JPH0847602A - Vacuum evaporating method and vacuum evaporator - Google Patents

Abstract

PURPOSE:To effectively heat a sample during concentration operation to shorten the concentration time by introducing gas which becomes a heat transfer medium during the sample concentration operation around the sample to eliminate the vacuum condition around the sample. CONSTITUTION:After a tube containing a sample to be concentrated or dried is fitted to a rotor 1 and a cover 3 is closed, the rotor 1 is rotated by a driving motor 7 to give centrifugal force to the sample. Next, a vacuum pump and a heater are turned on to make the inside of a vessel 2 in vacuum condition, and also the temp. of an atmosphere is raised to evaporate liquid components in the sample. When the liquid components in the sample are evaporated, the sample temp. is lowered because the temp. of the sample is deprived as the heat of vaporization. Then, the vacuum pump is once stopped during the sample concentration operation, and a stop valve 17 is operated to introduce air into the vessel 2, and operation for temporarily releasing the vacuum condition in the vessel 2 is repeated every elapse of prescribed time. In this way, the sample is temporarily heated during concentration operation to shorten the concentration time of the sample.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum concentrating method and a vacuum concentrating apparatus, and more particularly to a sample vacuum concentrating method and a vacuum concentrating method for heating a sample containing a sample under reduced pressure while applying a centrifugal force by rotation. The present invention relates to a concentrating device.

[0002]

2. Description of the Related Art Conventionally, in order to concentrate or dry a sample containing a liquid component such as an organic solvent or water, the sample is stored under reduced pressure while applying a centrifugal force to the tube containing the sample by rotation. There is a method of vacuum concentration of a sample which heats and efficiently evaporates the liquid component of the sample without bumping. As an apparatus for carrying out such a vacuum concentration method, for example, an apparatus having a structure as shown in FIG. 5 is currently used.

Here, in FIG. 5, 101 is a rotating body for applying a centrifugal force to the sample, 102 is a container for housing the rotating body 101, and 103 is a lid for opening and closing the upper opening 102a of the container 102. The inside of the container 102 is hermetically closed by the lid 103, and a vacuum pump (not shown) connected to a vacuum pump connection port 104 formed on the side wall of the container 102 reduces the pressure during a sample concentration operation. It is said that

Reference numeral 105 in FIG. 5 designates the rotating body 101.
Which is a drive means for rotating the
An indirect drive system using a magnetic coupling is adopted to improve the airtightness inside the container 102, a rotating shaft 106 rotatably supported near the center inside the container 102, and a drive motor arranged below the container 102. The output shaft 108 of 107 is indirectly connected to the output shaft 108 by magnets 110 and 111 which are arranged to face each other with a plate 109 forming a part of the bottom surface of the container 102 interposed therebetween.

Further, reference numeral 112 in FIG. 5 denotes a heater mounted on the outer peripheral wall surface of the container 102,
The heating heater 112 applies heat for promoting evaporation of the liquid component contained in the sample, and 113 is
A pipe for introducing air into the container 102 that has been subjected to a depressurized state, and an opening / closing valve 1 is provided at the base end of the pipe 113.
14 are provided.

The conventional vacuum concentrator having the above structure is operated as follows. First, attach a tube containing a sample to be concentrated or dried to the rotating body 101,
After closing the lid 103, the rotator 101 is rotated by the drive motor 107 to apply a centrifugal force due to the rotation to the sample. This is performed in order to prevent the sample from bumping or scattering due to the heating operation of the sample to be described later under a rapid depressurization.

Next, while the centrifugal force is applied to the sample, the vacuum pump and the heater are turned on to depressurize the inside of the container 102 and raise the ambient temperature to efficiently remove the liquid component contained in the sample. Vaporize.

After a lapse of a predetermined time, the drive motor, the vacuum pump and the heater are turned off to stop the vacuum concentration operation and operate the on-off valve 114 to release the depressurized state in the container 102. Then, the lid 103 is opened to obtain a concentrated or dried sample.

[0009]

However, here,
First, in the method for concentrating or drying a sample using the conventional vacuum concentrating device described above, the heating heater 112 mounted on the outer peripheral wall surface of the container 102 is used under reduced pressure, that is, a heat transfer medium during the sample concentrating operation. The heater 112 is intended to indirectly heat the sample when the gas (air) is diluted or does not exist.
However, there is a problem that the sample is not effectively heated, the temperature is lowered by the heat of vaporization of the sample, the sample is frozen, the concentration efficiency of the sample is lowered, and the concentration time is prolonged.

In order to prevent this, as a method of heating the sample, an infrared heater is installed in the container 102, or the lid 103 of the container is made of heat-resistant glass and the infrared heater is installed on the heat-resistant glass. Therefore, it has been attempted to effectively heat the sample even under reduced pressure by the radiant heat from the infrared heater. However, in the method of installing an infrared heater in the container 102, when air is introduced into the container to release the depressurized state in order to remove the sample from the container after the concentration operation of the sample is completed, Due to the high surface temperature of the infrared heater installed inside, the liquid components in the vaporized sample, such as acetone and ethanol, may ignite or explode due to the presence of the introduced air. In addition, in the method of installing the infrared heater on the upper portion of the lid 103 made of heat-resistant glass, the lid becomes expensive, and the infrared irradiation from the top directly hits the sample with infrared rays,
The temperature of the surface portion of the sample becomes too high, and in the case of a biological sample in particular, there is a problem in its adoption because the sample is altered.

In the above-mentioned conventional method for concentrating or drying a sample using a vacuum concentrating device, the user first confirms the end of the concentrating operation which differs depending on the type and amount of the liquid component of the sample used. The side performs the above concentration operation while measuring the time with a stopwatch etc.
The subsequent concentration operation is a situation in which the operation time is set by a timer or the like based on the experience value, and on the user side, it is necessary to take patience to confirm the end of the concentration operation. There was also the issue of not becoming.

Further, in a sample to be concentrated or dried by using a vacuum concentrator, an organic solvent such as acetone, which generates a corrosive gas as a liquid component of the sample,
Although many samples use ethanol or the like, in the conventional vacuum concentrator described above, the rotor 1
01 and the container 102 for accommodating the rotating body 101 are made of a corrosion-resistant material, and the corrosion resistance is ensured, a drive for rotatably accommodating the rotating shaft 106 that is the driving means of the rotating body 101. Regarding the corrosion resistance in the room 115,
The rotary shaft 106 is simply housed in the drive chamber 115 with the seal member 116 interposed therebetween, and the drive chamber 115 is hermetically sealed to prevent invasion of corrosive gas and maintain its corrosion resistance. there were. Therefore, when the concentration or drying operation of the sample is repeated by the vacuum concentrator, the sealing property of the seal member 116 in contact with the rotary shaft 106 is naturally deteriorated due to wear and deterioration, and finally the corrosive gas can be prevented from entering. The drive chamber 115
The corrosive gas also invades into the inside of the drive unit chamber 115,
Alternatively, there is a case where the bearing or the like existing in the drive unit chamber 115 is corroded so that it cannot be used as a device.

The present invention has been made in view of various problems of the above-described conventional vacuum concentration method and vacuum concentration apparatus, and the first purpose thereof is to effectively heat the sample during the concentration operation. The purpose of the present invention is to provide a vacuum concentration method capable of shortening the concentration time. The second aspect of the present invention
It is an object of the present invention to provide a vacuum concentration method capable of accurately determining the end time of the concentration operation. Further, a third object of the present invention is to provide a vacuum concentrating device which can completely prevent invasion of corrosive gas into the drive chamber containing the rotary shaft.

[0014]

[Means for Solving the Problems] In order to achieve the first object described above, the present invention comprises heating a sample to be concentrated or dried under reduced pressure while applying a centrifugal force to the sample, and In a vacuum concentration method of a sample for efficiently evaporating a liquid component to be evaporated without bumping, a reduced pressure state around the sample is introduced into the periphery of the sample at least once by a gas serving as a heat transfer medium during the concentration operation of the sample. By doing so, a vacuum concentration method was adopted in which heating was effectively performed during the concentration operation of the sample.

Further, in order to achieve the second object, the present invention heats the sample to be concentrated or dried while applying a centrifugal force to the sample under reduced pressure to bump the liquid component contained in the sample. In a vacuum concentration method of a sample for efficiently evaporating without performing a vacuum, the end of the concentration operation of the sample by the vacuum concentration method is judged from the amount of change in the temperature around the sample per predetermined time during the concentration operation. The concentration method was used.

Further, in order to achieve the above-mentioned third object, the present invention provides a rotating body for imparting a centrifugal force to a sample, a container for accommodating the rotating body in a sealed state, and a depressurized state in the container. In a vacuum concentrating device having a vacuum pump, a drive unit that rotates the rotating body, a drive unit chamber that houses the drive unit, and heating means that heats the inside of the container, in the container, in the container While connecting a pipe with an on-off valve for introducing a gas serving as a heat transfer medium, the pipe is also connected to the drive unit chamber, and a gas serving as a heat transfer medium is simultaneously supplied into the depressurized container and the drive unit chamber. A vacuum concentrator was prepared so that it could be introduced.

[0017]

According to the above-described vacuum concentration method according to the present invention, the sample is heated under reduced pressure, that is, the sample is heated in a state where the gas (air) serving as the heat transfer medium is dilute or absent. Compared with the method, since the heating is performed at least once in the presence of the gas serving as the heat transfer medium around the sample, the sample is heated temporarily but effectively during the concentration operation, and the sample is concentrated. There is an effect that the time can be shortened.

Further, according to the above-described vacuum concentration method according to the present invention, when the liquid component of the sample evaporates and the concentration operation approaches the end, the sample temperature is less likely to decrease due to the heat of vaporization. Since the end of the sample concentration operation is judged from the amount of change in the ambient temperature of the sample during a predetermined time during the concentration operation, the user can adjust the concentration operation time with a stopwatch etc. as in the conventional vacuum concentration method. Since it is not necessary to check each time, there is an effect that the end time of the concentration operation can be accurately and easily determined.

Further, in the above-described vacuum concentrating apparatus according to the present invention, a pipe with an opening / closing valve for introducing a gas serving as a heat transfer medium is connected to a container for accommodating the rotating body, and
Since the pipe is also connected to the drive chamber so that the gas serving as the heat transfer medium can be simultaneously introduced into the depressurized container and the drive chamber, the pressure inside the drive chamber is always the same. The pressure does not become lower than the pressure, and there is an effect of a device that can completely prevent the corrosive gas generated from the sample in the container from entering the drive unit chamber.

[0020]

EXAMPLES The vacuum concentrating method and the vacuum concentrating apparatus according to the present invention will be described in detail below with reference to examples.

Here, FIG. 1 is a vertical cross-sectional view showing an embodiment of an apparatus for carrying out a vacuum concentration method according to the present invention and a vacuum concentration apparatus according to the present invention, in which 1 is a sample. A rotary body 2 for giving a centrifugal force is a container for accommodating the rotary body 1, and 3 is a lid body for opening and closing the upper opening 2a of the container 2. The inside of the container 2 is sealed by the lid 3,
A vacuum pump (not shown) connected to a vacuum pump connection port 4 formed on the side wall of the container 2 makes a depressurized state during the concentration operation of the sample.

Reference numeral 5 in the drawing denotes a drive means for rotating the rotating body 1. The drive means 5 employs an indirect drive system using a magnetic coupling in order to enhance the airtightness in the container 2. A rotary shaft 6 rotatably supported in the vicinity of the center of the container 2 and an output shaft 8 of a drive motor 7 arranged below the container 2 are arranged to face each other with a bottom plate 9 of the container 2 interposed therebetween. It has a structure in which the magnets 10 and 11 are indirectly connected.

Further, in the figure, 12 is a heating heater mounted on the outer peripheral wall surface of the container 2, and heat for promoting evaporation of the liquid component contained in the sample is applied by the heating heater 12, and Reference numeral 13 denotes a pipe for introducing air into the container 2 that has been subjected to a depressurized state, and the pipe 13 is provided near the connecting portion of the pipe 13 to the container 2.
A valve device 14 for maintaining the pressure inside the container 2 slightly higher than the pressure inside the container 2 is provided, and the pipe 13 is branched in the middle thereof, and the branch pipe 15 is the above-mentioned rotary unit existing inside the container 2. It is connected to a drive chamber 16 that houses the shaft 6.

Reference numeral 17 in the drawing denotes an on-off valve provided at the base end of the pipe 13, and by operating the on-off valve 17, air is introduced into the container 2 and the drive chamber 16 at the same time. Is configured. 18 is the lid 3
The temperature sensor attached to the temperature sensor 18 detects the temperature around the sample during the concentration operation.

In carrying out the vacuum concentration method according to the present invention using the vacuum concentration device according to the present invention configured as described above, first, a tube containing a sample to be concentrated or dried is placed in the rotary body. 1 and after closing the lid 3, the rotating body 1 is rotated by the drive motor 7 to apply a centrifugal force due to the rotation to the sample.

Next, while the centrifugal force is applied to the sample, the vacuum pump and the heater are turned on to depressurize the inside of the container 2 and raise the ambient temperature to remove the liquid components contained in the sample. Evaporate.

When the liquid component in the sample is actively evaporated by the heating operation under reduced pressure as described above, the sample temperature is deprived as heat of vaporization and the temperature is lowered, so that the vacuum pump is temporarily operated during the concentration operation of the sample. Stop, open / close valve 1
The operation of introducing air into the container 2 by operating 7 and temporarily releasing the depressurized state in the container 2 is repeated every time a predetermined time elapses. As a result, the air that is temporarily introduced into the container 2 during the concentration operation is not
It is heated by exchanging heat with the wall surface of the container 2 heated by the above, and the heat transfer of this heated air effectively heats the rotor 1 and the sample mounted on the rotor 1 during the concentration operation. The temperature of the sample, which has begun to decrease, can be raised again to actively evaporate the liquid component in the sample.

At this time, in the vacuum concentrating device according to the present invention, the pipe 1 for introducing air into the container 2 as described above.
A valve device 14 for maintaining the pressure in the pipe 13 slightly higher than the pressure in the container 2 is provided near the connection portion of the pipe 3 to the container 2, and the pipe 13 is branched in the middle thereof. Is connected to the drive chamber 16 that accommodates the rotary shaft 6 existing in the container 2, so that the on-off valve 17
When the operation for introducing air into the container 2 is performed by operating, the air is also introduced into the drive chamber 16 that is in a depressurized state due to deterioration of the seal member 19 at the same time, and the interior of the drive chamber 16 is always Therefore, even if the depressurization in the container 2 and the release of the depressurization are frequently repeated, the corrosive gas generated from the sample in the container 2 invades into the drive unit chamber 16. There is no such thing.

When the concentration of the sample is increased by the above operation and the liquid component in the sample is reduced, the amount of decrease in the sample temperature after releasing the depressurized state (after heating by introducing air), which has been repeated every time the above predetermined time elapses, The decrease in the sample temperature is detected by the temperature sensor 18, and when the decrease in the sample temperature reaches a desired change, the drive motor, the vacuum pump and the heating heater are turned off, and the vacuum concentration is performed. Stop the operation.

In the present invention, during the above-mentioned operation, the depressurized state around the sample is released by introducing air, which is a heat transfer medium during the sample concentration operation, into the sample periphery,
The first feature of the present invention is that heating is effectively performed during the concentration operation of the sample. In order to confirm the effect, the following test 1 is performed using the apparatus of the above-mentioned embodiment.
~ 4 were performed.

The present invention is also characterized in that during the above operation, the end of the sample concentration operation is judged from the amount of change in the temperature around the sample per predetermined time, which is possible. In order to confirm the property, the following test 5 was conducted using the apparatus of the above-mentioned example.

Further, according to the present invention, a pipe with an on-off valve for introducing a gas serving as a heat transfer medium is connected to the container, and the pipe is also connected to a drive unit chamber for accommodating a rotary shaft, so that the pressure is reduced. It is configured so that a gas serving as a heat transfer medium can be introduced into the container and the driving chamber at the same time, and the corrosive gas generated from the sample in the container is completely blocked from entering the driving chamber. In order to confirm the effect, wear and deterioration of the seal member 19 in the apparatus of the above-described embodiment is assumed, and the following will be performed in the state in which fine holes are formed in the seal member 19. Exam 6
Was performed.

(Test 1) Into a tube containing a sample, 5 ml of water was placed per tube, 24 tubes were attached to the above-mentioned rotor 1, and the tube was rotated at 1200 rpm by a vacuum pump. The inside of the container 2 was set to a vacuum degree of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and the vacuum concentration operation of the sample was started.
A vacuum pump is turned on every 9 minutes from the start of the sample concentration operation.
The operation was stopped for a minute, the opening / closing valve 17 was operated when the vacuum pump was stopped, air was introduced into the container 2, and the depressurized state in the container 2 was temporarily released during the concentration operation.
After 90 minutes had elapsed from the start of the concentration, the concentration operation was terminated and the residual amount of water as a sample was measured. The measurement result is described in Table 1 as Test 1. Further, the detection data of the sample temperature during the concentration operation by the temperature sensor 18 and the detection data of the degree of vacuum in the container 2 by the pressure sensor provided near the vacuum pump connection port 4 are shown as Test 1 in FIG.

(Test 2) 5 ml of water was put in each tube containing the sample, 24 tubes were attached to the rotating body 1, and the tube was rotated at 1200 rpm by a vacuum pump. The inside of the container 2 was set to a vacuum degree of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and the vacuum concentration operation of the sample was started.
After 90 minutes had elapsed from the start of the concentration, the concentration operation was terminated and the residual amount of water as a sample was measured. The measurement results are also shown in Table 1 as Test 2. Further, the detection data of the sample temperature during the concentration operation by the temperature sensor 18 and the detection data of the degree of vacuum in the container 2 by the pressure sensor provided near the vacuum pump connection port 4 are also shown in FIG.

(Test 3) 1 ml of a 50% aqueous solution of ethanol was put in each tube containing the sample, and 60 tubes were mounted on the rotor 1, and the rotation speed was 1200.
Container 2 by vacuum pump while rotating at rpm
The inside was set to a vacuum degree of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and the vacuum concentration operation of the sample was started. The vacuum pump is stopped for 2 minutes every 9 minutes from the start of the sample concentration operation, and when the vacuum pump is stopped, the on-off valve 17 is operated to introduce air into the container 2 to concentrate the depressurized state in the container 2. The operation of temporarily releasing it was repeated. After the lapse of 60 minutes from the start of the concentration, the concentration operation was terminated and the remaining amount of ethanol in the 50% aqueous solution as a sample was measured. The measurement result is shown in Table 1 as Test 3. Further, the detection data of the sample temperature during the concentration operation by the temperature sensor 18 and the detection data of the degree of vacuum in the container 2 by the pressure sensor provided near the vacuum pump connection port 4 are shown as test 3 in FIG.

(Test 4) 1 ml of a 50% aqueous solution of ethanol was put in each tube containing the sample, and 60 tubes were attached to the above-mentioned rotor 1, and the rotation speed was 1200.
Container 2 by vacuum pump while rotating at rpm
The inside was set to a vacuum degree of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and the vacuum concentration operation of the sample was started. After the lapse of 60 minutes from the start of the concentration, the concentration operation was terminated and the remaining amount of ethanol in the 50% aqueous solution as a sample was measured. The measurement results are also shown in Table 1 as Test 4. Further, the detection data of the sample temperature during the concentration operation by the temperature sensor 18 and the detection data of the degree of vacuum in the container 2 by the pressure sensor provided in the vicinity of the vacuum pump connection port 4 are also shown in FIG.

(Test 5) 1 ml of water was put in each tube containing the sample, and 60 tubes were attached to the above-mentioned rotor 1 and rotated by a vacuum pump while rotating at 1200 rpm. The inside of the container 2 was set to a vacuum degree of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and the vacuum concentration operation of the sample was started.
A vacuum pump is turned on every 9 minutes from the start of the sample concentration operation.
The operation of stopping for a minute, operating the open / close valve 17 when the vacuum pump was stopped to introduce air into the container 2, and temporarily releasing the depressurized state in the container 2 was repeated 10 times, and the sample concentration operation was completed. . Temperature sensor 1 during the above concentration operation
FIG. 4 shows the detection data of the sample temperature by 8 and the detection data of the degree of vacuum in the container 2 by the pressure sensor provided near the vacuum pump connection port 4. Further, the amount of change in the sample temperature for each cycle is read from the detected data of the sample temperature by the temperature sensor 18, and the value is shown in Table 2.

(Test 6) 1 ml of chloroform was put in each tube containing the sample, and the tube was replaced with 6 tubes.
0 pieces are attached to the rotating body 1 and are rotated at a rotation speed of 1200 rpm, and the inside of the container 2 is heated to 10T by a vacuum pump.
The vacuum degree was set to about orr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and the vacuum concentration operation of the sample was started. The vacuum pump is stopped for 2 minutes every 9 minutes from the start of the sample concentration operation, and when the vacuum pump is stopped, the on-off valve 17 is operated to introduce air into the container 2 to temporarily reduce the depressurized state in the container 2. Repeat the operation to release to 100 times,
The sample concentration operation was completed. After completion of the concentration operation,
When the presence or absence of corrosion in the drive unit chamber 16 was visually inspected, the presence of corrosion was not recognized.

[0039]

[Table 1]

[Table 2]

According to the above tests 1 to 4, when the decompressed state around the sample during the concentration operation is temporarily released by introducing air as a heat transfer medium, the sample is effectively heated, and the concentration operation is performed. It can be seen that the time can be shortened. In addition, the concentration of the sample is increased by the above test 5,
When the liquid component in the sample decreases, the decrease in the sample temperature after releasing the depressurized state (after heating by introducing air), which has been repeated every time the predetermined time has elapsed, decreases, and if the change in this decrease is detected It is understood that it is possible to judge the end of the concentration operation of the sample. Further, according to Test 6 above, if the air is introduced into the drive chamber at the same time as the inside of the container, even if the seal member is worn or deteriorated, it is possible to completely prevent the corrosive gas from entering the drive chamber. It can be seen that the structure is such that corrosion is unlikely to occur.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment,
Various modifications and changes can be made based on the technical idea of the present invention.

For example, in the above-mentioned embodiment, the vacuum concentration method in which the depressurized state around the sample is repeatedly released at every elapse of a predetermined time during the concentration operation of the sample has been described. Even if the depressurized state around the sample is released and the gas as the heat transfer medium is introduced around the sample, the heating of the sample is performed more effectively than the conventional technique which is always performed under the depressurized state. A vacuum concentration method in which the depressurized state is released or the depressurized state is released irregularly may be used.

In the above embodiment, the end time of the sample concentration operation is judged from the amount of change in the sample temperature after the depressurized state, which has been repeated every predetermined time, is released (after heating by introducing air). I explained the vacuum concentration method,
As can be seen from the sample temperature detection data of Test 4 in FIG. 3, even when the sample is constantly heated under reduced pressure, the amount of change in the temperature around the sample over a predetermined period of time changes as the sample concentration operation proceeds. The amount of change may be detected to determine the end time of the sample concentration operation.

Further, in the apparatus of the above embodiment, the container 2
A valve device 14 for maintaining the pressure in the pipe 13 slightly higher than the pressure in the container 2 is provided in the vicinity of a connection portion of the pipe 13 for introducing air into the container 2, and is provided in the pipe 13. By having the structure in which the branch pipe 15 is connected to the drive chamber 16 that houses the rotary shaft 6 existing in the container 2,
When the on-off valve 17 is operated to introduce air into the container 2, at the same time, air is also introduced into the drive unit chamber 16 which is in a depressurized state due to deterioration of the seal member 19 or the like, and is constantly driven.
The internal pressure is kept higher than the internal pressure of the container 2. However, even if the valve device 14 provided in the pipe 13 is not provided, at least the internal pressure of the drive chamber 16 is always the internal pressure of the internal container 2. Since the corrosive gas generated from the sample in the container 2 can be prevented from entering into the drive part chamber 16, the pressure does not become lower than the pressure of
As described above, the vacuum concentrator having the structure without the valve device 14 is also effective.

[0045]

According to the above-described vacuum concentration method of the present invention, the sample is always heated under reduced pressure, that is, in the state where the gas (air) serving as the heat transfer medium is diluted or does not exist. Compared to the conventional vacuum concentration method, since the sample is heated at least once in the presence of the gas that serves as the heat transfer medium, the sample is heated temporarily but effectively during the concentration operation. It is effective in shortening the concentration time.

It should be noted that according to the above-described vacuum concentration method of the present invention, when the liquid component of the sample evaporates and the concentration operation approaches the end, the sample temperature is less likely to decrease due to the heat of vaporization. Since the end of the sample concentration operation is judged from the amount of change in the temperature around the sample per predetermined time, it is necessary for the user to confirm the concentration operation time with a stopwatch etc., as in the conventional vacuum concentration method. The effect is that the end time of the concentration operation can be accurately and easily determined.

Further, in the above-described vacuum concentrating apparatus according to the present invention, a pipe with an opening / closing valve for introducing a gas serving as a heat transfer medium is connected to a container accommodating the rotating body, and
Since the pipe is also connected to the drive chamber so that the gas serving as the heat transfer medium can be simultaneously introduced into the depressurized container and the drive chamber, the pressure inside the drive chamber is always the same. The pressure does not become lower than the pressure, and the corrosive gas generated from the sample in the container can be completely prevented from entering the drive unit chamber, and the corrosion resistance of the drive unit chamber can be dramatically improved.

[Brief description of drawings]

FIG. 1 is an apparatus for carrying out a vacuum concentration method according to the present invention,
FIG. 2 is a vertical sectional view showing an embodiment of a vacuum concentrating device according to the present invention.

FIG. 2 shows the detection data of the sample temperature during the concentration operation by the temperature sensor and the detection data of the degree of vacuum in the container by the pressure sensor provided in the vicinity of the vacuum pump connection port when the test 1 and the test 2 are performed. It is a graph.

FIG. 3 shows detection data of the sample temperature during the concentration operation by the temperature sensor and data of the degree of vacuum in the container by the pressure sensor provided near the connection port of the vacuum pump when the tests 3 and 4 are performed. It is a graph.

FIG. 4 is a graph showing the detection data of the sample temperature during the concentration operation by the temperature sensor and the detection data of the degree of vacuum in the container by the pressure sensor provided in the vicinity of the vacuum pump connection port when Test 5 is performed. .

FIG. 5 is a vertical cross-sectional view showing an example of a vacuum concentrating device used when performing a conventional vacuum concentrating method.

[Explanation of symbols]

1 Rotating body for giving centrifugal force to sample 2 Container for storing rotating body 2a Upper opening of container 3 Lid of container 4 Vacuum pump connection port formed on side wall of container 5 Driving means for rotating rotating body 6 Inside container Rotating shaft rotatably supported near the center 7 Drive motor disposed below the outside of the container 8 Output shaft of the drive motor 9 Bottom plate of the container 10 Magnet 11 Magnet 12 Heater mounted on the outer peripheral wall of the container 13 Inside the container Piping for introducing air into the pipe 14 Valve device for maintaining the pressure in the pipe slightly higher than the pressure in the container 15 Branch pipe provided in the pipe 16 Drive part chamber 17 for accommodating the rotary shaft 17 Provided at the base end of the pipe Opened / closed valve 18 Temperature sensor attached to lid 19 Sealing member for drive unit chamber

Claims (6)

[Claims] 1. A vacuum concentration method for a sample, wherein a sample to be concentrated or dried is heated under reduced pressure while a centrifugal force is applied to the sample to efficiently evaporate a liquid component contained in the sample without bumping. The depressurized state around the sample is released by introducing a gas serving as a heat transfer medium at least once around the sample during the concentration operation of the sample so that the heating during the concentration operation of the sample is effectively performed. A vacuum concentration method, which is characterized in that 2. The vacuum concentration method according to claim 1, wherein the release of the reduced pressure state around the sample is repeated every a predetermined time during the concentration operation of the sample. 3. A vacuum concentration method for a sample, wherein a sample to be concentrated or dried is heated under reduced pressure while a centrifugal force is applied to the sample to efficiently evaporate a liquid component contained in the sample without bumping. A vacuum concentration method, wherein the end of the concentration operation of the sample by the vacuum concentration method is judged from the amount of change in the temperature around the sample during the concentration operation per a predetermined time. 4. The amount of change in the temperature around the sample per predetermined time for judging the end of the concentration operation is such that the depressurized state around the sample indicates that a gas serving as a heat transfer medium during the concentration operation of the sample has passed a predetermined time. 4. The vacuum concentration method according to claim 3, wherein the amount of change is the amount of change in the temperature around the sample per predetermined time when it is repeatedly introduced and released around the sample every time. 5. A rotating body for imparting a centrifugal force to a sample, a sealed container for housing the rotating body, a vacuum pump for reducing the pressure in the container, and a drive unit for rotating the rotating body. In a vacuum concentrating device having a drive chamber for accommodating the drive and a heating means for heating the inside of the container, a pipe with an on-off valve for introducing a gas serving as a heat transfer medium into the container is connected to the container. At the same time, the pipe is connected to the drive unit chamber so that a gas serving as a heat transfer medium can be introduced into the depressurized container and the drive unit chamber at the same time. . 6. The valve device for maintaining the pressure in the pipe, which is slightly higher than the pressure in the container, in the pipe for introducing the gas serving as the heat transfer medium. Vacuum concentrator.