JPS6258455B2 - - Google Patents
Info
- Publication number
- JPS6258455B2 JPS6258455B2 JP19970381A JP19970381A JPS6258455B2 JP S6258455 B2 JPS6258455 B2 JP S6258455B2 JP 19970381 A JP19970381 A JP 19970381A JP 19970381 A JP19970381 A JP 19970381A JP S6258455 B2 JPS6258455 B2 JP S6258455B2
- Authority
- JP
- Japan
- Prior art keywords
- decoupling
- nucleus
- observation
- frequency
- decoupled
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000005481 NMR spectroscopy Methods 0.000 claims description 5
- 238000000691 measurement method Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 description 19
- 239000013256 coordination polymer Substances 0.000 description 8
- 230000005415 magnetization Effects 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- 239000000523 sample Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000020169 heat generation Effects 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 244000043261 Hevea brasiliensis Species 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000005388 cross polarization Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229920003052 natural elastomer Polymers 0.000 description 1
- 229920001194 natural rubber Polymers 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000004636 vulcanized rubber Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/62—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using double resonance
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Magnetic Resonance Imaging Apparatus (AREA)
Description
【発明の詳細な説明】
本発明は固体と液体の中間の性質を持つ試料の
測定に用いて好適な核磁気共鳴測定方法に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear magnetic resonance measurement method suitable for use in measuring samples with properties intermediate between solid and liquid.
多重核磁気共鳴装置では観測核(例えば 13C)
に共鳴を起こさせると同時に他の特定核(例えば
1H)についても共鳴状態となし、観測核と特定
核との間のスピンースピン結合を切断する所謂デ
カツプリングが行われるが、近時このデカツプリ
ング法の一つとしてクロスポラリゼーシヨンデカ
ツプリング法(CP法)が提案されている。この
CP法はデカツプリングする核を前もつて分極さ
せこれを観測核にトランスフアーするもので、特
に固体試料の測定に用いて感度向上の点から有効
であり現在では固体の物性研究に不可欠なものと
なつてきている。 In multiple nuclear magnetic resonance equipment, the observation nucleus (e.g. 13 C)
while causing resonance with other specific nuclei (e.g.
1 H) is also brought into a resonance state and the so-called decoupling is performed to break the spin-spin bond between the observed nucleus and the specific nucleus. Act) has been proposed. this
The CP method polarizes the decoupled nucleus in advance and transfers this to the observation nucleus.It is particularly effective in improving sensitivity when measuring solid samples, and is now indispensable for research on the physical properties of solids. I'm getting used to it.
本発明者がこのCP法を用いて各種試料につい
て測定を行つたところ、CP法では非常に弱い共
鳴信号しか得られない試料があることが見出され
た。それは加硫ゴム類、高分子の非晶成分等であ
り、これらの試料は固体と液体の中間的な性質を
持つ。これらの試料では 1H核から 13C核へのク
ロスポラリゼーシヨンの移動に要する時間T2CH
に比べ、 1Hの回転系における縦緩和時間T1ρが
十分に長くないという共通点があり、そのため(a)
1Hの分極が 13Cへトランスフアされないうちに
1Hのスピンが減衰してしまう、(b)数KHzもの高
速回転を行つているので 1H系のエネルギーが回
転運動を通して格子へ逃げてしまつて 1HのT1ρ
が短くなり、結果的に(a)と同じになつてしまう等
の原因により非常に弱い共鳴信号しか得られない
ものと思われる。 When the present inventor conducted measurements on various samples using the CP method, it was found that there were samples for which only a very weak resonance signal could be obtained using the CP method. These samples include vulcanized rubber and amorphous components of polymers, and these samples have properties intermediate between solid and liquid. In these samples, the time required for cross-polarization to move from 1 H nuclei to 13 C nuclei is T 2 CH
Compared to 1 H, there is a common feature that the longitudinal relaxation time T 1 ρ in the rotating system is not long enough, so (a)
Before the polarization of 1 H is transferred to 13 C
The spin of 1 H is attenuated. (b) Since it is rotating at a high speed of several KHz, the energy of the 1 H system escapes to the lattice through rotational motion, and T 1 ρ of 1 H
It is thought that only a very weak resonance signal can be obtained due to reasons such as becoming shorter and resulting in the same result as in (a).
従つてこれらの試料に対してはCP法に代つて
溶液試料で行われている完全デカツプリング法
(デカツプリング用高周波を連続的に試料に照射
する)か、FID信号観測時(データサンプリング
時)のみデカツプリング用高周波を照射する所謂
ゲーテツドデカツプリング法(GD法)を用いる
しかないが、前者は固体試料の場合極めて大きな
強度のデカツプリング用高周波を照射しなければ
ならず発熱の面で採用できず、後者はデカツプリ
ングの目的は十分達せられるが信号観測時以外に
デカツプリング用高周波が照射されないので、ニ
ユークリアオーバーハウザー効果(Nuclear
Overhouser Effect=NOE)によるFID信号の増
強(約3倍)が得られず、感度が十分でないとい
う欠点がある。 Therefore, for these samples, either the complete decoupling method (continuously irradiating the sample with high-frequency waves for decoupling), which is performed on solution samples instead of the CP method, or decoupling only when observing FID signals (during data sampling) are required. The only option is to use the so-called gated decoupling method (GD method), which irradiates solid samples with high-frequency decoupling waves, but the former requires irradiation with extremely high-intensity decoupling high-frequency waves in the case of solid samples, and cannot be used due to heat generation. The latter can fully achieve the purpose of decoupling, but since the high frequency for decoupling is not irradiated except when observing signals, the Nuclear Overhauser effect (Nuclear Overhauser effect)
The drawback is that the FID signal cannot be enhanced (approximately 3 times) due to Overhouser Effect (NOE), and the sensitivity is not sufficient.
本発明は上述した諸点に鑑みてなされたもので
あり、デカツプリングすべき核の90゜パルスを
FID信号観測時以外の期間にくり返し照射するこ
とにより、CP法で測定しにくい試料であつても
NOEによる感度の向上のため十分強い共鳴信号
を得ることができしかも検出器の発熱をさけるこ
とのできる核磁気共鳴測定方法を提供するもので
ある。 The present invention has been made in view of the above-mentioned points, and is designed to reduce the 90° pulse of the nucleus to be decoupled.
By repeatedly irradiating during periods other than FID signal observation, even samples that are difficult to measure using the CP method can be
The object of the present invention is to provide a nuclear magnetic resonance measurement method that can obtain a sufficiently strong resonance signal to improve sensitivity due to NOE and can avoid heat generation in the detector.
以下図面を用いて本発明を詳説する。 The present invention will be explained in detail below using the drawings.
第1図は本発明にかかる方法を実施するための
装置の一例を示し、同図において1は観測用2は
デカツプリング用の高周波発振器である。該発振
器1,2から発生した観測用高周波及びデカツプ
リング用高周波は、ゲート3,4及び増幅器5,
6を介して静磁場中に配置された観測用照射コイ
ル7、デカツプリング用照射コイル8へ夫々送ら
れ、試料管9中の試料に照射される。10は上記
ゲート3,4を任意にON―OFFするための制御
回路である。 FIG. 1 shows an example of an apparatus for implementing the method according to the present invention, in which 1 is a high-frequency oscillator for observation, and 2 is a high-frequency oscillator for decoupling. The observation high frequency and decoupling high frequency generated from the oscillators 1 and 2 are transmitted to gates 3 and 4 and amplifiers 5 and 5.
6 to an observation irradiation coil 7 and a decoupling irradiation coil 8 placed in a static magnetic field, and irradiates the sample in a sample tube 9. Reference numeral 10 denotes a control circuit for arbitrarily turning on and off the gates 3 and 4.
今観測核を 13C、デカツプリングする核を 1H
とすると、発振器1の周波数は 13Cの共鳴周波数
に設定され、発振器2の周波数は 1Hの共鳴周波
数に設定される。第2図a,bは制御回路10に
よつてON―OFFされるゲート4、ゲート3のタ
イミング図を夫々示す。同図bにおけるtw2は
13C核の90゜パルス(磁化を90゜回転させるパル
ス)となる時間幅が与えられ、この 13C核の90゜
パルスの後に現れる第2図cに示す様な自由誘導
減衰信号(FID信号)が図示しない受信系によつ
て観測され、サンプリングされてフーリエ変換さ
れる。このサンプリング期間をカバーする様にゲ
ート4はONとなり発振器2から発生したデカツ
プリング用高周波が試料に照射される。 The observation nucleus is now 13 C, and the decoupling nucleus is 1 H.
Then, the frequency of oscillator 1 is set to a resonant frequency of 13 C, and the frequency of oscillator 2 is set to a resonant frequency of 1 H. FIGS. 2a and 2b show timing diagrams of the gates 4 and 3, which are turned on and off by the control circuit 10, respectively. tw 2 in figure b is
Given the time width of a 90° pulse of the 13 C nucleus (a pulse that rotates the magnetization by 90°), a free induction decay signal (FID signal) as shown in Figure 2c appears after the 90° pulse of the 13 C nucleus. ) is observed by a receiving system (not shown), sampled, and Fourier transformed. The gate 4 is turned ON so as to cover this sampling period, and the high frequency wave for decoupling generated from the oscillator 2 is irradiated onto the sample.
ここまではGD法と同じであるが、本発明では
第2図bのタイミングでの観測用高周波パルス照
射に先立ちデカツプリングすべき 1H核の90゜パ
ルスを繰返し試料に照射することを特徴としてい
る。即ち第2図aにおけるtw1は 1H核の90゜パ
ルスとなる時間幅が与えられ、それにより 1H核
の90゜パルスが繰返し照射されるため、この90゜
パルスにより 1Hの磁化は常に90゜倒された状態
(所謂飽和状態)に保たれる。この様に観測用高
周波パルスの照射に先立ち 1H核の90゜パルスを
くり返し照射して飽和状態としている本発明では
前述したNOEにより信号の増大を得ることがで
き、しかも、その照射が間歇的であるため連続的
に照射される完全デカツプリング法に比べ照射電
力が桁違いに少なくて良いのでプローブにおける
発熱を大幅に減少させることが可能となる。尚、
1H核の90゜パルスの間隔t1は 1H核の縦緩和時
間T1と横緩和時間T2の間(T2<t1<T1)にあるよ
うに設定する必要がある。即ち最初の90゜パルス
で90゜倒れた磁化は縦磁化と横磁化に分けて考え
れば夫々T1,T2で元に戻つてゆくが、次の90゜
パルスはT2が経過して横磁化がランダムな方向
を向いて存在し、且つ縦磁化が元に戻る前(T1
が経過しないうち)に照射する必要がある。普通
固体ではT1は数百msecからsecオーダー、T2は
μsecオーダーであり、t1はその間の数msec程度
に設定すれば良い。 Up to this point, the method is the same as the GD method, but the present invention is characterized by repeatedly irradiating the sample with 90° pulses of 1 H nuclei to be decoupled, prior to the irradiation of high-frequency pulses for observation at the timing shown in Figure 2 b. . In other words, tw 1 in Figure 2a is given a time width that is a 90° pulse of the 1 H nucleus, and as a result, the 90° pulse of the 1 H nucleus is repeatedly irradiated, so this 90° pulse reduces the magnetization of 1 H. It is always kept in a 90° tilted state (so-called saturated state). In this way, the present invention, which repeatedly irradiates 90° pulses of 1 H nuclei to reach a saturated state prior to irradiation with high-frequency pulses for observation, can increase the signal due to the NOE described above, and furthermore, the irradiation is performed intermittently. Therefore, compared to the complete decoupling method in which irradiation is performed continuously, the irradiation power is orders of magnitude lower, making it possible to significantly reduce heat generation in the probe. still,
The interval t 1 between the 90° pulses of the 1 H nucleus must be set so that it is between the longitudinal relaxation time T 1 and the transverse relaxation time T 2 of the 1 H nucleus (T 2 <t 1 <T 1 ). In other words, if we consider the magnetization tilted by 90° in the first 90° pulse to be divided into longitudinal magnetization and transverse magnetization, it will return to its original state at T 1 and T 2 respectively, but the next 90° pulse will return to its original state after T 2 has elapsed. The magnetization exists in a random direction and before the longitudinal magnetization returns to its original state (T 1
It is necessary to irradiate before the end of the period). Normally, in a solid state, T 1 is on the order of several hundred msec to seconds, T 2 is on the order of μsec, and t 1 may be set to about several milliseconds in between.
第3図は加硫した天然ゴムについて測定した
13Cスペクトルを示し、aはCP法、bはゲーテツ
ドデカツプル法、cは本発明を夫々用いている。
いずれも繰返しは10秒、観測周波数は25MHzであ
り、積算回数はaが2000回、b,cが400回であ
る。本発明を用いて得られたスペクトルはCP法
によるものよりも桁違いに強度が大きく、又、ゲ
ーテツドデカツプリング法と比べても2倍程度の
強度が得られていることがわかる。 Figure 3 shows measurements taken on vulcanized natural rubber.
13C spectra are shown in which a is the CP method, b is the gated decoupled method, and c is the present invention.
In both cases, the repetition time is 10 seconds, the observation frequency is 25 MHz, and the cumulative number of times is 2000 for a and 400 for b and c. It can be seen that the intensity of the spectrum obtained using the present invention is an order of magnitude higher than that obtained using the CP method, and the intensity is about twice as high as that obtained using the gated decoupling method.
尚上述した実施例は観測用高周波パルスが単一
の場合であつたが、T1測定のように複数のパル
スを組合わせて照射する場合にも適用することが
でき、その時もFID信号をサンプリングする期間
を除く期間にデカツプリングする核の90゜パルス
をくり返し照射するようにすることに変わりな
い。 Although the above-mentioned embodiment was based on a single high-frequency pulse for observation, it can also be applied to cases where multiple pulses are combined and irradiated as in T1 measurement, and the FID signal can also be sampled at that time. There is no change in the fact that the 90° pulse of the decoupled nucleus is repeatedly irradiated during the period excluding the period in which the decoupling occurs.
又90゜パルスの間隔t1はT2<t1<T1の関係さえ
満足すれば常に一定である必要は必ずしもない。 Further, the interval t 1 between the 90° pulses does not necessarily have to be constant as long as the relationship T 2 <t 1 <T 1 is satisfied.
以上詳述した如く本発明によればCP法で検出
しにくい試料であつても、ゲーテツドデカツプル
法よりも感度良く簡単に測定することが可能とな
る。 As detailed above, according to the present invention, even samples that are difficult to detect by the CP method can be easily measured with better sensitivity than the gated decoupled method.
第1図は本発明を実施するための装置の一例を
示す図、第2図はその動作を説明するためのタイ
ミング図、第3図は本発明と他法を用いた測定結
果の比較を示す図である。
1,2:高周波発振器、3,4:ゲート、7:
観測用照射コイル、8:デカツプリング用照射コ
イル、10:制御回路。
Fig. 1 is a diagram showing an example of a device for carrying out the present invention, Fig. 2 is a timing diagram for explaining its operation, and Fig. 3 is a comparison of measurement results using the present invention and other methods. It is a diagram. 1, 2: High frequency oscillator, 3, 4: Gate, 7:
Observation irradiation coil, 8: Decoupling irradiation coil, 10: Control circuit.
Claims (1)
高周波を照射する核磁気共鳴測定方法において、
FID信号観測期間以外の期間デカツプルする核に
ついての90゜パルスを繰返し照射すると共に、該
90゜パルス照射の間隔tが試料中のデカツプルす
る核の縦緩和時間T1より短く、横緩和時間T2よ
りも長くなるように設定することを特徴とする核
磁気共鳴測定方法。1 In a nuclear magnetic resonance measurement method in which a sample is irradiated with a high frequency wave for decoupling as well as a high frequency wave for observation,
During periods other than the FID signal observation period, we repeatedly irradiate 90° pulses on decoupled nuclei, and
A nuclear magnetic resonance measurement method characterized in that the interval t of 90° pulse irradiation is set to be shorter than the longitudinal relaxation time T1 and longer than the transverse relaxation time T2 of decoupled nuclei in the sample.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19970381A JPS58100745A (en) | 1981-12-11 | 1981-12-11 | Measuring method for nuclear magnetic resonance |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19970381A JPS58100745A (en) | 1981-12-11 | 1981-12-11 | Measuring method for nuclear magnetic resonance |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS58100745A JPS58100745A (en) | 1983-06-15 |
JPS6258455B2 true JPS6258455B2 (en) | 1987-12-05 |
Family
ID=16412203
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP19970381A Granted JPS58100745A (en) | 1981-12-11 | 1981-12-11 | Measuring method for nuclear magnetic resonance |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58100745A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6454044U (en) * | 1987-09-30 | 1989-04-04 |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6689348B1 (en) * | 2018-11-09 | 2020-04-28 | Thk株式会社 | Guidance device |
-
1981
- 1981-12-11 JP JP19970381A patent/JPS58100745A/en active Granted
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6454044U (en) * | 1987-09-30 | 1989-04-04 |
Also Published As
Publication number | Publication date |
---|---|
JPS58100745A (en) | 1983-06-15 |
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