JPH0198963A - High temperature size eliminating chromatography device and its using method - Google Patents

Abstract

PURPOSE:To use a solvent which is solidified at a room temperature, and also, to easily perform an analytical measurement of a special sample such as a liquid crystal high polymer by controlling all of each part of a device and a passage system within a prescribed temperature range. CONSTITUTION:A pump 12 sucks a solvent in a solvent tank 11 and feeds a liquid. A sample injecting part 15 injects a sample of a prescribed quantity by bringing a syringe to manual operation to the solvent which has been fed out of the pump 12. A column 23 separates each component in the sample supplied from the injecting part 15 by a molecule size eliminating mechanism. A differential refractive index detector 16 detects each component which has been separated and allowed to flow out of the column 23. Also, a branch pipe 13 for drawing out a bubble in a passage system is provided. In this state, the column 23 and the detector 16 are brought to temperature control by a column thermostatic oven 28 and a circulating type thermostatic oven communicating to a water bath 29, respectively. Moreover, the solvent tank 11, the pump 12, the injecting part 15 and the passage system are heated by a ribbon heater, a hot plate, an air thermostatic oven, etc. and their set temperatures are controlled by a temperature controller 30.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a liquid chromatography device, and is particularly suitable for using a solvent that solidifies at room temperature, and has two-seven methods for reducing the amount of the solvent used. The present invention relates to a high-temperature size exclusion chromatography device and a method of using the same.

[Prior Art] Conventionally, gas chromatographs, which have been widely used for the separation and analysis of samples such as organic compounds, are limited to gas or vapor samples, making it difficult to measure non-volatile substances or substances that decompose when heated. Can not do it. On the other hand, liquid chromatographs use a liquid as a mobile phase, so if the sample is soluble in some kind of liquid, it can be measured. Because of these advantages, there has been remarkable progress in analysis technology using liquid chromatography.

In recent years, high-pressure-resistant, high-performance column packing materials have been developed, and it has become possible to use high-pressure liquid metering pumps.As a result, the linear velocity of the eluent passing through the column has increased significantly, and the separation speed has increased compared to gas chromatography. High performance liquid chromatography (HPLC) devices, which are comparable to autograph devices, have become widely used.

Currently, commercially available high-performance liquid chromatography devices are:
Some are used at room temperature and others are used at room temperature to 150°C. Among these, high-temperature size exclusion chromatography devices that can be operated from room temperature to 150°C handle polymer solutions that are insoluble at room temperature and dissolve only at high temperatures, so they are generally automatic measurement devices as explained below. It is true.

FIG. 8 is a block diagram schematically showing the configuration of such a conventional high temperature size exclusion chromatography apparatus.

In the figure, 1 is a solvent tank, 2 is a pre-pump, 3 is a main pump, 4 is a sample injection device, 5 is a column, 6 is a detector, 7 is a waste liquid tank, and 8 is a controller that controls each part of the apparatus. The sample injection device 4 includes a rotary table on which a plurality of capsules containing samples are set, and drives and controls this rotary table to automatically insert a syringe needle into a predetermined capsule, aspirate the sample, and fill each capsule. is configured to automatically measure samples within the

[Problems to be Solved by the Invention] By the way, liquid crystal polymers such as liquid crystal aromatic polyesters do not dissolve in most organic solvents regardless of room temperature or high temperature, but pentafluorocarbons with a melting point of 35°C Phenol (PPP) dissolves at an appropriate temperature above its melting point. Therefore, the inventor of the present invention attempted to dissolve the above-mentioned liquid crystal polymer in pentafluorophenol and analyze it using a conventional high-temperature device, but the conventional high-temperature device showed the following various problems. A problem arose.

In other words, because conventional high-temperature devices are designed to use solvents that are liquid at room temperature, there is no temperature control mechanism for the pre-pump and the piping that connects it. Unable to flow solvent through the system.

Additionally, even assuming that the surrounding area including the pre-pump is temperature-controlled, if a solvent that solidifies at room temperature, such as pentafluorophenol, is used, the solvent will condense in the flow path when the device temperature is returned to room temperature. Because it solidifies, if you try to raise the temperature again and take measurements, bubbles will form in the flow path, and conventional high-temperature devices cannot effectively remove the bubbles in the flow path between the pump and the solvent tank. Another fundamental problem is that the lack of a mechanism allows these air bubbles to enter the pump that pumps out the solvent, preventing the pump from starting.

In addition, even if conventional high-temperature equipment is equipped with a mechanism for controlling the temperature around the pre-pump and removing air bubbles, the entire equipment is large due to the automation of measurement, and as a result, the dead volume of the flow path system is increased. is large. Therefore, a large amount of solvent is required to fill the channel system with solvent. This is disadvantageous for analyzes using expensive solvents such as pentafluorophenol.

Size-exclusion chromatography devices for high temperatures do not necessarily need automatic operation as long as sample injection can be performed manually.

The present invention has been made in view of these circumstances, and is a system in which the temperature of the entire flow path system including the solvent tank is controlled, and air bubbles generated in the flow path between the solvent tank and the liquid pump are removed. The present invention aims to provide a high-temperature size exclusion chromatography device in which the dead volume of the channel system is small.

On the other hand, when the device is operating (heated state) and when stopped (room temperature state)
When using a solvent that undergoes a repeated solid-to-liquid phase change, this phase change is necessarily accompanied by a change in volume. When using a column packed with a packing material that has a separation ability by an exclusion mechanism, ■ the swelling degree of the gel changes significantly, ■ the pores of the gel and solid particles are destroyed or deformed, and ■ the pores of the packing material. It is expected that a gas phase will be generated inside the column, including the inside, and that the entire column shape will be deformed, which may reduce the efficiency of the column.

Therefore, the method of using the high-temperature size exclusion chromatography device according to the present invention aims to provide a method of using the device that prevents such a decrease in column efficiency.

[Means for Solving the Problems] The present invention employs the following means to solve the above problems.

That is, the high-temperature size exclusion chromatography apparatus according to the present invention includes a solvent tank, a pump that sucks the solvent in the solvent tank and sends the liquid, and a syringe that is manually operated to feed the solvent sent from the pump. A sample injection part for injecting a fixed amount of sample, and a filler such as a gel type or glass particles with pores to separate each component in the sample supplied from the injection part by a molecular size exclusion mechanism. a column, a detector for detecting each component separated and discharged from the column, a branch pipe for removing air bubbles provided in the flow path on the suction side of the pump, and a flow path system connecting each part of the device and these. and a temperature control mechanism that controls the temperature of all of the branch pipes within a certain temperature range, thereby allowing the solvent, which is solid at room temperature, to flow throughout the channel in a liquid state.

Storage tanks made of various materials are known as solvent tanks, but
For example, Pyrex, Teflon, stainless steel, etc. are used. As a simple solution, for example, a container containing a solvent such as pentafluorophenol can be used as it is.

As a pump for liquid feeding, a pump capable of obtaining a high discharge force for high performance liquid chromatography is desirable.

As this type of pump, either a mechanically driven pump or a gas pressure driven pump can be used, but it is desirable that the internal volume and dead volume of the pump be small.

The injection section for injecting the sample by manually operating the syringe preferably has a structure in which the barrel of the syringe enters a hole in a temperature-controlled block and is heated during injection. Further, the overall mechanism of the injection group is not particularly limited, but for example, there is an accumulation tube section that accumulates a certain amount of the sample injected from a syringe, and a storage tube section that transfers the sample stored in the accumulation tube section to the solvent flow path. It consists of a switching valve that feeds the air.

The column may be made of, for example, stainless steel, glass, or synthetic resin, and its shape may be spiral, U-shaped, linear, or the like. As the filler to be filled in this, particles having a size exclusion separation function such as polymer gel such as polystyrene gel, silica gel, and glass particles having pores are used.

The type of detector is not particularly limited and may be appropriately determined depending on the type of sample, but examples include a differential refractive index (R1) detector, an ultraviolet/visible absorption (UV/VIS) detector, etc. Examples include a flame ionization (FID) detector, a viscosity detector, a low angle laser light scattering (LALLS) detector, and an infrared absorption (JR) detector.

The branch pipe for removing air bubbles is a pipe similar to the channel pipe that does not flow the solvent.
For example, it is made of a styrene tube, a Teflon tube, etc., and has a structure in which air bubbles can be extracted from the outside of the device with a syringe or the like. This branch pipe must be provided on the suction side of the pump, and furthermore, when pressure is applied with liquid from this branch pipe, it is prevented from flowing into the solvent side, and this pressure is applied to the pump head. It is desirable to provide a similar valve.

As the temperature control mechanism, an appropriate mechanism is adopted depending on the functions of each part of the apparatus. For example, when pentafluorophenol is used as a solvent, it is necessary to control each part of the apparatus to a temperature of at least 35° C. or higher, which is the melting point of pentafluorophenol.

On the other hand, the upper limit of temperature control is determined by, for example, the usable temperature of the detector, and for example, when a differential refractive index (R1) detector is used, the upper limit is about 150°C. A column constant temperature bath is used to control the column temperature due to the need to obtain stable data. As this type of constant temperature bath, either an air constant temperature bath or a liquid high temperature bath may be used. For each part of the apparatus other than parts requiring particularly strict temperature control, such as the R1 detector and column, an air bath system or a heater block system is adopted.

A ribbon heater or the like may be wrapped around the flow path piping, solvent tank, etc. to control the temperature. In addition, as long as the branch pipe for removing air bubbles described above does not lead out from the flow pipe for too long, it can be maintained in a heated state by the residual heat transferred from the flow pipe without particularly attaching a heater to the branch pipe. can.

On the other hand, the method of using the device according to the present invention is that when performing analytical measurements using the device, a solid solvent such as pentafluorophenol is used, and a column packed with a packing material having the size exclusion mechanism is placed in a predetermined manner. It is characterized in that the column is left at a predetermined temperature without flowing the solvent until the temperature reaches an equilibrium state, and the solvent is passed through the column after the column filled with the packing material reaches a sufficient equilibrium. In this way, by flowing the solvent after the column packed with the packing material has sufficiently reached equilibrium, no gaps are formed in the column, and a decrease in column efficiency is minimized.

Embodiment FIG. 1 is a block diagram schematically showing the configuration of an apparatus according to the present invention.

In the figure, reference numeral 1 is a solvent tank, and I2 is a pump for high performance liquid chromatography that sucks the solvent in the solvent tank 11 and sends the liquid. A branch pipe 13 is provided on the suction side of the pump 12 to remove air bubbles from the flow path system. This branch pipe 13
By inserting a syringe into the opening at the tip and suctioning the syringe, air bubbles generated in the flow path on the suction side of the pump 12 can be easily removed. After removing the air bubbles, pressurizing the shilling supplies pressurized solvent to the pump 12, and the pump 12 can be easily started. Furthermore, since the branch pipe 13 is heated or given residual heat by a temperature control mechanism to be described later, bubbles can be easily removed even from a solvent that solidifies at room temperature.

There is a distributor 14 on the liquid sending side of the pump 12.
The solvent flowing out is distributed to the sample injection section 15 and the contrast side cell of the differential refractive index detector 16.

The sample injection unit 15 includes a block 18 that heats the syringe 17 to a predetermined temperature, and an accumulation tube 1 that accumulates a certain amount of the injected sample by manually operating the syringe 17.
9 and a switching valve 20. When no sample is injected, the solvent supplied from the distributor 14 flows out to the column side via the switching valve 20. On the other hand, during sample injection, the switching valve 20 is switched so that the solvent supplied from the distributor 14 passes through the storage tube 19. As a result, the sample accumulated in the accumulation tube 19 is mixed with the solvent and transferred to the column side. In addition, the code|symbol 21 is a branch pipe for overflowing the sample injected in excess.

The solvent flowing out from the sample injection part 15 is supplied to the column 23 via the filter 22. The column 23 was filled with polystyrene gel (Shodex K-8
0M, 1 piece, Showa Denko) was used. The solvent separated and flowed out from the column 23 is supplied to the sample side cell of the differential refractive index detector 16. The differential refractive index detector 16 has a sensitivity approximately proportional to the difference in refractive index between the solvent in the control side cell and the solute in the sample side cell, and exhibits a response proportional to the solute concentration.

In addition, the reference numeral 24 is a waste liquid tank that collects the solvent flowing out from the differential refractive index detector 16, 25 is a recorder that records the signal detected by the differential refractive index detector 16, and 26 is a unit that appropriately calculates the signal recorded in the recorder. The processing computer 27 is a plotter that plots the measurement results processed by the computer 26.

Next, the temperature control mechanism provided in this device will be explained.

The temperature of the column 23 is controlled by a column constant temperature bath 28. Further, the differential refractive index detector 16 is connected to the water bath 2.
The temperature is controlled by a circulating constant temperature bath connected to 9. The other solvent bath 11, pump 12, sample injection part 15, and flow path system are appropriately heated by a ribbon heater, hot plate, air constant temperature bath, etc., and the set temperatures of these are controlled by a temperature controller 30.

As described above, in the device according to this example, when the entire system reaches a predetermined temperature and the entire column reaches equilibrium, if pressure is applied at the same time as removing air bubbles from the air vent, the liquid delivery by the pump becomes extremely difficult. Because it is easy to start, and because sample injection is performed manually, the equipment is simplified, the dead volume of the flow path is very small, and the amount of solvent required to fill the flow path is reduced. The amount is about 5CC. Incidentally, because conventional automatic equipment has a large dead volume,
Approximately 50 cc of solvent is required to fill the channel system.

Next, the solvent, sample, and measurement conditions used in this example will be explained.

■ Pentafluorophenol (P P P ) (Ar
liquid crystal aromatic polyester Sample A: Xydar 5RT-500 (Drich Chemical)
) Sample B: Ekonol fiber (Sumitomo Chemical Industries)
Sample C: Vectra A-900 (Ce!anes
e) Discreet condition ■ Column temperature Pentafluorophenol is solid at room temperature, and the viscosity of the solution near its melting point (35°C) is high. Therefore, it is thought that it is better to perform measurements at high temperatures, and we investigated the optimal temperature. Changes in column efficiency due to benzene were measured at temperatures of 40°C to 70°C. The results are shown in FIG.

At 40°C to 60°C, the column efficiency increases significantly as the temperature increases. This is thought to be related to both the swelling of the polystyrene gel and the decrease in solvent viscosity.

The fact that the increasing curve becomes slower at 60°C to 70°C may also indicate that the polystyrene gel has become excessively swollen. That is, this seems to suggest that the swelling state of the polystyrene gel is close to the optimum at 60 to 70°C. Although it is expected that the efficiency will be somewhat higher at temperatures higher than this, it is clear that the life of the column will be shorter as it is used at higher temperatures, so in this example, it was used at a temperature around 60°C. I made it.

■ Column stability Pentafluorophenol is
Since phase changes between liquid and solid occur repeatedly during C) and stop (room temperature), repeating the cycle of operation (heating) and stop (cooling) as described above may reduce column efficiency.

FIG. 3 is a diagram showing changes in column efficiency due to repeated cycles of heating and cooling.

In the same figure, the x mark indicates that the column temperature was raised from room temperature to 40°C, the solvent was flowed at a rate of 0.5 ml/min, and then the column temperature was raised to 60°C, and benzene was removed. This is the result of repeating the operation of measuring column efficiency using the same method. Column efficiency decreases considerably with every cycle.

The Δ mark indicates that the column temperature is 40°C without lowering it to room temperature.
After leaving it for 24 hours (without flowing the solvent), reduce the flow rate to 0.
．． This is the result of repeating the operation of flowing the solvent at 5 ml/min, raising the column temperature to 60°C, and measuring the column efficiency after 1 hour. Again, a decrease in column efficiency is observed.

O mark indicates that the column temperature is raised from room temperature to 60°C without flowing the solvent, and the flow rate is 0 after about 1 hour or more.
．． This is the result of repeatedly performing an operation in which the efficiency of the column was measured by flowing the solvent at a rate of 5 m 1 /min. In this case, the decrease in column efficiency is very small.

From the above results, polystyrene gel filler is heated at 60°C.
It contracts by lowering the temperature from to room temperature, and again,
Even if the temperature is raised to 40°C and the pentafluorophenol becomes liquid, it will not completely swell to the state of 60°C, so in this state, the highly viscous pentafluorophenol is flowed at a flow rate of 0.5mff/min. It is thought that this causes the packing material to be packed together, creating gaps in the column, resulting in a decrease in column efficiency. On the other hand, if the column is left without flowing the solvent until the swelling is completely recovered at 60°C, and then the solvent is started flowing, the decrease in column efficiency will be very small.

Based on these findings, when starting the operation of the apparatus of this example, the column temperature was raised from room temperature to 60°C without flowing the solvent, and after about 1 hour, the column temperature was increased to 0.3 m/! GPCPC measurement was performed by flowing the solvent at a flow rate of /mln.

(2) Preparation of a calibration curve using polystyrene A size exclusion chromatography curve of monodisperse polystyrene of known molecular weight was measured, and the results shown in FIG. 4 were obtained. It was confirmed that molecular weight distribution can be measured satisfactorily using this device and its method of use.

YoshiJJLito kidney q side stagnation ■ ■Sample A: Xydar 5RT-500 test NO., 6m
Add 2mj2 of pentafluorophenol to g,
Heat and melt at about 60°C. This was filtered under pressure using a 0.45 μm filter, and the filtrate was measured by GPCPC. 0.2 mIV of the sample solution was injected into the sample injection part using a syringe, and the GPC curve shown in FIG. 5 was obtained.

■Sample B: Ekonol fiber sample 2mI for 0.6mg! , of pentafluorophenol was added and placed in a glass ampoule at 200°C.
Perform lysis. This was filtered under pressure using a 0.45 μm filter, and the filtrate was measured by GPCPC. A sample was injected in the same manner as in (2) above, and the GPC curve shown in FIG. 6 was obtained.

■Sample C: Add 2 ml of pentafluorophenol to 6 mg of Vectra A-900 sample po, and dissolve at about 120'C. This is 0.4
It was filtered under pressure through a 5 μm filter, and the filtrate was subjected to C and PC measurements. The sample was poured in the same manner as in (2) above, and the GPC curve shown in FIG. 7 was obtained.

Note that, as described above, this embodiment is configured to minimize the dead volume of the flow path system, so one GP
The amount of solvent required for CPC measurement was about 15 m2. Further, the required amount of solvent can be reduced by reducing the inner diameter and length of the column, so it is easy to reduce the amount to 1/3 to 115 of that in this example.

[Effects of the Invention] As described above, the high temperature size exclusion chromatography apparatus according to the present invention provides the following effects.

■ Since all parts of the device and flow path system are controlled within a fixed temperature range, it is possible to use solvents that solidify at room temperature, making it easy to analyze and measure special samples such as liquid crystal polymers. can.

■ Furthermore, the high-temperature size exclusion chromatography device according to the present invention has a branch pipe for removing air bubbles in the flow path on the suction side of the liquid pump, so air bubbles generated in the flow path system can be easily removed. The bubbles do not prevent the pump from starting, and it can be easily used even with a solvent that is solid at room temperature, such as pentafluorophenol.

(2) Furthermore, since the high-temperature size exclusion chromatography apparatus according to the present invention has a structure in which the sample is injected by manual operation, the apparatus is simplified and analytical measurements can be easily performed. Furthermore, by simplifying the apparatus, the dead volume of the channel system can be reduced, and the amount of solvent required to fill the channel system is reduced, which is advantageous when using an expensive solvent.

On the other hand, according to the method of using the device according to the present invention, the solvent is passed through the column filled with a packing material having a size exclusion mechanism after the column is sufficiently equilibrated at a predetermined temperature. The molecular weight distribution of poorly soluble polymers such as aromatic polyesters can be measured easily and accurately using a solvent that is solid at room temperature, such as pentafluorophenol.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing the configuration of a high-temperature size exclusion chromatography device according to an embodiment of the present invention, and FIG. 2 shows the relationship between column temperature and column efficiency of the device according to the embodiment. 3 is a diagram showing changes in column efficiency due to repeated cycles of heating and cooling, FIG. 4 is a diagram showing a calibration curve using polystyrene, and FIGS. 5 to 7 are diagrams showing changes in column efficiency due to repeated cycles of heating and cooling. Measured samples A, B, C
FIG. 8 is a block diagram schematically showing the configuration of a conventional automatic injection type high temperature size exclusion chromatography apparatus. 11...Solvent tank 12...Pump 13...Bubble removal branch pipe 14...Distributor 15...Sample injection section 16...Differential refractive index detector 17...Syringe 18...・Syringe heating block 19...Storage tube 20...Switching valve 22...Filter 23...Column 28...Column constant temperature bath 29...Water bath 30...Temperature controller Applicant Toray Industries, Inc. Research Center Representative Patent Attorney Tsutomu Sugitani

Claims (3)

[Claims] (1) a solvent tank, a pump that sucks and sends the solvent in the solvent tank, and a sample injection unit that injects a predetermined amount of sample into the solvent sent out from the pump by manually operating a syringe; a gel type for separating each component in the sample supplied from the injection part by a molecular size exclusion mechanism;
Alternatively, a column filled with a filler such as glass particles having pores, a detector for detecting each component separated and discharged from the column, and a branch for removing air bubbles provided in the flow path on the suction side of the pump. By controlling the temperature of the tube, each part of the device, the flow path system connecting these parts, and the branch pipe within a certain temperature range, the solvent, which is solid at room temperature, can be made to flow throughout the flow path in a liquid state. A high temperature size exclusion chromatography device characterized by comprising a temperature control mechanism. (2) a solvent tank, a pump that suctions and sends the solvent in the solvent tank, and a sample injection unit that injects a predetermined amount of sample into the solvent sent out from the pump by manually operating a syringe; a gel type for separating each component in the sample supplied from the injection part by a molecular size exclusion mechanism;
Alternatively, a column filled with a filler such as glass particles having pores, a detector for detecting each component separated and discharged from the column, and a branch for removing air bubbles provided in the flow path on the suction side of the pump. By controlling the temperature of the tube, each part of the device, the flow path system connecting these parts, and the branch pipe within a certain temperature range, the solvent, which is solid at room temperature, can be made to flow throughout the flow path in a liquid state. A method of using a high-temperature size exclusion chromatography device equipped with a temperature control mechanism, which is used to analyze and measure liquid crystal aromatics that are soluble in solid solvents at room temperature but insoluble in other common solvents. Then, the solvent is liquefied and the column filled with the packing material that can be separated by the size exclusion mechanism is left at a predetermined temperature for a certain period of time without flowing the solvent until the state of the column filled with the packing material that can be separated by the size exclusion mechanism reaches an equilibrium state at the predetermined temperature. . A method for using a high-temperature size exclusion chromatography apparatus, characterized in that a solvent is passed through the column system containing a packing material capable of separation by the size exclusion mechanism after reaching an equilibrium state. (3) The method of using the high-temperature size exclusion chromatography apparatus according to claim 2, wherein the solvent that is solid at room temperature is pentafluorophenol.