168 results about "Vapor phase chromatography" patented technology

The invention discloses a method and a system for identifying mixed gas in transformer oil, a product and a medium, and relates to the technical field of testing or analyzing materials by means of measuring chemical or physical properties of the materials, and the method comprises the following steps: acquiring an internal structure diagram of a transformer, determining spatial position relations of parts and corresponding temperature distribution characteristics, and obtaining solubility differences of different spatial positions according to the spatial position relations and the corresponding temperature distribution characteristics. During operation, mixed gas concentration data of a plurality of detection points are collected, initial gas concentration data are recorded when an operation threshold range is deviated, and gas concentration change data are corrected according to solubility differences of different temperature zones. Calculating gas concentration space-time distribution characteristics, and determining a gas accumulation area according to the gas concentration space-time distribution characteristics and a space position relation. And separating the mixed gas components by using a gas chromatographic method, comparing preset gas types with the content of each component, and determining the corresponding gas type of each internal region. By implementing the method, the accuracy of identifying the types of the mixed gas in the transformer oil can be improved.

The invention relates to a method for simultaneously detecting three related substances in an olpinapone starting material. According to the detection method, the three related substances in an opinapone starting material are simultaneously detected by using a gas chromatographic method of a hydrogen flame ionization detector. According to the detection method, the problem that three related substances cannot be detected simultaneously due to weak ultraviolet absorption and large difference under the liquid chromatography condition can be solved, the matrix effect generated by an opiapone starting material under the gas chromatography condition can be eliminated, the condition that the separation degree of the three related substances is poor is improved, and the detection accuracy is improved while the detection efficiency is improved. And the true and reliable quality of the initial material of the olpinapone is also ensured. The method can be used for simultaneously and quantitatively detecting three related substances higher than 0.02% in the initial material of the opinapone, and is high in sensitivity, good in separation degree, high in practicability and simple and rapid in detection process.

Methods and systems for carrier gas identification in gas chromatography are described herein. In one aspect, a gas chromatography system can include a pneumatic system including an input flowpath in fluidic communication with a first output flowpath and a second output flowpath; a first flow sensor configured to generate a flow measurement signal corresponding to a first property of a gas; a second flow sensor configured to generate a second flow measurement signal corresponding to a second property of the gas different than the first gas property; and a controller programmed to: determine the first flow measurement signal for the flow of gas through the pneumatic system; determine the second flow measurement signal for the flow of gas through the pneumatic system; and identify a type of gas for the flow of gas through the pneumatic system from the first and second flow measurement signals.

A method for evaluating an unknown gas sample includes acquiring a chromatogram of the unknown gas sample and processing the chromatogram to identify a peak. The peak is evaluated to determine if it is representative of a single gas species in the unknown gas sample. The peak is fit with at least first and second curves when the peak is not representative of a single gas species. First and second areas under the corresponding first and second curves are computed and processed to compute a composition of the unknown gas sample or a ratio of concentrations of individual gases in the unknown gas sample.

Gas chromatography (GC) relies on the interaction of vapor molecules with the stationary phase coated on the column inner wall to separate different vapor molecules. Here, graphene is integrated as the ultrathin and electrically tunable stationary phase within a GC column. Graphene has different interactions with different vapor molecules, which leads to separation of those vapor molecules. In addition, by configuring graphene into a field effect transistor (FET) design, the molecule-graphene interaction can be controlled or tuned by adjusting the graphene Fermi level through the FET gate voltage. As a result, the binding energy between graphene and adsorbed vapor molecules can be tuned and hence the elution time and / or elution order of vapor molecules can be changed.

The invention discloses a method for calculating the molar substitution degree of hydroxyethyl starch by applying a nuclear magnetic resonance carbon spectrum, and belongs to the technical field of analysis and detection. The method comprises the following steps: carrying out nuclear magnetic resonance test on a sample to be detected to obtain a nuclear magnetic resonance 13C spectrum, and determining the molar substitution degree of hydroxyethyl starch according to the peak integral ratio of hydroxyethyl alpha carbon or beta carbon in hydroxyethyl starch glucose to glucose 1-position heterogenous carbon; compared with a traditional Morgan method and a traditional gas chromatography method, the method has the advantages that the operation process is simplified, time and labor are saved, the consumption of experimental consumables and reagents is greatly reduced, the molar substitution degree can be intuitively calculated on the basis of not damaging the structure of a sample, and the method is simpler, more convenient, high in accuracy, simple and convenient to operate and high in detection speed; the method can be used for detecting the molar substitution degree of hydroxyethyl starch.

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 present invention belongs to the technical field of chemical production, and specifically relates to a sample pretreatment method for detecting the carbon content of titanium tetrachloride by high-temperature calcination, which solves the defect in the prior art that all carbon-containing substances cannot be analyzed and added up by infrared spectroscopy and gas chromatography, resulting in the influence on the accuracy of total carbon determination; the technical solution includes: weighing a certain mass of titanium tetrachloride and a Lewis acid, adding the Lewis acid to the titanium tetrachloride, heating and refluxing to precipitate the residual carbon in the titanium tetrachloride, collecting the residual carbon precipitate through a filtering instrument, and cleaning the filtering instrument with a suitable reagent to ensure complete separation of the titanium tetrachloride and the residual carbon. Then, the residual carbon is completely dried and the mass is recorded, and after drying, it is calcined at high temperature until complete and the mass is recorded. The carbon content of the titanium tetrachloride is calculated according to the mass loss before and after calcination and the mass of the weighed titanium tetrachloride.

The invention relates to the technical field of food detection, in particular to a method for determining the iodine content in formula food for special medical purposes. The determination method comprises the following steps: (1) weighing potassium iodide, and adding water for dissolving to obtain a reference substance working solution; (2) adding water into a test sample to obtain a sample suspension, and performing alkali ashing treatment to obtain a sample solution; (3) adding a sulfuric acid solution and a reagent adopted for alkali ashing treatment into the reference substance working solution, and respectively performing derivatization treatment and organic solvent extraction on the reference substance working solution and the sample solution to obtain a reference substance solution and a test solution; (4) testing by adopting a gas chromatographic method, and calculating the iodine content; reagents adopted in the alkali ashing treatment are a potassium hydroxide solution, a potassium nitrate solution and a potassium permanganate solution (or manganese dioxide); the derivatization treatment comprises the steps of adding a sodium sulfite solution, standing, and adding a ketone reagent and a hydrogen peroxide solution to carry out a derivatization reaction. The method has the advantages of being low in cost, high in safety and high in accuracy.

The invention discloses a method for detecting related substances of tribromoacetone by gas chromatography, which belongs to the technical field of chemical detection, the related substances of tribromoacetone are detected by gas chromatography, an instrument is a gas chromatograph, a detector is an FID detector, a capillary column taking 100% methylpolysiloxane (MEGA-1) as a stationary liquid is used as a chromatographic column, carrier gas is N2, the flow velocity is 2.0 mL / min, the split ratio is 50: 1, and the detection time is 30 minutes. Temperature programming: the initial temperature is 80 DEG C, and the temperature is raised to 250 DEG C at the rate of 10 DEG C per minute and maintained for 10 minutes; a sample injection mode is as follows: direct sample injection is performed, the temperature of a sample injection port is 260 DEG C, and the temperature of a detector is 280 DEG C; according to the present invention, the sample introduction volume is 0.2 [mu] l, the related substances in the tribromoacetone can be effectively separated, the content of the related substances can be quantitatively detected, the acetone, the bromoacetone, the 1, 3-dibromoacetone and the 1, 1, 3, 3-tetrabromoacetone sequentially appear peaks, and the method has characteristics of simple operation, strong specificity, good repeatability, good intermediate precision and good durability, and can accurately and rapidly determine the content of the various related substances in the tribromoacetone.

The invention belongs to the technical field of medicine detection, and particularly relates to a method for determining enantiomers in a levocarnitine intermediate by gas chromatography. The method for determining the enantiomer in the levocarnitine intermediate by the gas chromatography comprises the following steps: taking a capillary column which takes dimethyl polysiloxane bonded with cyclodextrin as a stationary liquid as a chromatographic column; the method comprises the following steps: dissolving and diluting a test product (R)-4-chloro-3-hydroxy ethyl butyrate by using ethyl acetate, and deriving by adding acetic anhydride and pyridine to prepare a test product solution; and injecting the test solution into a gas chromatograph, recording a chromatogram, and calculating the content of the enantiomer (S)-4-chloro-3-hydroxybutyric acid ethyl ester in the levocarnitine intermediate (R)-4-chloro-3-hydroxybutyric acid ethyl ester according to an area normalization method. The method for determining the enantiomer in the levocarnitine intermediate by the gas chromatography provided by the invention is accurate and fast in detection, and provides a basis for quality control of levocarnitine.

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.

A working oil composition for shock absorbers, which contains the following components (A) and (B): (A) an ester base oil having a pour point of-45 DEG C or less and a 10% distillation temperature of 300 DEG C or more as determined by the gas chromatography distillation test method specified in JIS K 2254: 1998; and (B) zinc dialkyl dithiophosphate.

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 relates to the technical field of analytical chemistry, in particular to an analytical method of 1, 2, 3-tri (2-cyanoethoxy) propane, which adopts gas chromatography for detection, and adopts a hydrogen flame ionization detector as a detector; the capillary chromatographic column is a weak-polarity column or a medium-polarity column; the temperature of a hydrogen flame ionization detector is 300-350 DEG C; the temperature of a sample inlet is 200-250 DEG C; the column temperature of a capillary gas chromatographic column is firstly set to be 40-80 DEG C, the holding time is 5-10 min, then the temperature is increased to 250-300 DEG C at the speed of 10-15 DEG C / min, and the holding time is 20-30 min; the carrier gas is nitrogen or helium. The analysis method is low in operation cost, the chromatographic column has good thermal stability, the peak shape, the separation degree and the repeatability are better, the accuracy is higher, and the method has the characteristics of rapidness, simplicity, accuracy and the like.

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 discloses a detection method for determining a residual solvent in gastrodin by headspace sampling-gas chromatography. The detection method comprises the following steps: (1) preparing a reference substance solution containing the residual solvent to be detected; (2) preparing a test solution containing gastrodin; and (3) injecting the reference solution and the test solution into a gas chromatograph in a headspace sampling manner, and calculating the content of the residual solvent by peak area according to an external standard method. The diluent is used for preparing a reference substance solution and a test solution, a sample is exposed in a gas phase space in a headspace sampling mode, the response of volatile substances is improved, meanwhile, all volatile low-boiling-point to-be-detected residual solvents are effectively captured and detected in a gradient chromatographic column heating mode, the detection method is simple, and the detection efficiency is high. The method has the advantages of high specificity, high precision and high sensitivity, can simultaneously detect a plurality of residual solvents to be detected, greatly saves the detection time and cost, and is beneficial to improving the quality monitoring effect of gastrodin drugs.

Methods and systems for carrier gas identification in gas chromatography are described herein. In one aspect, a gas chromatography system can include a pneumatic system including an input flowpath in fluidic communication with a first output flowpath and a second output flowpath; a first flow sensor configured to generate a flow measurement signal corresponding to a first property of a gas; a second flow sensor configured to generate a second flow measurement signal corresponding to a second property of the gas different than the first gas property; and a controller programmed to: determine the first flow measurement signal for the flow of gas through the pneumatic system; determine the second flow measurement signal for the flow of gas through the pneumatic system; and identify a type of gas for the flow of gas through the pneumatic system from the first and second flow measurement signals.

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 relates to a method for simultaneously detecting two organic silicon impurities in a ziprasidone hydrochloride intermediate product. According to the detection method, the two organic silicon impurities in the ziprasidone hydrochloride intermediate product are simultaneously detected by using a gas chromatographic method of a hydrogen flame ionization detector. The detection method not only can solve the problem that the two organic silicon impurities cannot be quantified without characteristic ultraviolet absorption under the condition of liquid chromatography, but also can control one of the organic silicon impurities not to be easily degraded and converted into the other organic silicon impurity under the condition of gas phase high temperature, thereby ensuring that the quality of the ziprasidone hydrochloride intermediate product is real and reliable. The method can be used for simultaneously and quantitatively detecting two organic silicon impurities higher than 0.02% in the ziprasidone hydrochloride intermediate product, and is high in sensitivity, good in separation degree, high in practicability and simple and rapid in detection process.

The invention provides a method for detecting the concentration of residual monomers in (methyl) acrylic resin. According to the detection method, the residual monomers in the (methyl) acrylic resin can be accurately, rapidly and effectively separated, and the concentration of the residual monomers can be quantitatively analyzed; according to the detection method, a thermal analyzer is combined with a temperature programmed injection port-gas chromatography (PTV-GC), so that the influence of high-temperature decomposition of the (methyl) acrylic resin on the concentration of the residual monomer can be well reduced within a detection limit range, and a test structure of the concentration of the residual monomer is more accurate and stable.

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 provides a method for determining the content of TAED in washing powder, and belongs to the technical field of washing powder component content detection. According to the invention, acetic acid, deionized water and acetonitrile are used as solvents; the method comprises the following steps: determining the content of TAED in washing powder by adopting a gas chromatographic method, heating by adopting a gradient heating strategy in the determination process, establishing a standard curve by adopting an external standard method, and quantitatively analyzing the determination result by utilizing the TAED standard curve to obtain the content of TAED in a washing powder sample. An acetonitrile-5% acetic acid (v: v = 3: 1) solution is adopted, so that hydrolysis of TAED can be effectively inhibited, more TAED in a sample can be extracted, and meanwhile, the influence of interfering substances in the sample is reduced; a plurality of concentration gradients of TAED standard solutions are used for establishing the standard curve, so that the accuracy and reliability of the result are ensured.

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.