JP2003139831A - Double-pipe type sample container for magnetic resonance measurement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-pipe type sample container for magnetic resonance measurement that is constituted to efficiently perform high-accuracy and high-sensitivity measurement by making the introduction and discharge of fluid samples to and from a measuring area smoothly executable. SOLUTION: This sample container 1 used for measuring the magnetic resonance of the samples has an external pipe 2 having an space section inside and a closed lower end section, an internal pipe 3 having a central flow hole 31 through which the samples can flow along the center axis in the vertical direction and arranged in the external pipe 2 so that a clearance may be formed between the pipes 2 and 3, and a cap section 4 to which the pipes 2 and 3 are connected. The internal pipe 3 is provided with fixed-diameter sections 32 and 36 formed to have prescribed outside diameters and a small-diameter section 34 formed in the outer peripheral section of the pipe 3 above the lower end of the pipe 3 by a prescribed distance and having a smaller outside diameter than the sections 32 and 36 have. The space between the internal wall of the external pipe 2 and the small-diameter section 34 of the internal pipe 3 constitutes the measuring area and the samples are introduced to the measuring area from one side of the small-diameter section 34 in the vertical direction and discharged from the other side of the section 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample container for measuring a fluid sample in a flowing state in a magnetic resonance apparatus for measuring a magnetic resonance phenomenon by holding the fluid sample at a predetermined temperature and pressure, The present invention relates to a sample container suitable for measuring physical properties of various fluid samples (including supercritical fluids) or samples dissolved in various fluids.

[0002]

2. Description of the Related Art A method for feeding a fluid sample from a line for transporting the fluid sample to a magnetic resonance signal detecting section of a magnetic resonance apparatus and measuring a magnetic resonance signal in a state in which the fluid sample is circulated or in a stationary state is as follows. It has many advantages such as automatic measurement while automatically supplying a fluid sample, and combined analysis with other analysis devices. When a fluid sample is sent to the magnetic resonance signal detector to measure the physical properties of various fluid samples (including supercritical fluids) or samples dissolved in various fluids, the measurement cell (sample container It is important to accurately control or adjust the smooth inflow and outflow of the fluid sample to and from the sample), the time for the fluid sample to pass through the measurement region (residence time), and the volume of the fluid sample in the measurement region.

As a method for measuring a magnetic resonance signal in a measuring cell while circulating a fluid sample, there has been one in which the measuring cell is designed and manufactured integrally with a magnetic resonance signal detecting section. In this measuring device, a supply pipe is connected below the measurement cell and a discharge pipe is connected above it. Then, the fluid sample is supplied from below to the measurement cell arranged inside the detection coil, the magnetic resonance signal of the fluid sample in the flowing state is measured, and the fluid sample is discharged upward.

In this type of measuring apparatus, the measuring cell is covered with a cylindrical magnet, and the measuring cell can be attached and detached only from the vertical direction, and the sample supply pipe and discharge in a narrow space can be performed. Since it was necessary to connect and disconnect the pipes and the number of parts was large, workability was poor. That is, when cleaning or replacing the measurement cell, the magnetic resonance signal detection unit must be disassembled, and the work is complicated and requires specialized knowledge and skill. Moreover, even when using different types of measurement cells, it is necessary to modify the magnetic resonance signal detection unit itself and install a desired measurement cell each time, which makes it difficult to change the type of measurement cell. There was a problem.

On the other hand, as a flow-through type measuring cell for carrying out measurement while circulating a fluid sample, a flow-through type measuring cell which can be replaced with a batch-type measuring cell used for usual batch type measurement has been proposed. If such an exchangeable flow-through type measuring cell is used, the flow-through type measuring cell is installed in the magnetic resonance signal detecting unit without the need for remodeling or complicated disassembling of the magnetic resonance signal detecting unit. Can be measured.

[0006] As such a flow-through type measuring cell, there is one in which a capillary (capillary) -shaped quartz tube is folded back in a multiple manner and a fluid sample is circulated in the quartz tube to carry out the measurement at the multiple folded back portion. However, this capillary type measuring cell is difficult to manufacture because of its complicated structure,
Since it is made of capillaries, it remains vulnerable to mechanical shock and easily damaged.

In addition to this, in this capillary type measuring cell, the volume of the sample inside the quartz tube becomes smaller than the volume of the quartz tube itself, and the filling rate of the sample in the detection coil becomes smaller. There is. To measure the magnetic resonance signal with high sensitivity, it is necessary to increase the filling rate of the sample in the detection coil. In the capillary type measurement cell, the volume of the quartz tube itself and the volume of the void between the quartz tubes due to the folding of the quartz tube are large, so the filling rate of the sample cannot be sufficiently increased, and as a result, the nuclide of low sensitivity is It has been difficult to perform the measurement of 1 and the measurement of a low-concentration sample.

In addition, the inventors of the present invention have disclosed in Japanese Patent Application Laid-Open No. 20
A measurement cell as disclosed in Japanese Patent Publication No. 00-241518 has been proposed. FIG. 7 shows an enlarged sectional view in the vicinity of the measurement area of this measurement cell. This measurement cell 11 is used as a flow-through type measurement cell, and continuously introduces and discharges a fluid sample into and from a measurement region 17 arranged in a cylindrical outer tube 12, while continuously measuring a magnetic resonance signal of the fluid sample. Is measured. The outer tube 12 is formed in a simple cylindrical shape, and the material is ceramics in consideration of mechanical strength, corrosion resistance, heat resistance, pressure resistance, etc., and there is no problem in strength.

In the outer tube 12, detachable spacers 13 and 14 made of fluororesin are arranged. Spacer 1
The space between 3 and the spacer 14 is used as the measuring area 17. When the measurement cell is installed in the magnetic resonance signal detection section, the measurement region 17 is arranged at the detection position by the detection coil, and while the fluid sample is circulated in the measurement region 17, the magnetic field of the fluid sample is continuously measured. The resonance signal can be measured.

A central hole is formed in the spacer 13 along the central axis, and a supply pipe 15 made of a Ti--Al alloy is arranged and fixed in the central hole. The fluid sample to be measured is supplied to the measurement region 17 through the supply hole 16 of the supply pipe 15. However, since the supply pipe 15 is made of metal, it is installed only in a portion away from the measurement region 17 so as not to affect the measurement of the magnetic resonance signal. The fluid sample after the measurement is discharged from the measurement region 17 through the gap between the inner wall of the outer tube 12 and the spacer 13.

In this measuring cell 11, the sample volume can be considerably increased, and there is no problem in mechanical strength. However, as shown by the arrow in FIG.
Since the flow path is such that it is introduced from above 7 and discharged above measurement region 17, the flow path of the fluid sample is folded back within measurement region 17 and the uniformity of flow of fluid sample within measurement region 17 is reached. There was a problem that it was hindered.

In particular, the fluid sample existing under the measurement region 17 cannot be discharged smoothly, and the sample is likely to stay.
This tendency becomes particularly strong in a fluid having a large viscosity. As described above, it is important to accurately control or adjust the time during which the fluid sample stays in the measurement region in order to perform highly accurate measurement. There is a problem that the samples with different times are mixed and the flow is disturbed, and the measurement error increases.

[0013]

As described above, the currently known magnetic resonance measurement cells have their respective problems, and the physical properties of a measurement sample can be measured with high efficiency and high accuracy by the flow-through type magnetic resonance measurement. And it could not be done with high sensitivity. That is, there is a problem in any of workability during measurement, measurement accuracy, and measurement sensitivity.

Therefore, according to the present invention, the fluid sample can be smoothly introduced into and discharged from the measurement area to improve the uniformity of the flow of the fluid sample in the measurement area, and to perform highly accurate measurement efficiently. An object is to provide a sample container for magnetic resonance measurement that can be frequently performed.

[0015]

In order to achieve the above object, a sample container of the present invention is a sample container for measuring magnetic resonance of a sample, which is provided with a central axis in the vertical direction, and is internally An outer tube having a space for storing a sample and having a closed lower end, and a central flow hole through which the sample can flow are formed along a central axis in the vertical direction, and the outer tube is provided inside the outer tube. It has an inner pipe arranged so as to have a gap between the inner wall of the pipe and a cap portion to which the outer pipe and the inner pipe are connected, and the inner pipe is formed to have a predetermined outer diameter. A constant diameter portion and a small diameter portion having an outer diameter smaller than the constant diameter portion are provided above the lower end of the inner pipe by a predetermined distance, and between the inner wall of the outer pipe and the small diameter portion. The space constitutes a measurement region for performing the measurement of the sample,
The sample is introduced into the measurement region from one side in the vertical direction of the small diameter portion and discharged from the other side.

Further, in the above sample container, the sample is introduced into the sample container through the central flow hole, folded back at the tip of the inner tube, and passed through a gap between the outer tube and the inner tube. It is preferable that the gas is introduced into the measurement region from below and is discharged upward from the measurement region through the gap between the outer pipe and the inner pipe.

Further, in the above sample container, it is preferable that the small diameter portion of the inner tube is formed in a rotational body shape rotationally symmetrical about a central axis.

Further, in the above-mentioned sample container, it is preferable that tapered portions are formed above and below the small diameter portion of the inner tube to connect the small diameter portion and the constant diameter portion without a step.

Further, in the above-mentioned sample container, it is preferable that the lower end of the inner tube is formed into a hemispherical shape.

Further, in the above sample container, the cap portion is provided with a supply port for introducing the sample into the sample container and a discharge port for discharging the sample from the sample container. Is preferred.

Further, in the above sample container, the inner tube is exchangeably connected to the cap portion, and the inner tube is selected from a plurality of types in which the outer diameter of the small diameter portion is different, It is preferable that the volume of the sample in the measurement region can be adjusted.

Further, in the above sample container, the inner tube is exchangeably connected to the cap portion, and the inner tube is selected from a plurality of types in which the outer diameter of the small diameter portion is different, It is preferable that the time for which the sample passes through the measurement region can be adjusted.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of a measurement cell 1 as a sample container of the present invention. The measuring cell 1 comprises an outer tube 2, an inner tube 3 and a cap 4. In this figure, the outer tube 2 and the inner tube 3 are shown in a partially cutaway sectional view, and the cap 4 is shown in a sectional view. Outer tube 2
Has a cylindrical shape with a lower end closed in a hemispherical shape, and has a screw part for fixing the cap 4 at the upper end. Since the outer tube 2 is formed in such a simple and smooth shape, stress concentration due to the pressure of the fluid sample is small and the mechanical strength of the outer tube 2 is improved.

The material of the outer tube 2, the inner tube 3 and the cap 4 is preferably non-magnetic and has good workability, and the outer tube 2 and the inner tube 3 are for detecting magnetic resonance signals. It is necessary that the material is sufficiently transparent to the applied high frequency magnetic field and the high frequency magnetic field induced by the sample. Further, it is preferable that the material is a material that does not generate a disturbing noise component in the frequency band in which the magnetic resonance signal is measured. This material has mechanical strength, corrosion resistance,
Considering heat resistance and pressure resistance, special engineering plastic polyetheretherketone (trade name:
PEEK) is suitable. For the cap 4, a non-magnetic and corrosion-resistant metal such as stainless steel or titanium can also be used.
Further, for the outer tube 2 and the inner tube 3, a ceramic material obtained by sintering alumina, zirconia, silicon nitride or the like can be used.

An inner tube 3 is arranged and fixed inside the outer tube 2. The inner pipe 3 is formed in a rod-shaped rotating body shape, and further, a central circulation hole 31 is formed along the central axis thereof. The outer peripheral surface of the inner pipe 3 is formed to have constant diameter portions 32 and 36 with a diameter having a constant gap with the inner wall of the outer pipe 2. Between the lower constant diameter portion 32 and the upper constant diameter portion 36, a small diameter portion 34 having a smaller diameter than the constant diameter portions 32, 36 is provided. The small-diameter portion 34 is thus provided above the lower end of the inner pipe 3 by a predetermined distance.

The space between the small-diameter portion 34 and the inner wall of the outer tube 2 is used as the measurement region 10 (see FIG. 2), and while continuously introducing and discharging the fluid sample into and from the measurement region 10. The magnetic resonance signal of the fluid sample is measured. When the measurement cell 1 is installed in the magnetic resonance signal detection section (not shown), the measurement region 10 is arranged at the detection position by the detection coil. The measurement area 10 is
As in the illustrated embodiment, it is preferable that the shape of the rotating body is rotationally symmetric with respect to the central axis in the vertical direction, and that the shape is vertically symmetrical with respect to the central horizontal plane in the vertical direction. With such a shape, the uniformity of the magnetic field for measurement becomes good, and high-resolution measurement becomes possible.

Tapered portions 33 and 35 for connecting the small diameter portion 34 and the constant diameter portions 32 and 36 continuously without a step are formed at upper and lower positions adjacent to the small diameter portion 34. In this way, the small diameter portion 34 and the constant diameter portions 32 and 36 are connected to the tapered portion 3
Since the connection is made by 3, 35 without any step, the flow of the fluid sample is not disturbed and the flow of the fluid sample in the measurement region 10 is uniform.

The lower end of the inner tube 3 is formed in a hemispherical shape having a uniform gap with the bottom surface of the outer tube 2. The fluid sample that has descended through the central flow hole 31 is smoothly folded back in the flow direction along the lower end of this hemisphere, and then rises and is introduced into the measurement region 10. A fixing portion such as a screw portion that can be detachably fixed to the cap 4 is formed at an upper end portion of the inner pipe 3.

The cap 4 is for fixing the inner tube 3 and the outer tube 2 to each other and integrally installing them in the magnetic resonance signal detecting section. The cap 4 is provided with a supply port 43 for supplying the fluid sample to the measurement cell 1 and a discharge port 44 for discharging the fluid sample from the measurement cell 1. When the upper end portion of the inner pipe 3 is attached to the inner pipe attachment portion 42 of the cap 4 and the upper end portion of the outer pipe 2 is attached to the outer pipe attachment portion 41, the supply port 43 is connected to the central circulation hole 31 in a sealed state, The outlet 44 is hermetically connected to the gap between the inner pipe 3 and the outer pipe 2.

The member 5 for batch measurement is the constant diameter portion 3 of the inner pipe 3.
It is formed in a cylindrical shape having the same outer diameter as the outer diameter of 2, and is formed shorter than the inner pipe 3. The batch measuring member 5 is also provided with a central hole. The inner tube 3 is removed from the cap 4, and the batch measurement member 5 is used instead.
By attaching the, the measurement cell 1 can be used to perform batch-type measurement. The batch type measurement is performed as follows.

When the batch measuring member 5 is attached instead of the inner pipe 3, the supply port 43 is connected to the central hole of the batch measuring member 5 in a hermetically sealed state, and the discharge port is formed between the batch measuring member 5 and the outer pipe 2. It is hermetically connected to the gap between them. The fluid sample is supplied to the measurement region from the supply port 43 or the discharge port 44 through the center hole of the batch measurement member 5 or the gap between the batch measurement member 5 and the outer tube 2, and then the supply port 43 and the discharge port The outlet 44 is closed to stop the supply, and the measurement is performed on the sample in a stationary state. When the measurement is completed, the outer tube 2 is removed from the cap 4, and the measured sample is removed from the outer tube 2. If the outer tube 2 is attached to the cap 4 again and the measurement cell 1 is installed in the magnetic resonance signal detecting section, the next fluid sample can be supplied to perform the next measurement.

FIG. 2 is an enlarged cross-sectional view of the measuring cell 1 having the inner tube 3 and the outer tube 2 attached, in the vicinity of the lower end and the measuring region. The flow state of the fluid sample is indicated by an arrow.
As described above, the fluid sample is fed from the supply port 43 to the central flow hole 3
1 to the measuring area 10. Central circulation hole 31
The fluid sample which has descended is smoothly turned back along the hemispherical lower end of the inner tube 3 and turns upward. Further, the fluid sample is introduced from the constant diameter portion 32 through the taper portion 33 into the small diameter portion 34, that is, the measurement region 10.

The measured fluid sample whose magnetic resonance signal has been measured in the measurement region 10 is discharged upward through the gap between the constant diameter portion 36 and the outer tube 2 via the tapered portion 35. In this way, since the fluid sample is introduced into the measurement region 10 from below and discharged upward, the flow of the fluid sample is not folded back in the measurement region 10 and the fluid sample is smoothly flowed in a uniform flow. Introduced and discharged. It is also prevented that a part of the fluid sample remains and remains in the measurement region 10.
As a result, when the physical properties of the sample that continuously flows into the measurement cell are measured in real time, it is possible to perform accurate measurement without the temporally preceding and following samples being mixed, and the measurement accuracy of the physical properties of the sample is improved. .

Further, since the fluid sample to be measured is concentrated in the measurement region 10 by the small diameter portion 34 of the inner tube 3 and is excluded from other regions as much as possible,
Convection due to the difference in internal temperature of the fluid sample can be prevented. That is, since the heat transfer time is short and the temperature distribution is uniform in a short time within the measurement area 10 limited to a narrow space, convection due to a temperature difference is less likely to occur. Also,
Since the fluid sample passes through the measurement region 10 in a uniform flow,
It is possible to prevent a part of the fluid sample from staying in the measurement region 10 and convection due to a difference in internal temperature of the fluid sample. This also improves the measurement accuracy.

Although the fluid sample has been described as being supplied from the central flow hole 31 of the inner tube 3 and discharged from the gap between the inner tube 3 and the outer tube 2, conversely, the fluid sample is supplied to the inner tube. Three
Is supplied from the gap between the inner pipe 3 and the outer pipe 2, and the central flow hole 31 of the inner pipe 3
May be discharged from. In that case, the fluid sample is introduced from above the measurement region 10 and discharged below. When the temperature of the fluid sample in the measurement cell 1 and the temperature of the fluid sample supplied from the outside of the measurement cell 1 are the same, both supply directions are the same.

When the temperature of the fluid sample in the measuring cell 1 and the temperature of the fluid sample supplied from the outside of the measuring cell 1 are different from each other, as shown in FIG. It is preferable to supply from the inner tube 3 and to discharge from the gap between the outer tube 2 and the inner tube 3. This is because, while the fluid sample passes through the central flow hole 31 of the inner tube 3, heat is exchanged with the measurement region 10 and the fluid samples existing before and after the measurement region 10 to reach thermal equilibrium. As a result, even when the fluid sample is supplied at a relatively high flow rate without performing preliminary temperature adjustment, it is possible to perform measurement with the influence of temperature eliminated as much as possible.

Further, as shown in FIG. 1, the measurement area 10 is provided below the measurement cell 1. Therefore, when the ambient temperature of the measuring cell 1 and the temperature of the supplied sample are different, it is better to supply from the central flow hole 31 of the inner tube 3 by keeping the lower part of the measuring cell 1 or heating from the lower part. 43
It is easy to keep the sample temperature in and the sample temperature in the measurement region the same. On the other hand, when the atmosphere temperature of the measurement cell 1 and the temperature of the supply sample are the same, the atmosphere temperature and the temperature of the supply sample are kept the same by supplying from the gap between the inner tube 3 and the outer tube 2. Cheap.

In the measuring cell 1 of the present invention, the pressure of the fluid sample is received by the outer tube 2 and the cap 4. The inner tube 3 is entirely arranged in the outer tube 2, and the same pressure acts from the inside and the outside, so that it is not necessary to consider the pressure resistance. Therefore, the wall thickness of the small diameter portion 34 of the inner pipe 3 can be made extremely thin as long as there is no problem in processing. Since the volume of the measurement region 10 is increased by reducing the wall thickness of the small diameter portion 34, the sample volume in the detection coil can be increased, and the filling rate of the sample can be increased to improve the measurement sensitivity. .

As a specific example, in a magnetic resonance signal detecting section using a measuring cell with an outer diameter of 10 mm, when the vertical length of the detecting coil is about 15 mm, the measuring cell 1 of the present invention measures Set the sample volume in the region 10 to 0.3
It is possible to make it ³ cm ³ or more. This makes it possible to sufficiently measure low-sensitivity nuclides and low-concentration samples.

The volume of the sample in the measurement region 10 can be adjusted by changing the wall thickness of the small diameter portion 34. Furthermore, if the volume of the measurement region 10 changes, the time (residence time) during which the fluid sample passes through the measurement region 10 changes even if the fluid sample is supplied at the same flow rate. You can also That is, a plurality of inner tubes 3 having different outer diameters of the small diameter portion 34 are prepared, and these are exchanged and used as needed to adjust the volume of the measurement region 10 and the residence time of the fluid sample. You can This replacement work is also easy. As a result, the measurement can be performed with the optimum sample volume and residence time according to the type of fluid sample, and the measurement sensitivity and measurement accuracy can be improved. The stay time can be adjusted not only by adjusting the sample volume in the measurement region 10 but also by adjusting the flow rate (flow velocity) of the fluid sample supply.

FIG. 3 is a diagram showing a measurement result obtained by actually measuring with the measuring cell 1. This is the result of measuring the proton resonance signal of acetone in deuterated chloroform. A commercially available spectroscope and detector were used for the measurement.
The horizontal axis of FIG. 3 represents the resonance frequency in parts per million (ppm) according to the deviation amount from the sweep center frequency, and the vertical axis represents the detection intensity of the resonance signal. From the measurement result, the proton resonance signal of acetone is about 3.5 Hz in half width.
It was obtained with a high resolution of (0.007 ppm), demonstrating the performance of the measurement cell of the present invention.

FIG. 4 is a diagram showing another measurement result by the measurement cell 1. This is the result of measuring the proton resonance signal of ethylbenzene in deuterated chloroform. The measuring equipment and the coordinate axes of the graph are the same as those in FIG. The measurement results clearly show that the resonance signals of the two types of ethyl group protons of ethylbenzene are split into multiple peaks due to vicinal bonds.

Next, in the measurement cell 1 of the present invention, it is verified whether or not the fluid sample is smoothly flowing into and out of the measurement region, and at the same time, a part of the fluid sample is accumulated and the temperature difference is increased. An experiment was conducted to verify whether or not convection was generated by. Assuming that the longitudinal relaxation time of the fluid sample passing through the magnetic resonance signal measurement region at a certain flow velocity is T ₁ ^obs , the longitudinal relaxation time T ₁ ^obs of this flowing state is the case when the fluid sample is stationary. It is known that the longitudinal relaxation time becomes shorter than T ₁ ^static , and their relation is given by the following equation 1. 1 / T ₁ ^obs = 1 / T ₁ ^static + 1 / τ Equation 1

Here, τ is the residence time of the fluid sample in the measurement region. This residence time τ is represented by the following Expression 2 by the sample volume V in the measurement region and the volume flow velocity ν of the fluid sample. τ = V / ν Equation 2 From Equation 1 and Equation 2, the following Equation 3 is obtained. 1 / T ₁ ^obs = 1 / T ₁ ^static + ν / V Equation 3

[0045] That is, by changing the volumetric flow rate ν of the fluid sample subjected to measurement of longitudinal relaxation time T ₁ ^obs, longitudinal relaxation time T ₁ ^obs
If the reciprocal of is plotted in correspondence with the volume flow velocity ν, a straight line having the slope of the reciprocal of the sample volume V in the measurement region can be obtained. Therefore, whether or not the fluid sample smoothly flows through the measurement region 10 in the measurement cell 1 is determined from the measurement value of the sample volume V obtained from the flow velocity dependence of the longitudinal relaxation time and the dimensions of the measurement cell and the detection coil. It can be verified by comparing it with the calculated value.

FIG. 5 is a diagram showing the measurement results obtained by performing the above-described measurement in order to verify the sample circulation state in the measuring cell of the present invention. The horizontal axis represents the volume flow velocity ν, and the vertical axis represents the reciprocal of the vertical relaxation time T ₁ ^obs . As a fluid sample, a carbon tetrachloride solution containing 1% by weight of chloroform was supplied at 25 ° C., and the flow rate dependence of the longitudinal relaxation time of the proton resonance signal of chloroform was measured.

From the measurement results of FIG. 5, it can be seen that the reciprocal of the longitudinal relaxation time T ₁ ^obs increases linearly with the increase of the volume flow velocity ν. Further, the sample volume V in the measurement region obtained from the inclination of the straight line is 0.27 cm ³ . The outer tube 2 has an outer diameter of 10 mm and an inner diameter of 5.2 mm,
Since the outer diameter of the small diameter portion 34 of the inner tube 3 is 2 mm and the vertical length of the detection coil is 15 mm, the sample volume expected from the measurement area and the geometrical dimensions of the detection coil is 0.2.
It was 8 cm ³ . In this way, the sample volume obtained from the measurement results of FIG. 5 and the sample volume expected from the geometrical dimensions were substantially in agreement. By this measurement, it was confirmed that the fluid sample smoothly circulated in the measuring cell of the present invention.

Next, an experiment was conducted to confirm whether the measuring cell of the present invention can withstand high pressure conditions. The outer tube 2 is made of polyether ether ketone, and its dimensions are an outer diameter of 10 mm and an inner diameter of 5.2 mm. Water at room temperature was pressurized and supplied into the measurement cell, and leakage from the measurement cell and damage to the measurement cell were examined. It was confirmed that the measuring cell of the present invention did not leak a fluid sample and the damage of the measuring cell did not occur up to a static pressure of 50 MPa. Therefore, it was confirmed that it can operate safely even under high pressure conditions.

Further, it was verified by the following experiment that the magnetic resonance signal under the high pressure condition can be measured by the measuring cell of the present invention. In the experiment, batch type measurement was performed using the batch measurement member 5. Carbon dioxide was used as the fluid sample, and the magnetic resonance signal of the carbon nucleus having a mass number of 13 which exists naturally was measured while changing the pressure from 2 MPa to 12 MPa at 40 ° C. The measurement result is shown in FIG. Figure 6
Then, the pressure of the fluid sample is changed from 2.03 MPa to 12.00
Resonance curves when the pressure is changed up to MPa are displayed in an overlapping manner.

Carbon dioxide has a pressure of 7.4 MPa and a temperature of 3
It has a critical point at 1.1 ° C., and becomes supercritical state above the pressure and temperature, and shows a mode of compressible high-density fluid. It is known that the density of this supercritical fluid changes greatly due to minute changes in temperature and pressure, especially near the critical point. The temperature of this experiment (40
C), carbon dioxide is bounded around 9 MPa,
It rapidly changes from a dilute state to a high-density state.

The magnetic resonance signal measured by the external reference method shifts to the lower frequency side as the volume susceptibility of the fluid sample decreases. And if the fluid sample is diamagnetic,
Its volume susceptibility decreases in proportion to the density of the fluid sample.
Looking at the measurement results in FIG. 6, a sharp change in the density of carbon dioxide is clearly shown, and a large shift toward the low frequency side is made with a boundary near 9 MPa. This experiment confirmed that the measurement cell of the present invention can be used to measure a magnetic resonance signal under high pressure conditions.

The supercritical fluid has a property of easily causing convection due to nonuniformity of temperature in the measuring cell. When convection occurs, the measurement accuracy and the reproducibility are deteriorated when the magnetic resonance signal is measured. Cause adverse effects. In the measurement cell of the present invention, even if the temperature is non-uniform, since convection is structurally difficult to occur, highly accurate measurement is possible without being adversely affected by convection in supercritical fluid measurement. Becomes

[0053]

Since the present invention is constructed as described above, it has the following effects.

Since the inner tube having the central flow hole and the small diameter portion is arranged in the outer tube to form the sample container having the double-tube structure, the sample is introduced from one side in the vertical direction of the measurement region to the other side. It is possible to improve the uniformity of the flow of the sample in the measurement region by smoothly discharging the sample from the measurement region and smoothly introducing and discharging the sample into the measurement region. As a result, when the physical properties of the sample that continuously flows into the measurement cell are measured in real time, it is possible to perform accurate measurement without the temporally preceding and following samples being mixed, and the measurement accuracy of the physical properties of the sample is improved. . Since the sample is concentrated in the measurement region by the small diameter portion of the inner tube, convection due to the internal temperature difference of the fluid sample can be prevented. Further, the sample container can be easily installed in the magnetic resonance signal detecting section without modifying the detecting section. Furthermore, the sample volume for measurement can be made sufficiently large, and a sample requiring high-sensitivity measurement can be sufficiently dealt with.

The sample is introduced into the sample container through the central flow hole of the inner tube, folded back at the tip of the inner tube and introduced into the measurement region from below, and passes through the gap between the outer tube and the inner pipe from the measurement region to the upper part. Since the temperature of the sample supplied from the outside is different from the sample temperature in the sample container,
Since the thermal equilibrium is reached before reaching the measurement region, the influence of external temperature can be reduced.

Since the small diameter portion of the inner tube is formed in a rotationally symmetric shape about the central axis, the measurement region also has a rotationally symmetric shape, and the uniformity of the magnetic field for measurement becomes good, and high resolution is achieved. Can be measured. Further, by making the shape symmetrical in the vertical direction as well, it is possible to perform measurement with higher accuracy and higher resolution.

Since the taper portions which connect the small diameter portion and the constant diameter portion without steps are formed above and below the small diameter portion of the inner tube, the uniformity of the sample flow in the measurement region can be further improved. This makes it possible to perform highly accurate measurement.

Since the lower end of the inner tube is formed in a hemispherical shape, the sample can be smoothly folded back in the supply direction, no retention occurs in the folded portion, and the uniformity of the sample flow can be further improved. This makes it possible to perform highly accurate measurement.

Since the cap portion is provided with a supply port for introducing the sample into the sample container and a discharge port for discharging the sample from the sample container, attachment of a supply / discharge pipe or the like to the sample container is performed. The measurement cell can be replaced easily and the cleaning operation can be performed efficiently.

Since the inner pipe is exchangeably connected to the cap portion, the inner pipe is selected from a plurality of types having different outer diameters of the small diameter portion and attached, whereby the symmetry of the measuring region and the pressure resistance of the measuring cell are set. It is possible to adjust the volume of the sample in the measurement region without deteriorating the property. Further, when the volume of the measurement region is reduced, it is not necessary to reduce the length of the measurement region in the vertical direction, and the symmetry in the vertical direction can be maintained.

Since the inner tube is replaceably connected to the cap portion, the inner tube is selected from a plurality of types having different outer diameters of the small diameter portion and attached, whereby the symmetry of the measuring region and the pressure resistance of the measuring cell are set. It is possible to adjust the time taken for the sample to pass through the measurement region without deteriorating the property.

Since the sample container is capable of measuring the magnetic resonance of the sample under a high pressure condition and has a structure for suppressing the convection of the sample, it is possible to measure in a supercritical fluid. Also, high-precision measurement is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a measurement cell of the present invention.

FIG. 2 is an enlarged cross-sectional view of the lower end portion of the measurement cell and the vicinity of the measurement region.

FIG. 3 is a diagram showing a measurement result by the measurement cell of the present invention.

FIG. 4 is a diagram showing another measurement result by the measurement cell of the present invention.

FIG. 5 is a diagram showing a measurement result for confirming a sample circulation state in the measurement cell of the present invention.

FIG. 6 is a diagram showing a measurement result under a high pressure condition by the measurement cell of the present invention.

FIG. 7 is an enlarged cross-sectional view in the vicinity of a measurement region of a conventional measurement cell.

[Explanation of symbols]

1 ... Measuring cell 2 ... Outer tube 3 ... Inner tube 4 ... Cap 5 ... Batch measurement member 10 ... Measuring area 11 ... Measuring cell 12 ... Outer tube 13, 14 ... Spacer 15 ... Supply pipe 16 ... Supply hole 17 ... Measuring area 31 ... Central circulation hole 32, 36 ... Constant diameter part 33, 35 ... Tapered part 34 ... Small diameter part 41 ... Outer pipe mounting part 42 ... Inner pipe mounting part 43 ... Supply port 44 ... Discharge port

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuya Umeki             4-2-1 Gotake, Miyagino-ku, Sendai City, Miyagi Prefecture               National Institute of Advanced Industrial Science and Technology Tohoku             In the center (72) Inventor Takashi Aizawa             4-2-1 Gotake, Miyagino-ku, Sendai City, Miyagi Prefecture               National Institute of Advanced Industrial Science and Technology Tohoku             In the center (72) Inventor Yutaka Ikushima             4-2-1 Gotake, Miyagino-ku, Sendai City, Miyagi Prefecture               National Institute of Advanced Industrial Science and Technology Tohoku             In the center (72) Inventor Isao Saito             4-2-1 Gotake, Miyagino-ku, Sendai City, Miyagi Prefecture               National Institute of Advanced Industrial Science and Technology Tohoku             In the center (72) Inventor Kazuo Torii             4-2-1 Gotake, Miyagino-ku, Sendai City, Miyagi Prefecture               National Institute of Advanced Industrial Science and Technology Tohoku             In the center (72) Inventor Junzo Yana             3-43-2 Ebisu, Shibuya-ku, Tokyo Nikkiso Co., Ltd.             Inside the company (72) Inventor Hiromi Yamazaki             498-1 Shizuya, Haibara-cho, Haibara-gun, Shizuoka Prefecture             Shizuoka Manufacturing Co., Ltd. (72) Inventor Junko Yoshimura             498-1 Shizuya, Haibara-cho, Haibara-gun, Shizuoka Prefecture             Shizuoka Manufacturing Co., Ltd.

Claims (8)

[Claims] 1. A sample container for measuring magnetic resonance of a sample, the outer tube having a central axis in the up-and-down direction, in which a space for accommodating the sample is formed, and a lower end is closed. (2) and a central flow hole (31) through which the sample can flow along the central axis in the vertical direction, and between the inner tube of the outer tube (2) and the inner wall of the outer tube (2). An inner pipe (3) arranged to have a gap, and a cap portion (4) to which the outer pipe (2) and the inner pipe (3) are connected, the inner pipe (3) Constant diameter part (3 with a predetermined outer diameter
2, 36) and a small diameter portion (34) having an outer diameter smaller than the constant diameter portion (32, 36) above the lower end of the inner pipe (3) by a predetermined distance. The space between the inner wall of the outer tube (2) and the small diameter portion (34) constitutes a measurement region for performing the measurement of the sample, and the sample is above and below the small diameter portion (34). A sample container that is introduced into the measurement region from one side in the direction and discharged from the other side. 2. The sample container according to claim 1, wherein the sample is introduced into the sample container through the central flow hole (31), folded back at the tip of the inner tube (3), It is introduced into the measurement region from below through a gap between the pipe (2) and the inner pipe (3), and upward from the measurement region through a gap between the outer pipe (2) and the inner pipe (3). Sample container that is to be discharged to. 3. The sample container according to claim 1, wherein the small diameter portion (34) of the inner tube (3) has a rotational body shape that is rotationally symmetrical about a central axis. A sample container that is formed on the. 4. The sample container according to claim 1, wherein the small diameter portion (34) and the small diameter portion (34) are provided above and below the small diameter portion (34) of the inner tube (3). A sample container in which tapered portions (33, 35) for connecting the constant diameter portions (32, 36) to each other without steps are formed. 5. The sample container according to any one of claims 1 to 4, wherein the lower end of the inner tube (3) is formed in a hemispherical shape. 6. The sample container according to claim 1, wherein the cap portion (4) has a supply port (43) for introducing the sample into the sample container. And a discharge port (44) for discharging the sample from the sample container. 7. The sample container according to claim 1, wherein the inner tube (3) is replaceably connected to the cap portion (4). (3) the small diameter portion (34)
A sample container in which the volume of the sample in the measurement region can be adjusted by selecting from a plurality of types having different outer diameters. 8. The sample container according to claim 1, wherein the inner pipe (3) is replaceably connected to the cap portion (4). (3) the small diameter portion (34)
A sample container in which the time for which the sample passes through the measurement region can be adjusted by selecting from a plurality of types having different outer diameters.