JP2003270126A - Instrument for measuring solubility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exactly measure solubility in a supercritical fluid. <P>SOLUTION: This solubility measuring instrument 110 for measuring the solubility of a sample in the supercritical fluid is provided with a cell 128 filled with the fluid and the sample, in which the sample is dissolved into the fluid and in which the solubility is measured, a supercritical condition generating means 118 for bringing the fluid in the cell 128 into a supercritical condition, and a detector 114 for measuring solubility information of the sample in the supercritical fluid inside the cell 128. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solubility measuring device, and more particularly to solubility measuring in a supercritical fluid.

[0002]

2. Description of the Related Art A substance can be in a solid, liquid or gas phase by changing its temperature and pressure below a certain critical temperature. However, above the critical temperature, no matter how much pressure is applied, it can no longer become a liquid. A fluid in such a state is called a supercritical fluid, and exhibits extremely high solubility and high reactivity not found in ordinary gases. Such supercritical fluids are attracting attention for their high reactivity, and are used for studies of specific reactions in supercritical fluids, studies of reactions that proceed only in supercritical fluids, and the like. In addition, the great dissolving power of supercritical fluids has attracted attention,
It is used to decompose substances that are difficult to dissolve in normal temperature and pressure fluids.

[0003]

By the way, the present inventor has paid attention to the solubility of various substances in a supercritical fluid that no one has noticed in the past. That is, for example, in crystallization and coating, the solubility of the target component to be crystallized and the component to be coated under various pressures and temperatures affects the size and shape of the crystal. In addition, in the synthesis in a supercritical fluid, the solubility of reagents and the like to be reacted is large, which affects the reaction rate and yield of the compound. Solubility is also basic information necessary for studying the efficiency and extraction conditions of extraction and the like.

In order to measure this solubility, conventionally, a method is considered in which a target component is separated and weighed. That is, the fluid and the sample are filled in the dissolution container, and the fluid in the dissolution container is brought into a supercritical state to dissolve the sample in the supercritical fluid. In order to convert the dissolved amount of the sample into solids, the solution is taken out of the dissolution container and dried. After drying, the weight of the sample was weighed to determine the amount of dissolution.

However, since this conventional method requires time and labor, it cannot be adopted as the solving means. As described above, the present inventor recognizes the importance of measuring the solubility in a supercritical fluid, but hitherto there has been no technique capable of obtaining a satisfactory measurement result. The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a solubility measuring apparatus capable of appropriately measuring the solubility in a supercritical fluid.

[0006]

Means for Solving the Problems As a result of extensive studies conducted by the present inventor on the measurement of the solubility of a substance in a supercritical fluid, as a result, a detector is provided in the dissolution vessel to directly detect the supercritical fluid in the dissolution vessel. It was found that the solubility of a substance in a fluid in a supercritical state can be always measured by measuring spectral information such as absorption of a sample therein, and the present invention has been completed.

First, the process leading to the above knowledge will be described. The present inventor has paid attention to solubility measurement in a supercritical fluid that no one has noticed in the past, but hitherto there has been no technique capable of obtaining a satisfactory measurement result. Therefore, next to the conventional method of separating the target component and weighing it, a supercritical extraction device, an SFC, and an HPLC device are connected via a valve, and the valve is opened during extraction of the target component whose solubility is to be measured. A method of switching and quantifying by a technique of chromatography can be considered.

It is also conceivable to prepare a flow path for circulation in the supercritical extraction system and put a high pressure cell such as a spectrophotometer therein to measure the absorbance. A simplified apparatus for performing these conventional methods can be shown in FIG. The solubility measuring apparatus 10 shown in the figure includes a dissolution container (or column) 12 and a detector 14.

The dissolution container (or column) 12 and the detector 14 are connected by an outflow side pipe 16. Substantially only container (or column) 12 is contained within oven 18. Then, after dissolving the sample in the supercritical fluid in the container (or column) 12, the solution is sent to the detector 14 via the outflow side pipe 16. The detector 14 measures the spectral information 20 such as the absorption of the sample, and the solubility of the sample is obtained by data processing.

However, even if these conventional methods are used, satisfactory measurement results have not been obtained. Therefore, as a result of further research conducted by the present inventor on the measuring device, the cause of not being able to obtain a satisfactory measuring result with the solubility measuring device 10 was found.

That is, normally, the oven 18 is substantially provided only in the container (or column) 12, and is not provided in the entire flow path of the outflow side pipe 16 or the detector 14. For this reason, the temperature of the solution in the container (or column) 12 gradually decreases until it reaches the detector 14 via the outflow side pipe 16, so that the actual temperature of the solution at the detector 14 is It may fall below the original supercritical temperature.

Therefore, in the detector 14, the solubility measurement is performed under such a temperature, that is, in a state where the temperature is subcritical or lower. Then, particularly under subcritical conditions, there is a case where remarkable dissolution of the sample, which was not observed under supercritical conditions, may proceed. As described above, in the conventional solubility measuring device 10, the measurement different from the solubility in the original supercritical state was carried out by the detector 14, and therefore, a satisfactory measurement result was not obtained.

Therefore, the present inventor always installs a detector in the dissolution container and directly measures the solubility information of the substance in the supercritical fluid in the dissolution container, so that the substance in the fluid in the supercritical state is always detected. Found that the solubility can be measured,
The present invention has been completed. That is, the solubility measuring apparatus according to the present invention to achieve the above object is a solubility measuring apparatus for measuring the solubility of a sample in a supercritical fluid, and a cell, a supercritical condition generating means, and a detector, It is characterized by including.

Here, a fluid and a sample are put in the cell, and the dissolution of the sample in the fluid and the measurement of the solubility thereof are performed. The supercritical condition generating means brings the fluid in the cell into a supercritical state. The detector is directly or indirectly provided in the cell and measures the solubility information of the sample in the supercritical fluid in the cell.

As the detector of the present invention, any detector can be used as long as it can directly measure the solubility information of the sample in the supercritical fluid in the cell. For example, depending on the measurement method, ultraviolet / visible / near infrared spectrophotometer,
An optical detector such as an infrared spectrophotometer, a spectrophotometer such as a fluorescence / Raman spectrophotometer, or an electrical detector can be used as an example. The solubility information here means, for example, solubility (dissolution amount, dissolution rate), that is, for example, spectral information or the like for obtaining some information regarding the dissolved amount. To make the fluid in the cell into a supercritical state here means
It means to bring the fluid under the conditions of its critical temperature and critical pressure or higher.

In the present invention, the cell is an optical cell, the detector is an optical detector, and a light observation window provided in the optical cell is provided. Then, the optical detector is provided directly in the light observation window of the optical cell, and the optical detector measures the spectral information for obtaining the solubility information of the sample in the supercritical fluid in the optical cell. This is particularly preferable in the supercritical state because the measurement is easy.

Further, in the present invention, the cell is an optical cell, the detector is an optical detector, a light observation window provided in the optical cell, and a supercritical state in the optical cell. Light guiding means for guiding light including spectral information for obtaining solubility information of the sample in the fluid to the detecting means from the light observation window. And, the optical detector is provided in the light observation window of the optical cell via the light guiding means, and the spectral information of the sample in the supercritical fluid in the optical cell is measured by the optical detector. However, it is particularly preferable in the supercritical state because the measurement is easy.

As the light guide means of the present invention, any means can be used as long as it can guide the solubility information from the sample in the supercritical fluid in the optical cell to the detector. For example, an optical fiber or a light guide can be used as an example. Further, in the present invention, the fluid is carbon dioxide, and it is preferable that the fluid includes a calibration information storage unit and a data processing unit.

Here, the calibration information storage unit stores calibration information prepared by dissolving a standard sample in n-hexane, which is excellent in that it is very similar to the physical properties of supercritical carbon dioxide. . Further, the data processing unit applies the measurement result of the actual sample obtained by the detector to the calibration information stored in the calibration information storage unit to obtain the solubility of the actual sample in the supercritical carbon dioxide.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a solubility measuring device according to one embodiment of the present invention. Incidentally, the portion corresponding to that of FIG. Solubility measuring device 1 shown in FIG.
Reference numeral 10 denotes a CO ₂ cylinder 124, a supercritical fluid feed pump 126, an optical cell (cell) 128, a supercritical condition generating means 118, an optical detector (detector) 114, and a data processing means 130. Prepare

The CO ₂ cylinder 124 and the supercritical fluid feed pump 126 are connected by a pipe 132. The supercritical fluid feed pump 126 and the optical cell 128 are connected by a pipe 139 via stop valves 134, 136 and 138. The optical cell 128 and the detector 114 are optically connected via an optical fiber 140. Detector 1
14 and the data processing device 130 are electrically connected by a signal line 142. Then, the carbon dioxide (fluid) from the CO ₂ cylinder 124 is pressurized by the pump 126, quantitatively sent out, and filled in the optical cell 128. The sample is also filled in the optical cell 128 together with the carbon dioxide by an injector (not shown) or the like.

The measurement light from the detector 114 is sent to the optical cell 128 via the optical fiber 140, and the optical cell 12
The solution in 8 is irradiated. The light containing the absorption spectrum information (solubility information) from the solution is detected by the detector 114 via the optical fiber 140. The electric signal photoelectrically converted by the detector 114 is sent to the data processing device 130,
Data processing is performed by the data processing device 130, and the solubility is obtained.

Here, the optical cell 128 has, for example, an internal volume of 3 cm ³ , an optical path length of 5 mm, a maximum operating temperature of 100 ° C.,
It is configured to have a pressure of 30 MPa or the like, and is used for dissolving a sample in supercritical carbon dioxide and measuring ultraviolet / visible absorption spectrum data of the solution. That is, the optical cell 128 has a role as a dissolution container in which a sample is dissolved in supercritical carbon dioxide and a role as an optical cell in which a solution in the dissolution container is measured. That is, the optical cell 128 is an entrance window (light observation window) made of, for example, sapphire as a window material.
144 and an emission window (light observation window) 146 are arranged opposite to each other. The optical fiber 140 includes an incident side optical fiber (light guiding means) 148 and an emitting side optical fiber (light guiding means).
It comprises 150.

An incident side optical fiber 148 is provided in the entrance window 144 of the optical cell 128, and the exit window 1 of the optical cell 128 is provided.
An output side optical fiber 150 is provided at 46. And
The measurement light from the detector 114 is incident side optical fiber 148.
Is guided to the entrance window 144 of the optical cell 128. Light is guided to the solution in the optical cell 128 through the incident window 144,
The solution in the optical cell 128 is irradiated. The light containing the absorption spectrum information from the solution reaches the exit window 146 of the optical cell 128. The light from the emission window 146 is transmitted through the emission side optical fiber (light guide means) 150 to the detector 114.
Be guided to.

The supercritical condition generating means 118 is provided with a water tank 152 containing water and a heater 154, for example. The optical cell 12 is placed in a water tank 152 containing the water.
8 and a heater 154. And the heater 1
By heating the water in the water tank 152 by 54,
The optical cell 128 in the water tank 152 is heated to bring carbon dioxide in the optical cell 128 into a supercritical state.

The detector 114 is composed of, for example, an ultraviolet / visible spectrophotometer, and obtains ultraviolet / visible absorption spectrum information (solubility information) of the actual sample in the optical cell 128. The data processing device 130 is composed of, for example, a computer, and includes a CPU 156 and a memory 158.
The memory 158 includes a measurement result storage unit 160 and a solubility storage unit 162. The measurement result storage unit 160 stores the ultraviolet / visible absorption spectrum information from the detector 114. Then, when the calculation of the solubility is instructed, the CPU 15
6 accesses the measurement result storage unit 150,
Solubility is determined using visible absorption spectrum information. The result is stored in the solubility storage unit 162.

By configuring the solubility measuring device 110 in this way, it is possible to always measure how much the actual sample is dissolved in the carbon dioxide in the supercritical state. In this embodiment, the temperature sensor 164
And a pressure sensor 166.

Here, the temperature sensor 164 is the water tank 1
The temperature of the water in 52 is output. In addition, the pressure sensor 16
6 is provided in the pipe 139 and outputs a pressure. Then, the data processing device 130 uses the temperature sensor 164,
The pressure sensor 166 monitors whether the temperature and pressure of carbon dioxide in the optical cell 128 are maintained in a supercritical state.

That is, the data processing device 130 adjusts the temperature of the water in the water tank 152 with the heater 154 based on the temperature information from the temperature sensor 164, so that the temperature of carbon dioxide in the optical cell 128 is controlled to be higher than the temperature of the carbon dioxide. The temperature is adjusted to a constant critical temperature. The data processing device 130 also uses the optical cell 1 based on the pressure information from the pressure sensor 166.
The pressure of carbon dioxide in 28 is adjusted by the stop valves 134, 1
At 36 and 138, the pressure is adjusted to a constant pressure in the supercritical state.

Further, in this embodiment, the stirrer 16 is used.
8 and a rotor 170. Where the stirrer 168
The optical cell 128 is placed on the rotor 170.
Is rotatably provided in the optical cell 128 so as to face the stirrer 168. Then, the rotor 170 is rotated by the stirrer 168, whereby the optical cell 128
The solution inside is being stirred.

Further, in this embodiment, the back pressure control valve 1
74 and a sample collector 176. The back pressure control valve 174 is connected to the optical cell 128 via a stop valve 178 by a pipe 180.
A sample collector 176 is connected to the subsequent stage of No. 4. Then, by releasing the back pressure control valve 174 after the measurement, the solution from the optical cell 128 is collected in the sample collector 17
Captured by 6.

Further, in the present embodiment, the trap 17
8 and a vacuum pump 180. The pipe 180 is
Back pressure control valve 174 and trap 178 in liquid nitrogen 182
Is connected to the vacuum pump 180 after the trap 178.

The solubility measuring device 110 according to this embodiment
Is configured as described above, and its operation will be described below. First, in order to develop reactions and separation processes that use supercritical fluids, knowledge about the solubility of target substances (substances to be extracted, reactants, catalysts, etc.) in supercritical fluids is essential. However, in order to obtain accurate solubility data, a skilled researcher must use expensive high-pressure equipment to perform long-term measurement under high pressure.

Therefore, in the present embodiment, the solubility measuring apparatus 1 is used in order to perform highly accurate measurement in a short time even with a small amount of sample.
10 is used. First, the sample and carbon dioxide are filled in the optical cell 128. That is, the CO ₂ cylinder 124
Carbon dioxide from the above is pressurized by the pump 126 and quantitatively sent out, and the optical cell 128 is filled with the carbon dioxide. The sample is also filled in the optical cell 128 together with carbon dioxide by an injector (not shown) or the like. After the filling, the optical cell 1
Dissolve the sample at 28.

That is, inside the optical cell 128, the heater 1
It is controlled to a constant temperature above the critical temperature of carbon dioxide by 54, and is controlled to a constant pressure above the critical pressure of carbon dioxide by a pump 126, a stop valve and the like. Therefore, the carbon dioxide in the optical cell 128 is in a supercritical state, and the sample is dissolved in the supercritical carbon dioxide in the optical cell 128.

Here, in general, the solubility was measured by introducing a solution dissolved in a dissolution vessel or a column into a detector through a pipe and measuring with the detector. However, in the original supercritical state, The solubility of the sample cannot be measured. Therefore, what is characteristic of the present invention is that how much the sample is always dissolved in the fluid in the supercritical state is measured. For this reason, in the present embodiment, the optical cell 128 in which the sample is dissolved in supercritical carbon dioxide and the solubility thereof is measured is used. And the optical cell 1
28, the absorption spectrum information of the sample in the supercritical carbon dioxide in the optical cell 128 is directly measured using the detector 114 via the optical fiber 140.

That is, in this embodiment, the measurement light from the detector 114 is sent to the entrance window 144 of the optical cell 128 via the entrance-side optical fiber 148, and the entrance window 1
The solution in the optical cell 128 is irradiated via 44. The light containing the absorption spectrum information from the solution is transmitted to the optical cell 12
8 through the exit side optical fiber 150, and is detected by the detector 114. Photoelectric conversion is performed by the detector 114, the electric signal thereof is sent to the data processing unit 130, data processing is performed by the data processing unit 130, and the solubility is obtained.

As a result, in this embodiment, the sample is dissolved in supercritical carbon dioxide, and the optical cell 128 in which the solubility is measured is directly connected to the optical cell 128 using the detector 114 via the optical fiber 140. Since the absorption spectrum information of the sample in the supercritical carbon dioxide inside is measured, it is always measured how much the real sample is eluted in the fluid in the supercritical state. Therefore, the present embodiment is compared with the conventional method, that is, the solution from the dissolution container is brought into the detector through the pipe and the solubility is measured by the detector, and the sample is reliably contained in the fluid in the supercritical state. It measures how much is eluted.

Moreover, in this embodiment, since the optical measurement is directly performed by the optical cell 128 for dissolving the sample, the conventional method, that is, after the sample is dissolved, the sample is taken out from the dissolution container and dried to measure the weight. The measurement time and labor can be greatly reduced as compared with those performed.

<Management of Supercritical Conditions> By the way, in the measurement of solubility under supercritical conditions, it is very important to manage the temperature and pressure inside the optical cell 128. For this reason, in the present embodiment, the optical cell 128 is placed in the water tank 152, which is an oven and is filled with water. Therefore, the temperature inside the optical cell 128 can be controlled very well. Particularly, the water tank 152 of 1 ton (1 m in length, 1 m in width, 1 m in depth) is excellent in temperature control among the water tanks. By housing the optical cell 128 in such a water tank 152, the temperature in the optical cell 128 can be maintained at a constant temperature in the supercritical state of carbon dioxide, as compared with the one housed in another.

Further, in a supercritical fluid, the conventional estimation of solubility using the equation of state or the like often causes a large error, so that it cannot be said to be practical yet. Therefore, in the present embodiment, in order to calculate the solubility with high accuracy, the following solubility calculation formula and calibration curve are used.

<Solubility Calculation Formula> In other words, when the solubility in a supercritical fluid is measured by the UV-visible absorption method, when the solubility increases, the absorbance, especially the absorbance at the peak top, may be saturated immediately. . Therefore, in the present embodiment, the components of the Lambert-Beer equation shown in the following formula 1 are adopted for the calculation of the solubility.

[0043]

[Equation 1]

As described above, instead of using the absorbance of the peak saturated due to the high concentration of the target substance, the integrated value of the absorbance in the wave number region where the absorbance near the skirt of the peak is not so large is used. Sufficiently accurate measurement can be performed even in the high concentration range.

<Calibration curve> Conventionally, regarding the measurement of solubility in a supercritical fluid, no standardization of a method for preparing a calibration curve has been made. Therefore, it is an urgent need to solve how to prepare a calibration curve for a target substance. Met. Therefore, the present inventor
We have found n-hexane as a liquid solvent with very similar physical properties to the supercritical carbon dioxide fluid. That is, a standard sample is dissolved in an n-hexane solution to prepare a standard solution. It was found that the calibration curve prepared using this standard solution has almost the same slope as the calibration curve prepared using supercritical carbon dioxide.

Therefore, in the present embodiment, the calibration curve prepared using the n-hexane solution as described above is stored in the calibration information storage section 184. Then, when receiving the instruction to calculate the solubility, the CPU 156 accesses the measurement result storage unit 160, applies the measurement result of the actual sample to the calibration information stored in the calibration information storage unit 184, performs quantification, and The concentration of the sample is determined and the solubility is determined. As a result, in the present embodiment, since the calibration curve can be easily created by using n-hexane, which is relatively easy to handle, it becomes easy to apply and quantify the calibration curve of the measurement result. .

Next, the solubilities of the wood treating chemicals (insect repellents and preservatives) in the supercritical carbon dioxide obtained by the solubility measuring apparatus 110 according to this embodiment were measured. Solubility of three kinds of insect repellents (imidacloprid, silafluofen, bifenthrin) was measured in a pressure range of 1 to 30 MPa for two isotherms at 35 ° C and 70 ° C. An example of the measurement result is shown in FIG. In addition, FIG. I shows the measurement results of bifenthrin, FIG. II shows the results of silafluofen, and FIG. III shows the results of imidacloprid.

Here, C [mol / l] on the vertical axis is the solubility of the target substance in supercritical carbon dioxide. The time required to measure one point is 15 to 30 minutes including the average waiting time, and the time required to create one isotherm is about 3 hours on average. As a result, the solubility measuring apparatus 11 according to the present embodiment
According to 0, rapid measurement of solubility was possible from low concentration to high concentration.

As described above, according to the solubility measuring apparatus of this embodiment, it is possible to dissolve the sample in the supercritical carbon dioxide in the optical cell 128 and measure the ultraviolet / visible absorption spectrum of the solution. . That is, in this embodiment, the absorption spectrum information of the sample in the supercritical fluid in the optical cell 128 can be directly measured by using the optical fiber 140 in the optical cell 128.

As a result, the present embodiment can reliably measure how much the sample is dissolved in carbon dioxide in the supercritical state. Moreover, in this embodiment,
The sample is taken out of the dissolution container, dried, and compared with the solid-converted one, the solubility in supercritical carbon dioxide can be easily measured.

In this embodiment, the calibration information prepared by dissolving the standard sample in n-hexane is used as the detector 11.
The solubility of the actual sample in the supercritical carbon dioxide is determined by applying the measurement result of the actual sample obtained in 4 to quantitatively. As a result, the calibration curve can be created with higher accuracy compared to those using other ones.
Solubility can be calculated with high accuracy. Further, in the present embodiment, since the solubility can be calculated using the skirt portion of the absorption spectrum data obtained by the detector 114,
It is possible to accurately measure even the solubility in the high concentration region.

As described above, in this embodiment, it is possible to measure the solubility quickly, and the measurement is completed in a short time. In the above configuration, an example in which an optical detector is provided in the optical cell via a light observation window and an optical fiber has been described, but the present invention is not limited to this.
As long as it is possible to directly obtain the absorbance information of the solution inside the optical cell, any one can be used. For example, instead of the optical fiber, a light guide means such as a light guide may be used. Also, without using the light guide means,
The optical detector may be provided directly on the light observation window of the optical cell.

Although carbon dioxide is used as the fluid in the above construction, any other fluid such as water can be used. Further, in the above configuration, using an optical cell as a cell, an example using an optical detector as a detector is described, which is particularly preferable in the supercritical state because its measurement is easy, Other detectors can be used as long as they give information about the dissolved amount of the sample. For example, an electric detector can be used, and the electric detection can provide information on the dissolved amount of the sample.

In the above-mentioned configuration, the example in which the cell is housed in the water tank containing water for controlling the temperature of the supercritical portion has been described. However, instead of the water tank, the cell is housed in an air bath, It is also possible to control the temperature of the supercritical portion by subjecting the cell to an air bath.

[0055]

As described above, according to the solubility measuring device of the present invention, the cell in which the sample is dissolved in the fluid and the solubility thereof is measured, and the supercritical fluid in the cell is brought into a supercritical state. The critical condition generating means and the detector for measuring the solubility information of the sample in the supercritical fluid in the cell were provided. As a result, the present invention can properly measure the solubility of the sample in the supercritical fluid. Further, in the present invention, by providing an optical detector directly in the optical cell or through the light guiding means, the solubility in the supercritical fluid can be properly measured. Further, in the present invention, by applying the measurement result of the actual sample obtained by the detector to the calibration information prepared by dissolving the standard sample in n-hexane, the actual sample in the supercritical carbon dioxide is obtained. The solubility of the sample can be properly determined.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of a solubility measuring device according to an embodiment of the present invention.

FIG. 2 is an example of solubility obtained by the solubility measuring device shown in FIG.

FIG. 3 is an explanatory diagram of a schematic configuration of a general solubility measuring device.

[Explanation of symbols]

110 Solubility measuring device 114 Optical detector (detector) 118 Means for generating supercritical conditions 128 optical cells 144 incident window (light observation window) 146 exit window (light observation window) 140 optical fiber (light guiding means) 184 Calibration information storage unit

Continued front page    F term (reference) 2G057 AA01 AC01 AC03 AD04 BA05                       DB05 DC07 EA01 GA01                 2G059 AA01 AA03 BB04 CC04 CC13                       DD12 DD15 DD16 DD20 EE01                       EE12 FF08 JJ17 KK01 MM01                       MM10 MM12                 2G060 AA06 AE40 FA15 FB03

Claims (4)

[Claims] 1. A solubility measuring apparatus for measuring the solubility of a sample in a supercritical fluid, comprising a cell in which a fluid and a sample are placed, and in which the sample is dissolved in the fluid and the solubility thereof is measured, A supercritical condition generating means for bringing a fluid in the cell into a supercritical state; and a detector which is directly or indirectly provided in the cell and measures the solubility information of the sample in the supercritical fluid in the cell. A solubility measuring device characterized by the above. 2. The solubility measuring device according to claim 1, wherein the cell is an optical cell, the detector is an optical detector, and a light observation window provided in the optical cell is provided. The optical detector is provided directly in the light observation window of the optical cell, and the optical detector measures the spectral information for obtaining the solubility information of the sample in the supercritical fluid in the optical cell. Characteristic solubility measuring device. 3. The solubility measuring apparatus according to claim 1, wherein the cell is an optical cell, the detector is an optical detector, and a light observation window provided in the optical cell, Light guiding means for guiding light including spectral information for obtaining solubility information of a sample in a supercritical fluid in an optical cell to the detecting means from the light observation window, and optical observation of the optical cell A solubility measuring apparatus, characterized in that the window is provided with the optical detector via the light guiding means, and the spectral information of a sample in a supercritical fluid in the optical cell is measured by the optical detector. 4. The solubility measuring device according to claim 1, wherein the fluid is carbon dioxide, and the calibration information is stored by dissolving a standard sample in n-hexane. Information storage unit, applying the measurement results of the actual sample obtained by the detector to the calibration information stored in the calibration information storage unit, a data processing unit for determining the solubility of the actual sample in the supercritical carbon dioxide, A solubility measuring device comprising: