JP2002143601A - Method and apparatus for concentrating solvent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply concentrate a solvent used at the time of analyzing a chemical substance. SOLUTION: The solvent is concentrated so as not to dry a sample in a narrow pipe formed in the lowermost part of a vessel by keeping the temperature of the vessel at a prescribed temperature and reducing the pressure in the vessel by discharging the vapor of the solvent while supplying an inert gas in the vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method and an apparatus for concentrating a solvent which is subjected to solvent extraction or cleanup (purification) of an extract to a small amount of a solvent when analyzing a chemical substance. It is.

[0002]

2. Description of the Related Art As a method for concentrating an organic solvent, a rotary evaporator is generally used when a large amount of a solvent is concentrated, and a Kuderner Danish concentrator is used when a small amount of a solvent is concentrated. A concentrating device is used in which an open system is used for heating and blowing nitrogen gas to release the air into the atmosphere. Further, a device for heating and concentrating at atmospheric pressure in a closed system has been developed.

[0003] Rotary evaporators have been around for a long time and are used in most laboratories dealing with solvents.
The principle is that an eggplant flask is connected to a rotating device equipped with a cooler, and the bottom of the eggplant flask is immersed in a warm bath and concentrated while heating and heating. Further, in order to increase the concentration speed, a method has been adopted in which an aspirator or the like is connected after a cooler and heating is performed under reduced pressure, thereby quickly concentrating the solvent.

[0004]

In a rotary evaporator or a Kudelner Danish device, only one sample can be concentrated by one device, and it takes a lot of cost to prepare a necessary number of devices and requires a large space in a laboratory. Also, once used, not only the used flask, but also the inside of a complicated apparatus must be washed and treated to prevent contamination, so that it cannot be used for the next concentration, which is very inefficient.

[0005] On the other hand, an open-air type concentrator releases an organic solvent into the atmosphere, which is a source of environmental pollution. or,
Although multiple samples can be processed simultaneously, it is an open system and must be heated to the boiling point of the solvent for concentration under atmospheric pressure. Furthermore, a sample containing a relatively low-boiling component or a component that is easily decomposed by heat cannot be heated to a high temperature, so that there is a problem that the concentration time is extremely long. In addition, the evaporating solvent results in a mixture of multiple samples, and there is a possibility of contamination between samples.

[0006] Atmospheric pressure concentrators in closed systems must be heated to the boiling point of the solvent to condense, which is very time consuming and is suitable for handling solvents and samples that do not require elevated temperatures. Absent.

Further, most of the existing concentrators have a structure in which the concentrated sample adheres to the inner wall of a container such as a flask. Therefore, in order to collect the entire target component, after collecting the concentrated solution, it is necessary to wash and collect the inside of the flask or the concentrating container with a clean solvent many times, and wash away the sample attached to the entire surface. Requires a considerable amount of solvent. For example, even if it is concentrated to 1 ml, if it is washed several times, only a few ml of the washing liquid is required, and if the entire washing liquid is recovered, it will increase to 5 ml, which is not suitable for micro concentration. In particular, in dioxin analysis, about 200 ml of a solution must be concentrated to several hundred μl, and furthermore, extreme prevention of contamination and easy handling in operation are required. Further, when heated to 40 ° C. or more, dioxins of 4 chloride or less are scattered, resulting in loss of the sample, so that careful handling is required.

[0008] Further, while rapid evaporation of the solvent is required in any concentrator, when a low-boiling point compound is used as the target component as in dioxin analysis, the solvent is completely evaporated and does not dry out. Is important. This is because the possibility that the target component evaporates together with the evaporation solvent and scatters increases. Therefore, at the final stage of concentration, the state of the solvent is visually confirmed, and the evaporation operation is stopped.
It was difficult to stop the operation reliably with a small amount.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention is capable of simultaneously concentrating a large number of samples and concentrating the solvent in a short period of time, has a small installation area, can be formed compact, and has an open system. A solvent concentration method and apparatus that does not affect the environment and does not affect other samples, furthermore, does not require washing of the container and requires less washing solvent, and prevents the solvent from drying out. First, while keeping the container at a desired temperature, while supplying the inert gas to the container and depressurizing the inside of the container by discharging the solvent vapor, the sample is placed in the thin tube formed at the bottom of the container. Second, the container is vibrated while keeping the container at a desired temperature and depressurizing the container by discharging solvent vapor while supplying an inert gas to the container. By The feature is to prevent the sample from adhering to the container. Third, the container is detachably attached to the heating device, and the connector for connecting the vacuum suction device and the inert gas supply device is detachably attached to the container. On the other hand, the suction flow path and the supply flow path are provided independently for each container. Fourthly, the container is detachably mounted on the heating device, and the heating device is shaken. On the other hand, the connection connector for the vacuum suction device and the inert gas supply device is detachably mounted on the container, and the vacuum suction device and the inert gas supply device are independently provided for each container. It can be connected freely.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. 1 is a container, which uses a flask for concentration. The connection connector 2 is detachably installed in the mouth portion 11. The connection connector 2 has a fitting portion 21 to the mouth portion 11 which can be freely fitted by transparent sliding, and an inert gas supply portion 24 including a gas connection port 22 and a pipe 23 extending below the gas connection port 22; A solvent suction unit 27 is formed by a port 25 and a through hole 26 around the tube 23. A thin tube 12 having an inner diameter of 8 mm or less is formed at the lowermost part of the container 1. Since the surface area of the solvent is small in the thin tube 12,
The evaporation rate becomes extremely slow, and it does not evaporate to dryness unless left for a long time. Further, it is recommended to provide some kind of cooling mechanism 121 around the narrow tube 12, for example, a cooling water circulating device, a refrigerant circulating device, and a cooling block. As a result, drying can be reliably prevented, and a simple operation becomes possible because it is not necessary to visually check the amount of the solvent or to automatically control the time.

An inert gas supply pipe 3 is connected to the gas connection port 22.
0 is detachably connected. The inert gas supply pipe 30
Is a stop valve 32, a pressure regulator 33,
The pressure gauge 34, the flow meter 35, the mass flow controller 36, and the activated carbon 37 are connected to each other, and these constitute the inert gas supply device 3. Further, by providing the above-described stop valve 32 in the suction flow path of each container 1, it is possible to prevent wasteful consumption of inert gas even when the number of containers 1 is small.

Reference numeral 4 denotes a heating device which uses an aluminum block system, a mantle heater, and a water bath, but can also use a constant temperature water tank. Container 1 when using aluminum block
Is inserted into the through hole and used.

Reference numeral 5 denotes a shaking device, which can use an appropriate shaking device, for example, a vibrator system, a traction device or the like. The heating device 4 is fixed to a shaking device 5, and a shaking table 51 of the shaking device 5 is mounted on the base body 6 so as to be able to shake. When using the constant temperature water tank as the heating device 4, the shaking constant temperature water tank 41 for shaking the whole can be used.

Reference numeral 7 denotes a solvent recovery device which functions as a reduced-pressure suction device.
2. A pressure gauge 73 provided as necessary, and a liquid reservoir 74 is detachable or installable below the curl 72. Reference numeral 8 denotes a decompression condenser as a decompression suction device, which communicates with the discharge pipe 9. The solvent recovery device 7 may be connected via the gas connection port 22 of the connection connector 2 and the discharge pipe 9 without installing the decompression condenser 8. or,
It is preferable to install a liquid reservoir 81 below the decompression condenser 8. The outlet 72 is provided in the curl 72 of the solvent recovery device 7.
1 is provided. In addition, as a mechanism for automatically controlling the entire concentrator, a flowchart shown in FIG. 2 is shown as an example.

Reference numeral 10 denotes a controller, which indicates a general concept of a controller that controls various types of the following controllers. A temperature controller including a temperature sensor of a heater such as a constant temperature water tank, a speed controller of a shaking device, a control of an inert gas supply amount by connecting the inert gas supply pipe 3 to a mass flow controller 36, and a suction pump of a solvent recovery device 7. Partially automatic or fully automatic according to the control of the solvent discharge amount or the degree of depressurization by the control of 71 and the control of the signal of the pressure gauge 73 according to the respective control degrees such as the control of the suction pump 71 and a program incorporating them in advance. It becomes possible, for example, by adjusting the evaporation rate of the solvent, by controlling the degree of reduced pressure,
The rate of concentration can be adjusted. In the figure, reference numeral 101 denotes a storage section of the container 1 and indicates a wide area including a constant temperature water tank and a shaking device.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In actual use, a heating device 4 capable of installing a desired number of containers 1 is used. A connection connector 2 is fitted into each container 1, and an inert gas supply pipe 30 is connected to the gas connection port 22 and a discharge pipe 9 is connected to the solvent suction port 25. For connection of the inert supply pipe 30 and the discharge pipe 9,
A desired connection method such as a screw type or a fitting type is adopted. Of course,
The sample is put in the container 1 in advance, the container 1 is set in the heating device 4, and the container 1 is heated by the heating device 4 in which the inert gas supply pipe 30 and the discharge pipe 9 are set. Warm up. On the other hand, a required amount of inert gas such as nitrogen gas is supplied from the inert gas supply pipe 30 in accordance with the sample.

The amount of nitrogen to be supplied depends on the amount of the solvent to be concentrated, but it is not necessary to flow a large amount. Even when concentrating 200 ml of the solvent, about 50 to 100 ml / min of nitrogen gas is sufficient. Since the flow of the nitrogen gas serves to smooth the movement of the evaporated organic solvent and to easily guide the organic solvent toward the cooler, it is not necessary to flow a large amount. There is little relation between the flow rate of the nitrogen gas and the concentration rate of the solvent, and it is considered that the nitrogen gas serves as an aid to assist the smooth movement of the solvent vapor.

For example, when the solvent of the sample solution is toluene, to heat and concentrate while flowing a nitrogen gas without shaking, the flow rate of the nitrogen gas to be flowed so that the degree of reduced pressure does not become -97 Kpa or less due to the boiling point. About 10 to 1
Concentration is performed while adjusting to about 00 ml. As the liquid level approaches the bottom of the vessel, the rate of concentration becomes slower. In particular, when concentration progresses to the thin tube provided at the bottom of the vessel, the surface area of the solvent decreases, and the rate of concentration further decreases. Therefore, when the solvent of the sample solution is concentrated and removed, the effect of preventing the sample solution from being dried is increased.

Further, when concentration is performed by shaking, the concentration rate of the solvent is higher than when nitrogen gas is flown. However, it was found that at a shaking speed of 50 rpm, the effect was not so large. At a shaking speed of 100 rpm, the concentration time could be reduced by about half. The results of these experiments are shown in FIG. Further, if the shaking speed is higher than that, the solvent causes irregular vibration inside the flask and jumps up to the upper part of the inner wall of the container 1 and contaminates the container 1. Therefore, the shaking speed of about 100 rpm is optimal. I found it to be. However, the optimum value of the shaking slightly varies depending on the type of the solvent, the viscosity and the like.

Further, after the solvent is concentrated to a certain amount, the evaporation rate of the solvent is reduced by circulating a refrigerant through the thin tube portion, and it is confirmed that the target sample amount has been obtained, and the concentration operation is terminated. If the concentrating device is provided with an automatic adjusting mechanism of the shaking speed and an automatic adjusting mechanism based on the nitrogen gas flow time and the degree of reduced pressure, conditions for preventing evaporation to dryness can be set in the shortest enrichment time. That is, at the start of concentration, a very small amount of nitrogen gas is flowed, and the shaking speed is set at 10%.
Set to 0 rpm and stop shaking at the time when the solvent decreases to a few grams. After the shaking is stopped, the nitrogen gas flow rate is increased while controlling the degree of decompression so as not to be lower than -97 kpa (when the solvent is toluene). The final concentration can be carried out without drying down to very small amounts up to several hundred microliters.

[0021]

As described above, according to the first aspect of the present invention, the container is maintained at a desired temperature, and while the inside of the container is depressurized by discharging the solvent vapor while supplying an inert gas to the container, Since the sample was concentrated in a thin tube formed at the bottom of the sample without drying it, the sample was heated to a temperature convenient for evaporation of the solvent, and the solvent vapor was moved by the gas flow by the injection of the inert gas, and the solvent was gradually discharged. To prevent the sample from adhering to the inner wall of the container and prevent bumping. Further, the evaporation of the solvent can be promoted by reducing the pressure in the container such as by suctioning the solvent. The discharged solvent and the like are completely recovered and heated to the boiling point, which has the effect of shortening the time taken by synergy.

According to the second aspect, at the bottom of the container,
Since the capillary having a diameter of 8 mm or less is provided, when the concentration proceeds to the bottom of the container, the surface area of the solvent is reduced, and the concentration rate is further reduced. Therefore, when the solvent of the sample solution is concentrated, the effect of preventing the solvent from evaporating to dryness is enhanced.

According to the third aspect of the present invention, the container is kept at a desired temperature, and the container is vibrated while supplying an inert gas to the container and reducing the pressure inside the container by discharging the solvent vapor. In order to prevent the solvent from adhering to the container, the solvent vapor is moved by the gas flow generated by the injection of the inert gas while heating the solvent to a temperature convenient for evaporating the solvent, thereby promoting the solvent discharge. In addition, the evaporation speed can be enhanced by shaking the container, the sample can be prevented from adhering to the inner wall of the container, and bumping can be prevented.

Further, the evaporation of the solvent can be promoted by reducing the pressure in the container such as by suctioning the solvent. Of course, they act not synergistically but simultaneously and act synergistically to perform a remarkable concentration operation. Further, the discharged solvent and the like are completely recovered, and there is an effect that the time required for heating to the boiling point and for taking a long time can be shortened by a synergistic action.

According to a fourth aspect of the present invention, a container is removably mounted on the heating device, and a connector for connecting a reduced-pressure suction device and an inert gas supply device is removably mounted on the container. Since the suction flow path and the supply flow path are provided independently for each container, in addition to the effect of claim 1, a required number of containers for concentrating a larger number of samples can be installed in the required number of devices, and the size is extremely small. This saves setup costs and makes efficient use of space possible. Since a device for supplying an inert gas to the container and a pressure reducing device are separately provided for suctioning the solvent, cross contamination can be prevented. Further, the structure of the portion in contact with the sample is simple and is formed separately, so that the cleaning operation is extremely easy.

According to a fifth aspect of the present invention, the container is detachably mounted on the heating device, and the heating device is installed on a shaking table, while the container has a reduced pressure suction device and an inert gas supply device. Attaching the connection connector with the detachable,
A vacuum connector and an inert gas supply device can be independently connected to the connection connector for each container.
In addition to the effects described in the above, in combination with a shaking table and other vacuum suction device, inert gas supply device, heating device, the concentration rate is faster than before, naturally preventing the sample from remaining on the inner wall of the container, bumping And an efficient solvent concentration method could be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a flow of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a flow of another embodiment of the present invention.

FIG. 3 is a schematic front view of an apparatus according to an embodiment of the present invention.

FIG. 4 is a side view of the same.

FIG. 5 is an explanatory front view of a main part of the present invention.

FIG. 6 is a partially enlarged explanatory view of the above.

FIG. 7 is a comparison table of concentration rates depending on the shaking speed of the container.

[Explanation of symbols]

 Reference Signs List 1 container 2 connection connector 3 inert gas supply device 4 heating device 5 shaking device 6 base 7 solvent recovery device 8 decompression condenser 9 discharge pipe 10 controller

Continued on the front page (72) Inventor Ken Tatsuguchi Fukushima Fukushima Plant F-3 Fukushima Plant F-term (reference) 2G052 AD26 EB11 ED01 FB08 HC25 4D076 AA07 AA12 AA24 BA01 BA02 BA07 BC03 CA01 CA02 CD22 CD50 DA04 EA10Y EA14Y EA16Y FA31 HA14 JA03 JA04 JA05

Claims (5)

[Claims] 1. A method for maintaining a container at a desired temperature, while supplying an inert gas to the container and depressurizing the inside of the container by discharging a solvent vapor, while keeping the sample in a thin tube formed at the lowermost portion of the container without drying the sample. A method for concentrating a solvent, comprising concentrating. 2. The method for concentrating a solvent according to claim 1, wherein a container having a thin tube having a diameter of 8 mm or less is provided at the lowermost portion of the container. 3. A method for preventing a sample from adhering to a container by maintaining the container at a desired temperature and vibrating the container while supplying an inert gas to the container and depressurizing the inside of the container by discharging a solvent vapor. A method for concentrating a solvent, comprising: 4. A container is detachably mounted on the heating device, and a connector for connecting a decompression suction device and an inert gas supply device is detachably mounted on the container. A solvent concentrating device, wherein a path is provided independently for each container. 5. A container is detachably mounted on the heating device, and the heating device is installed on a shaking table, and a connector for connecting a reduced-pressure suction device and an inert gas supply device is detachably mounted on the container. And a connector for connecting a decompression suction device and an inert gas supply device to each container independently for each container.