阅读说明：本技术 一种利用仲氢诱导极化的高场原位极化装置及方法 (High-field in-situ polarization device and method utilizing para-hydrogen to induce polarization ) 是由 王伟宇 徐君 邓风 于 2020-05-18 设计创作，主要内容包括：本发明公开了一种利用仲氢诱导极化的高场原位极化装置,反应气体进气通道的出气端与第三直通阀一端连接,第三直通阀另一端分别与仲氢进气通道的出气端、第四直通阀端和第五直通阀一端连接,第五直通阀另一端与第三单向阀的进端连接,第三单向阀的出端分别与第八直通阀一端和第六直通阀一端连接,第八直通阀另一端与反应采样管连接,第六直通阀另一端依次通过真空仓、第七直通阀、真空计与真空泵连接,第八直通阀与第三单向阀的出端连接的一端处设置有第三压力表,反应采样管放置于核磁共振磁体内。本发明还公开了一种利用仲氢诱导极化的高场原位极化方法。本发明结构简单,控制操作简便,实现高效的极化产生及稳定的极化核磁谱图信号采集。(The invention discloses a high-field in-situ polarization device utilizing para-hydrogen induced polarization, wherein the gas outlet end of a reaction gas inlet channel is connected with one end of a third straight-through valve, the other end of the third straight-through valve is respectively connected with the gas outlet end of the para-hydrogen inlet channel, the fourth straight-through valve end and one end of a fifth straight-through valve, the other end of the fifth straight-through valve is connected with the inlet end of a third one-way valve, the outlet end of the third one-way valve is respectively connected with one end of an eighth straight-through valve and one end of a sixth straight-through valve, the other end of the eighth straight-through valve is connected with a reaction sampling pipe, the other end of the sixth straight-through valve is connected with a vacuum pump through a vacuum chamber, a seventh straight-through valve and a vacuum gauge in sequence, a third pressure gauge is arranged at one end of the eighth straight-through. The invention also discloses a high-field in-situ polarization method utilizing para-hydrogen induced polarization. The invention has simple structure, simple and convenient control and operation, and realizes efficient polarization generation and stable polarization nuclear magnetic spectrum signal acquisition.)

1. A high-field in-situ polarization device using parahydrogen to induce polarization comprises a vacuum pump (19) and is characterized by comprising a parahydrogen inlet channel, a reaction gas inlet channel and a reaction sampling tube (22),

the gas outlet end of a reaction gas inlet channel is connected with one end of a third straight-through valve (11), the other end of the third straight-through valve (11) is respectively connected with the gas outlet end of a parahydrogen inlet channel, one end of a fourth straight-through valve (12) and one end of a fifth straight-through valve (13), the other end of the fifth straight-through valve (13) is connected with the inlet end of a third one-way valve (14), the outlet end of the third one-way valve (14) is respectively connected with one end of an eighth straight-through valve (21) and one end of a sixth straight-through valve (15), the other end of the eighth straight-through valve (21) is connected with a reaction sampling pipe (22), and the other end of the sixth straight-through valve (15) sequentially passes through a, the seventh straight-through valve (17) and the vacuum gauge (18) are connected with a vacuum pump (19), a third pressure gauge (20) is arranged at one end of the eighth straight-through valve (21) connected with the outlet end of the third one-way valve (14), and a reaction sampling pipe (22) is placed in the nuclear magnetic resonance magnet.

2. The high-field in-situ polarization device using para-hydrogen induced polarization as claimed in claim 1,

the parahydrogen inlet channel comprises a first pressure gauge (1), a first straight-through valve (2), a first one-way valve (3), a first gas purifier (4) and a first mass flow controller (5),

one end of the first straight-through valve (2) is an air inlet end of a parahydrogen air inlet channel and is provided with a first pressure gauge (1), the other end of the first straight-through valve (2) is connected with an air inlet end of a first one-way valve (3), an outlet end of the first one-way valve (3) is connected with one end of a first mass flow controller (5) through a first gas purifier (4), and the other end of the first mass flow controller (5) forms an air outlet end of the parahydrogen air inlet channel.

3. The high-field in-situ polarization device using para-hydrogen induced polarization as claimed in claim 2,

the reaction gas inlet channel comprises a second pressure gauge (6), a second straight-through valve (7), a second one-way valve (8), a second gas purifier (9) and a second mass flow controller (10),

one end of the second straight-through valve (7) is an air inlet end of a reaction gas inlet channel and is provided with a second pressure gauge (6), the other end of the second straight-through valve (7) is connected with an inlet end of a second one-way valve (8), an outlet end of the second one-way valve (8) is connected with one end of a second mass flow controller (10) through a second gas purifier (9), and the other end of the second mass flow controller (10) is an air outlet end of the reaction gas inlet channel.

4. The high-field in-situ polarization device using para-hydrogen induced polarization as claimed in claim 3, wherein the reaction sampling tube (22) is made of glass and has a diameter of 5mm or 10 mm.

5. A high-field in-situ polarization apparatus using para-hydrogen induced polarization according to claim 3, wherein the volume of said vacuum chamber (16) is 0.5 mL.

6. A high-field in-situ polarization method using para-hydrogen induced polarization, which uses the high-field in-situ polarization device using para-hydrogen induced polarization as claimed in claim 3, comprising the following steps

Step 1, placing a liquid sample in a reaction sampling pipe (22), closing a first straight-through valve (2), a second straight-through valve (7), a third straight-through valve (11), a fourth straight-through valve (12) and an eighth straight-through valve (21), and simultaneously opening a fifth straight-through valve (13), a sixth straight-through valve (15) and a seventh straight-through valve (17);

the vacuum pump (19) performs air extraction, and the pipeline air pressure is detected by the vacuum gauge (18) until the target pressure range is reached;

step 2, closing the sixth straight-through valve (15) and the seventh straight-through valve (17), closing the vacuum pump (19), and starting the first straight-through valve (2);

controlling the flow rate of the first mass flow controller (5) to be 0-50sccm, introducing parahydrogen gas, starting an eighth straight-through valve (21) after the third pressure gauge (20) displays that the pressure is greater than 1bar, introducing the parahydrogen gas into a reaction sampling pipe (22) to start bubbling, and closing the first mass flow controller (5) after setting time;

step 3, closing the fifth straight-through valve (13), opening the sixth straight-through valve (15), and triggering magnetic resonance sampling until the magnetic resonance sampling is finished;

step 4, placing a solid catalyst sample in a reaction sampling pipe (22), closing a first straight-through valve (2), a second straight-through valve (7), a fourth straight-through valve (12) and an eighth straight-through valve (21), and simultaneously opening a third straight-through valve (11), a fifth straight-through valve (13), a sixth straight-through valve (15) and a seventh straight-through valve (17);

the vacuum pump (19) performs air extraction, and the pipeline air pressure is detected by the vacuum gauge (18) until the target pressure range is reached;

step 5, closing the sixth straight-through valve (15) and the seventh straight-through valve (17), closing the vacuum pump (19), and starting the first straight-through valve (2) and the second straight-through valve (7);

para-hydrogen gas is introduced into the first mass flow controller (5) at the flow rate of 0-50sccm, reaction gas is introduced into the second mass flow controller (10) at the flow rate of 0-50sccm, and after the third pressure gauge (20) displays that the pressure is greater than 1bar, the eighth straight-through valve (21) is opened to trigger magnetic resonance sampling until the magnetic resonance sampling is finished.

Technical Field

The invention relates to the technical field of magnetic resonance spectrograms, in particular to a high-field in-situ polarization device utilizing para-hydrogen induced polarization and a high-field in-situ polarization method utilizing para-hydrogen induced polarization. The method is suitable for the nuclear magnetic resonance polarization technology of an in-situ reaction system under a high magnetic field environment by taking parahydrogen gas as a polarization source, such as a gas-solid reaction system, a gas-liquid-solid reaction system and the like.

Background

Nuclear Magnetic Resonance (NMR) technology can provide key information on material composition, molecular structure and related kinetics, is a very important research method and analysis means, and is widely applied to various fields such as biology, chemistry, medicine, physics and the like. The nuclear magnetic signal intensity is proportional to the difference of nuclear spin energy level distribution in static magnetic field, while the ratio of nuclear spin energy level distribution in conventional static magnetic field is only 10^-5The magnitude and thus intrinsic sensitivity of nuclear magnetic resonance are low, which makes acquisition of nuclear magnetic signals very difficult, and limits deeper application thereof to a certain extent. By utilizing Para-hydrogen Induced Polarization technology (Para-hydrogen Induced Polarization), nuclear magnetic observation object molecules are combined with Para-hydrogen molecules, so that the particle layout number difference on different energy levels is improved by orders of magnitude, namely, the original thermal equilibrium state is reached to a Polarization state, signals can be enhanced by 4-5 orders of magnitude, the strength of NMR signals is greatly improved, and the problem of sensitivity is solved.

Among para-hydrogen induced polarization techniques, the high field in situ polarization technique (PASADENA) is one of the main methods for obtaining polarization enhancement. The method takes para-hydrogen molecules as a polarization source, performs addition reaction on the para-hydrogen molecules and asymmetric reactants under the condition of high magnetic field, breaks the original symmetry under the condition of keeping spin coupling among hydrogen atoms, and simultaneously triggers in-situ acquisition of nuclear magnetic resonance spectrograms to obtain polarization enhancement of nuclear magnetic signals. At present, no corresponding device design is available at home to meet the requirement, the existing high-field in-situ polarization technology polarization device at home has poor magnetic field stability and influences spectrogram quality, nuclear magnetic sampling has certain delay, polarization signals are lost, signal intensity is reduced, and meanwhile, an instrument device is heavy and cannot meet the application requirement under a specific environment.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a high-field in-situ polarization device for polarization induction by using para-hydrogen, which can realize the generation of polarization signals under the high-field in-situ condition; the continuity of polarization generation and nuclear magnetic signal acquisition is met; the stability of a magnetic field in the process of collecting the polarization signal is ensured; the device has simple structure, simple and convenient control operation and easy maintenance.

The invention also aims to provide a high-field in-situ polarization method by using para-hydrogen induced polarization, which is matched with a high-field in-situ polarization device to realize the generation and collection of high-field in-situ polarization signals under various reaction systems.

In order to achieve the purpose, the invention adopts the following technical measures:

a high-field in-situ polarization device utilizing para-hydrogen induced polarization, which comprises a vacuum pump, a para-hydrogen gas inlet channel, a reaction gas inlet channel and a reaction sampling tube,

the outlet end of a reaction gas inlet channel is connected with one end of a third straight-through valve, the other end of the third straight-through valve is respectively connected with the outlet end of an parahydrogen inlet channel, the end of a fourth straight-through valve and one end of a fifth straight-through valve, the other end of the fifth straight-through valve is connected with the inlet end of a third one-way valve, the outlet end of the third one-way valve is respectively connected with one end of an eighth straight-through valve and one end of a sixth straight-through valve, the other end of the eighth straight-through valve is connected with a reaction sampling pipe, the other end of the sixth straight-through valve is connected with a vacuum pump through a vacuum chamber, a seventh straight-through valve and a vacuum meter in sequence, a third pressure gauge is arranged at one end of the eighth straight-through valve, which.

The parahydrogen inlet channel comprises a first pressure gauge, a first direct-current valve, a first one-way valve, a first gas purifier and a first mass flow controller,

one end of the first straight-through valve is an air inlet end of the parahydrogen air inlet channel and is provided with a first pressure gauge, the other end of the first straight-through valve is connected with an air inlet end of the first one-way valve, an outlet end of the first one-way valve is connected with one end of a first mass flow controller through a first gas purifier, and the other end of the first mass flow controller forms an air outlet end of the parahydrogen air inlet channel.

The reaction gas inlet channel comprises a second pressure gauge, a second straight-through valve, a second one-way valve, a second gas purifier and a second mass flow controller,

one end of the second straight-through valve is an air inlet end of the reaction gas inlet channel and is provided with a second pressure gauge, the other end of the second straight-through valve is connected with an inlet end of the second one-way valve, an outlet end of the second one-way valve is connected with one end of a second mass flow controller through a second gas purifier, and the other end of the second mass flow controller is an air outlet end of the reaction gas inlet channel.

The reaction sampling tube is made of glass, and the diameter of the tube is 5mm or 10 mm.

The volume of the vacuum chamber described above was 0.5 mL.

A high-field in-situ polarization method using para-hydrogen induced polarization, comprising the steps of:

step 1, placing a liquid sample in a reaction sampling pipe, closing a first through valve, a second through valve, a third through valve, a fourth through valve and an eighth through valve, and simultaneously opening a fifth through valve, a sixth through valve and a seventh through valve;

the vacuum pump performs air extraction, and the pipeline air pressure is detected by a vacuum gauge until the target pressure range is reached;

step 2, closing the sixth straight-through valve and the seventh straight-through valve, closing the vacuum pump, and starting the first straight-through valve;

controlling the flow rate of the first mass flow controller to be 0-50sccm, introducing parahydrogen gas, starting an eighth straight-through valve after the third pressure gauge displays a pressure greater than 1bar, introducing the parahydrogen gas into the reaction sampling pipe to start bubbling, and closing the first mass flow controller after setting time;

step 3, closing the fifth straight-through valve, opening the sixth straight-through valve, and triggering magnetic resonance sampling until the magnetic resonance sampling is finished;

step 4, placing a solid catalyst sample in the reaction sampling pipe, closing the first through valve, the second through valve, the fourth through valve and the eighth through valve, and simultaneously opening the third through valve, the fifth through valve, the sixth through valve and the seventh through valve;

the vacuum pump performs air extraction, and the pipeline air pressure is detected by the vacuum gauge until the target pressure range is reached;

step 5, closing the sixth straight-through valve and the seventh straight-through valve, closing the vacuum pump, and starting the first straight-through valve and the second straight-through valve;

and controlling the flow rate of the first mass flow controller to be 0-50sccm to introduce parahydrogen gas, controlling the flow rate of the second mass flow controller to be 0-50sccm to introduce reaction gas, and starting the eighth straight-through valve to trigger magnetic resonance sampling after the third pressure gauge displays that the pressure is greater than 1bar until the magnetic resonance sampling is finished.

Compared with the prior art, the invention has the following advantages and effects:

1. the invention has simple structure, high stability and convenient manufacture and maintenance;

2. the reaction sampling tube has fixed size and good applicability and applicability;

3. the magnetic field of the reaction sampling tube is uniform and stable by the combined use of the straight-through valve, the vacuum bin and the vacuum pump;

4. realizing the polarization generation of a target product with a constant speed by a mass flow controller;

5. the multi-gas-path test expansion is realized by controlling the straight-through valve;

6. the operation is simple, and after the secondary hydrogen source is connected, the switch of the straight-through valve and the mass flow controller is controlled.

Drawings

FIG. 1 is a schematic diagram of a high-field in-situ polarization apparatus using para-hydrogen induced polarization.

FIG. 2 is a schematic diagram of a high-field in-situ polarization principle and polarization signals.

FIG. 3 is a spectrum of a high-field in-situ polarized nuclear magnetic signal measured in an actual experiment.

In the figure: 1-a first pressure gauge (selectable model: WIKA Cl.1.6), 2-a first through valve (selectable model: Urchuan SS-723K2), 3-a first one-way valve (selectable model: Urchuan SS-113), 4-a first gas purifier (selectable model: Dalianripril scientific and technological instrument JY-1, JY-4), 5-a first mass flow controller (selectable model: Qixinhuachuang D07), 6-a second pressure gauge (selectable model: WIKA Cl.1.6), 7-a second through valve (selectable model: Urchuan SS-723K2), 8-a second one-way valve (selectable model: Urchuan SS-113), 9-a second gas purifier (selectable model: Dalianripril scientific and technological instrument JY-1, JY-4), 10-a second mass flow controller (selectable model: Qixinhuachuang D07), 11-third straight-through valve (selectable model: Sichuan bear SS-723K2), 12-fourth straight-through valve (selectable model: Sichuan bear SS-723K2), 13-fifth straight-through valve (selectable model: Sichuan bear SS-723K2), 14-third one-way valve (selectable model: Sichuan bear SS-113), 15-sixth straight-through valve (selectable model: Sichuan bear SS-723K2), 16-vacuum chamber (commercially available or self-made steel pipe), 17-seventh straight-through valve (selectable model: Sichuan bear SS-723K2), 18-vacuum gauge (selectable model: Beijing university radio factory DL-90), 19-vacuum pump (selectable model: Tianjin Xin Instrument factory TW-2A), 20-third pressure gauge (selectable model: WIKA Cl.1.6), 21-eighth straight-through valve (selectable model: Sichuan bear SS-K2), 22-reaction sampling tube (commercially available or self-made by glass tube).

Detailed description of the preferred embodiments

The present invention will be described in further detail with reference to examples for the purpose of facilitating understanding and practice of the invention by those of ordinary skill in the art, and it is to be understood that the present invention has been described in the illustrative embodiments and is not to be construed as limited thereto.