JP2010032223A - Method for attaching liquid specimen to probe, liquid specimen container, and tool used for its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately measure a liquid specimen with the liquid specimen set even on an MAS (Magic Angle Spinning) probe for solid NMR (Nuclear Magnetic Resonance), and to effectively measure even a minute liquid specimen. <P>SOLUTION: In a method for attaching the liquid specimen, the liquid specimen is sealed in a specimen container comprising a tubular body, a bottom part closing one side thereof, and a hermetic stopper closing the other side thereof. The height position of the liquid specimen is adjusted so that the middle part of the liquid specimen corresponds to the center part of an NMR measurement coil with the liquid specimen attached to the probe. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for attaching a liquid sample to a magic angle spinning (MAS) probe in nuclear magnetic resonance (NMR) measurement, in particular, a method for enabling measurement of a liquid sample using a MAS probe for solid NMR, a liquid sample container, and It relates to a tool used for use.

In the known solid-state NMR measurement shown in Non-Patent Document 1, acquisition of a chemical shift reference value, setting of a measurement pulse sequence, or probe setting, particularly when measuring a quadrupole nucleus having a wide line width that is difficult to observe, etc. For adjustment and the like, there is a case where it is desired to perform NMR measurement of a solution sample that does not require MAS for a known standard substance with a MAS probe for solid-state NMR.
However, it was impossible to attach a liquid sample to a MAS probe originally set for a solid, and it was impossible to achieve such a need.
Laboratory Chemistry Lecture 8 "NMR / ESR" 5th edition, The Chemical Society of Japan, (Maruzen, 2006)

  In view of such circumstances, the present invention enables setting a liquid sample even for a solid NMR MAS probe so that it can be measured appropriately, and enabling effective measurement of even a small liquid sample. Was made as an issue.

  The liquid sample mounting method according to the first aspect of the present invention is such that a central portion of a liquid sample sealed in a sample container comprising a cylindrical main body, a bottom portion for closing one side, and a sealing plug for closing the other side is attached to the probe. The height position of the liquid sample is adjusted so as to correspond to the center of the NMR measurement coil.

  Invention 2 is a liquid sample container used in the liquid sample mounting method of Invention 1, comprising a cylindrical main body, a bottom part for closing one of the cylindrical bodies, and a sealing stopper for closing the other, and the amount of the liquid sample to be enclosed Corresponding to the above, the bottom portion is arranged with respect to the cylindrical main body so that the central portion of the sealed liquid sample is located at a fixed position of the cylindrical main body in the probe mounting state. .

  Invention 3 is a liquid sample container used in the liquid sample mounting method of Invention 1, comprising a cylindrical main body, a bottom portion for closing one of the cylindrical main bodies, and a sealing plug for closing the other, and the cylindrical main body of the bottom portion. The fixed position in the length direction is adjustable.

  Invention 4 is a liquid sample container used for the method of attaching a liquid sample of Invention 1, comprising a cylindrical main body, a bottom part for closing one of them, and a sealing plug for closing the other, and a head from the cylindrical main body. A spacer bolt capable of adjusting the protruding length of the portion is provided outside the bottom portion, and the height of the attachment to the probe can be adjusted by the spacer bolt.

  Invention 5 is the liquid sample container of Invention 2 or 3, wherein a spacer bolt capable of adjusting the protrusion length of the head from the cylindrical main body is provided outside the bottom, and the spacer bolt The mounting height position to the probe is adjustable.

  A sixth aspect of the present invention is a measuring instrument for measuring the amount of liquid sample enclosed in the liquid sample container used in the liquid sample mounting method according to any of the first to fifth aspects of the present invention, wherein the container is stored in a standing posture with the bottom portion down. A scale indicating whether or not the central portion of the liquid sample sealed in the container is in a certain range is provided on the side surface of the shaped member.

  A seventh aspect of the present invention is a seal plug handling tool for a liquid sample container used in the liquid sample mounting method according to any one of the first to fifth aspects, wherein the sealing plug is inserted into and removed from a central line at a plurality of locations around the central line. The gripping portion for gripping the head of the sealing plug and a gripping portion expanding / contracting structure for expanding and contracting the inner space of the gripping portion.

The liquid sample sealed in the sample container and stabilized in shape by the method of the invention 1 is subjected to NMR measurement in the same manner as the solid sample, and the measurement of the liquid sample is performed while using the probe for solid data. Is possible.
Further, by measuring in this way, stable measurement can be performed regardless of the amount of the sample.

  Since the bottom of the liquid sample container of the invention 2 is arranged corresponding to the amount of the liquid sample to be sealed, the method of the invention 1 can be performed by sealing a predetermined amount of the sample in the container. It becomes possible to carry out easily.

The liquid sample container of the invention 3 is configured such that the volume of the container can be adjusted by adjusting the position of the bottom so that an appropriate position can be maintained in accordance with the amount of the liquid sample that can be used.
Thus, in the invention 2, it is necessary to prepare a plurality of containers having different capacities, but in the present invention, each container can be made to correspond to the amount of the liquid sample that can be used.

In the invention 4, by using the spacer bolt, the difference in the liquid level caused by the difference in the amount of the encapsulated liquid sample is adjusted, and to the probe by the amount not accompanied by the capacity change as in the inventions 2 and 3. This is advantageous in that it can be easily adjusted when mounting.
However, since the adjustable range is very small, it is possible to easily adjust with higher accuracy by using the invention 2 or 3 together as in the invention 5.

  The measuring tool of the invention 6 is a measuring tool for easily confirming whether an appropriate amount of the liquid sample is sealed in the container, and whether or not an accurate measurement is possible without obtaining an NMR measurement result. Can be easily determined in advance.

In the invention 7, since the liquid sample container has a small diameter of about 4 mm, it is very difficult to handle the sealing stopper. In particular, with a plug that enhances the sealing performance by volume elasticity, it is difficult to put it in and out of the cylindrical body with fingers.
On the other hand, when the handling tool of the present invention is used, the head of the sealing plug is strongly held and the holding does not interfere with the insertion and removal from the cylindrical main body, so that it can be used both when inserting and withdrawing. Became.

In NMR measurement, a sample placed in a static magnetic field is irradiated with a high-frequency magnetic field by a measurement coil, and the electromagnetic response of the sample during and after that is observed by the measurement coil.
The MAS probe has a mechanism for rotating a solid sample contained in a cylindrical sample tube at a high speed (MAS) on an axis inclined by approximately 54.7 degrees (MAS angle) with respect to the direction of the static magnetic field. Usually, a superconducting magnet is used to generate a static magnetic field, and the direction of the magnetic field is set in the vertical direction. Therefore, in the MAS probe, the sample space is cylindrical and is set slightly inclined upward with respect to the horizontal.
When measuring, if the distance from the bottom of the sample space to the center of the measurement coil (measurement center) is h, the sample must be held in the range of h ± a so as to be symmetrical with respect to the measurement center. Is done. Since the value of a varies depending on the amount of sample used, in the case of a liquid sample, it is necessary to adjust the height L of the bottom of the container corresponding to the variation of a. The height of the bottom and the measurement center are related by an expression represented by “L = ha”. The amount of sample to be measured varies depending on the following various factors.
(1) In general, when the amount of the sample is increased, there is an advantage that the signal intensity is increased. On the other hand, since the uniformity of the static magnetic field is required in a wide space, it is difficult to adjust the uniformity of the static magnetic field by the shim coil. In addition, the uniformity of the strength of the high-frequency magnetic field generated by the coil is poor near the end of the measurement coil, so that the uniformity of the effective pulse magnetic field strength (pulse strength × pulse width) applied to the sample is deteriorated. As a result, the line width and linearity of the measurement signal are generally deteriorated. Therefore, when the length of the measurement coil is b, in many cases, it is desirable that “2a ≦ b”. In addition, when importance is attached to the line width and linearity, the measurement is desired to be performed using as small a sample as possible within a range in which the signal intensity can be ensured. Therefore, it is necessary to balance the quantity and quality as necessary.
(2) Depending on the sample, synthesis and separation may be difficult and may be obtained in very small amounts.
(3) When used for adjustment prior to solid-state NMR measurement, it is required to set the amount of the solution sample so that a matches the size of the solid sample.

8 and 9 are photographs showing the MAS probe (P) in the NMR measurement targeted by the present invention.
FIG. 9 shows a state in which a solid sample is set on the MAS probe. Exterior parts such as shields have been removed to make the structure easier to see. The solid sample is held in a dedicated solid MAS sample tube and set in the sample mount (H). The solid MAS sample tube includes a turbine blade for rotation driving and a body that also serves as a rotor of an air bearing, and is formed into a rod shape having a thickness and a length that are held in the sample mounting base (H) of the probe (P). Is set. The lid (X) also serves as a thrust bearing, and is set so that the solid MAS sample tube does not protrude outside during high-speed rotation.
The container of the present invention has a cylindrical main body (20) (20b) having a thickness and length corresponding to this solid MAS sample tube as a basic component.
And in the said probe (P), the center part (measurement center) of a NMR measurement coil is set so as to correspond to the specific position of the approximate center part of the length direction of the said solid MAS sample tube. In the following embodiments, the objective is to set the center of the liquid sample as the measurement center in a state where the center of the liquid sample is attached to the probe of the cylindrical main body (20) (20b). Further, considering the convenience of loading / unloading to / from the probe, the total length is set slightly longer than the solid MAS sample tube, and a part thereof protrudes from the sample mounting base (H).
In the present invention, the liquid sample includes not only a sample that is liquid at room temperature but also an aggregate sample of fine particles.

The cylindrical body is made of a hard material such as glass, ceramics, or resin (Dyflon: registered trademark), and the sealing plug (10) has hardness and elasticity close to a hard rubber such as Teflon (registered trademark). It consists of material.
In addition, the cross-sectional shape is not limited to the cylinder shown in the embodiment, and the corner is hermetically sealed (10) (having a cross-sectional shape similar to that of the cylindrical main body) even if it is a polygonal column shape such as a triangle, square, or hexagon If there is a roundness so that the outer periphery of the can enter without gaps, it can be carried out without any problems.

The material of the container is required to have the following properties so as not to affect the NMR measurement. First, it does not disturb the uniformity of the static magnetic field, that is, the magnetic susceptibility is small. It is required that the so-called non-magnetic body is not sufficient, and there is no influence of a minute amount of impurities. Second, it must not disturb the high-frequency magnetic field produced by the measuring coil, that is, it must be an insulator and a material with low dielectric loss. The frequency of the high frequency magnetic field is determined depending on the strength of the static magnetic field and the measurement nuclide, and generally takes a value in the range of 1 to 2000 MHz. Third, it must be chemically stable to the measurement sample and solvent. Fourth, it should not affect the measurement even if it contains or does not contain an element of the same nuclide as the measurement nucleus that causes unnecessary NMR signals (background signal). This is particularly important for the cylindrical body (20) installed inside the measuring coil.
Fluororesin represented by Daiflon (registered trademark: trifluorinated fluororesin) and Teflon (registered trademark: tetrafluorinated fluororesin) not only fulfills the above requirements well, but also has excellent workability. It is a particularly suitable material for the practice of the present invention. In particular, Daiflon (registered trademark) is suitable for the cylindrical body (20, 20a) because it has appropriate rigidity and transparency, and Teflon (registered trademark) is suitable for the sealing plug (10) because it has appropriate elasticity. Suitable for movable bottom (40, 50). Further, when hydrogen nuclei are not measured (a background signal of hydrogen nuclei is allowed), polypropylene or the like, which is a cheaper material, can be used instead of Daiflon (registered trademark).
Depending on the measurement nucleus, in order to avoid the influence of the background signal, it may be preferable to use glass or ceramics typified by zirconia or alumina.
Since the spacer bolt (30) is away from the measurement center, the influence of the background signal and the like is relatively small. Therefore, various engineering plastic materials typified by polyacetal (POM) and polyetheretherketone (PEEK) can be used giving priority to processability and mechanical properties.

  In use, the container is held in a standing position with the bottom down, and the solution sample is injected to a predetermined amount using a syringe or a capillary pipette so as to be in contact with the lower part of the container and sealed with a sealing stopper (10). The The solution sample set in this way is held in the vicinity of the lower part of the container by the surface tension between the container and the inner wall of the container, and does not spill out even when the container is tilted to near horizontal.

The present embodiment is an example in which a bottom portion (22) is integrally formed with a cylindrical tubular body (20).
The cylindrical main body (20) and the bottom part (22) are integrally formed by injection molding or the like, and the bottom part (22) matches the distance (L) from the lower end of the cylindrical main body (20) with the specified sample volume, and the specified amount. Is set so that the central portion of the depth is located at the central portion in the longitudinal direction of the cylindrical main body (20).

The storage space (21) of the cylindrical main body (20) has the bottom (22) as a lower end, and a sealing plug (10) is inserted into the upper end to be sealed.
The sealing plug (10) includes a head portion (11) having the same outer diameter as the outer diameter of the cylindrical body (20), a plug portion (12) integrated at the lower end thereof, and the plug portion (12). The bulging part (13) formed in the lower end is integrally formed.
The plug portion (12) has the same diameter as the inner diameter (d) of the cylindrical body (20), and the bulge portion (13) has the same thickness as the plug portion (12) due to its volume elasticity. It is a part thicker than the plug part (12), and when it is press-fitted into the cylindrical body (20), the bulging part (13) is pressed by the pressing force due to elastic deformation of the bulging part (13). ) And the plug portion (12) are in close contact with the inner surface of the cylindrical body (20) to seal the inside.

(30) is a spacer bolt having a shape in which the head (32) is integrally formed at the lower end of the male screw (31). A female screw (24) for screwing the male screw (31) is formed in the lower part (23) of the cylindrical main body (20). Thus, the spacer bolt (30) is screwed into the lower part of the cylindrical main body (20), and the protruding length of the head (32) can be adjusted by the screwed length.
In this case, the distance (L) is a distance from the upper bottom of the bottom (22) to the lower surface of the head (32) of the spacer bolt (30).
In this way, the mounting height with respect to the sample mounting base (H) can be adjusted.

The present embodiment is an example in which the position of the bottom (40) is adjustable, and will be described below with reference to FIGS.
In addition, about the structure similar to the said Example 1, the same code | symbol was attached | subjected to drawing and detailed description was abbreviate | omitted.
The cylindrical tubular body (20b) has a straight shape having the same cross-sectional shape over its entire length.
The bottom (40) is made of the same material as the sealing plug (10) and has the same diameter as the inner diameter (d) of the cylindrical main body (20b). Receiving surfaces (41) and (41) are provided on the upper and lower surfaces, and a bulging portion (42) that can have a diameter similar to the inner diameter (d) by volume elastic deformation is formed in the upper and lower central portions. .
In this way, by using the rod-like member (not shown) and pushing the bottom portion (40) into the cylindrical main body (20b) in the orientation as shown in FIG. With the elastic deformation, the bottom position can be changed and adjusted in the longitudinal direction while maintaining the sealing property with the inner surface (21b) of the cylindrical main body (20b).

In the present embodiment, another example (50) of the bottom of the second embodiment will be described with reference to FIG.
The bottom part (50) has a bottom surface (51) on the top surface and has an insertion hole (53) opened downward in the interior, and the other points are the same as the bottom part (40) of the second embodiment. is there.
Since the elasticity of the bottom portion of the present embodiment is moderately adjusted due to the presence of the insertion hole (53), the bulge portion can be set to be larger, so that the demand for processing accuracy is eased and the bottom portion (50). The force required to move is stable. Further, the bottom portion (50) can be pulled out in the bottom direction by screwing and holding a tapping screw into the insertion hole (53).

The present embodiment shows an example of an auxiliary cylinder to be applied to a sample mounting base (H) having sample receiving portions having different thicknesses with reference to FIG.
In addition, although the object container showed the thing of Example 1 as an example, of course, no difficulty arises in making Example 2 and 3 into object.
The auxiliary cylinder (60) is a cylindrical body having the same inner diameter as the outer diameter (D) of the container, and is set so that the container can be held inside by the frictional force between them. The outer diameter of the auxiliary cylinder (60) has a thickness corresponding to a predetermined sample mounting base (H), and the material is the same as that of the container, or the NMR measurement having the properties listed in [0020]. The one that does not affect is used.
In this way, it is possible to cope with the difference between the probe and the sample mount caused by the difference in measurement purpose and NMR apparatus.

In this embodiment, an example of a measuring tool for measuring whether or not the amount of the sample enclosed is appropriate is shown with reference to FIG.
In addition, although the object container showed the thing of Example 1 as an example, of course, no difficulty arises in making Example 2 and 3 into object.
The measuring tool (70) has an inner diameter larger than the outer diameter of the container, and is made of a transparent cylindrical body having a bottom, so that the container (20) can be put upright.
And in a predetermined location, the scale (Mc) which shows the location where the upper and lower center of the sample liquid (S) enclosed with the container should be located, the scale (Ms) which shows the position applicable to the upper end of a measurement coil, and a lower end A scale (Mb) indicating the position corresponding to is attached.
In this way, it is confirmed in advance whether or not the sample liquid (S) is present at a position corresponding to the predetermined sample mounting base (H), and if necessary, the spacer bolt (30) is advanced or retracted or sealed. A guideline for adjusting the amount can be given.

A present Example shows the example of the sealing stopper handling tool for taking in and out the sealing stopper (10) of a sample from a cylindrical main body (20) with reference to FIG.
The inner cylinder (110) has an upper half divided into three by a slit (111) and is shaped to open outward as a whole, and its upper end is formed in a tapered shape. A male screw (120) is fixed to the root portion of the inner cylinder (110). An outer cylinder (130) is disposed outside the inner cylinder (110), and a female screw (131) screwed into the male screw (120) is formed on the inner surface of the root portion of the outer cylinder (130). It is.
The distal end of the outer cylinder (130) is also formed in a tapered shape, and the distal end of the inner cylinder (110) is pushed by tightening the screw and is tightened inward against its elasticity.
(140) is a grip with a fixed root of the inner cylinder (110).

In this way, the outer cylinder (130) is opened, the head (11) of the sealing plug (10) is inserted at the tip of the inner cylinder (110), and then the outer cylinder (130) is rotated. And the front-end | tip of the said inner cylinder (110) is clamp | tightened and the said head (11) is clamped and hold | maintained from the circumference | surroundings.
In this way, by holding the sealing plug (10), the cylindrical main body (20) can be put in and out of the cylindrical main body (20) more easily than directly holding it with a finger.
Moreover, since the sealing plug (10) can be inserted into the cylindrical main body (20) by applying force, it is practically possible to improve the sealing performance by providing the bulging portion (13) as described above. became.

Longitudinal front view showing Example 1 Longitudinal front view showing Example 2 The front view which shows the bottom part of Example 2. The front view which shows the bottom part of Example 3 Longitudinal front view showing a supplementary tool of Example 4 Front view showing a measuring instrument of Example 5 Longitudinal front view showing the sealing plug handling tool of Example 6 The photograph which shows the principal part of a MAS probe. The photograph which shows the state which mounted Example 1 on the sample mounting base (H). The photograph which shows the use condition of Example 1 and Example 3. FIG. (A) is Example 1 and (B) is Example 3, and the bottom (50b) is formed by forming a circumferential groove on the outer periphery of Example 3 to facilitate insertion.

Explanation of symbols

(D) Outer diameter (H) Sample mount (L) Distance (a) 1/2 of sample height
(H) Distance from the bottom of the sample space to the center of the measurement coil (measurement center) (Mb) (Mc) (Ms) Scale (P) MAS probe (S) Sample liquid (X) Sample mounting base lid (d) Inner diameter (10) Seal plug (11) Head (12) Plug (13) Swelling part (20) (20b) Tubular body (21) Storage space (21b) Inner surface (22) (40) (50) ( 50b) Bottom portion (23) Lower portion (24) Female screw (30) Spacer bolt (31) Male screw (32) Head portion (40) Bottom portion (41) Receiving surface (42) Swelling portion (50) Bottom portion (51) Bottom surface (52) Swelling part (53) Insertion hole (60) Auxiliary cylinder (70) Measuring tool (110) Inner cylinder (111) Slit (120) Male screw (130) Outer cylinder (131) Female screw (140) Grip

Claims (7)

  A method for attaching a liquid sample to a MAS probe in NMR measurement, wherein a central portion of a liquid sample enclosed in a sample container comprising a cylindrical main body, a bottom portion for closing one side, and a sealing stopper for closing the other side, A liquid sample mounting method, wherein the height position of the liquid sample is adjusted so as to correspond to the center of the NMR measurement coil in the mounting state to the probe.   A liquid sample container for use in the liquid sample mounting method according to claim 1, comprising a cylindrical main body, a bottom portion for closing one of the cylindrical main bodies, and a sealing stopper for closing the other, and the amount of the liquid sample to be enclosed Correspondingly, the liquid is characterized in that the bottom part is arranged with respect to the cylindrical main body so that the central part of the enclosed liquid sample is located at a fixed position of the cylindrical main body in the probe mounting state. Sample container.   A liquid sample container for use in the liquid sample mounting method according to claim 1, comprising a cylindrical main body, a bottom portion that closes one of the cylindrical main bodies, and a sealing plug that closes the other. A liquid sample container characterized in that a fixing position in a length direction can be adjusted.   A liquid sample container used in the liquid sample mounting method according to claim 1, comprising a cylindrical main body, a bottom portion for closing one of the cylindrical main bodies, and a sealing plug for closing the other, and a head portion from the cylindrical main body. The liquid sample container is characterized in that a spacer bolt whose projecting length is adjustable is provided outside the bottom portion, and the height of the mounting height to the probe can be adjusted by the spacer bolt.   The liquid sample container according to claim 2 or 3, wherein a spacer bolt capable of adjusting a protruding length of a head from the cylindrical main body is provided outside the bottom portion, and the spacer bolt A liquid sample container characterized in that an attachment height position to a probe can be adjusted.   A measuring instrument for measuring the amount of liquid sample enclosed in a liquid sample container used in the liquid sample mounting method according to claim 1, wherein the container is stored in a standing posture with the bottom portion down. A measuring tool, wherein a scale indicating whether or not the central portion of the liquid sample sealed in the container is in a certain range is provided on a side surface of the member.   It is a sealing stopper handling tool to the liquid sample container used for the liquid sample attachment method in any one of Claim 1 to 5, Comprising: The insertion / extraction direction of the said sealing stopper is made into a centerline, and it is in several places around the centerline A sealing plug handling tool comprising: a gripping part for gripping a head part of the sealing plug; and a gripping part expansion / contraction structure for expanding and contracting an inner interval of the gripping part.