JP2005140559A - Sample tube for nuclear magnetic resonance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample tube for nuclear magnetic resonance system made capable of repeatable measurement by keeping constant the distance between an inner tube and an outer tube and minimizing sample volume, and provided with the function of suppressing the volumetric convection of the sample. <P>SOLUTION: In the sample tube for nuclear magnetic resonance system consisting of an inner tube with bottom 1 and an outer tube with a bottom 5, the bottom of the inner tube with bottom 1 constituted freely fitting in the outer tube with the bottom 5 is formed to two different outer diameters. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is used in the technical field of a nuclear magnetic resonance (NMR) apparatus for analyzing a small amount of sample using a superconducting magnet, and specifically, a sample suitable for use in a nuclear magnetic resonance apparatus. It is about the tube.

  When analyzing a small amount of sample in a nuclear magnetic resonance apparatus, it is necessary that the sample tube does not disturb the uniformity of the magnetic field. Therefore, conventionally, (a) the inner tube is configured as a thin container (about 0.25 mm) with a very small volume, and a sample is stored in the container. (B) A sample tube is formed in a thin capillary shape, and the sample is stored inside or outside thereof. (C) As shown in FIGS. 3 and 4 of Patent Document 1 by the present applicant, the inner bottom surface of the outer tube and the bottom surface of the inner tube made of a material with adjusted magnetic susceptibility are configured in parallel, and the sample is placed between them. There was something that was sandwiched.

  Attached FIG. 3 illustrates the configuration of the sample tube described in Patent Document 1 described in (c) above, in which 10 is an inner tube with a bottom having one end open, and 13 is an open tube. One end is an outer tube having a bottom as an insertion port 13H, 11 is a thin-diameter portion of the inner tube 10, and 12 is a wall thickness formed using a glass material having a magnetic susceptibility approximate to the magnetic susceptibility of the sample ST. A core portion, 12A, indicates the bottom surface of the inner core portion 12 formed in a planar shape.

Further, in FIG. 3, reference numeral 15 denotes an outer core portion formed thick on the bottom surface portion of the outer tube 13 using the same glass substance as the inner core portion 12, and 14 denotes a sample ST formed on the upper portion of the outer core portion 15. In this storage chamber, the inner bottom portion 14A of the outer core portion 15 constituting the storage chamber 14 and the bottom surface 12A of the inner core portion 12 opposed thereto are configured in parallel.
JP-A-7-84023

  However, the conventional sample tubes described in (a) and (b) above can obtain a spectrum with a relatively good resolution in electromagnetism NMR, in which a magnetic field is applied in a direction perpendicular to the tube axis. In NMR using a superconducting magnet that applies a magnetic field in parallel, there is a problem that the effect of the interface between the top and bottom is significant, and high resolution cannot be obtained.

  Further, the conventional sample tube described in Patent Document 1 and FIG. 3 described in (c) above is the distance between the outer tube 13 and the inner tube 10, specifically, the inner bottom surface 14A of the outer core portion 15. Since the volume of the sample ST changes depending on the distance between the inner core 12 and the bottom surface 12A of the inner core portion 12, reproducible measurement is difficult, and there is a certain limit in reducing the volume of the sample.

  Therefore, the technical problem of the present invention is that the distance between the outer tube and the inner tube is made constant, enabling reproducible measurement, enabling a small sample volume, and volume convection of the sample. It is an object to provide a sample tube for a nuclear magnetic resonance apparatus having a function of suppressing the above.

(1) In order to solve the above technical problem, a sample tube for a nuclear magnetic resonance apparatus according to claim 1 of the present invention is fitted with a bottomed outer tube having an open end and an inside of the bottomed outer tube. A sample tube for a nuclear magnetic resonance apparatus comprising a bottomed inner tube configured to be freely inserted, wherein at least the bottom of the bottomed inner tube is configured to have two different outer diameters. The sample solvent is used by being sandwiched in a gap formed between the inner bottom surface and the bottom of the bottomed inner tube.

(2) Further, in the sample tube for a nuclear magnetic resonance apparatus according to claim 2 of the present invention, of the two different outer diameters of the bottomed inner tube, the larger outer diameter is substantially equal to the inner diameter of the bottomed outer tube. It is characterized by the fact that the tips of the smaller outer diameters are configured to be in close contact with the inner bottom surface of the bottomed outer tube.

(3) Further, in the sample tube for a nuclear magnetic resonance apparatus according to claim 3 of the present invention, the bottom surface portion of the bottomed outer tube is a thick outer core portion, and the bottom surface portion of the bottomed inner tube is thick. In addition to the inner core portion, the inner bottom surface of these outer core portions and the bottom surface of the inner core portion are configured in parallel, and a protrusion with a smaller diameter than the inner core portion projects in the axial direction on the bottom surface of the inner core portion. It is characterized by having installed.

  According to the means described in the above (1) to (3), the magnetic environment around the sample has high symmetry with respect to the magnetic field direction by adjusting the material of the glass and matching the magnetic susceptibility with the sample. Even when a superconducting magnet was used, high resolution could be obtained.

  Further, according to the above means, by making the outer diameter of the bottomed inner tube double, the volume of the sample existing between the inner surface of the bottomed outer tube and the bottomed inner tube is further reduced, and the sample is By closer to the NMR detection coil, only the highly sensitive part can be used, and the inner tube bottom is in close contact with the inner inner bottom of the outer tube to measure the sample volume constantly. Enable. In addition, these two effects make it possible to measure an electrolyte solution and diffusion that have been extremely difficult to measure due to electromagnetic energy loss. Furthermore, according to the above means, the convection effect can be reduced in a wide temperature range of −40 to 100 ° C.

  As described above, according to the sample tube for a nuclear magnetic resonance apparatus according to the present invention, the sample is placed between the upper inner tube and the lower inner tube inserted into the outer tube, and outside the upper inner tube and the lower outer tube. As a result, the magnetic environment with respect to the magnetic field directed in the direction of the tube axis can be made uniform, high resolution can be obtained, and measurement can be performed with less than half the amount of the sample. In addition, according to the present invention, self-diffusion with negligible convection effect can be measured in a wide temperature range of −40 to 100 ° C.

  The embodiment of the sample tube for a nuclear magnetic resonance apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 (a) is a partially sectional front view showing the present invention in an exploded manner, and FIG. ) Is an enlarged cross-sectional view of a main part showing an example of use of the present invention. In these drawings, reference numeral 1 denotes a bottomed inner tube having an open end, and 5 denotes an end of the open inner tube. The inner tube 1 and the outer tube 5 each having a bottomed outer tube having an insertion port 5H for fitting 1 and having a substantially cylindrical cross-section as a whole are made of a normal glass material.

  Further, in the figure, reference numeral 2 denotes a thin tube portion formed on the lower portion of the inner tube 1, and the lower tube portion 2 has a magnetic susceptibility that approximates the magnetic susceptibility of the sample (sample solvent ST). It consists of the inner core part 3 formed thick using a substance. Reference numeral 4 denotes a protrusion formed in the center of the bottom surface 3 ′ of the inner core portion 3 formed in a flat shape. The protrusion 4 protruding in the axial direction is made of the same glass material as the inner core portion 3. The diameter is smaller than that of the inner core portion 3. Reference numeral 4A denotes the tip surface of the protrusion 4, and the protrusion 4 formed in a cylindrical shape as a whole has a diameter of 2 mm and a length (L) of, for example, 2 mm, 3 mm, 4 mm, and 5 mm. .

  Further, the outer diameter of the bottomed inner tube 1 configured to be freely fitted into the bottomed outer tube 5 is formed to be substantially the same as the inner diameter of the bottomed outer tube 5 having an outer diameter of 5 mm, for example. And although the outer diameter of the said inner core part 3 is formed identically with the outer diameter of the bottomed inner pipe 1, it is needless to say that each of the dimensions described above is an example of implementation.

  Further, in the drawings, reference numeral 7 denotes an outer core portion formed thick on the bottom surface of the bottomed outer tube 5. The outer core portion 7 is formed using the same glass material as the inner core portion 3, and the inner bottom surface 6 </ b> A is formed in a planar shape parallel to the bottom surface 3 ′ of the inner core portion 3. The surface 4A is configured to be in close contact.

  Reference numeral 6 denotes a storage chamber for a sample ST (solvent sample) formed at the bottom of the bottomed outer tube 5. The sample ST is first injected into the storage chamber 6 through the insertion port 5H of the bottomed outer tube 5, and then the bottomed. The inner tube 1 is fitted into the bottomed outer tube 5 until the tip surface 4A of the protrusion 4 is in close contact with the inner bottom surface 6A of the outer core portion 7, and the sample ST is inserted into the bottomed inner tube 1. It can be accommodated in a state of being pushed in between the bottom surface 3 ′ of the inner core portion 3 and the inner bottom surface 6 A of the bottomed outer tube 5.

  As a result, the magnetic environment around the sample ST has high symmetry with respect to the direction of the magnetic field, so that high resolution can be obtained when a superconducting magnet is used, and the presence of the protrusions 4 indicates that the sample ST is present. As described above, the volume of the sample ST can be reduced and volume convection of the sample ST can be prevented. Further, the sample ST can be brought close to the NMR detection coil so that only a highly sensitive portion can be used, and the tip surface 4A of the protrusion 4 is used in close contact with the inner bottom surface 6A of the bottomed outer tube 5, thereby allowing the sample ST to be used. It has become possible to measure the electrolyte solution and diffusion, which has been extremely difficult to measure due to electromagnetic energy loss. As described above.

Next, experimental examples using the sample tube according to the present invention and the experimental results will be described.
The NMR measurement was performed with a 4.7T wide bore SCM equipped with a JEOL console, PFG probe (H / multi and H / F) and an amplifier, a TecMag RF unit and NTNMR. A temperature controller made by JEOL was used for temperature change. For the self-diffusion measurement, the simplest sequence of Hahn's echo pulse sequence with PFG inserted was used. The PFG interval Δ was measured at four points of 30, 50, 100, and 200 ms. Diffusion plots were performed by changing the length δ of the PFG in the range of 0.01 to 1 ms while keeping the size of the PFG constant.

  A DG neat sample and an electrolyte solution of DG doped with LiN (SO2CF3) 2 (abbreviated as LiTFSl) at a DG oxygen / Li ratio of 20: 1 were used. DG is C6H14O3 (MW = 13.4) fp = −64 ° C., bp = 160 ° C., viscosity at 25 ° C. = 0.989 cP.

  In general, the influence of the convection effect on the self-diffusion coefficient D in a uniform liquid is considered to be small if the observed value of D coincides when Δ is changed. In our experience, when the temperature is set to 30 ° C., even if the sample height is 5 mm in the homogeneous liquid, the same D is always required at Δ = 30, 50, 100, and 200 ms. However, as the temperature is increased, the observed value of D increases as Δ increases, and a one-digit order difference may occur. FIG. 2 plots changes in temperature of observed values when D of DG is used for various sample tubes. The measurement data of the normal double pipe without the protrusion of the inner pipe and the sample height of 5 mm are shown. Here, only data measured at Δ = 30 m and 50 m are plotted. As the temperature rises, the apparent D increases abruptly from about 60 ° C., and the degree is more remarkable when Δ = 50 ms. If Δ is lengthened, a more remarkable increase in D is observed. At low temperatures, no convective effect was observed.

  On the other hand, in the sample tube of the present invention in which the length of the protrusion 4 is 4 mm, a difference in the D observation value due to the difference in Δ occurred at 80 ° C. or higher. In the sample tube with the length of the protrusion 4 of 3 mm and 2 mm, there was no difference in the D observation value even when Δ was changed. In the upper right window of FIG. 2, D measured by Δ = 50 and 30 ms in a temperature range of −40 ° C. to 100 ° C. using a 2 mm sample tube is plotted. The activation energy is 13.3 ± 0.1 kJ / mol in the high sound region and 18.6 ± 0.2 kJ / mol in the low temperature region. The values measured with a sample height of 5 mm and no protrusions in the low temperature region agree well. T1 was measured with 5 mm and 2 mm sample tubes. Both coincided in the high sound region, and a slightly longer T1 value was obtained from the 2 mm sample tube in the low temperature region.

(A) is a partial cross-sectional front view showing an exploded sample tube for a nuclear magnetic resonance apparatus according to the present invention, and (b) is an enlarged cross-sectional view of a main part showing a state in use. The graph which showed the experimental data of NMR measurement. (A) is a partial cross-sectional front view showing a sample tube according to a conventional example in an exploded manner, and (B) is an enlarged cross-sectional view of a main part showing a state in use.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bottomed inner pipe 3 Inner core part 3 'Bottom face 4 Projection 4A Tip surface 5 Bottomed outer pipe 6 Storage chamber 6A Inner bottom face 7 Outer core part ST Sample

Claims (3)

A sample tube for a nuclear magnetic resonance apparatus comprising a bottomed outer tube having an open end and a bottomed inner tube configured to be freely fitted into the bottomed outer tube,
At least the bottom of the above-mentioned bottomed inner tube is configured to have two different outer diameters, and the sample solvent is sandwiched between gaps formed between the inner bottom surface of these bottomed outer tubes and the bottom of the bottomed inner tube. A sample tube for a nuclear magnetic resonance apparatus characterized by being used. Of the two different outer diameters of the bottomed inner tube, the larger outer diameter is configured to be approximately equal to the inner diameter of the bottomed outer tube, and the tip having the smaller outer diameter is in close contact with the inner bottom surface of the bottomed outer tube. The sample tube for a nuclear magnetic resonance apparatus according to claim 1, wherein the sample tube has a shape to be formed. The bottom surface of the bottomed outer tube is a thick outer core portion, the bottom surface portion of the bottomed inner tube is a thick inner core portion, and the inner bottom surface of these outer core portions and the bottom surface of the inner core portion The sample for a nuclear magnetic resonance apparatus according to claim 1, wherein a projecting portion having a diameter smaller than that of the inner core portion is provided in the axial direction on the bottom surface of the inner core portion. tube.

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