JP2001000801A - Vacuum concentrating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly judge the end time of concentration operation by judging the end of the concentration operation from the variation per a fixed time with respect to the temp. of periphery of a sample in the vacuum concentrating method by heating the sample under vacuum while applying centrifugal force to the sample and vaporizing a liquid component contained in the sample. SOLUTION: A tube housing the sample is attached to a rotary body 1 and the centrifugal force is applied to the sample by rotating the rotary body 1 with a drive motor 7. A vacuum pump connected to a joint port 4 and a heater 12 are respectively operated to evacuate the inside of a vessel 2 and to increase the temp. of the vessel 2 to vaporize the liquid component contained in the sample. A process that the vacuum pump is once stopped during the concentration operation and a stop valve 17 is opened to introduce air into the vessel 2 to temporarily cancel the vacuum is repeated every fixed time. In such a case, the change of lowering with respect to the temp. of sample after the vacuum is canceled is detected by a temp. sensor 18. When the detected value reaches a fixed value, the vacuum concentration operation is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum concentration method,
In particular, the present invention relates to a method for concentrating a sample in vacuum by applying a centrifugal force by rotation to a container containing the sample and heating the sample under reduced pressure.

[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 containing the sample is subjected to a centrifugal force by rotation while applying a centrifugal force to the tube under reduced pressure. There is a method of vacuum concentration of a sample that heats and efficiently evaporates the liquid component of the sample without bumping. As an apparatus for performing such a vacuum concentration method, for example, an apparatus having a structure as shown in FIG. 5 is currently used.

In FIG. 5, reference numeral 101 denotes a rotating body for applying a centrifugal force to a sample; 102, a container for accommodating the rotating body 101; 103, a lid for opening and closing an upper opening 102a of the container 102; The inside of the container 102 is closed by the lid 103, and is depressurized by a vacuum pump (not shown) connected to a vacuum pump connection port 104 formed on the side wall of the container 102 during a sample concentration operation. It is said.

[0005] In FIG. 5, reference numeral 105 denotes the rotating body 101.
A driving means for rotating the
An indirect drive system using a magnetic coupling is employed to enhance the airtightness of the inside of the container 102, and a rotation shaft 106 rotatably supported near the center of the container 102 and a drive motor arranged below the outside of the container 102. The output shaft 107 is indirectly connected to the output shaft 108 by magnets 110 and 111 opposed to each other with a plate 109 constituting a part of the bottom surface of the container 102 interposed therebetween.

Further, in FIG. 5, reference numeral 112 denotes a heater mounted on the outer peripheral wall of the container 102,
Heat is applied by the heater 112 to promote the evaporation of the liquid component contained in the sample.
A pipe for introducing air into the container 102 provided in a reduced pressure state.
14 are provided.

[0006] The conventional vacuum concentrator constructed as described above is operated as follows. First, a tube containing a sample to be concentrated or dried is attached to the rotating body 101,
After the lid 103 is closed, 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 a heating operation of the sample under a rapid pressure reduction described later.

Next, with the centrifugal force applied to the sample, the vacuum pump and the heater are turned on, the inside of the container 102 is depressurized and the ambient temperature is raised, and the liquid component contained in the sample is efficiently removed. Is evaporated.

After a lapse of a predetermined time, the drive motor, the vacuum pump and the heater are turned off, the vacuum concentration operation is stopped, and the open / close valve 114 is operated to release the reduced pressure state in the container 102. Then, the lid 103 is opened to obtain a concentrated or dried sample.

[0009]

However, here,
In the above-described method of concentrating or drying a sample using a conventional vacuum concentrator, the user first stops once in order to confirm the completion of the concentration operation that differs depending on the type and amount of the liquid component of the sample to be used. The enrichment operation is performed while measuring time with a watch or the like, and the enrichment operation after that is a situation in which the operation time is set by a timer or the like based on the experience value, and for the user side, the enrichment operation is terminated. There was a problem that it was necessary to carry out a task of perseverance in order to confirm the situation.

[0010] Some of the samples to be concentrated or dried using a vacuum concentrator include those using an organic solvent which generates a corrosive gas such as acetone or ethanol as a liquid component of the sample. Despite many
In the conventional vacuum concentrator described above, the rotating body 10
1 and a container 102 for accommodating the rotating body 101 are formed of a corrosion-resistant material, and while the corrosion resistance is ensured, a drive for rotatably accommodating a rotating shaft 106 as a driving means of the rotating body 101. Regarding the corrosion resistance in the compartment 115,
The rotary shaft 106 is simply housed in the drive unit chamber 115 with the seal member 116 interposed therebetween, and the drive unit chamber 115 is made to have a sealed structure to prevent the invasion of corrosive gas and maintain its corrosion resistance. there were. Therefore, when the operation of concentrating or drying the sample is repeated by the vacuum concentrator, the seal member 116 in contact with the rotating shaft 106 naturally loses its sealability due to abrasion and deterioration, and finally can prevent the invasion of corrosive gas. The drive unit room 115
Corrosive gas invades into the inside, and the inner wall surface of the drive unit chamber 115,
Alternatively, a bearing or the like existing in the drive unit chamber 115 may be corroded, and a situation may arise in which the device cannot be used.

The present invention has been made in view of the problems of the above-mentioned conventional vacuum concentrating method, and has the following objects.
It is an object of the present invention to provide a vacuum concentration method capable of accurately judging the end time of a concentration operation.

[0012]

According to the present invention, in order to achieve the above object, a sample to be concentrated or dried is heated under reduced pressure while applying a centrifugal force to a liquid component contained in the sample. In a vacuum concentration method for a sample that is efficiently evaporated without bumping, the end of the sample concentration operation by the vacuum concentration method is determined based on a change amount of the temperature around the sample per predetermined time during the concentration operation. A vacuum concentration method was used.

[0013]

According to the vacuum concentrating method according to the present invention, the sample temperature is less likely to decrease due to heat of vaporization when the liquid component of the sample evaporates and the concentrating operation approaches the end. The end of the enrichment operation is determined by the amount of change in the temperature around the sample per predetermined time during the enrichment operation, so that the user can check the enrichment operation time with a stopwatch or the like, as in the conventional vacuum enrichment method. It is not necessary to perform
In addition, there is an effect that allows easy determination.

[0014]

EXAMPLES Hereinafter, the above-described vacuum concentration method according to the present invention will be described in detail with reference to examples.

FIG. 1 is a longitudinal sectional view showing an embodiment of an apparatus for performing a vacuum concentration method according to the present invention. In FIG. 1, reference numeral 1 denotes a rotating body that applies a centrifugal force to a sample; The container 3 for accommodating the rotating body 1 is an upper opening 2a of the container 2.
It is a lid that opens and closes. The inside of the container 2 is closed by the lid 3 and is evacuated by a vacuum pump (not shown) connected to a vacuum pump connection port 4 formed on the side wall of the container 2 during a sample concentration operation. It is said.

Reference numeral 5 in the figure denotes driving means for rotating the rotating body 1, and the driving means 5 employs an indirect driving method using a magnetic joint in order to enhance the hermeticity of the container 2. A rotating shaft 6 rotatably supported near the center in the container 2 and an output shaft 8 of a drive motor 7 disposed below the outside of the container 2 are opposed to each other with a bottom plate 9 of the container 2 interposed therebetween. The structure is indirectly connected by magnets 10 and 11.

Further, in the figure, reference numeral 12 denotes a heater mounted on the outer peripheral wall surface of the container 2, to which heat for promoting evaporation of a liquid component contained in the sample is applied by the heater 12. Reference numeral 13 denotes a pipe for introducing air into the container 2 provided in a reduced pressure state, and a pipe 13 is provided near a connection portion of the pipe 13 to the container 2.
A valve device 14 for maintaining the pressure in the container 2 slightly higher than the pressure in the container 2 is provided, and a pipe 13 is branched in the middle thereof. It is connected to a drive chamber 16 that houses the shaft 6.

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

In carrying out the vacuum concentrating method according to the present invention using the vacuum concentrating apparatus constructed as described above, first, a tube containing a sample to be concentrated or dried is mounted on the rotating body 1. After the lid 3 is closed, the rotator 1 is rotated by the drive motor 7 to apply a centrifugal force due to the rotation to the sample.

Next, with the centrifugal force applied to the sample, the vacuum pump and the heater are turned on, the inside of the container 2 is depressurized and the ambient temperature is raised, and the liquid component contained in the sample is removed. Allow to evaporate.

When the liquid component in the sample evaporates vigorously by the heating operation under the above-mentioned reduced pressure, the temperature of the sample is taken as heat of vaporization and the temperature decreases. Therefore, during the operation of concentrating the sample, the vacuum pump is once turned on. Stop, open / close valve 1
The operation of introducing air into the container 2 by operating the button 7 and temporarily releasing the reduced pressure state in the container 2 is repeated every predetermined time. Thereby, the air temporarily introduced into the container 2 during the concentration operation is supplied to the heater 12.
Is heated by exchanging heat with the wall surface of the container 2 heated by the heating, and the heat transfer of the heated air effectively heats the rotating body 1 and the sample mounted on the rotating body 1 during the concentration operation. Then, the temperature of the sample that has begun to decrease can be increased again, and the liquid components in the sample can be actively evaporated.

At this time, in the vacuum concentrator, the pressure in the pipe 13 is slightly higher than the pressure in the vessel 2 near the connection of the pipe 13 for introducing air into the vessel 2 to the vessel 2. In addition to providing a valve device 14 for maintaining the valve, the pipe 13 is branched in the middle thereof, and the branch pipe 15 is connected to a drive section chamber 16 that houses the rotating shaft 6 existing in the container 2. When the operation of introducing air into the container 2 is performed by operating the sealing member 19,
Air is also introduced into the drive unit chamber 16 which is in a reduced pressure state due to deterioration of the container, and the inside of the drive unit chamber 16 is always maintained at a higher pressure than the inside of the container 2. Is repeated, the corrosive gas generated from the sample in the container 2 does not enter the driving section chamber 16.

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

The present invention is characterized in that, during the above operation, the end of the sample concentration operation is determined from the amount of change in the temperature around the sample per a predetermined time. In order to confirm the above, the following test was performed using the apparatus of the above embodiment.

(Test 1) 5 ml of water per tube is put into a tube for storing a sample, and 24 tubes are mounted on the rotating body 1 and rotated at 1200 rpm by a vacuum pump. The inside of the container 2 was evacuated to a degree of vacuum of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and a vacuum concentration operation of the sample was started.
From the start of the sample concentration operation, the vacuum pump is turned on every 9 minutes.
Then, when the vacuum pump was stopped, the on-off valve 17 was operated to introduce air into the container 2, and the operation of temporarily releasing the reduced pressure state in the container 2 during the concentration operation was repeated.
After a lapse of 90 minutes from the start of the concentration, the concentration operation was terminated, and the remaining amount of the water sample was measured. The measurement results are shown 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 described as Test 1 in FIG. Further, the amount of change in the sample temperature per predetermined time (9 minutes) during the vacuum concentration operation in each cycle is read from the detection data of the sample temperature by the temperature sensor 18, and the value is shown in Table 2.

(Test 2) 5 ml of water per tube is put into a tube for storing a sample, and 24 tubes are mounted on the rotating body 1 and rotated at 1200 rpm by a vacuum pump. The inside of the container 2 was evacuated to a degree of vacuum of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and a vacuum concentration operation of the sample was started.
After a lapse of 90 minutes from the start of the concentration, the concentration operation was terminated, and the remaining amount of the water sample was measured. The measurement results are 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. Further, the amount of change in the sample temperature per predetermined time (10 minutes) during the vacuum concentration operation every 10 minutes is read from the detection data of the sample temperature by the temperature sensor 18, and the values are shown in Table 3.

(Test 3) 1 ml of 50% aqueous ethanol was put into each tube containing a sample, and 60 tubes were mounted on the rotating body 1 at a rotation speed of 1200.
While rotating at rpm, the container 2 was
The inside was evacuated to a degree of vacuum of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and a vacuum concentration operation of the sample was started. Every 9 minutes from the start of the sample concentration operation, the vacuum pump is stopped for 2 minutes, and when the vacuum pump is stopped, the open / close valve 17 is operated to introduce air into the container 2 and the reduced pressure in the container 2 is concentrated. The operation to temporarily release was repeated. After a lapse of 60 minutes from the start of the concentration, the concentration operation was terminated, and the remaining amount of the 50% aqueous solution of ethanol as the sample was measured. The measurement results are shown in Table 1 as Test 3. 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 described as Test 3 in FIG. Further, the amount of change in the sample temperature per predetermined time (9 minutes) during the vacuum concentration operation for each cycle is read from the data on the sample temperature detected by the temperature sensor 18, and the values are shown in Table 4.

(Test 4) 1 ml of 50% aqueous ethanol was put into each tube containing a sample, and 60 tubes were mounted on the rotating body 1 at a rotation speed of 1200.
While rotating at rpm, the container 2 was
The inside was evacuated to a degree of vacuum of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and a vacuum concentration operation of the sample was started. After a lapse of 60 minutes from the start of the concentration, the concentration operation was terminated, and the remaining amount of the 50% aqueous solution of ethanol as the sample was measured. The measurement results are 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 near the vacuum pump connection port 4 are also shown in FIG. Further, the amount of change in the sample temperature per predetermined time (10 minutes) during the vacuum concentration operation every 10 minutes is read from the detection data of the sample temperature by the temperature sensor 18, and the values are shown in Table 5.

(Test 5) 1 ml of water per tube was put into a tube for storing a sample, and 60 tubes were mounted on the rotating body 1 and rotated at 1200 rpm by a vacuum pump. The inside of the container 2 was evacuated to a degree of vacuum of about 5 Torr, the wall surface of the container 2 was heated to about 45 ° by the heater 12, and a vacuum concentration operation of the sample was started.
From the start of the sample concentration operation, the vacuum pump is turned on every 9 minutes.
After stopping the vacuum pump, the operation of opening and closing the 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, thereby completing the sample concentration operation. . Temperature sensor 1 during the above concentration operation
FIG. 4 shows the detection data of the sample temperature by the sample 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. In addition, the amount of change in the sample temperature per predetermined time (9 minutes) during the vacuum concentration operation for each cycle is read from the detection data of the sample temperature by the temperature sensor 18, and the value is shown in Table 6.

(Test 6) Into a tube containing a sample, 1 ml of chloroform was placed per tube, and the tube was placed in a tube.
0 Attached to the rotating body 1 and rotated at 1200 rpm, the inside of the container 2 is
The degree of vacuum 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. Every 9 minutes after the start of the sample concentration operation, the vacuum pump is stopped for 2 minutes, and when the vacuum pump is stopped, the open / close valve 17 is operated to introduce air into the container 2 to temporarily reduce the depressurized state in the container 2. Is repeated 100 times,
The operation of concentrating the sample was completed. After completion of the above 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.

[0031]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

According to the tests 1, 3, and 5, the concentration of the sample progresses, and when the liquid component in the sample decreases, the sample after releasing the reduced pressure state (after heating by introducing air) which has been repeated every predetermined time has elapsed. It can be seen that the amount of decrease in the temperature decreases, and the end of the sample concentration operation can be determined by detecting the change in the amount of decrease. Tests 2 and 4
Therefore, even when the sample is always heated under reduced pressure, the change amount of the temperature around the sample per predetermined time changes as the sample concentration operation proceeds. It can be seen that it is also possible to determine the end time. Further, according to the above Test 6,
By adopting a configuration in which air is introduced into the drive unit chamber at the same time as the inside of the container, even if the seal member is worn or deteriorated, the invasion of corrosive gas into the drive unit room can be completely prevented, and the structure is hardly corroded. You can see that.

The embodiment of the present invention has been described above.
The present invention is not limited to the above-described examples at all,
Various modifications and changes are possible based on the technical concept of the present invention.

[0034]

According to the vacuum concentrating method according to the present invention described above, when the liquid component of the sample evaporates and the concentrating operation approaches the end, the sample temperature is less likely to decrease due to heat of vaporization. Focusing attention, the end of the sample concentration operation is determined from the amount of change in the temperature around the sample per predetermined time, so that the user checks the concentration operation time with a stopwatch etc. like a conventional vacuum concentration method Therefore, there is an effect that the end time of the concentration operation can be determined accurately and easily.

In particular, the amount of change in the temperature around the sample per predetermined time for judging the end of the concentration operation is determined by the decompression state around the sample, and the gas serving as a heat transfer medium during the concentration operation of the sample is passed for a predetermined time. When the amount of change in the temperature around the sample per predetermined time when the sample is repeatedly introduced around the sample and released every time is used, there is an effect that the end time of the concentration operation can be more accurately determined.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of an apparatus for performing a vacuum concentration method 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 near the vacuum pump connection port when Tests 1 and 2 are performed. It is a graph.

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

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

FIG. 5 is a longitudinal sectional view showing an example of a vacuum concentrator used when performing a conventional vacuum concentrating method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Rotating body which gives a centrifugal force to a sample 2 Container which stores a rotating body 2a Upper opening of a container 3 Lid of a container 4 Vacuum pump connection port formed in a side wall of a container 5 Driving means for rotating a rotating body 6 Inside of a container A rotating shaft rotatably supported in the vicinity of the center 7 A drive motor arranged below the outside of the container 8 An output shaft of the drive motor 9 A bottom plate of the container 10 Magnet 11 Magnet 12 A heater mounted on the outer peripheral wall surface of the container 13 Inside the container 14 A valve device for maintaining the pressure in the pipe slightly higher than the pressure in the container 15 A branch pipe provided in the pipe 16 A drive unit chamber for accommodating the rotating shaft 17 Provided at the base end of the pipe Open / close valve 18 Temperature sensor attached to lid 19 Sealing member for drive unit room

Claims (2)

[Claims] 1. A vacuum concentration method for a sample in which a sample to be concentrated or dried is heated under reduced pressure while applying a centrifugal force to the sample to efficiently evaporate a liquid component contained in the sample without bumping. A vacuum concentration method, wherein the end of the sample concentration operation by the vacuum concentration method is determined from a change in the temperature around the sample per a predetermined time during the concentration operation. 2. The amount of change in the temperature around the sample per a predetermined time for judging the end of the concentration operation is determined by changing the depressurized state around the sample to the time when the gas serving as the heat transfer medium during the concentration operation of the sample is passed for a predetermined time. 2. The vacuum concentrating method according to claim 1, wherein the amount of change in the temperature around the sample per predetermined time when the sample is repeatedly introduced around the sample and released every time.