58 results about "Ammonium formate" patented technology

The invention discloses an enzyme catalytic synthesis method of a luliconazole chiral intermediate, which comprises the following steps: adding a recombinant escherichia coli wet cell for expressing alcohol dehydrogenase, a recombinant escherichia coli wet cell for expressing formate dehydrogenase, a buffer solution, a substrate, a cosolvent, ammonium formate and a coenzyme into a reaction container, reacting at 25-35 DEG C for 2-24 hours, extracting, separating, and carrying out rotary evaporation, thereby obtaining the luliconazole chiral intermediate. The luliconazole chiral intermediate is obtained; the substrate is 2, 2 ', 4'-trichloroacetophenone; the alcohol dehydrogenase is a mutant of AKR3. The method is mild in reaction condition, environmentally friendly, high in regioselectivity and stereoselectivity, high in conversion rate, high in chiral purity, small in enzyme dosage, low in preparation cost and suitable for industrial production.

The invention belongs to an amide intermediate treatment device and method for hydrazine hydrate production. Comprising a concentration tank, the concentration tank is provided with a water-phase reaction liquid inlet pipeline and a catalyst inlet, the catalyst inlet is connected with a quartz sand catalyst preparation unit, an outlet of the concentration tank is connected with a concentrated material inlet of an intermediate recovery kettle, and the intermediate recovery kettle is further connected with an ammonia feeding pipeline. An ammoniation liquid outlet of the intermediate recovery kettle is connected with a separation and recovery unit, and a liquid phase outlet of the separation and recovery unit is connected with a hydrazine compound synthesis section; a steam discharge pipeline is arranged at the top of the concentration tank; the method has the advantages that moisture in the water-phase reaction liquid can be removed, ammonium formate is converted into formamide and recycled, meanwhile, metal ions are prevented from being contained in ammoniation liquid, and further, the treatment cost is reduced and continuous treatment is achieved on the basis of energy conservation and consumption reduction.

The invention belongs to the technical field of vitamin content detection, and particularly relates to a method for measuring the content of various water-soluble vitamins B. The water-soluble vitamins B comprise vitamin B1, vitamin B2, vitamin B3, vitamin B6, vitamin B7, vitamin B12 and nicotinamide. A high performance liquid chromatograph and an electrospray detector are used as detection instruments, and chromatographic conditions are as follows: a mobile phase A is ammonium formate or ammonium acetate, a mobile phase B is methanol, and gradient elution is performed; the gradient elution procedure is as follows: a solvent of a test sample is a mixed solution of acetonitrile, water and glacial acetic acid, and the volume ratio of the acetonitrile to the water to the glacial acetic acid is 5: 95: 0.5; the atomization temperature of the electrospray detector is 35 DEG C; the method is better in separation degree and higher in specificity and sensitivity.

The application provides an alpha-carboxyl-beta-diimine nickel complex and a preparation method and application thereof and a preparation method of ethylene-methyl acrylate copolymer. The alpha-carboxyl-beta-diimine nickel complex has a structure shown in general formula (I): in the general formula (I), Ar is selected from 2,6-dialkylphenyl; X is chlorine or bromine; and L is acetonitrile or benzonitrile. The preparation method of the alpha-carboxyl-beta-diimine nickel complex is that acetylacetone is reacted with 2,6-dialkylaniline, then reacted with ammonium formate under the action of alkyl lithium, and then reacted with a halogenated nickel salt in an acetonitrile or benzonitrile solvent to obtain the alpha-carboxyl-beta-diimine nickel complex. The application further provides a preparation method of ethylene-methyl acrylate copolymer, which uses the alpha-carboxyl-beta-diimine nickel complex as a main catalyst. The application improves the copolymer molecular weight and the methyl acrylate insertion rate, and makes the prepared EMA similar to the branched structure of a commercial product prepared by a free radical process.

The invention belongs to the technical field of metallurgical binders, and particularly relates to a Bayer process red mud-based composite pellet binder, a preparation method thereof and iron ore pellets. The invention relates to a water-based adsorbent, which is prepared from the following components in percentage by mass: 60 to 80 percent of Bayer process red mud subjected to microwave-ultrasonic wave synergistic activation treatment, 10 to 25 percent of superfine slag powder, 2 to 8 percent of nano SiO2 and 1 to 5 percent of mixture of sodium lignin sulfonate and ammonium formate, the parameters of the microwave-ultrasonic wave synergistic activating treatment are as follows: the microwave power is 600 to 1000W, the ultrasonic wave frequency is 30 to 50kHz, and the treatment time is 20 to 40min. Compared with an existing technology of only microwave single activation or red mud-bentonite compounding, in the embodiment of the invention, microwave-ultrasonic wave synergistic activation and a mixture of superfine slag powder-nano SiO2-sodium lignin sulfonate and ammonium formate are introduced into the red mud-based binder in a ternary synergistic manner for the first time; and the problems of activity, strength and grade loss are synchronously solved on the premise of not introducing bentonite.

The invention belongs to the technical field of carbon fiber material modification, and relates to an activated carbon fiber modification method, a modified activated carbon fiber and application thereof. The preparation method comprises the following specific steps: (1) mixing activated carbon fibers, a maleic acid solution and an ammonium formate solution according to a mass fraction ratio of (0.1-1): (2-10): (2-10), and reacting at 50-70 DEG C; and (2) after the reaction is finished, taking out a reaction product, cleaning and drying to obtain the modified activated carbon fiber. Results show that under the compound modification condition of 6% of ammonium formate and 4% of maleic acid, the SO2 adsorption capacity of the activated carbon fiber material after compound modification reaches 18.294 mg / g and is improved by 141.36% compared with that of an unmodified original sheet.

The invention discloses 2-((4-aminopyridine-2-yl) amino)-4-methylphenol as well as a synthesis method and application thereof, 2-bromo-4-methylphenol and 4-nitropyridine-2-amine are taken as raw materials, and an intermediate 4-methyl-2-((4-nitropyridine-2-yl) amino) phenol is obtained through condensation reaction; and reducing the intermediate under the action of ammonium formate and a catalyst to obtain the 2-((4-aminopyridine-2-yl) amino)-4-methylphenol. The method is simple and convenient to operate, mild in operation condition and high in reaction rate, the obtained product is high in purity and yield, the dispersity and antistatic performance of the insoluble sulfur can be improved, and the method is suitable for industrial mass production.

The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of a pyrrolopyrimidine-4-amine derivative, which selects methanol, ammonium formate and formic acid as a reaction system to carry out directional reaction, avoids the use of high-pressure hydrogen and a high-pressure kettle, avoids the safety risk caused by high-pressure operation, and improves the yield of the pyrrolopyrimidine-4-amine derivative. And the alcoholic solution solves the problems of low solubility and obvious amplification effect of a starting material when water is used as a solvent in the prior art, and realizes homogeneous reaction. By adopting the fixed bed reaction unit, the problem of pipeline blockage caused by sublimation of ammonium formate is solved, the potential safety hazard in large-scale production is eliminated, the fixed bed reaction unit is used for continuous catalytic reaction to replace the traditional staged reaction, the production period is remarkably shortened, the production efficiency is improved, and the method is suitable for large-scale industrial production.

Provided are: a separation solution for an aluminum foil laminate, which can reduce elution of an aluminum foil into the separation solution and reduce the amount of impurities when a recovered aluminum foil is melted and cast, and which has sufficient ability to separate an aluminum foil laminate into a resin and an aluminum foil; and a method for separation and recovery of an aluminum foil laminate using same. The present invention is capable of providing a separation solution for an aluminum foil laminate, which contains an ammonium salt comprising at least one of ammonium formate and ammonium acetate, one or more acids selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, formic acid and acetic acid, and water, the separation solution being characterized in that a content ratio obtained by dividing the content (mass%) of the ammonium salt in the separation solution by the content of the acid (mass%) in the separation solution is 0.1-40.0.

This invention discloses a process and coating structure for rare earth modified trivalent chromium pearl chromium plating on zinc alloys. The process includes sequentially preparing a cyanide-free copper plating layer, a cyanide-free copper-zinc alloy plating layer, a high-corrosion-resistant nickel-phosphorus alloy plating layer, a bright nickel-cobalt alloy plating layer, a pearl nickel plating layer, a rare earth modified trivalent chromium pearl chromium plating layer, and an anti-discoloration protective film on a zinc alloy substrate. The rare earth modified trivalent chromium pearl chromium plating process is as follows: chromium chloride hexahydrate 90-130 g / L, potassium chloride 90-160 g / L, ammonium chloride 90-160 g / L, ammonium bromide 18-28 g / L, ammonium formate 40-60 g / L, boric acid 45-65 g / L, rare earth additives 8-12 mL / L, leveling agent 2-4 mL / L, accelerator 1-3 mL / L, plating bath pH 2.5-3.2, plating bath temperature 25-35℃, and cathode current density 8-16 A / dm². The rare earth additives have a synergistic effect on improving the performance of trivalent chromium plating solution. No rust was observed on the surface of the plated parts after undergoing a neutral salt spray test for 132 hours according to GB / T 10125–2021 standard.

The present application relates to a kind of HPLC-MS / MS detection method of detecting in human plasma, desloratadine and 3-hydroxydesloratadine in human plasma, it includes the following steps: (1) human plasma sample pretreatment;(2) liquid chromatography-mass spectrometry detection, using mobile phase A and mobile phase B as mixed mobile phase is carried out gradient elution, wherein: mobile phase A is methanol-acetonitrile mixed solution, in mixed solution methanol and acetonitrile volume ratio is 4-6:6-4;Mobile phase B is 2-20mM ammonium formate aqueous solution;(3) the determination of the concentration of human plasma in lopatadine, desloratadine and 3-hydroxydesloratadine.The present application uses lopatadine-d4, desloratadine-d5, 3-hydroxydesloratadine-d4 as deuterium internal standard, using Agilent, ZORBAX Eclipse XDB-Phenyl is carried out gradient elution, deuterium internal standard and the measured substance has the same retention time, chemical property and matrix effect, the reproducibility, accuracy of determining the concentration of lopatadine, desloratadine and 3-hydroxydesloratadine in plasma are good.The method of the present application can be used to evaluate the bioequivalence of lopatadine.

This invention discloses a catalyst and method for the continuous synthesis of formamide from ammonium carbonate or ammonium bicarbonate, belonging to the field of chemical technology. The catalyst is a boron-nitrogen co-doped activated carbon supported palladium catalyst prepared by using a palladium precursor, boric acid, and nitrogen-doped activated carbon. The method uses ammonium carbonate solution or ammonium bicarbonate solution as raw material, and in a continuous flow reactor, the above-mentioned catalyst catalyzes the hydrogenation of ammonium carbonate or ammonium bicarbonate to synthesize formate. The formate is then dehydrated to obtain formamide. The catalyst of this invention has advantages such as high activity and high stability, and can efficiently and stably produce ammonium formate in a continuous flow reactor, which can then be further dehydrated to obtain formamide, thus providing a green, low-carbon, and safe method for the synthesis of formamide.

The invention discloses an enzymatic synthesis method of a melogabalin intermediate and related alcohol dehydrogenase, racemic 3-ethyl bicyclo [3.2. 0] hept-3-ene-6-ketone is used as a substrate, a genetically engineered bacterium for producing alcohol dehydrogenase is used as an enzyme catalyst, a genetically engineered bacterium for producing formate dehydrogenase, ammonium formate and coenzyme are matched, an enzymatic reaction is carried out under a stirring condition, and the melogabalin intermediate is obtained. And carrying out purification and separation on a reaction product to obtain the melogabalin intermediate (1R, 5S)-3-ethyl bicyclo [3.2. 0] hept-3-ene-6-ketone. The method has the advantages of simple reaction, few steps, mild reaction, less pollution and the like, and has great industrial application potential and commercial value.

The invention discloses an aqueous zinc ion battery electrolyte, a preparation method thereof and an aqueous zinc ion battery, and belongs to the technical field of aqueous zinc ion batteries. The aqueous zinc ion battery electrolyte comprises deionized water, an electrolyte salt and an additive ammonium formate. Ammonium formate is adopted as an additive, formate ions of the ammonium formate are small in steric hindrance and molecular weight, a compact shielding layer can be formed, migration resistance in electrolyte is low, and the ammonium formate can enter a zinc ion solvation shell layer to change the structure of the zinc ion solvation shell layer; formate has weak hydrogen-bond interaction with water molecules, can inhibit generation of low-temperature ice crystals, and can quickly react with H < + > to respond to pH fluctuation of an electrode interface; and the ammonium group can be adsorbed on the surface of the zinc negative electrode to play a role in electrostatic shielding. Therefore, when the aqueous zinc ion battery electrolyte is applied to a battery, a dendritic crystal phenomenon caused by hydrogen evolution, corrosion and non-uniform zinc ion deposition of a zinc negative electrode in the electrolyte can be effectively inhibited, the cycle life of the battery is prolonged, and the coulombic efficiency and the low-temperature stability of the battery are improved.

A green electrosynthesis method of ammonium formate under a non-noble metal catalytic system comprises the following steps: cleaning copper foam with isopropanol and a hydrochloric acid solution in sequence, then placing the cleaned copper foam in a three-electrode electrolytic tank as a working electrode to obtain copper foam with the surface covered with a light blue precursor film, washing the precursor film with deionized water, and drying the washed precursor film for a long time to obtain the green electrosynthesis method of ammonium formate under a non-noble metal catalytic system. And carrying out heat preservation in a flowing argon atmosphere to obtain the nanowire structure anode electrode consisting of metal copper, copper oxide and cuprous oxide. According to the invention, the anode adopts an in-situ constructed gradient heterojunction nanowire structure, metal Cu provides an excellent electron conduction channel, rapid charge transmission under high current density is ensured, optimal balance is realized in a nitrate eight-electron reduction path through the cathode, and NOI initial adsorption and activation are facilitated.

This invention discloses a method for the enzymatic synthesis of L-aminobutyric acid (GABA), comprising the following steps: using threonine and ammonium formate as substrates, a three-enzyme combined catalytic reaction is carried out using leucine dehydrogenase, threonine deaminase, and formate dehydrogenase at a temperature of 40-55°C and a pH of 7.0-9.0 to obtain L-aminobutyric acid. The leucine dehydrogenase is the leucine dehydrogenase with the amino acid sequence shown in SEQ ID NO:1 or a mutant thereof. This invention can rapidly convert threonine to L-aminobutyric acid, yielding L-aminobutyric acid with high optical purity, thus improving economic efficiency.

The invention relates to magnesium formate and a preparation method thereof, and the preparation method of the magnesium formate comprises the following steps: by taking bischofite and ammonium formate as raw materials, carrying out liquid phase reaction in a water phase medium to generate a mixture containing the magnesium formate and ammonium chloride; and solid magnesium formate is separated from the mixture. According to the invention, bischofite (MgCl2. 6H2O) is innovatively selected as a magnesium source, and the substance is a cheap by-product in industrial processes of extracting lithium from a salt lake, preparing salt from seawater and the like and is wide in source, so that the cost of raw materials is greatly reduced. Meanwhile, ammonium formate (NH4HCOO) is adopted to replace traditional formic acid or organic amine and is stable in property, safe and easy to decompose, use of strong corrosive acid or toxic solvent is avoided from the source, and the development trend of green chemistry is met.

The invention discloses a preparation method of a low-temperature selective catalytic reducing agent solution for vehicles, and belongs to the technical field of catalytic reducing agent solutions, the preparation method comprises the following steps: purifying urea, purifying ammonium formate, dissolving, filtering, finely filtering and ultra-filtering; the step of purifying ammonium formate comprises the following steps: mixing ammonium formate and three-stage water, stirring at 78-80 DEG C, carrying out first-stage cooling, adding treated montmorillonite, carrying out second-stage cooling and third-stage cooling, centrifuging, and carrying out vacuum drying, so as to obtain purified ammonium formate; a preparation method of the treated montmorillonite comprises the following steps: mixing dried polyethylene glycol 400, dried polyethylene glycol 2000 and absolute ethyl alcohol, stirring at 60-65 DEG C, adding Na-montmorillonite, stirring, centrifuging, taking precipitate, drying in vacuum, grinding and sieving to obtain the treated montmorillonite; the prepared automotive selective catalytic reducing agent solution is low in freezing point and low in metal ion content.

The invention relates to a preparation method of a paliperidone palmitate key intermediate, which comprises the following steps: by taking formic acid as a solvent, carrying out reductive amination reaction on 3-methoxy-2-piperidone (SM1) and ammonium formate to obtain 3-methoxy-2-aminopiperidine, and then dehydrating the 3-methoxy-2-aminopiperidine and 3-acetyl-4, 5-dihydro-2 (3H)-furanone (ADHF) in the presence of p-toluenesulfonic acid to obtain an intermediate 2, 3-dimethoxy-2-piperidone. The preparation method comprises the following steps: carrying out a chlorination reaction on an intermediate 2 and oxalyl chloride to obtain an intermediate 3, and carrying out demethylation on the intermediate 3 in 48% HBr to obtain a target product 3-(2-chloroethyl)-9-hydroxy-2-methyl-6, 7, 8, 9-tetrahydro-4H-pyridine [1, 2-a] pyrimidine-4-ketone. According to the method, the production cost is remarkably reduced, the operation is simple, the reaction condition is mild, and the method is suitable for industrial production.

The invention discloses a method for rapidly measuring the content of lithium or sodium salt in an ion battery electrolyte. The method comprises the following steps: 1, preparing a sample solution to be measured; 2, preparing a standard solution; 3, setting instrument conditions: adopting a liquid chromatograph-mass spectrometer and a C18 type liquid chromatographic column, enabling a mobile phase to comprise a first mobile phase component and a second mobile phase component, enabling the first mobile phase component to be an aqueous solution containing acid and ammonium salt, enabling the acid to be selected from formic acid or acetic acid, and enabling the ammonium salt to be selected from ammonium formate or ammonium acetate; the second mobile phase component is methanol or acetonitrile; and 4, measuring and calculating.

This invention discloses an enzymatically catalytic synthesis method for a chiral intermediate of dzoxadamine. Using methyl acetoacetate as a substrate, buffer, substrate, alcohol dehydrogenase, formate dehydrogenase, ammonium formate, and coenzyme are added to a reaction vessel. The reaction is carried out at 20–40°C for 2–24 hours. After extraction, separation, and rotary evaporation, the chiral intermediate (R)-3-hydroxybutyrate methyl ester is obtained. The alcohol dehydrogenase is a mutant of ADH1 derived from Rollstonella, and the amino acid sequence of ADH1 is shown in SEQ ID No. 1. This invention offers mild reaction conditions, high stereoselectivity, and environmental friendliness. It also boasts high conversion rate, high chiral purity, low enzyme dosage, tolerance to high substrate concentrations, and low preparation cost, making it suitable for industrial production. Furthermore, it avoids chiral resolution and heavy metal residues in the product, overcoming the shortcomings of chemical methods.

This invention relates to the field of medical device testing technology, specifically to the application of LC-MS / MS in determining the content of indophenol sulfate and p-cresol sulfate in a hemoperfusion device. The method includes: mixing plasma and acetonitrile, vortexing and centrifuging, collecting the supernatant, eluting the supernatant through a C18 solid-phase extraction column, collecting the eluent, mixing the eluent with water and filtering to obtain the test solution; performing liquid chromatography and mass spectrometry on the test solution, wherein the mobile phase A of the liquid chromatography is a 3-8 mmol / L gradient concentration ammonium acetate solution containing 0.05% ammonium formate by volume, and the mobile phase B is methanol; S3: calculating the concentrations of indophenol sulfate and p-cresol sulfate in the test solution based on the labeled curve. This invention, through dual purification pretreatment and multi-ion-pair threshold matching technology, can effectively remove more than 95% of interfering protein-binding toxoids. The interference peak response value in blank plasma is less than 5% of the target analyte response value, solving the detection error problem caused by interference in traditional methods.

The invention discloses a flue gas denitration system based on ammonium carbamate, which comprises a feeding unit, a pyrolysis unit, a gas transmission unit, a reaction unit and an ammonia control unit, and the feeding rate of the feeding unit, the pyrolysis working condition of the pyrolysis unit and the ammonia nitrogen molar ratio output by the gas transmission unit are cooperatively regulated and controlled. The problems of high safety risk and corrosivity of traditional liquid ammonia and ammonia water are solved, the defects of high energy consumption and by-product blockage of urea ammonia preparation are overcome, the characteristics of low pyrolysis temperature and no by-product of ammonium carbamate are utilized, and by means of feeding redundancy design, pyrolysis uniformity optimization and accurate control over the ammonia concentration, the urea ammonia preparation method is suitable for industrial production. The problem that the ammonia control logic of an existing system is lagged is solved, efficient utilization of ammonia gas and efficient removal of nitrogen oxide are achieved, the denitration efficiency and the system stability are remarkably improved, and meanwhile the operation cost and the equipment maintenance frequency are reduced.

The invention discloses a method for detecting saponin components in ginseng and a preparation thereof. Relates to the field of medicinal material detection. The method for detecting the saponin components in the ginseng and the ginseng preparation comprises the following steps: S1, taking a ginseng sample or a ginseng-containing preparation, adding an extraction solvent, and extracting to obtain a test solution; s2, the test solution is injected into a liquid chromatograph, a chromatographic column is adopted for gradient elution, and octadecylsilane chemically bonded silica is adopted as a filling agent of the chromatographic column; s3, detecting pseudo-ginsenoside F11, ginsenoside Rf, ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Re by adopting an electrospray ionization source negative ion mode and a multi-reaction monitoring mode of a mass spectrometry detector; a mobile phase used for gradient elution is selected from acetonitrile-water, an acetonitrile-ammonium acetate solution, acetonitrile-ammonium formate, methanol-formic acid or an acetonitrile-tetrahydrofuran-ammonium formate solution. By combining C18 chromatographic column gradient elution with a mass spectrum multi-reaction monitoring (MRM) mode and providing a mobile phase system, the problems of narrow applicability, isomeride interference, strong matrix effect and the like of a method for detecting saponin components of ginseng and preparations thereof in the prior art are effectively solved.

The application discloses a high-performance thermosetting resin plugging material and a preparation method thereof and a water-based drilling fluid, relates to the technical field of oil field chemistry, and discloses the following steps in the preparation method of the plugging material: stirring and reacting an aromatic compound containing two double bonds with sodium tungstate, a transfer catalyst and a hydrogen peroxide solution at room temperature, purifying to obtain an epoxy compound, reacting an aromatic compound containing an aldehyde group with ammonium formate and a palladium-carbon catalyst under heating of nitrogen, obtaining an amine compound, transferring the epoxy compound and the amine compound into a size-adjustable mold, performing a temperature rising curing treatment, performing low-temperature ball milling on a crude product, obtaining plugging material particles, and using the plugging material particles to configure the water-based drilling fluid; the specific aromatic rigid skeleton monomer is selected, and the molar ratio of the epoxy and the curing agent is accurately controlled, so that the mechanical strength and the thermal stability of the material are significantly optimized, and the plugging material in the application has a good treatment effect on cracks and pores in complex strata.

This invention relates to the field of human milk oligosaccharide (HMO) detection technology, and proposes a high-coverage analytical method for HMOs based on high-resolution liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS). The method includes the following steps: detecting HMOs in the sample solution using UPLC-HRMS, comparing fragment ions, retention times, and the precise mass number and isotopic distribution of the primary precursor ion to achieve structural identification of HMOs in the breast milk sample; the chromatographic conditions in the UPLC-HRMS method include: using 50 mmol / L ammonium formate aqueous solution as mobile phase A, using pure acetonitrile as mobile phase B, and gradient elution; the content of mobile phase B is expressed as a volume percentage. This technical solution solves the problems of low coverage and low sensitivity in HMO detection and analysis in related technologies.

The invention discloses an LCMS / MS (Liquid Chromatography Mass Spectrometry / Mass Spectrometry) analysis and detection method for collinear residual impurities of mycophenolate mofetil capsules, and the LCMS / MS is adopted to analyze and detect a test sample in the step S1: chromatographic condition parameters are as follows: a chromatographic column with octadecylsilane chemically bonded silica as a filler is selected, the specification of the chromatographic column is 150mm * 4.6 mm, 2.7 mu m, and the column size is 1mm. A mobile phase is composed of an ammonium formate aqueous solution and an organic solvent mixed solution, and gradient elution is set according to the volume fraction; the flow velocity is 0.25 ml / min-0. 35 ml / min, the temperature of a chromatographic column is 38-42 DEG C, the temperature of a sample introduction disc is 5-10 DEG C, the sample introduction volume is 15-25 microliters, and mass spectrum condition parameters are as follows: an ion source is an electrospray ionization source, and the mode is a positive ion mode; and analyzing and detecting by adopting an external standard method. The method can effectively detect collinear residual impurities, and has the advantages of good sensitivity, high accuracy, high precision and good durability.

The invention discloses an enzyme catalytic synthesis method of a dorzolamide chiral intermediate, which comprises the following steps: by taking methyl acetoacetate as a substrate, adding a buffer solution, the substrate, alcohol dehydrogenase, formate dehydrogenase, ammonium formate and coenzyme into a reaction container, reacting at 20-40 DEG C for 2-24 hours, extracting, separating and carrying out rotary evaporation to obtain the dorzolamide chiral intermediate (R)-3-methyl hydroxybutyrate, the alcohol dehydrogenase is a mutant derived from ADH1 of Ralstonia, and the amino acid sequence of the ADH1 is shown as SEQ ID No. 1. The method has the advantages of mild reaction conditions, high stereoselectivity, greenness, environmental protection, high conversion rate, high chiral purity, less enzyme dosage, tolerance to high-concentration substrates, low preparation cost and suitability for industrial production, avoids chiral resolution and heavy metal residues in products, and makes up for the defects of chemical methods.

This application provides a method for separating modified hyaluronic acid oligosaccharides. The method includes the following steps: separating the modified hyaluronic acid oligosaccharides using liquid chromatography-mass spectrometry (LC-MS), wherein the LC-MS uses a porous graphitized carbon column, with gradient elution using mobile phase A and mobile phase B. Mobile phase A is an aqueous solution of ammonium formate or ammonium acetate, and mobile phase B is an aqueous solution of ammonium formate or ammonium acetate in acetonitrile. This separation method can effectively separate various modified hyaluronic acid oligosaccharides, providing support for further structural identification of these modified hyaluronic acid oligosaccharides.

The application discloses a method for detecting a fingerprint of non-volatile components of a composition for removing swelling and relieving pain, wherein the fingerprint is obtained by using a high performance liquid chromatograph, and high performance liquid chromatography conditions are as follows: a chromatographic column is a C18 chromatographic column; a detector is an evaporative light scattering detector; a mobile phase is as follows: a mobile phase A is methanol, a mobile phase B is a 0.1% ammonium formate-0.01% triethylamine aqueous solution, gradient elution is adopted, and the proportion of the mobile phase is all volume percentage; and an elution procedure is as follows: 0-30 min, the mobile phase A is 10% to 95%, and the mobile phase B is 90% to 5%. Finally, a fingerprint with 11 common peaks is established.