JPH05126928A - Temperature-jump nuclear magnetic resonance device - Google Patents

Abstract

PURPOSE:To change the temperature of a sample in a short time and, at the same time, to efficiently receive NMR signals. CONSTITUTION:This temperature-jump nuclear magnetic resonance device is provided with a coil 5 for microwaves which is coaxially arranged in a transmission-reception coil 4 and a driving and control means which drives and controls a microwave oscillator. When microwaves are radiated against a sample by driving the coil 5, with pulses the temperature of the sample can be raised in a short time and NMR signal can be efficiently received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a temperature jump nuclear magnetic resonance measuring apparatus capable of raising a sample temperature in a short time and performing, for example, a two-dimensional nuclear magnetic resonance (NMR) measurement of a state correlation between a solid phase and a liquid phase. It is about.

[0002]

2. Description of the Related Art Conventionally, in NMR measurement, analysis has been performed by changing the sample temperature. In such NMR measurement, the temperature of a gas such as air or nitrogen is controlled and blown onto the sample to change the sample temperature.

[0003]

When changing the sample temperature as described above, the temperature may be changed suddenly for analysis.
If the temperature is to be suddenly changed by the above method, it is necessary to switch the two gases whose temperature is controlled separately, but it is difficult to raise or lower the temperature in a short time because of the heat capacity of the gas blower. It was

The present invention is intended to solve the above problems and provides a temperature jump nuclear magnetic resonance measurement apparatus capable of changing the temperature in a short time and efficiently receiving an NMR signal. With the goal.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a nuclear magnetic resonance measuring apparatus for controlling the temperature of a sample placed in a static magnetic field and irradiating an electromagnetic wave from the transmitting / receiving coil to detect a nuclear magnetic resonance signal. A microwave coil connected coaxially to the microwave oscillator and a drive control means for driving and controlling the microwave oscillator are provided coaxially inside the, and the microwave coil is pulse-driven to the sample. It is characterized in that it is irradiated with microwaves. Further, the present invention relates to a nuclear magnetic resonance measuring apparatus which controls a temperature of a sample placed in a static magnetic field and radiates an electromagnetic wave from a transmission / reception coil to detect a nuclear magnetic resonance signal, and a microwave oscillator connected to the transmission / reception coil. And a drive control means for driving and controlling the microwave oscillator, and the transmission / reception coil is used to irradiate the sample with microwaves.

[0006]

According to the present invention, a microwave coil is arranged inside the NMR transmitter / receiver coil coaxially therewith, and the sample temperature is raised in a short time by irradiating microwaves in a pulsed manner to start the reaction. The change in the NMR signal with the progress of the reaction is recorded step by step, or the temperature of the sample is raised near the phase transition by blowing a gas to the sample in advance, and the sample is irradiated by microwave for a short time. By jumping the temperature, it becomes possible to perform a two-dimensional nuclear magnetic resonance measurement of the state correlation between the solid phase and the liquid phase.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the structure of an NMR apparatus of the present invention, FIG. 2 is a diagram showing a time chart, and FIG. 3 is a detailed diagram of a detector. In the figure, 1 is a detector, 2 is a blower tube, 3 is a sample tube, 4
Is a transmitting / receiving coil, 5 is a microwave coil, 6 is a heater, 7 is an NMR spectrometer, 8 is a microwave generator, and 9 is a temperature controller.

A sample tube 3 is arranged in a blower tube 2 inserted in a detector 1, and a microwave coil 5 is provided inside the transmission / reception coil 4 close to the sample tube 3. The microwave coil 5 is driven by a microwave generator 8. The microwave generator 8 is driven by a pulser (not shown) built in the NMR spectrometer 7 to which a signal from the receiving coil is input. It is controlled. Also,
A heater 6 is provided in the blower tube 2 and is driven and controlled by a temperature control device 9 so that air sent from a blower device (not shown) is warmed and blown to the sample portion.

The NMR transmitting / receiving coil 4 and the microwave coil 5 are coaxial with each other as shown in FIG. 3, and the microwave coil 5 is arranged inside the transmitting / receiving coil 4. The reason why the microwave coil is arranged inside the transmission / reception coil is to increase the microwave irradiation efficiency and to prevent arc discharge from occurring on the surface of the transmission / reception coil due to microwave irradiation. If the transmission / reception coil is arranged inside the microwave coil, it will be arranged in a portion where the electric field of the microwave is strong, and the coil surface will be discharged. If the transmission / reception coil 4 and the microwave coil 5 are arranged other than coaxial, for example, they are orthogonal to each other, a reception signal is shielded because the microwave coil contains a copper plate or the like, and reception efficiency deteriorates. However, the coaxial arrangement can minimize the shield effect of the microwave coil and improve the reception efficiency. Since the irradiation microwave has a high frequency of about 2 GHz with respect to several hundreds of megahertz of the NMR signal, the number of turns of the microwave coil is set to about 1 turn so as to resonate with the microwave as shown in the figure. Be able to put in strong power.

In such an NMR apparatus, the temperature controller 9 raises the sample temperature to a temperature in the vicinity of a phase transition from a solid state to a liquid state, for example. Then, as shown in the time chart of FIG. 2, the first 90 °
The pulse {(π / 2) x} 20 excites the solid-state sample to develop the spin during the period t1, and the second 90 pulse {(π / 2) −x} 21 causes the spin to be on the z-axis. return. During this transition period, FIG.
The microwave generator is driven to irradiate the microwave as shown in Fig. 3, the sample is caused to undergo a phase transition from a solid state to a liquid state, and excited by a third 90 ° pulse {(π / 2) x} 22. After that, the FID signal of the liquid is observed for the period t2. During the period t1, the behavior of the magnetization developed in the solid state is
The phase and amplitude information is handed to the FID signal in the period t2 after the transition period. Therefore, the microwave generator is repeatedly driven to irradiate microwaves, and the FID is changed from the solid state to the liquid state by using the period t1 as a variable.
By observing the signal, the aggregate data S (t1, t
If 2) is obtained, a state correlation 2D NMR spectrum between the solid phase and the liquid phase can be obtained. Depending on the sample, the microwave irradiation of the present invention enables a temperature jump at a speed of about 10 ° C./msec.

In the above embodiment, the transmission / reception coil and the microwave coil are separately provided, but the shield effect of the microwave coil cannot be completely eliminated, so that the S / N ratio is improved. This is not preferable for. Therefore, for example, for an aqueous solution sample or the like, it is possible to increase the S / N ratio by using a single coil for the transmission / reception coil and the microwave coil. Are sufficiently far apart that there is no problem.

[0012]

As described above, according to the present invention, by using the microwave for controlling the temperature of the sample, the time control is facilitated without causing the time delay, and the microwave coil is resonated with the applied frequency. This makes it possible to selectively apply large energy to the sample.
Further, by arranging the microwave coil coaxially inside the transmission / reception coil, it is possible to improve microwave irradiation efficiency, prevent discharge in the transmission / reception coil, and improve reception efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of an NMR apparatus of the present invention.

FIG. 2 is a diagram showing a time chart.

FIG. 3 is a detailed view of a detector.

[Explanation of symbols]

1 ... Detector, 2 ... Blower tube, 3 ... Sample tube, 4 ... Transmitting / receiving coil, 5 ... Microwave coil, 6 ... Heater, 7 ... NMR
Spectrometer, 8 ... Microwave generator, 9 ... Temperature controller.

Claims (2)

[Claims] 1. A nuclear magnetic resonance measuring apparatus for controlling a temperature of a sample placed in a static magnetic field and irradiating an electromagnetic wave from a transmission / reception coil to detect a nuclear magnetic resonance signal, which is coaxially arranged inside the transmission / reception coil, A microwave coil connected to the microwave oscillator and drive control means for driving and controlling the microwave oscillator were provided, and the microwave coil was pulse-driven to irradiate the sample with the microwave. A temperature jump nuclear magnetic resonance measuring apparatus characterized by the above. 2. A nuclear magnetic resonance measuring apparatus for detecting a nuclear magnetic resonance signal by irradiating an electromagnetic wave from a transmitting / receiving coil to control the temperature of a sample arranged in a static magnetic field, and a microwave oscillator connected to the transmitting / receiving coil. A temperature jump nuclear magnetic resonance measurement apparatus comprising: a drive control unit for driving and controlling a microwave oscillator, wherein a microwave is applied to a sample by using a transmission / reception coil.