130 results about "Chemical purity" patented technology

The invention relates to the technical field of magnesium powder preparation, in particular to a preparation method of ultrahigh-mesh high-purity magnesium powder, which comprises the following steps: S1, preparing a system and loading raw materials, preparing equipment and loading magnesium ingots to obtain a sealed smelting crucible loaded with the high-purity magnesium ingots; according to the method, the stable preparation of the ultrahigh-mesh high-purity magnesium powder is realized by implementing the whole process, multi-stage and high-vacuum closed-loop control from smelting, transferring, atomizing to separating and packaging. Molten magnesium liquid is transferred among a plurality of independent containers which are vacuumized in advance and accurately controlled in temperature, non-contact conveying is achieved through pressure difference and gravity, the chance that melt makes contact with any active gas at the high temperature is eradicated fundamentally, the chemical purity of final powder is guaranteed, and the production efficiency is improved. The negative influence of oxide impurities on the electrochemical performance of the material is avoided.

The invention belongs to the technical field of inorganic mineral fiber preparation, and provides a high-strength and high-modulus inorganic mineral fiber prepared from water-quenched slag and a preparation method of the high-strength and high-modulus inorganic mineral fiber. Firstly, the chemical purity of raw materials is improved through density separation and acid pickling, meanwhile, Na2CO3 and Fe2O3 are added, the tendency of crystal precipitation is reduced, and the vitrification characteristic of water-quenched slag is improved; secondly, the composite oxide modifier further optimizes the structure of the glass network, and B2O3 enhances the chemical stability of the glass network and reduces the melt viscosity by forming a B-O-Si bond; y2O3 provides high electric field intensity, inhibits crystal precipitation and enhances the crosslinking degree of a network; v2O5 provides a redox buffer function through a variable valence state, so that the chemical environment in the melting process is optimized, and the creep resistance is improved; and finally, a compact Al2O3 coating is formed on the surface of the fiber, so that the mechanical strength, the oxidation resistance, the corrosion resistance and the high-temperature stability of the fiber are improved.

The invention provides a deuterium-labeled 3-indoleacrylic acid isotope compound and a preparation method thereof, and relates to the technical field of plant hormone detection, deuterated toluene is creatively nitrated and subjected to a ring closing reaction, then an aldehyde group is introduced, and finally hydrolysis is performed to obtain the target product deuterium-labeled 3-indoleacrylic acid isotope compound. The preparation method provided by the invention is strong in operability, relatively good in atom economy and excellent in reproducibility and stability, the isotope abundance of the prepared deuterium-labeled 3-indoleacrylic acid isotope compound can reach 98% or above, the chemical purity is 98% or above, and the deuterium-labeled 3-indoleacrylic acid isotope compound can be used as an internal standard substance for detecting plant hormones and has good application prospects. The method has important practical application value.

The invention discloses cyclohexene formate esterase, a mutant of cyclohexene formate esterase and application of cyclohexene formate esterase in production of (S)-3-cyclohexene-1-formic acid. According to the cyclohexene formate esterase and the mutant disclosed by the invention, 100-400g / L of racemic 3-cyclohexene-1-methyl formate can be split by taking wet thalli subjected to induced expression or crude enzyme liquid obtained by ultrasonically crushing the wet thalli as a catalyst, so that (S)-3-cyclohexene-1-formic acid with chemical purity and optical purity reaching 99% or above is synthesized. The enzyme activity of the cyclohexene formate esterase mutant provided by the invention is further improved, the reaction time and the catalyst dosage are obviously reduced compared with those of a substrate with the same catalysis concentration before mutation, the reaction condition is mild, the operation is relatively simple and convenient, and the cyclohexene formate esterase mutant has a very good industrial application prospect.

The invention provides a preparation method of an Al18F-labeled PSMA radiopharmaceutical, according to the preparation method, through adjustment of a reaction system, the labeling time efficiency, the radiochemical purity of a final product, the radiochemical conversion rate and the product yield are ensured, meanwhile, the requirement for the fluorination reaction temperature in the labeling process is effectively reduced, and the product yield is improved. The preparation method of the Al18F-labeled PSMA radiopharmaceutical provided based on the method has good applicability and thorough reaction, new impurities are not introduced into a final product due to reduction of the reaction temperature or adjustment of a reaction system, the variety and content of the impurities in the final product can be further reduced and controlled, and the preparation method is suitable for industrial production. And the medication safety of a patient is further ensured. In addition, the final product obtained by the preparation method provided by the invention has good inter-batch uniformity, and has good stability under the storage conditions of 30 DEG C + / -2 DEG C and 40 DEG C + / -2 DEG C.

< TableDetails number = '0001' > < Title / > < tbl: tgroup cool = '2' > < tbl: colspec cool = 'c001' cool = '46%' / > < tbl: colspec cool = 'c002' cool = '54%' / > < tbl: cool > < tbl: cool = '1' > impurity < / tbl: cool > < tbl: cool = '1' > HPLC percentage content < / tbl The mobile phase B is a 8mmol / L ammonium acetate solution, and the solvent is a mixed solvent of acetonitrile and water in a volume ratio of 95: 5; and carrying out gradient elution at a flow rate of 1.0 ml / min.

The present disclosure relates to a radiopharmaceutical compositions, methods, and kits comprising 177Lu-PSMA I&T. The compositions, methods, and kits may have a molar ratio of the PSMA I&T to 177Lu from greater than 8.0:1.0 to 11.0:1.0. The composition may be formulated as a solution for injection and the solution is suitable for administration at least 72 hours after formulation. The composition(s) have a radiochemical purity (RCP) of 95% or greater, 95.5% or greater, 96% or greater, 96.5% or greater, 97% or greater, 97.5% or greater, 98.0% or greater, 98.5% or greater, 99% or greater, or 99.5% or greater at administration.

The invention provides a deuterium-labeled quetiapine fumarate isotope compound, a preparation method thereof and a food detection method, and relates to the technical field of food detection. The deuterium-labeled quetiapine fumarate isotope compound is obtained by introducing deuterated Boc piperazine to react with 11-chlorodibenzo [b, f] [1, 4] thiazepine, then removing a protecting group and grafting 2-chloroethoxyethanol. According to the preparation method provided by the invention, by screening proper reaction reagents and optimizing the reaction temperature and the reaction duration, the product conversion rate is greatly improved, and stable mass production in the industry is facilitated. The chemical purity of the deuterium-labeled quetiapine fumarate obtained by the preparation method provided by the invention can reach 98.3% or above, the isotope abundance exceeds 97%, and the deuterium-labeled quetiapine fumarate can be used as an internal standard substance in the field of food quality inspection, and has important practical application value.

The invention belongs to the field of medical isotope separation and preparation, and particularly relates to a method for separating and purifying < 212 > Pb from a thorium solution, which comprises the following steps: 1) leacheate is introduced into a Pb selective adsorption column to pretreat the Pb selective adsorption column, and then < 232 > Th salt solution and leacheate are introduced in sequence; 2) continuously introducing a desorption solution into the Pb selective adsorption column, enabling the desorption solution passing through the Pb selective adsorption column to flow into the Th selective adsorption column, and collecting the outflowing desorption solution; a desorption solution only containing 212Pb is obtained; according to the method, the 212Pb in the high-concentration thorium solution can be separated and purified at the same time. While < 232 > Th impurity entrainment and pollution in a < 212 > Pb product are remarkably reduced, compared with a single-column process, the separation time is basically not increased. The separated 212Pb product has high radionuclide purity and chemical purity at the same time, and can meet related pharmaceutical requirements.

The invention belongs to the technical field of synthesis, and particularly relates to a synthesis method of urea [14C]. The synthesis method of the urea [14C] comprises the following steps: (1) reacting carbonate [14C] with ammonia gas to obtain cyanamide salt [14C]; (2) hydrolyzing the cyanamide salt [14C] obtained in the step (1) with concentrated sulfuric acid at the hydrolysis temperature of 35-45 DEG C; and (3) adjusting the pH value of the hydrolysate obtained in the step (2) with ammonia water, concentrating and purifying to obtain urea [14C]. The synthesis method provided by the invention has the advantages of mild conditions, efficient reaction, high product yield (up to 95% or above), high purity (the chemical purity is greater than or equal to 99%) and the like, and is suitable for large-scale preparation of key raw materials of helicobacter pylori diagnostic reagents.

The invention discloses a preparation method of nebivolol, which combines an enzyme method and a chemical method, and integrates enzyme selectivity and operability of the chemical method. Meanwhile, nebivolol is constructed by adopting a brand new intermediate, chiral center construction is efficient and convenient, the chemical purity and optical purity of the product meet the quality requirements of raw material medicines, atoms are more economical, preparation is more efficient, and industrialization is facilitated.

The invention discloses a chlorpromazine-d6 compound as well as hydrochloride, a preparation method and application thereof, and belongs to the technical field of organic synthesis and analysis detection, the chlorpromazine-d6 compound is 3-(2-chloro-10-phenothiazinyl)-N, N-bis (methyl-d3)-1-propylamine, and the preparation method comprises the following steps: taking 2-chlorophenothiazine as a raw material, adding a catalyst, and reacting at the temperature of 60-80 DEG C for 1-2 hours to obtain the chlorpromazine-d6 compound. Carrying out aza-Michael addition and reductive amination reaction to finally obtain chlorpromazine-d6; the obtained chlorpromazine-d6 is subjected to hydrochloric acid acidification, such that chlorpromazine-d6 hydrochloride is obtained; the invention provides a novel deuterated internal standard substance for analysis and detection. In addition, the invention provides a new process for preparing chlorpromazine-d6 and hydrochloride thereof with proprietary intellectual property rights, the preparation method is novel, and has the advantages of simple operation, mild reaction conditions, short process route, high efficiency, low cost, environmental protection and the like; the obtained chlorpromazine-d6 and the hydrochloride thereof have the advantages of high chemical purity, high deuteration rate, high deuterium atom stability and the like.

The present invention relates to tungsten(VI) oxytetrachloride, which is notable for its particular chemical purity, and also to a method for its production.

The invention belongs to the field of radioactive chemical synthesis, and particularly relates to carbon-14 labeled tetrahydroprogesterone as well as a preparation method and application thereof. The carbon-14 labeled tetrahydroprogesterone provided by the invention has a structure as shown in a formula I; the carbon-14 labeled tetrahydroprogesterone provided by the invention has the advantages that the labeled sites are determined, the radiochemical purity and the chemical purity are relatively high, the nuclide carbon-14 is firmly labeled in tetrahydroprogesterone molecules and is not easy to fall off, and the requirements of tracer experiments in pharmacokinetics can be met.

The present invention relates to a 68 Ga-labeled exendin 4 radioactive probe [ 68 Ga]Ga‑C 12 ‑HBED‑CC‑MAL‑Cys 39 ‑Exendin‑4 and its preparation method belong to the technical field of radiopharmaceutical chemistry; its structural formula is as follows: #imgabs0# The labeling time of the radioactive probe of the present invention is 10 minutes, the labeling yield is greater than 98%, the radiochemical purity of the product determined by radio‑HPLC is greater than 98%, the product shows high affinity and high specificity for the glucagon-like peptide‑1 receptor, has a higher target organ uptake and a longer blood circulation time, and is a more potential glucagon-like peptide‑1 receptor imaging agent.

The invention provides a fluorination method of a PSMA radiopharmaceutical intermediate, and further provides a preparation method of an Al18F-labeled PSMA radiopharmaceutical preparation based on the fluorination method, and the fluorination method and the preparation method have the advantages that through adjustment of a reaction system, the purity of the PSMA radiopharmaceutical intermediate is improved, and the purity of the PSMA radiopharmaceutical preparation is improved. The preparation method of the PSMA radiopharmaceutical preparation marked by the Al18F has the advantages that marking time efficiency, radiochemical purity of a final product, radiochemical conversion rate and product yield are guaranteed, requirements on fluorination reaction temperature in a marking process are effectively lowered, and the preparation method of the PSMA radiopharmaceutical preparation marked by the Al18F based on the fluorination method is good in applicability, thorough in reaction and high in yield. New impurities are not introduced into the final product due to reduction of the reaction temperature or adjustment of a reaction system, and the preparation method can further reduce and control the variety and content of the impurities in the final product, so that the medication safety of patients is further ensured. In addition, the final product preparation product obtained by the fluorination method or the preparation method provided by the invention has good inter-batch uniformity, and has good stability under the storage conditions of 30 DEG C + / -2 DEG C and 40 DEG C + / -2 DEG C.

The invention relates to chemical technology for producing high-purity magnesium oxide used in the pharmaceutical, cosmetic, and food industries, in the production of ceramics, glasses, optical materials, electronic materials, catalysts, polymer materials, transformer steel.High-purity magnesium oxide having a specific surface area, determined by the BET method, in the range from 5 to 70 m2 / g, an average particle size (d50), determined by laser diffraction, of not more than 5 μm, characterized in that it has a mass fraction of impurity elements of each of Pb, Cd, As, Hg of not more than 0.1 ppm, a mass fraction of impurity elements of each of Ba, Zn, Ti, Mn, Co, Mo, V, Sb, Sr of not more than 1 ppm, a mass fraction of impurity elements of each of Al, F of not more than 5 ppm, a mass fraction of impurity elements of each of P, Cr, Ni, K, Li of not more than 10 ppm, a mass fraction of Fe of not more than 50 ppm, a mass fraction of Si of not more than 0.01%, a mass fraction of impurity elements of each of Ca, B of not more than 0.02%, a mass fraction of sulphates SO42−k of not more than 0.02%, a mass fraction of Na impurity of not more than 0.05%, a mass fraction of chloride impurity of not more than 0.05% and includes primary particles and agglomerates consisting of primary particles.High-purity magnesium oxide is obtained by calcination of magnesium hydroxide obtained by reacting a purified concentrated aqueous solution of magnesium chloride with an aqueous solution of sodium hydroxide in a continuous manner at a temperature of 40-90° C., stirring at a speed of 20-300 rpm at a molar ratio of OH−:Mg++ ions within the range (1.9÷2.1):1 with the continuous supply of a suspension of magnesium hydroxide seed crystals into the reaction mass in an amount of 5-200% of the total mass of the supplied initial reagents, and the magnesium hydroxide seed crystals are pre-treated with a concentrated aqueous solution of magnesium chloride, after interaction of the reagents, a suspension of magnesium hydroxide is sent for aging at a temperature of 40-90° C., then hydrothermal crystallization of magnesium hydroxide particles is carried out in the presence of dihydric alcohol: ethylene glycol or propylene glycol, at a temperature in the range from 120 to 220° C., pressure in the range from 0.1 to 2.3 MPa, and a duration ranging from 1 to 10 hours, the resulting suspension of magnesium hydroxide is filtered, washed, and calcination of magnesium hydroxide is carried out at a temperature of 700-1100° C.The obtained high-purity magnesium oxide has high chemical purity, adjustable specific surface area, pore volume and pore size distribution, particle size distribution and activity.

The application discloses a kind of radionuclide 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds 18 The present application discloses a method for detecting the radiochemical purity of F-labeled FAPI compounds, which comprises using thin layer chromatography to detect the radiochemical purity of F-labeled FAPI compounds

This invention belongs to the field of baicalin crystallization technology, and relates to a leaf-shaped baicalin crystal, its preparation method, and its application. The crystal has a leaf-like microstructure with a length ranging from 1 μm to 17 μm; the bulk density of the crystal is 0.1-0.2 g / mL, and the compactness is 0.2-0.4 g / mL. The leaf-shaped baicalin crystals provided by this invention are easy to compress into tablets and have a high surface area / volume ratio, which is beneficial for its adsorption and dissolution in vivo. The preparation process is simple to operate and can directionally prepare leaf-shaped baicalin crystals. The purity of the obtained leaf-shaped baicalin crystals can reach 93% or higher, significantly improving the chemical purity and forming a unique low bulk density physical property.

This invention relates to a method for preparing the fenelone intermediate 2-cyanoethyl(4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1,6-naphthidine-3-carboxylic acid ester, and also relates to diastereomeric salts (Va), (Vb), (Vc), and / or (Vd). This method is simple to operate, and the diastereomeric salts can be obtained with very high chemical and enantiomeric purity (tartrate ester content <0.05%) through a single dissociation, avoiding the raw material loss and waste problems caused by multiple dissociations. It also has low production costs and meets the requirements of green production.

The group of inventions relates to the field of medicine, pharmacology and the chemical and pharmaceutical industry and includes an improved method for producing (10S, 13S, 16R, 17R)-17-hydroxy-10,13,16-trimethyl-17-propanoyl-7,8,12,14,15,16-hexahydro-6H-cyclopenta[a]phenanthrene-3-one (compound of formula (I)) and the use thereof for industrial batch, semi-continuous and continuous chemical production. Also described is a method for producing an intermediate compound, Vamorolone Acetate. The method for producing the compound of formula (I) is carried out according to the schema depicted. The production method makes it possible to produce the compound of formula (I) with a purity suitable for the use thereof in a finished dosage form for subjects requiring treatment for Duchenne muscular dystrophy. Thus, the technical results of the present invention consist in an improved production method which results in: a high yield and chemical purity, including stereoisomeric purity, of the compound of formula (I) and intermediate products in the synthesis of the compound of formula (I), which are suitable for use in a finished dosage form for subjects requiring treatment for Duchenne muscular dystrophy; the adaptability of the synthesis of the compound of formula (I) to industrial production; environmentally-friendly production; and a decrease in the formation of undesirable by-products.

The invention relates to the field of chemistry and chemical engineering, in particular to a method for preparing high-purity lactide through double-solvent phase change extraction. A compound containing oxygen-containing functional groups such as alcohol, ether, ketone, carboxylic acid and amide is selected as a hydrogen bond acceptor solvent, and water is selected as a hydrolysis solvent. Wherein the hydrogen bond acceptor solvent is combined with free acid impurities (hydrogen bond donors) in the crude lactide to form a deep eutectic solvent, and the water hydrolyzes meso-lactide into lactic acid retaining D, L-lactide. In the process, the whole system is subjected to heating, melting, blending, cooling, crystallizing and separating out, finally, solid-phase high-purity D, L lactide is subjected to separation and drying treatment, the chemical purity is improved to 99% or above from 40%-95%, and the optical purity is improved to 98% or above. According to the scheme, the operation is simple and convenient, the separation efficiency is high, the method is environment-friendly, the energy consumption is remarkably reduced, the defects of traditional high-temperature distillation and repeated recrystallization are avoided, and an efficient and environment-friendly new scheme is provided for industrial purification of lactide.

The invention discloses an alloy for hydrogen isotope gas storage and a preparation method thereof. The chemical formula of the hydrogen isotope gas storage alloy is ZrMn2-x, wherein x is more than or equal to 0.25 and less than or equal to 0.5. Compared with the prior art, the alloy has the following beneficial effects: 1, the alloy prepared by the invention has lower hydrogen absorption / desorption isotope equilibrium pressure, and when the alloy is used for tritium gas storage, the quantity of tritium remaining in a gas phase in the storage process can be greatly reduced, so that helium generated by decay of tritium remaining in the gas phase is reduced to the greatest extent; and 2, the prepared alloy does not contain catalytic active elements, and generation of tritiated methane gas in the tritium release process of the tritium storage alloy is avoided, so that the chemical purity of tritium gas is improved. And 3, the main element of the alloy is the low-cost Mn element, so that the cost of the hydrogen isotope gas storage alloy can be greatly reduced.

The application belongs to the field of analytical chemistry detection, and particularly relates to a method for detecting radiochemical purity of an actinium 225 Ac] conjugate. The method adopts high performance liquid chromatography combined with a gamma counter, a mobile phase includes mobile phase A and mobile phase B, the mobile phase A is a mixed solution of buffer salt and cationic pair reagent, and the mobile phase B is acetonitrile. 225 The detection method can accurately detect the radiochemical purity of the actinium 225 Ac] conjugate, is stable and reliable, has high sensitivity, and is of great significance for quality control and research of the actinium [Ac] conjugate product.

The invention relates to the technical field of chemical synthesis, and particularly discloses a synthesis method of (4-chlorphenyl) (4-hydroxy-3, 5-dimethoxyphenyl) ketone. Comprising the following steps: 1) reacting a compound shown as a formula I with N, O-dimethyl hydroxylamine hydrochloride under the action of alkali and a condensing agent to generate a compound shown as a formula II, 2) mixing the compound shown as the formula II with the alkali, dropwise adding the mixture into a Grignard reagent under temperature control, and stirring while keeping the temperature to obtain a compound shown as a formula III, and 3) demethylating the compound shown as the formula III under the action of lewis acid, stirring while keeping the temperature under the protection of nitrogen to obtain a compound shown as a formula III. And obtaining a compound of formula IV. The method for synthesizing the (4-chlorphenyl) (4-hydroxy-3, 5-dimethoxyphenyl) ketone has the advantages that the process route is novel, the total yield is larger than 60%, the route is short, the chemical purity is high, a sulfuric acid reagent and a chlorine acylation reagent are avoided, generation of by-products is remarkably reduced, the purification difficulty and the possibility of equipment corrosion are reduced, the generation amount of three wastes is reduced, and the method is suitable for industrial production. And the production quality and the atom utilization rate of the product are improved.

The crystalline form II of erobicixibat. The X-ray powder diffraction pattern of crystalline form II has specific peaks at 2θ values of 9.4±0.2° and 7.8±0.2°, and has one or more of the following characteristic peaks: 3.9±0.2°, 11.7±0.2°, 16.1±0.2°, 17.6±0.2°, 18.3±0.2°, 19.6±0.2°, 20.9±0.2°, 22.1±0.2°, and 25.8±0.2°. Crystalline form II is stable, has low hygroscopicity, and when exposed to a high humidity environment of 25°C / 92.5%RH, the chemical purity of crystalline form II does not change significantly, and the X-ray powder diffraction pattern of the crystalline form also does not change accordingly. Furthermore, crystalline form II is accompanied by a simple and convenient preparation method, has low requirements for the preparation process and storage conditions, and has high medical value.

The invention relates to a dental prosthesis system having an implant (1) for osseointegration into a jaw bone, in particular made of ceramic, an abutment (2), in particular made of ceramic, and a connecting screw (3) for connecting the implant (1) and the abutment (2). The connecting screw (2) consists of a metallic zirconium with a chemical purity of at least 85 wt.%, in particular at least 90 wt.%.

The present invention discloses a method and system for detecting the production quality of aluminum hydroxide based on data analysis, which mainly relates to the field of quality detection technology. Among them, the method includes obtaining preset standard quality parameters and preset quality tolerance intervals; obtaining M storage grids; obtaining M storage grid sample chemical purity sets, M storage grid sample particle size distribution sets, M storage grid sample crystal structure sets and M storage grid sample water content sets; based on the preset standard quality parameters, centralized identification of quality deviations is performed to obtain M storage grid production quality deviation values, and the mean value is calculated in combination with the obtained Q incremental storage grid production quality deviation values ​​to determine the target production quality detection result. The method solves the technical problem in the prior art that when aluminum hydroxide is subjected to batch quality inspection, the inspection quality has a low fit with the actual situation and the inspection results are inaccurate, thereby achieving the technical effect of improving the reliability of the inspection.

The invention relates to the technical field of rice stress-resistant cultivation, and discloses a rice root system salt tolerance adjusting method based on exogenous spermidine, which comprises the following core steps: in the critical period of rice root system development, directionally applying a spermidine solution subjected to purity verification to a rice root system area, by accurately regulating and controlling the application concentration, frequency, duration and application environment conditions of spermidine, the osmotic regulation capability and the anti-oxidation system function of a rice root system in a high-salt environment with the soil conductivity larger than or equal to 2 dS / m are improved, the salt tolerance of the root system is remarkably improved, and then growth and development of rice are guaranteed. The spermidine is a straight-chain polyamine compound with good biocompatibility, the chemical purity is not lower than 98%, no heavy metal is left, and the contents of lead, cadmium and mercury are all smaller than or equal to 0.1 mg / kg. According to the invention, precise targeted regulation and control of the salt tolerance of the rice root system are realized, and the regulation effect is stable and remarkable.