JP2006138699A - Recycling liquid chromatograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recycling liquid chromatograph which prevents the diffusion back flow and stagnation of a sample not only to eliminate the contamination of a solvent tank, but also to exert no effect of a pulsation noise on a detector. <P>SOLUTION: In the recycling liquid chromatograph, constituted of the solvent tank for housing a solvent, a pump for sucking the solvent from the solvent tank, a sample injection device for injecting the sample to be analyzed, a column for separating the sample and a detector for extracting the separation result in the column as electrical signal, a conventional circulation dedicated flow channel is removed, and a buffer flow channel for a recycling flow channel capable of communicating with the pump is provided. Accordingly, diffusion back flow of the sample to the solvent tank is prevented and eliminates not only solvent tank contamination, but also exerts no effect on the pulsation noise on the detector. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recycled liquid chromatograph having a recycling mechanism.

In a conventional recycle liquid chromatograph, for example, as shown in FIG. 3, the solvent is supplied from the solvent tank 1 and sucked from the solvent suction port 2 and fed by the pump 4 during normal liquid feeding. The The solvent is sent under pressure by the pump 4. The sample is moved in and out by the sample injection device 5, the sample is separated through the column 6, and discharged through the detector 7 to the discharge port 9. At the time of recycling, the recycling valve 8 is switched, and the solvent that has come out of the detector 7 is supplied to the pump 4. The sample passes through the column 6 again, and further separation proceeds.
JP-A-8-35958

  However, in the conventional liquid chromatograph, the recycling flow path is not closed, and a phenomenon is observed in which the sample diffuses from the T-shaped connector 3 and flows backward to the solvent tank 1 side. As a result, the flow path to the suction port 2, the solvent tank 1, and the solvent in the tank may be contaminated, and the sample may stay in the circulation dedicated flow path R when the recycling is completed. Moreover, it is difficult to collect these samples, and valuable samples may be wasted.

  For the purpose of preventing this reverse flow phenomenon, when the solvent tank 1 and the T-shaped connector 3 are shut off during recycling to form a closed flow path, the flow path on the solvent tank 1 side that has absorbed pressure pulsation due to suction of the pump 4 until then. Disappears, the pulsation is superimposed on the detector 7, particularly the differential refractometer, as noise, and monitoring by the detector 7 becomes impossible, and the end of recycling cannot be determined.

  In addition, in order to form a recycling channel, a dedicated circulation channel R that is a closed channel when not recycled is required between the recycling valve 8 and the T-shaped connector 3. A part of the stagnation stayed, and the monitoring of the detector output signal was adversely affected when the recycling operation was performed during the subsequent sample injection.

  The present invention has been proposed in view of the above, and provides a recycled liquid chromatograph that prevents diffusion of the sample from flowing back into the solvent tank to eliminate contamination of the solvent tank and does not affect the detector with pulsating noise. It is intended.

  In order to achieve the above object, the liquid chromatograph of the present invention comprises a solvent tank that contains a solvent, a pump that sucks the solvent from the solvent tank, a sample injection device that injects a sample to be analyzed, and a sample separation Is a liquid chromatograph comprising a column in which the separation is performed and a detector for taking out the result of separation in the column as an electrical signal, wherein the conventional circulation dedicated flow path is abolished and a recycle flow path capable of communicating with the pump It is characterized in that a buffer flow path is provided.

  Further, the present invention selects a flow path for discharging the eluate from the detector, a recycle path for guiding the eluate from the detector to the pump suction port, and a buffer path for the recycle path It is characterized by having a flow path switching valve that is connected electrically.

  Further, the present invention is characterized in that a liquid level sensor is provided in the recycling flow path buffer flow path and an overflow flow path is provided.

  Further, the present invention is characterized by providing a function of collecting a sample diffused during a recycling operation and cleaning a contaminated flow path.

  In the present invention, the flow path switching valve is operated during the recycling to guide the eluate from the detector to the pump suction port, and the recycling flow path buffer channel and the pump suction port are communicated with each other. It is characterized by.

  Since this invention consists of an above-described structure, there can exist an effect which is demonstrated below.

  The liquid chromatograph of the present invention includes a solvent tank that contains a solvent, a pump that sucks the solvent from the solvent tank, a sample injection device that injects a sample to be analyzed, a column in which a sample is separated, and the column In addition to eliminating the conventional circulation dedicated flow path and providing a recycle flow path buffer flow path that can communicate with the pump, it is possible to reduce the diffusion back flow of the sample. This prevents contamination of the solvent tank and does not affect the detector with pulsation noise.

  In the present invention, a flow path for discharging the eluate from the detector, a recycle flow path for guiding the eluate from the detector to the pump suction port, and a buffer flow path for the recycle flow path are selected. In addition, since the flow path switching valve that is connected in a regular manner is provided, it is possible to prevent the sample from diffusing and flowing back and to eliminate contamination of the solvent tank. In addition, the pump pulsation noise does not affect the detector, and accurate analysis is possible.

  In the present invention, since the liquid level sensor is provided in the recycling flow path buffer flow path and the overflow flow path is provided, the liquid level of the recycling flow path buffer flow path can be kept constant.

  Further, in the present invention, the function of collecting the sample diffused during the recycling operation and the function of cleaning the contaminated flow path are provided, so that it can be collected when the sample flows backward during the recycling. Moreover, the contaminated flow path can be washed. Furthermore, these operations can be easily performed in parallel with the sample discharging operation.

  Further, in the present invention, the flow path switching valve is operated at the time of recycling to guide the eluate from the detector to the pump suction port, and the recycling flow path buffer channel and the pump suction port are communicated. The diffusion backflow of the sample to the solvent tank is prevented to eliminate the contamination of the solvent tank, and the detector is not affected by pulsation noise.

  Operates the flow path switching valve during recycling to guide the eluate from the detector to the pump suction port, and connects the buffer flow path for the recycling flow path and the pump suction port to prevent backflow of the sample during recycling. In addition, the object of eliminating the influence of pulsating noise on the detector can be achieved.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is a flow chart showing an embodiment of a recycle liquid chromatograph according to the present invention. Here, the recycled liquid chromatograph 10 includes a solvent tank 11 that contains a solvent, a pump 14 that sucks the solvent from the solvent tank 11, a sample injection device 15 that injects a sample to be analyzed, and a sample separation. The column 16 and the detector 17 that extracts the result of separation in the column 16 as an electric signal, and has a recycle channel buffer channel 22 that can communicate with the pump 14.

  The flow path 29 connected to the solvent tank 11 has a solvent suction port 12 disposed in the solvent tank and is connected to the flow path switching valve 25. The flow path 29 branches in the middle and is connected to the recycle flow path buffer flow path 22, and the other end is connected to the flow path switching valve 25. The recycle flow path buffer flow path 22 includes a solvent supply valve 26 and a liquid level sensor 23. Further, the recycling flow path buffer flow path 22 has an overflow line 24, and the other end of the overflow line 24 communicates with the diffusion sample collection port 27.

  The flow path switching valve 25 is connected to a flow path 30 having a cleaning / recovery port 28 and a recovery valve 21. Furthermore, a flow path leading to the discharge port 19 and a flow path leading to the pump 14 are connected.

  In the recycle liquid chromatograph 10 configured as described above, first, the flow path switching valve 25 is operated, and the pump 14 is operated in a state following the collect side (the solid line flow path in FIG. 1). As a result, the solvent in the solvent tank 11 is sucked from the solvent suction port 12, passed through the flow path switching valve 25, and sent by the pump 14 to be discharged through the sample injection device 15, the column 16, the detector 17, and the flow path switching valve 25 again. It is discharged from the outlet 19.

  At this time, the recycle flow path buffer flow path 22 is filled with a solvent up to a specified amount by the solvent supply valve 26 controlled by the liquid level sensor 23. Subsequently, the sample is introduced from the sample injection device 15, and the sample separated by the column 16 is monitored by the output signal of the detector 17.

  In addition, for a sample that is insufficiently separated and needs to be recycled, the flow path switching valve 25 is operated as shown in FIG. 2 to switch to the recycle side (the solid line flow path in the figure) to form a recycle flow path. The unseparated portion of the sample is led to the pump suction port, fed by the pump 14, and led again to the column 16 for re-separation.

  At this time, the flow path from the solvent suction port 12 is switched to the cleaning / recovery port 28 side, and the recovery valve 21 is closed. Thereby, the diffusion backflow of the sample to the solvent tank 11 side is prevented.

  Further, the pulsation of the pressure by the pump 14 in this recycled state is absorbed by the recycle flow path buffer flow path 22 when the recycle flow path buffer flow path 22 is connected.

  When separation is sufficiently advanced in the recycle state and the sample is discharged, the flow path switching valve 25 is operated to switch to the collect side (broken line in FIG. 2). The sample is discharged from the discharge port 19. At this time, the solvent is supplied again from the solvent tank 11, but the flow path to the solvent suction port 12, the solvent tank 11, and the solvent in the tank are not contaminated as described above.

  The sample may flow backward through the buffer channel 22 for the recycling channel due to diffusion during the recycling operation. This can be easily recovered by operating the recovery valve 21 and discharged from the diffusion sample recovery port 27. Further, it can be cleaned by simultaneous operation with the solvent supply valve 26. These operations can be easily performed simultaneously with the above-described sample discharging operation.

  Furthermore, since the recycle liquid chromatograph 10 of the present invention does not have a circulation dedicated flow path portion as in the conventional apparatus, the sample does not stay after the recycle operation.

FIG. 1 is a flow chart showing an embodiment of a recycle liquid chromatograph according to the present invention. FIG. 2 is a flow chart showing the recycled state of the recycled liquid chromatograph. FIG. 3 is a flow chart showing an example of a conventional recycle liquid chromatograph.

Explanation of symbols

R Circulation dedicated channel 10 Recycled liquid chromatograph 11 Solvent tank 12 Solvent suction port 13 T-connector 14 Pump 15 Sample injection device 16 Column 17 Detector 18 Recycling valve 19 Discharge port
21 Recovery valve 22 Recycle flow path buffer flow path
23 Liquid level sensor 24 Overflow line 25 Flow path switching valve 26 Solvent supply valve 27 Diffusion sample recovery port 28 Wash recovery port 29, 30 Flow path

Claims (5)

A solvent tank for storing the solvent, a pump for sucking the solvent from the solvent tank,
A sample injection device for injecting a sample to be analyzed, a column in which the sample is separated,
In a liquid chromatograph comprising a detector that extracts the result of separation on the column as an electrical signal,
A recycle liquid chromatograph comprising a recycle flow path buffer flow path capable of communicating with the pump.   The recycle liquid chromatograph according to claim 1, wherein a flow path for discharging the eluate from the detector, a recycle path for guiding the eluate from the detector to the pump suction port, and the recycle flow path A recycled liquid chromatograph comprising a channel switching valve for selectively connecting a buffer channel. In the recycling liquid chromatograph according to claim 1 or 2,
A recycling liquid chromatograph, wherein a liquid level sensor is provided in the recycling flow path buffer flow path and an overflow flow path is provided.   The recycling liquid chromatograph according to any one of claims 1 to 3, further comprising a function of collecting a sample diffused during a recycling operation and cleaning a contaminated flow path.   The recycling liquid chromatograph according to any one of claims 1 to 4, wherein a flow path switching valve is operated during recycling to guide the eluate from the detector to the pump suction port, and the recycling flow chromatograph. A recycle liquid chromatograph characterized in that a buffer path for a road and a pump suction port communicate with each other.

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