameter accordingly, but changing the flow cell each time is extremely troublesome work.

[0007]

Therefore, in the present invention,
Even if the column size to be used becomes large, it is not necessary to change the flow cell pipe diameter, and even if there is only one flow cell, it is designed to be able to handle small flow rates to large flow rates. The pipe is provided with a bypass capable of flowing an excess eluent into the flow cell.

[0008]

The present invention will be described in detail below with reference to an embodiment shown in the drawings. Reference numeral 1 denotes an eluent container, a connecting pipe 2 having one end immersed in the eluent container 1 communicates with an injector 4 via a pump 3, and further communicates with a detector 6 via a column 5.

It is preferable that the pump 3 is selectively used from a pulseless flow pump, a single plunger pump, a double plunger pump, etc., and a pressure gauge with a damper is used for the connecting pipe 2.

As the detector 6, a spectrophotometer, a fluorescence photometer, an RI detector or the like is used according to the purpose. Depending on the purpose, the column 5 is selected for analysis or preparative use, and is selected and used depending on the purpose such as a glass column or a stainless steel column.

Reference numeral 7 is a flow cell, and it is preferable to appropriately select the optical path length and the pipe diameter so that a small flow rate to a large flow rate can be handled. The pipe 8 of the flow cell 7 is provided with three-way joints 9 and 10 on the inflow 81 side and the outflow side 82, respectively, and a bypass 11 is provided between both the three-way joints 9 and 10.
It is convenient to use a pipe for the bypass 11 and to freely replace the pipe diameter with a desired one.

Further, the bypass 11 may be provided with a flow rate controller 12 such as a needle valve (FIG. 2).
The three-way joint 9 is provided only on the inflow side 81 of the pipe 8 ,
The bypass 11 connected to the three-way joint 9 can be left as it is in the drain without being connected to the outflow side 82 (FIG. 3).

Next, the operating state will be described. The eluent is sent by the pump 3 through the connecting pipe 2,
Column 5 with sample injected from injector 4
Sent to. Here, the sample is appropriately dissociated and guided to the flow cell 7 of the detector 6. At this time, when the eluent exiting the column 5 reaches the three-way Josinto 9, part of the eluent flows to the flow cell 7 and the other You can run to the bypass 11. This flow rate ratio is determined by the inflow side 81 of the pipe 8 of the flow cell 7 and the pipe diameter of the bypass 11. Further, when a flow rate controller 12 such as a needle valve is installed in the bypass 11, the desired flow rate can be selected and set by this adjustment.

In the case of the conventional method of flowing all the eluent from the column into the flow cell, for example, in the case of a preparative flow cell having an optical path length of 2 mm and a pipe diameter of 0.5 mm, the adaptive flow rate is 1 to
The flow rate is about 30 mL / min, and at higher flow rates, the pressure rises due to the pipe diameter, but even under the same conditions, if 9 flows to the bypass 11 and 1 flows to the flow cell side,
The adaptive maximum flow rate can be 30 + 270 mL / min. That is, it is sufficient to use the bypass 11 having a diameter of 1.5 mm.

When the inflow side 81 and the outflow side 82 of the pipe 8 of the flow cell shown in FIG. 3 are not separately connected, the eluent from the outflow side 82 is discharged and discarded. .

[0016]

According to the present invention as described above, a bypass capable of flowing an excess eluent into the flow cell is provided in the flow cell piping of the detector. Therefore, the bypass diameter can be changed or the needle valve can be used as the bypass. By changing the split ratio by changing the flow ratio of the flow cell and the bypass, it is possible to widen the adaptive flow velocity range, and as a result,
One flow cell can be used for small to large flow without changing the flow cell, which is convenient for practical use.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an embodiment of the present invention.

FIG. 2 is an explanatory view of a portion for another embodiment of the same as above.

FIG. 3 is an explanatory diagram of a portion for another embodiment of the same as above.

[Explanation of symbols] 1 Eluent container 2 Connection pipe 3 Pump 4 Injector 5 Column 6 Detector 7 Flow cell 8 Piping 9 Three-way joint 10 Three-way joint 11 Bypass

Claims (3)

[Claims] 1. A flow cell for a liquid chromatograph, characterized in that a bypass for allowing an excess eluent to flow into the flow cell is provided in a pipe of the flow cell of the detector. 2. A flow cell for a liquid chromatograph, wherein a three-way joint is provided on a pipe inflow side of the flow cell, and a bypass having a desired diameter is detachably attached to the three-way joint. 3. A flow cell for a liquid chromatograph, characterized in that a flow cell has a pipe inflow side and an outflow side connected by a bypass, and a flow rate controller is provided in the bypass.