Method for preparing O-nitric acid

A technology of nitric acid and ammonium nitrate, applied in the direction of nitric acid, nitrogen oxides/oxyacids, etc., can solve the problem of a large increase in the consumption of heavy oxygen water, and achieve the effects of less 18O loss, high product purity, and simple process

Active Publication Date: 2009-11-11
SHANGHAI RES INST OF CHEM IND +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

For example, the product of the combination of hydrogen and oxygen-18 isotope weighs oxygen ( 18 O) water, also known as oxygen-18 water, has the molecular formula H 2 18 O, the molecular weight is 20.0, its chemical properties and ordinary water (H 2 16 O) exactly the same, heavy oxygen ( 18 O) Water is widely used

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  • Method for preparing O-nitric acid

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Effect test

Embodiment 1

[0026] Will 18 O abundance is 0.2% nitric acid 2mol and oxygen-18 water 25mol ( 18 O abundance is 98.5%) carry out the exchange reaction of oxygen isotope in the reaction kettle, the temperature is controlled at 70 ℃, the whole reaction kettle is kept in a closed state, and the reaction time is 10 days. In the reacted solution, excessive ammonia gas was passed to neutralize it, and the oxygen-18 water was distilled off under reduced pressure. The pressure was controlled at 80mmHg, and the temperature was controlled at 40-42°C. 18 O-ammonium nitrate crystals. Add excess methanesulfonic acid in the reactor, fully dissolve the 18 O-ammonium nitrate crystals, regenerated 18 O-nitric acid, carry out vacuum distillation again, pressure is controlled at 80mmHg, temperature is controlled at 40~42 ℃, will generate 18 O-nitric acid was evaporated into a liquid nitrogen cold trap to obtain 18 O abundance is 16% 18 O-nitric acid product 0.8mol.

Embodiment 2

[0028] Will 18 O abundance is 39% nitric acid 1.2mol and oxygen-18 water 10mol ( 18 O abundance is 98.5%) carry out the exchange reaction of oxygen isotope in the reaction kettle, the temperature is controlled at 70 ℃, the whole reaction kettle is kept in a closed state, and the reaction time is 6 days. In the solution after reaction, excess ammonia gas was passed to neutralize, and oxygen-18 water was distilled off under reduced pressure. The pressure was controlled at 100mmHg, and the temperature was controlled at 48-52°C. 18 O-ammonium nitrate crystals. Add excess hydrochloric acid in the reactor, fully dissolve the 18 O-ammonium nitrate crystals, regenerated 18 O-nitric acid, carry out vacuum distillation again, pressure is controlled at 100mmHg, temperature is controlled at 48~52 ℃, will generate 18 O-nitric acid was evaporated into a liquid nitrogen cold trap to obtain 18 O abundance is 76% 18 O-nitric acid product 0.6mol.

Embodiment 3

[0030] A sort of 18 The preparation method of O-nitric acid, this preparation method specifically comprises the following steps:

[0031] (1) After the isotope exchange reaction 18 O-nitric acid feedstock with 18 Oxygen-18 water with O abundance > 98% undergoes an oxygen isotope exchange reaction in the reactor, the 18 O-nitric acid feedstock 18 The atomic percentage of O abundance is 98%, the temperature is controlled at 50°C, the entire reactor is kept in a closed state, the reaction time is controlled at 10 days, and the molar ratio of nitric acid to oxygen-18 water is 1:20;

[0032] (2) Pass ammonia gas into the solution after the reaction to neutralize, distill under reduced pressure to remove the oxygen-18 water whose abundance has been reduced, control the pressure at 50mmHg, and control the temperature at 70°C to obtain 18 O-ammonium nitrate crystals;

[0033] (3) Add excessive trifluoroacetic acid in the reactor, fully dissolve the 18 O-ammonium nitrate crystals, ...

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Abstract

The invention relates to a method for preparing O-nitric acid, comprising the following steps of: (1) carrying out oxygen isotope exchange reaction between nitric acid material and oxygen-18 water in a sealed reaction kettle at the temperature between 50 DEG C and 80 DEG C for 1 to 10 days; (2) introducing ammonia gas to solution obtained after reaction for neutralization and removing oxygen-18 water with reduced abundance ratio through distillation at reduced pressure to obtain O-ammonium nitrate crystals in the reaction kettle; and (3) adding excessive acid to the reaction kettle to fully dissolve the O-ammonium nitrate crystals in the reaction kettle so as to regenerate O-nitric acid, and carrying out distillation at reduced pressure again to distill the regenerated O-nitric acid into liquid nitrogen trap so as to obtain the O-nitric acid product. Compared with the prior art, the invention has the advantages of simple process, easy operation, low energy consumption, high purity of products and low loss of O and the like.

Description

technical field [0001] The invention relates to a preparation method of a stable isotope oxygen-18 labeled compound, in particular to a 18 O-nitric acid preparation method. Background technique [0002] There are three stable isotopes of oxygen (O) in nature: 16 O. 17 O. 18 O, the mass numbers are 16, 17, and 18, and the natural abundances are 99.76%, 0.036%, and 0.204%, respectively, and they are all stable isotopes without radioactivity. Oxygen-18 is a stable isotope, and its application is mainly to use the similar physical and chemical properties of isotopes, that is, "isotope tracer technology", such as in the metabolism of organisms, the control of drug synthesis steps, environmental science and hydrogeology Research on chemistry, chemical chain characteristics and chemical reaction mechanism, nuclear medicine diagnosis, etc. [0003] According to different needs, different labeled compounds can be synthesized with oxygen-18 isotope. For example, the product of t...

Claims

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Application Information

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IPC IPC(8): C01B21/38
Inventor 秦川江张丽雅周建跃肖斌姜永悦李猷刘严
Owner SHANGHAI RES INST OF CHEM IND
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