89 results about "Vapor phase chromatography" patented technology

The invention belongs to the technical field of pharmaceutical analysis, and discloses a method for determining two potential genotoxic impurities in carbon [13C]-urea by gas chromatography. Comprising the following steps: (1) preparing a sample solution; (2) preparing a reference solution; (3) taking nitrogen as carrier gas, and detecting by adopting a medium-polarity or weak-polarity chromatographic column separation system; and (4) calculating by a peak area through an external standard method to obtain the accurate contents of methyl carbamate and ethyl carbamate in the carbon [13C]-urea. The method disclosed by the invention is simple to operate, good in specificity, linearity, precision and accuracy and high in sensitivity, and can realize accurate detection of residual potential genotoxic impurities, namely methyl carbamate and ethyl carbamate, in the carbon [13C]-urea.

The invention relates to a qualitative and quantitative detection method for difluoroethylene carbonate in electrolyte, which comprises the following steps: preparing a plurality of DFEC standard solutions, selecting a chromatographic column, setting test parameters of a gas chromatograph-mass spectrometer, and detecting the prepared DFEC standard solutions. Determining a standard curve, a detection limit and a quantitation limit according to the concentration of the standard solution and the detected peak area, and forming a standard curve equation according to the standard curve; detecting the pretreated to-be-detected electrolyte to obtain the peak area of the to-be-detected electrolyte, and searching according to the standard curve to obtain the concentration of the DFEC in the to-be-detected electrolyte, or calculating according to a standard curve equation to obtain the concentration of the DFEC; according to the method disclosed by the invention, high-sensitivity and high-selectivity detection on trace DFEC in the electrolyte is realized through the synergistic effect of the gas chromatography and the mass spectrum and setting of specific test parameters.

This invention relates to a bag-film laminate comprising a base layer, a gas barrier layer, and a sealant layer sequentially laminated together, wherein the amount of lubricant present on the surface of the sealant layer is 5 mg / m³. 2 Up to 25 mg / m 2 The surface roughness (Ra) of the sealant layer is 0.1 μm to 0.5 μm. The amount of lubricant is obtained by cutting the bag-film assembly into 100 mm × 100 mm sections in the MD direction and TD direction, dropping 5 ml of chloroform onto the surface of the sealant layer of the bag-film assembly and letting it stand for 1 minute to prepare a lubricant extraction solution, and then using gas chromatography to measure the amount of lubricant contained in the lubricant extraction solution.

The present application relates to a surfactant composition containing an alkyl hydroxy ether acetate (A) represented by the following general formula (1) and a compound (I) detected between retention time 10 minutes and 17 minutes in a gas chromatography using petroleum ether in conformity with JIS K8593, the ratio of the peak area of the compound (I) to the peak area of the petroleum ether determined by the gas chromatography being 0.02% to 50%.R 1 -CH(OH)-CH2-OCH2COOM 1 (1) [In the general formula (1), R 1 represents an alkyl group having 8 to 12 carbon atoms, M 1 represents a hydrogen atom, a sodium atom, a potassium atom or triethanolammonium.]

The invention belongs to the field of nicotine content testing, and particularly relates to an electronic cigarette cartridge and a method for detecting the nicotine content in electronic cigarette liquid. The detection method comprises the following steps: (1) preparing a series of standard working solutions containing a solvent and nicotine with different contents, taking a Raman intensity ratio of a nicotine characteristic peak to a solvent characteristic peak as a relative Raman intensity, carrying out linear fitting on the relative Raman intensity and a nicotine concentration, and establishing a standard curve; and (2) on the premise of not breaking the electronic cigarette cartridge, directly carrying out Raman spectrum test on the electronic cigarette liquid in the electronic cigarette cartridge, and quantifying the nicotine content of the electronic cigarette liquid according to the standard curve. According to the method, nondestructive testing is carried out on the premise that the electronic cigarette cartridge is not broken, the consistency with the detection result of a GB41701-2022 gas chromatography method is good, and it is indicated that the method can meet the actual detection result requirement in the aspect of the detection result accuracy.

The invention relates to a method for determining haloacetic acid in different water qualities through liquid-liquid extraction derivative gas chromatography, and belongs to the technical field of water quality analysis and detection.According to the method, at least one gas chromatograph, a sampling bottle with a plug, an extraction bottle with a plug, a derivative bottle with a plug, a microsyringe, a vortex oscillator and a heating block are used for determination of the method, the method mainly comprises the test steps of water sample collection, water sample extraction, water sample derivation, water sample determination and optimization detection, wherein optimization items mainly comprise a strong electrolyte, a volume ratio of sulfuric acid to methanol, instrument working conditions and the like. The method realizes detection of haloacetic acid in different water qualities, is high in sensitivity, good in accuracy and high in precision, and is suitable for drinking water, seawater, lake water, industrial wastewater and the like.

The invention discloses a rapid detection method for fatty acid composition in walnut oil, and relates to the field of edible vegetable oil quality analysis, and the rapid detection method comprises the following steps: preparing a sample set of walnut oil samples, and determining a reference true value of fatty acid in the walnut oil samples by adopting a gas chromatographic method; carrying out spectrum scanning on the walnut oil sample by using a Fourier transform near-infrared spectrometer to obtain an original spectrum, and carrying out standard normal variable transform and detrending and first-order derivative series pretreatment on the original spectrum to obtain a pretreated spectrum matrix; and associating the preprocessed spectrum matrix with the reference truth value, and screening a characteristic wavelength variable subset and optimizing a main factor number for each target fatty acid by adopting a partial least squares regression algorithm. According to the method, the quality judgment report is output by comparing the product quality standard, so that the problems that the traditional gas chromatography is complicated in pretreatment, long in time consumption and incapable of meeting the real-time quality control requirement of a production line are effectively solved.

The invention discloses a method for detecting the content of methanol in histidine, which adopts headspace sampling-gas chromatography and comprises the following steps: preparing a reference solution; preparing a test solution; performing chromatographic analysis; and measuring and calculating. According to the gas chromatography determination method for the methanol content in the histidine, high-sensitivity and high-accuracy detection of methanol residues in the histidine is realized by adopting a headspace sampling mode and combining with optimized chromatographic conditions. The method is high in specificity, wide in linear range, good in repeatability, excellent in durability and suitable for conventional detection of methanol residues in drug quality control.

The application provides a kind of acid oxime ratio analysis method of solvent rearrangement reaction product in caprolactam production process, comprising the following steps: S1, the content of sulfuric acid in solvent rearrangement reaction product is detected by potentiometric titration;S2, mixed extraction is carried out with extraction solvent and solvent rearrangement reaction product, the inert organic solvent content in extraction phase is determined by gas chromatography;The inert organic solvent content in water phase is determined by gas chromatography;S3, the acid oxime ratio of solvent rearrangement reaction product is calculated.The application carries out extraction using extraction solvent, extracts organic phase into extraction solvent, then tests the inert solvent content in extraction phase, the interference of inert solvent is excluded when acid oxime ratio is analyzed, the result is more accurate, which is beneficial to control rearrangement effective conversion rate, accurately evaluate rearrangement effect, facilitate process condition adjustment, and provide guidance basis for production.

The application belongs to the technical field of quality detection of traditional Chinese medicine preparation, and provides a method for establishing volatile / liposoluble component fingerprint spectrum of Xinnaoning capsules. The method comprises establishing volatile component fingerprint spectrum of Xinnaoning capsules and establishing liposoluble component fingerprint spectrum of Xinnaoning capsules, and is to take Xinnaoning capsule drug preparation as a detection object, and to establish a fingerprint spectrum method for the drug preparation by using gas chromatography and mass spectrometry. The method for establishing volatile / liposoluble component fingerprint spectrum of Xinnaoning capsules has the advantages of high stability, high precision and good repeatability. Moreover, the method can evaluate the similarity of liposoluble compounds of Xinnaoning capsules, and provide technical support for realizing more comprehensive and effective control of product quality.

This isocyanate composition contains: bis(isocyanatomethyl)bicyclo[2.2.1]heptane; and a specific compound having a molecular weight of 189, which is detected separately from bis(isocyanatomethyl)bicyclo[2.2.1]heptane by gas chromatography.

The invention discloses an analysis method for determining halogenated alkane impurities in tigliptin hydrobromide, and relates to the technical field of quality analysis. In order to solve the problem of detection of halogenated alkane impurities in tigliptin hydrobromide, the invention provides a convenient, efficient and accurate detection method. The method comprises the following steps: preparing a test solution and an impurity reference solution, and detecting by adopting a gas chromatographic method; the method can be used for accurately determining the content of halogenated alkane in tigliptin hydrobromide, plays a guiding role in development of a synthesis process, and contributes to establishment of quality standards of tigliptin hydrobromide bulk drugs.

The invention relates to the field of analytical chemistry, and particularly discloses a method for determining residual solvents N, N-dimethylformamide, dichloromethane, isopropanol, ethyl acetate, methyl tert-butyl ether, ethanol, acetone, tetrahydrofuran and ethylene glycol dimethyl ether in a litamilast raw material by adopting a headspace-gas chromatography method, and a method for determining residual solvents N, N-dimethylformamide, dichloromethane, isopropanol, ethyl acetate, methyl tert-butyl ether, ethanol, acetone, tetrahydrofuran and ethylene glycol dimethyl ether in a litamilast raw material by adopting a headspace-gas chromatography method. The method comprises the following steps of: detecting by using a capillary column with 6 percent of cyanopropyl phenyl-94 percent of dimethyl polysiloxane as a stationary liquid through headspace sample introduction gas chromatography and a flame ionization detector (FID). According to the method disclosed by the invention, nine residual solvents contained in the litamilast raw material can be completely separated in one system, the separation degree is greater than 1.5, the specificity is good, interference from blank solvents and other unknown impurities is avoided, the sensitivity is high, the detection accuracy is high, and the quality of litamilast can be effectively controlled.

The invention provides a method for detecting methyl lactate in a sodium lactate solution, a gas chromatography is combined with a headspace sampling technology, and chromatographic conditions are as follows: a chromatographic column is a capillary column taking polyethylene glycol or a compound with similar polarity as a stationary liquid; a sample inlet is 180 DEG C, and headspace sample injection is performed; a flame ionization detector is adopted, and the temperature is 230 DEG C; the carrier gas is nitrogen, the flow velocity is 2.0 ml / min, and the split ratio is 10: 1; the column temperature program is as follows: 35 DEG C is maintained for 3 minutes, the temperature is raised to 90 DEG C at 5 DEG C / min and maintained for 3 minutes, and then the temperature is raised to 200 DEG C at 15 DEG C / min and maintained Headspace conditions are as follows: the balance temperature of a headspace bottle is 90 DEG C, and the time is 30 minutes; a quantitative loop is 100 DEG C; the temperature of the transmission line is 110 DEG C; the circulation time is 40 minutes. The method can accurately and quantitatively detect methyl lactate, is convenient to operate, and has great significance in improving the quality control level of the sodium lactate solution, guaranteeing the application safety of the sodium lactate solution in the fields of medicines and foods and perfecting a quality standard system.

The invention discloses a method for rapidly detecting petroleum hydrocarbon in soil based on visible-near infrared spectroscopy. The method comprises the following steps: preparing standard samples with the concentration gradient of 0-3000 mg / kg, and establishing a spectrum database; preprocessing the spectral data by adopting Savitzky-Golay filtering and standard normal variable transformation; using a competitive self-adaptive reweighted sampling algorithm to optimize the characteristic wavelength, and constructing a partial least square regression quantitative model; and determining the optimal performance of the CARS algorithm by comparing three feature selection methods of full spectrum, BOSS and CARS, and the like. According to the present invention, the petroleum hydrocarbon content in the soil can be accurately, rapidly and quantitatively detected, the standard detection process is established, the gas chromatography is adopted to carry out comparison verification on the standard sample, the correlation coefficient of the two methods achieves 0.9988, the average relative error is 5.28%, and the accuracy and the reliability of the spectrum detection method are verified.

The invention relates to the field of chemical analysis, in particular to a method for detecting the content of vinyl acetate by headspace-gas chromatography. The invention relates to a method for detecting the content of vinyl acetate by headspace-gas chromatography, which comprises the following steps: 1) solution preparation: accurately weighing an internal standard substance, diluting with a solvent to obtain an internal standard stock solution, taking a plurality of headspace bottles, respectively adding vinyl acetate standard stock solutions with different volumes to prepare a standard series solution, weighing samples in the headspace bottles, and measuring the content of the internal standard substance in the headspace bottles; adding a solvent and an internal standard solution, and adding anhydrous sodium sulfate; 2, headspace sample injection analysis: sealing the headspace bottle, putting the headspace bottle into a sample disc of a headspace automatic sampler, setting headspace and gas chromatography parameters, and operating the headspace and gas chromatography parameters. The method integrates automatic headspace sampling, internal standard quantification, matrix effect elimination, chromatographic analysis optimization and other technologies, has extremely high accuracy and reliability, and also has excellent sensitivity and wide detection range.

The invention relates to the technical field of protease mutation, and discloses a bisabolol synthase mutant with high catalytic activity and application of the bisabolol synthase mutant. According to the method, alpha-bisabolol synthase derived from compositae herbaceous plant globe artichoke is taken as wild enzyme, mutants are virtually screened by applying a protein language model SaProt, a deep learning model Catapro and a protein stability prediction tool Dynaamt, and the effect of producing bisabolol is verified through experiments; according to the present invention, the mutants obtained by mutation of 11 specific amino acid sites such as D125N, F159Y, F159K, N346D, T372S, Y432F, N346S, D184E, N157E, E374A and T258S are obtained through the mutation of the above 11 specific amino acid sites; wherein through 96-hour shake flask fermentation and gas chromatography detection, the bisabolol yields of the obtained single-point mutation T258S and double-point mutation T258S / F159K are respectively increased by 72.6% and 90.2% compared with the wild type yield; the Kcat / Km value of the two-point mutation T258S / F159K is 4.57 times that of a wild type.

The invention discloses an extraction method of Brassica rapa seed oil, and belongs to the technical field of compound extraction. According to the method, green solvent dimethyl ether (DME) is combined with a response surface method to optimize process parameters (pressure, temperature and time) for extracting the turnip seed oil, fatty acid composition of the obtained turnip seed oil is analyzed through gas chromatography, and saponified matter of the turnip seed oil is prepared and used for follow-up activity and functional evaluation. After optimization, under the conditions that the extraction pressure is 6 MPa, the extraction temperature is 47 DEG C and the extraction time is 83 min, the DME extraction rate (31.72%) of the method is higher than that (30.94%) of Soxhlet extraction of a traditional extraction method. More importantly, rare unsaturated fatty acids such as nervonic acid and the like are effectively retained by lower extraction temperature, and 21 fatty acids are identified by component analysis. The unique fatty acid composition guaranteed by an optimized process is directly associated with the remarkable biological activity of the fatty acid composition. Core advantages of the method in turnip seed oil extraction are proved, and scientific basis and technical support are provided for industrialization of turnip seed oil in the field of cosmetics.

The invention belongs to the technical field of gas detection, and relates to a gas chromatography detection method for enriching insect aggregation pheromones in air by using an ionic liquid composite material, which comprises the following steps: taking an ionic liquid methanol solution as an impregnation liquid, adding an adsorption carrier, impregnating at room temperature, carrying out rotary evaporation to remove methanol, and drying to obtain the ionic liquid composite material, the ionic liquid composite material is used as an adsorbent, and nitrogen is used as carrier gas to activate and remove impurities of the adsorbent; sampling a gas sample by using the activated and impurity-removed adsorbent to obtain a sampling column; and performing thermal desorption on the sampling column, and determining the content of the insect aggregation pheromone in the sampling column by adopting a gas chromatographic method. The ionic liquid composite material is prepared by utilizing the designability of the structural property of the ionic liquid to serve as an adsorbent, selective enrichment of target insect aggregation pheromones with extremely low concentration is realized, and qualitative and quantitative detection of trace insect pheromones in air is realized.

This disclosure provides a vessel and methods for handling high-purity phosphorus fluoride compounds. The vessel can include a phosphorus fluoride component including a phosphorus fluoride compound with a purity of at least 99.9%, as measured by gas chromatography and / or infrared spectroscopy. Also disclosed is a method which includes obtaining a solid component containing a metal fluorophosphate compound and water, heating the solid component to remove water, and further heating to form a phosphorus fluoride compound with a purity of at least 99.9%, as measured by gas chromatography and / or infrared spectroscopy.

This application relates to the field of power equipment testing technology, and in particular to a method and apparatus for detecting the amount of dissolved gas degassing in oil. The method includes: acquiring oil sample information and operating condition information of the corresponding expandable gas collector; determining the pressure change data of the expandable gas collector based on the oil sample information and operating condition information; and calculating the total amount of dissolved gas degassing in the oil sample based on the pressure change data and a preset mapping relationship. This solves the problems of gas chromatography, which is cumbersome to operate, requires highly skilled personnel, has high instrument and consumable costs, and is time-consuming, making real-time monitoring impossible; and vacuum degassing, which requires strict vacuum levels, has high equipment purchase and maintenance costs, poor degassing effect stability, difficulty in guaranteeing detection accuracy, and is prone to oil sample contamination and complex operation.

The application provides a method for preparing adamantane, which comprises: isomerizing tetrahydrodicyclopentadiene in the presence of a mesoporous mordenite molecular sieve catalyst with acid sites established by an organic acid, in the presence of an optional organic solvent, and in a hydrogen-containing atmosphere; and calculating the NH3-TPD peak area of the catalyst by integration, wherein the peak area of the weak acid center of the catalyst is greater than or equal to 330, the peak area of the strong acid center of the catalyst is less than or equal to 282, and the specific surface area of the catalyst is greater than or equal to 300 m 2 / g. In the synthesis of adamantane by the method, the isomerization reaction of adamantane is carried out in the presence of the above catalyst, at a reaction temperature of 250 DEG C, a hydrogen pressure of 1 Mpa, and in a 100-ml stainless steel autoclave. The product composition is analyzed by gas chromatography, and the chromatographic column is an HP-5 capillary column with a column length of 30 m. The purity of adamantane can reach more than 99%.

The application discloses a device for determining gas permeability by gas chromatography, which comprises a test chamber, a shell, a test box, a carrier gas temperature control device, a test gas temperature control device, a first carrier gas pipe, a first test gas pipe, a first molecular sieve, a second molecular sieve, a second carrier gas pipe, a second test gas pipe, a third carrier gas pipe, a third test gas pipe, a fourth carrier gas pipe, a fourth test gas pipe, a carrier gas inlet connecting pipe, a test gas inlet connecting pipe, a carrier gas outlet connecting pipe, a test gas outlet connecting pipe, a fifth carrier gas pipe, a fifth test gas pipe, a sixth carrier gas pipe, a quantitative ring and a gas chromatograph. The device for determining gas permeability by gas chromatography is rationally structured, gas permeability can be determined by gas chromatography, the device is accurate, suitable for various gases, simple and convenient to operate, does not require special professional skills, has high test efficiency, is compact and reasonable in structure, small in size, flexible, convenient to disassemble and assemble and convenient to maintain.

Provided is a thermally expandable microcapsule able to be expanded to a greater degree. The present invention relates to a thermally expandable microcapsule which expands when heated and which has: a shell containing a thermoplastic resin; and a thermal expansion agent housed inside the shell. The shell contains a resin having a carboxyl group and / or a nitrile group. If the expansion initiation temperature is denoted by Ts (ºC) and the temperature at which the displacement in the intensity of a peak that indicates the thermal expansion agent during temperature increase based on the intensity at the start of temperature increase, as measured by gas chromatography, reaches 2% of the maximum intensity of a peak that indicates the thermal expansion agent at 280°C or lower is denoted by Ts_gas(2%), formula 1 is satisfied.　Formula 1: Ts_gas(2%)-Ts≥0ºC

This invention relates to the field of detection and analysis technology, and discloses a pre-column derivatization-liquid chromatography-tandem mass spectrometry (LC-MS / MS) method for the detection of perfluorocarboxylic acids and their substitutes. The highly sensitive and selective method provided by this invention, based on 3-nitrophenylhydrazine pre-column derivatization-LC-MS / MS, achieves good correlation (R0) of nine target analytes (C2-C9 perfluorocarboxylic acids and GenX) within a wide linear range of 0.0001-100 ng / mL. 2 The method has a detection limit as low as 0.83 ng / L and a quantitation limit of 2.76 ng / L, with a sensitivity of 0.83 ng / L for short-chain trifluoroacetic acid, significantly better than traditional gas chromatography. The spiked recoveries in ultrapure water matrix range from 88.2% to 115.7%, with inter-day and intra-day precisions of 0.2% to 17.61% and 3.5% to 16.3%, respectively, demonstrating good accuracy and reproducibility. This method incorporates highly polar short-chain perfluorocarboxylic acids, previously only analyzable by GC-MS, into the LC-MS / MS detection system. It also achieves trace detection of the novel pollutant GenX at the ng / L level, with significantly higher sensitivity than existing methods.

The present application belongs to the technical field of biochemical detection, and discloses a rapid detection method for sodium diacetate in duck blood, which solves the technical problem that the existing detection method cannot accurately detect low content of sodium diacetate in duck blood. The steps are as follows: (1) adding phosphoric acid to sodium diacetate standard solutions with different concentrations to obtain a to-be-detected standard solution; detecting the peak area of the to-be-detected standard solution by gas chromatography, and preparing a standard curve of the concentration of the sodium diacetate standard solution and the peak area; (2) pretreating duck blood samples to obtain a to-be-detected solution; (3) detecting the to-be-detected solution by gas chromatography, and bringing the obtained peak area into the standard curve of step (1) to obtain the concentration of sodium diacetate in the to-be-detected solution. The rapid detection method has a detection limit of 0.007 g / kg, a sample standard addition recovery rate of 92.5-102.4%, good repeatability, a coefficient of variation of less than 10%, and high detection accuracy.

The application provides a squalene fermentation liquor and a method for determining the content of extracted process sample acetone, n-heptane, ethanol and squalene, relates to the field of chemical industry, and specifically comprises the following steps: S1, preparing a test solution: determination of acetone, n-heptane and ethanol: accurately weighing n-propanol and a sample, and shaking to obtain; determination of squalene: accurately weighing squalene and n-propanol in a volumetric flask, adding ethyl acetate to the scale, and shaking to obtain; the test solution is detected by using a gas chromatography method, and the content of acetone, n-heptane, ethanol and squalene is calculated by using an internal standard method; the linear relationship between the theoretical concentration and the detected concentration in the concentration range is investigated, ethanol r=0.999, the average recovery rate is 101%; acetone r=1.000, the average recovery rate is 99%; n-heptane r=1.000, the average recovery rate is 100%; and squalene r=1.000, the average recovery rate is 100%.

The invention provides a method for detecting six isomers of trinitrotoluene, a separation method in the detection method is a gas chromatographic method, a quantitative detector in the detection method is a mass spectrometric detector, and a qualitative method in the detection method is standard sample verification. A chromatographic column in the gas chromatography is a capillary column; the temperature rise mode of a column oven in the gas chromatography is a programmed temperature rise mode. The rapid detection method for the six isomers of trinitrotoluene has the characteristics of good peak presentation, high resolution, strong repeatability and simple and rapid operation, can realize separation and content determination of the six isomers of trinitrotoluene in one step, saves the test cost, is convenient to popularize and has wide application prospects. And effective guarantee is provided for synthesis process monitoring and product quality control of TNT.

This isocyanate composition contains: bis(isocyanatomethyl)bicyclo[2.2.1]heptane; a first specific compound having a molecular weight of 199, which is detected separately from bis(isocyanatomethyl)bicyclo[2.2.1]heptane by gas chromatography; and a second specific compound having a molecular weight of 176, which is detected separately from bis(isocyanatomethyl)bicyclo[2.2.1]heptane and the first specific compound by gas chromatography.

The invention discloses a method for measuring refrigerant ratio by gas chromatography, and belongs to the technical field of refrigerant gas chromatographic analysis. According to the technical scheme, a sampling steel cylinder is used for sampling, a double-valve type steel cylinder or a single-valve type steel cylinder is used for preparing a standard sample, a gas chromatographic method is used for determining the content of R404 series and R507 series refrigerants in a matching mode, chromatographic columns are aluminum oxide capillary columns, detectors are hydrogen flame ionization detectors, and the gas chromatographic method is used for determining the content of R404 series refrigerants and R507 series refrigerants in a matching mode. The used carrier gas is high-purity nitrogen. According to the invention, the defects existing in the existing use standard detection are overcome, and the same gas chromatograph can detect R404 series refrigerants and analyze R507 series refrigerants on the basis of setting parameters, so that accurate detection is realized.