1133 results about "Chromatography gas" 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 and a system for measuring fragrance components of essence, and relates to the technical field of essence quality identification, and the method comprises the following steps: S1, constructing a liquid chromatography-gas chromatography-supercritical fluid chromatography multi-dimensional combined analysis system, the system comprises a liquid chromatography system, a gas chromatography system and a supercritical fluid chromatography system which are connected in sequence, and S2, carrying out separation detection on essence samples from different sources or formulas by using the liquid chromatography-gas chromatography-supercritical fluid chromatography multi-dimensional combined analysis system to obtain multi-dimensional chromatographic data containing volatile and non-volatile components. According to the present invention, with the liquid chromatography-gas chromatography-supercritical fluid chromatography multi-dimensional combined analysis system, the separation problem of the aroma components with similar structures can be effectively solved, and compared with the traditional technology, the separation degree is significantly improved, and the volatile and non-volatile component information in the essence can be completely obtained.

The invention discloses a method for detecting organic carbon components in soil based on gas chromatography-mass spectrometry, and particularly relates to the technical field of soil detection. The method comprises the following steps: pretreating fresh soil to obtain a fresh soil sample and an air-dried soil sample, respectively extracting organic carbon components to obtain a DOC extracting solution and an LOC extracting solution, and sequentially and respectively carrying out purification treatment, concentration treatment and derivatization on the DOC extracting solution and the LOC extracting solution to obtain a DOC to-be-detected solution and an LOC to-be-detected solution; respectively detecting the DOC to-be-detected liquid and the LOC to-be-detected liquid in a GC-MS instrument to obtain a total ion flow chromatogram, and carrying out qualitative and quantitative analysis to obtain organic carbon component data. Through step-by-step extraction, selective derivatization and GC-MS accurate analysis, molecular level separation, identification and quantification of water-soluble organic carbon DOC and oxidizable organic carbon LOC in soil are achieved, the method is particularly suitable for evaluating contribution of carbohydrate, amino acid and organic acid to the carbon turnover rate, and the method is good in selectivity and high in sensitivity.

The invention relates to a carbon capture absorbent degradation performance evaluation method and a determination device, the method comprises the following steps: accelerating aging degradation of a to-be-detected sample under high pressure oxygen and heating conditions, simulating the oxidation process of an absorbent in long-term operation, and shortening the experimental period; in the test process, the pressure and temperature of the reaction kettle are automatically collected, a pressure-time curve is established, and the degradation resistance of the sample is comprehensively judged according to the pressure drop rate and inflection point time. The method for evaluating the degradation performance of the carbon capture absorbent can be used for rapidly and comprehensively evaluating the sample, and meanwhile, the degradation degree can be analyzed and judged without the help of high-end equipment such as cation chromatography and gas chromatography, so that the method is convenient and efficient; the method is particularly suitable for testing and optimizing the oxidation resistance of novel absorbents such as composite absorbents and phase change absorbents.

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.

The invention provides an analysis method for high-throughput evaluation of tobacco nicotine synthesis capability, and belongs to the technical field of nicotine synthesis capability analys.The analysis method comprises the steps that tobacco seeds are disinfected, germinated and cultured for 14 days to obtain seedlings, the seedlings are transferred to a control medium and an induction medium added with 3 [mu] M of methyl jasmonate to be cultured for 15 days, and the seedlings are obtained; the method comprises the following steps: removing water from an overground part for 15 minutes at 105 DEG C, drying at 65 DEG C until the weight is constant, grinding the overground part into powder, adding a NaOH solution and ethyl acetate containing an internal standard, carrying out vortex mixing uniformly, carrying out ultrasonication for 15 minutes, taking supernate, filtering to obtain sample extract liquor, inputting peak area data into an intelligent prediction model based on a hierarchical weight mechanism, and processing to obtain prediction correction data, the nicotine concentration of a sample is calculated by combining gas chromatography detection with a standard curve, the concentration is corrected by utilizing predicted correction data, finally, nicotine content data is calculated according to the corrected concentration and the dry weight of the sample, and high-precision evaluation of the tobacco nicotine synthesis capability is realized.

The invention provides a method for detecting micron and nano plastics in soil or sediments and related application. The detection method comprises the following steps: providing a soil or sediment sample to be detected; the method comprises the following steps: pretreating a to-be-detected soil or sediment sample to obtain a to-be-detected solution; performing multi-stage filtration treatment on the solution to be detected to obtain micro-plastic particles in a plurality of particle size intervals; wherein the plurality of particle size intervals comprise a first particle size interval, a second particle size interval and a third particle size interval; the particle size of the first particle size interval is 1-5000 [mu] m; the particle size of the second particle size interval is 220-1000 nm; the particle size of the third particle size interval is 10-220nm; and performing quantitative analysis on the micro-plastic particles in the plurality of particle size intervals through pyrolysis-gas chromatography / mass spectrometry to obtain the mass concentration of the micro-plastic particles in the plurality of particle size intervals. The problem that the risk assessment of micron and nano plastics is not accurate enough at present can be solved to a certain extent.

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 discloses a food safety monitoring system and a monitoring method thereof, and relates to the technical field of food safety monitoring, and the method comprises the following steps: building a sealing integrity real-time acoustic monitoring link, obtaining an acoustic signal generated by trace leakage through a phase locking algorithm, and building a pressure differential matrix based on the acoustic signal; and inputting the pressure differential matrix into a constructed gas chromatography digital twinborn model, deducing a dynamic evolution process of a carrier gas flow field, and extracting an instantaneous flow velocity critical threshold under the current working condition. According to the invention, real-time prediction and regulation of gas chromatography flow velocity disturbance are realized through acoustic monitoring and digital twinborn modeling, magnetic fluid adjustment and temperature compensation are combined, retention time drift is inhibited, and detection stability and robustness are improved. Meanwhile, a self-adaptive peak position tracking and dynamic window adjusting mechanism is introduced, a chromatographic peak position is accurately recognized, errors are fed back to a front-end sensing link, a closed-loop optimization process is constructed, and the accuracy and reliability of food additive detection are guaranteed.

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.

A method for quality control checking a gas chromatography apparatus at a rig site, the GC apparatus including at least a main column and a makeup flow line in fluid communication with a detector manifold. The GC apparatus measures a first chromatogram of a gas sample with a first makeup gas flow rate and a second chromatogram of the gas sample with a second makeup gas flow rate, wherein the second makeup gas flow rate is greater than the first makeup gas flow rate. The elution times of at least one common peak in the first and second chromatograms are compared to indicate a leak or an obstruction in the makeup flow line or the detector manifold.

The invention discloses a method for determining volatile organic compounds in surface water by purging and trapping and gas chromatography-mass spectrometry, which comprises the following steps: acquiring mass spectrometry data of volatile organic compounds in a surface water sample, and separating and detecting a multi-component mixture in a complex matrix by gas chromatography-mass spectrometry, obtaining an original data set containing retention time and mass spectrum information; according to an output result of the classification model, carrying out qualitative analysis on unknown compounds in a to-be-detected sample, and if the classification probability is greater than a preset threshold value, determining the types of the compounds to obtain an accurate qualitative recognition result; and establishing a concentration standard curve by adopting a corresponding quantitative ion peak area according to a target compound confirmed in the qualitative identification result, and calculating a linear relation parameter between the peak area and the concentration to obtain a regression equation for quantitative analysis.

The invention mainly relates to the technical field of spectral analysis, and provides a white spirit brewing spectral analysis method and system based on a multi-modal large language model in order to efficiently and accurately obtain white spirit brewing information according to multi-modal spectral data of all links of white spirit brewing. The method is characterized by comprising the following steps of: collecting multi-mode spectrum data including gas chromatography data, infrared spectrum data and Raman spectrum data in each link of white spirit brewing; converting the multi-modal spectral data and the natural language instruction into a feature embedding vector which can be recognized by a large language model to train the large language model which is finely adjusted based on professional knowledge in the field of white spirit, and receiving a question of a user in a natural language instruction form by the trained large language model; wine making analysis tasks such as flavor compound identification, key microorganism detection, fermentation state evaluation and base wine quality grading are carried out, and finally analysis results and wine making process optimization suggestions are output in a natural language form, so that the accuracy and efficiency of spectrum data interpretation in the white wine making process are improved.

The invention discloses a method for detecting 18 phthalic acid ester substances in brewed sauce, which specifically comprises the following steps: step 1, obtaining a sample of the brewed sauce to be detected, adding a phthalic acid ester substance internal standard working solution containing deuterated isotope and water, uniformly mixing, adding sodium chloride and acetonitrile, continuously uniformly mixing, and detecting the content of the phthalic acid ester substances in the brewed sauce to be detected; carrying out ultrasonic extraction treatment for 5-15 minutes, adding an ultrasonic extracting solution into a mixture of PSA, C18 and MgSO4, and carrying out centrifugal treatment to obtain supernate; 2, carrying out nitrogen blowing on the supernate until the supernate is nearly dry, and fixing the volume by using normal hexane to obtain a sample to be detected; and step 3, detecting by adopting a gas chromatography-tandem mass spectrometer isotope internal standard method.

The invention discloses an analysis method for simultaneously detecting organochlorine pesticide and polychlorinated biphenyl, which comprises the following steps of: simultaneously extracting organochlorine pesticide and polychlorinated biphenyl in a water sample by adopting a mixed extraction solvent, dehydrating, concentrating and fixing the volume of extract liquor, separating and measuring by adopting a gas chromatography-mass spectrometry method, and quantifying by adopting an internal standard method. When the mixed extraction solvent is n-hexane / dichloromethane with the volume ratio of 9: 1 and 1% by mass of polyethylene glycol 4000 is added, the recovery rates of water samples with the measured concentrations of 5.00 ng / L, 20.0 ng / L, 40.0 ng / L and 80.0 ng / L are 83.6%-95.4%, 91.2%-105.6%, 93.5%-104.7% and 92.8%-106.9% respectively, the relative standard deviations are 6.1%-9.2%, 3.3%-8.2%, 3.2%-6.3% and 3.4%-7.5% respectively, compared with the prior art, the extraction efficiency is remarkably improved, and the method has the advantages that the method is simple, the cost is low, and the method is suitable for industrial production. The accuracy and precision of the method completely meet the determination and analysis requirements for measuring complex water samples.

The invention relates to the technical field of analysis and detection, in particular to a method for simulating and detecting micro / nano plastic released by food contact plastic products. The method provided by the invention aims at the blank of the existing food-source micro-plastic detection system, simulative component liquid is collected by simulating the contact between food components and food plastic products, micro-nano plastics are separated through a 1m filter membrane, and micro-sized plastics on the filter membrane are qualitatively and quantitatively detected by adopting a microscopic infrared spectrum and a scanning electron microscope. The water sample under the filter membrane is subjected to qualitative and quantitative treatment on the nano-plastic by a thermal cracking-gas chromatography-mass spectrometry combined technology and a nano-particle tracking analyzer, so that programmed comprehensive detection is realized. According to the method, the amount and what kind of micro-nano plastic can be released by the plastic product in a real use chain are more clearly revealed, support is provided for a market supervision system, health and life safety of the masses are guaranteed, and the method has a good application prospect.

The invention provides a method for preparing alkane olefin by catalyzing microalgae pyrolysis through an alkali modified molecular sieve, and belongs to the field of biomass energy utilization. According to the method, the ZSM-5 molecular sieve raw powder is modified by adopting the alkaline solution, so that the pore structure of the ZSM-5 molecular sieve can be improved, the distribution of acidic sites can be optimized, the regulation and control of a microalgae pyrolytic reaction path can be realized under relatively mild conditions, the deoxidation reaction can be promoted, the content of oxygen-containing products can be reduced, and the generation of alkane olefin substances can be promoted; the aromatization reaction strength is reduced, and the selectivity of light hydrocarbons is improved, so that the content of alkanes and olefins in the pyrolysis bio-oil reaches 70% or above, and the quality of the pyrolysis bio-oil is remarkably improved. Results of the embodiment show that the pyrolysis bio-oil provided by the invention is subjected to gas chromatography-mass spectrometry detection, and the alkane-olefin peak area content is greater than 70%.

The invention relates to the technical field of tobacco leaf element analysis, in particular to a detection method for volatile compounds in tobacco leaves and a clustering analysis method for the tobacco leaves. The method for detecting the volatile compounds in the tobacco leaves comprises the following steps: drying and pulverizing tobacco leaves to be detected to prepare sample powder of the tobacco leaves to be detected; extracting the mixed solution of the tobacco leaf sample powder to be detected and the internal standard solution by adopting a headspace solid-phase microextraction method to prepare an extracting solution; carrying out gas chromatography-mass spectrometry detection on the extract liquor; wherein an extraction head used by the headspace solid-phase microextraction method is a divinylbenzene / carbon molecular sieve / polydimethylsiloxane composite coating extraction head, and the parameters of the headspace solid-phase microextraction method are as follows: the extraction temperature is 75-85 DEG C, the extraction time is 45-55 minutes, the desorption time is 4-6 minutes, and the equilibrium time is 3-7 minutes. The method for detecting the volatile compounds in the tobacco leaves, provided by the invention, can effectively separate and analyze the volatile components, and is simple and efficient.

The invention discloses a gas chromatography sampling device and a gas chromatograph, and relates to the technical field of gas chromatographs. The gas chromatography sampling device comprises a supporting frame and further comprises a main lifting device which is fixedly installed on the supporting frame, the telescopic end of the main lifting device is fixedly connected with a supporting column, a rotating disc is rotatably installed on the outer wall of the supporting column, three sets of syringes which are distributed circumferentially are rotatably installed on the rotating disc, and the three sets of syringes are connected with the main lifting device. A switching part for driving the turntable to rotate is arranged on the supporting column; the sample disc is rotationally mounted on the supporting frame through a first vertical shaft, a disc is rotationally mounted on the supporting frame through a second vertical shaft, and a plurality of circular holes are circumferentially distributed in the disc; by means of the sample feeding device, alternate sample feeding work of a plurality of samples can be rapidly achieved, the sample feeding and detecting efficiency of the samples is remarkably improved, the rubber pads used each time in the detecting process can be replaced, and the detecting efficiency and accuracy of the samples are guaranteed.

The invention relates to the technical field of novel material chemical analysis, and discloses a triphenyl phosphate purity standard substance valuing method, which comprises the following steps: filtering, drying, dissolving and sterilizing a triphenyl phosphate sample; a triphenyl phosphate sample is comprehensively analyzed from different angles by comprehensively applying a GC-MS (Gas Chromatography-Mass Spectrometry) technology, an NMR (Nuclear Magnetic Resonance) technology, an infrared spectroscopy, a gas chromatography-flame ionization detector method, a Karl Fischer method and an inductively coupled plasma mass spectrometry, and finally, the purity value of the triphenyl phosphate purity standard substance is calculated by a mass balance method. The method provides a scientific and accurate technical means for quality control and standard formulation of the triphenyl phosphate product, has important practical application value for related industries in the fields of chemical engineering and material science, and is beneficial for improving the product quality and promoting industrial upgrading.

The invention discloses a method for researching a polyolefin resin odor compound based on a headspace-gas chromatography-ion mobility spectrometry technology. The method is specifically implemented according to the following steps: step 1, carrying out headspace-gas chromatography-ion mobility spectrometry detection on polyolefin resin; step 2, extracting signal peaks of volatile compounds of different brands of resin through software LAV to construct a fingerprint spectrum; step 3, carrying out qualitative analysis processing on the signal peak of the area selected in the step 2 through GC-IMS Library Search Software qualitative software, and carrying out qualitative analysis processing on the signal peak of the area selected in the step 2 through GC-IMS Library Search Software qualitative software; step 4, taking the signal intensity of each compound in the odor compound fingerprint as a basis for comparing odor substances of resins with different brands, the GC-IMS technology is applied to odor analysis of related materials such as polyolefin resins with various brands, sample pretreatment is simple, complex pretreatment is not needed, the detection period is short, and the detection accuracy is high. Compared with the prior art, the method has the advantages of high sensitivity, resolution and resolution, and can compare and analyze the difference of odor compounds of different samples through the obtained fingerprint spectrum, carry out visual monitoring, and reduce the difficulty of difference analysis of different samples.

The invention belongs to the technical field of chemical component detection, and particularly relates to a method for detecting residues of 1, 3-dichloro-2-propanol, 2, 3-dichloro-1-propanol and 3-chloro-1, 2-propylene glycol in dihydroxypropyl theophylline. The detection method comprises the following steps: (1) adding a solvent into diprophylline for dilution, and uniformly shaking to prepare a test solution; (2) detecting the liquid to be detected by adopting a gas chromatography-tandem mass spectrometry method, and calculating the content of 1, 3-dichloro-2-propanol, the content of 2, 3-dichloro-1-propanol and the content of 3-chloro-1, 2-propylene glycol in the diprophylline according to an external standard method; the solvent is a mixture of formic acid and DMF (Dimethyl Formamide). The method provided by the invention is good in specificity, high in sensitivity, good in repeatability and high in accuracy, and can be used for simultaneously detecting 1, 3-dichloro-2-propanol, 2, 3-dichloro-1-propanol and 3-chloro-1, 2-propylene glycol in the diprophylline.

The invention belongs to the field of chemical engineering, and relates to a process device and method for continuously synthesizing glycidyl (3-chloro-1, 2-propylene glycol and sodium hydroxide (hereinafter referred to as NaOH) as raw materials). The device comprises a raw material feeding pump, a heat exchanger, a micro-reactor, a delay tube reactor 1, a neutralization micro-reactor and a delay tube reactor 2 which are sequentially in fluid communication through pipelines, the heat exchangers are divided into two groups, one group is used for heat exchange of 3-chloro-1, 2-propylene glycol solution, and the other group is used for heat exchange of alkaline solution. According to the method, a 3-chloro-1, 2-propylene glycol solution and a sodium hydroxide solution (NaOH) are adopted as raw materials, glycidol is continuously prepared through a microchannel reactor, on the basis, an acid-base neutralization reaction can be carried out in situ according to needs to remove redundant alkali, redundant heat generated by the acid-base neutralization reaction is absorbed through a low-temperature material, and energy consumption is reduced; the product is analyzed by gas chromatography, and the generated glycidol does not have hydrolysates or auto-polymerization products, so that the product selectivity is higher.

The invention discloses a Maotai-flavor liquor process category and authenticity identification model construction method, an identification method, an identification device and equipment. The method comprises the following steps: acquiring data of liquor samples; preprocessing the sample data to obtain preprocessed sample data; the preprocessed sample data are input into an initial identification model constructed based on a graph neural network or a partial least square discrimination method, the initial identification model is trained, target identification models are obtained, and the target identification models comprise a gas chromatography identification model, an ion chromatography identification model and / or a three-dimensional fluorescence spectrum identification model. According to the method, multiple analysis technologies such as GC, IC and EEM and a chemometrics modeling analysis module are adopted, analysis results of different technologies are mutually verified, a target identification model with high prediction precision is constructed, and accurate identification of the process category and authenticity of the Maotai-flavor liquor is realized.

The invention discloses a method and system for measuring and calculating volatile organic compounds in exhaust gas discharged by a stationary pollution source, and the method comprises the steps: determining a sampling position and a sampling point of the exhaust gas discharged by the stationary pollution source, collecting the main product yield, main raw material or fuel consumption of a preset enterprise, and building a database; the method comprises the following steps: collecting waste gas through a waste gas sampling device, acquiring a waste gas chromatogram by adopting a mass spectrum detector, acquiring low-molecular-weight components by adopting a flame ionization detector FID, and acquiring volatile organic components; dividing the molecular weight low components into different concentration series, performing gas chromatographic analysis, drawing a working curve, and calculating correlation coefficients of the molecular weight low components of different concentration series and response areas; analyzing other compounds by adopting a mass spectrometric detector, calculating correlation coefficients of other compounds and response areas, calculating the concentration of the volatile organic compounds, and establishing pollution source data according to the database; and carrying out regression analysis by utilizing the database and the volatile organic compound concentration, and outputting a result.

The invention discloses a triphenyl phosphate standard substance structure identification method, and relates to the technical field of fluorine-containing gas emission reduction, and the method comprises the following steps: obtaining a standardized analysis sample through fluorine-containing matrix separation, target substance enrichment and solvation treatment; a multi-dimensional chromatographic system and a heart cutting technology are adopted, and temperature programming optimization is combined to realize separation and purification of a sample; carrying out multi-dimensional structure analysis and confirmation by using gas chromatography-mass spectrometry, infrared spectroscopy and nuclear magnetic resonance technologies; a five-stage progressive identification algorithm is constructed, and systematic identification is realized by combining a confidence evaluation system and a fluorine-containing interference correction technology; establishing a structural integrity verification and purity quantitative evaluation standard, and outputting a standardized identification report; a method applicability database is established through multi-type fluorine-containing environment verification and process condition adaptability testing. The method effectively solves the problem of accurate identification of triphenyl phosphate in a complex fluorine-containing matrix, and realizes effective removal of interference components such as light gas, hydrofluorocarbon, perfluorinated compounds and the like.

The invention relates to the technical field of fish meat source identification, in particular to a method for identifying different sources of fish meat by combining an electronic tongue with HS-SPME-GC / MS. The method comprises the following steps: obtaining a fish meat sample; performing taste detection on the fish meat sample by adopting an electronic tongue to obtain a taste detection result; after the fish meat sample is extracted, volatile odor substance detection is conducted through chromatography and mass spectrometry, volatile odor substances comprise one or more of dimethyl phthalate, nonanal, n-hexyl alcohol, naphthalene, octanol, 1-octylene-3-alcohol and alpha-platylene, and a volatile odor substance detection result is obtained; and identifying the fish meat source in combination with the taste detection result and the volatile odor substance detection result. According to the method, an electronic tongue technology and a headspace solid phase microextraction-gas chromatography-mass spectrometry technology are combined for use, and the taste and the smell are detected at the same time so as to distinguish fish meat from different sources, so that a more reliable quality evaluation system can be established, accurate traceability and grading are supported, and different user requirements are met.

The invention discloses a quality mining and evaluation method of a wolfberry characteristic flavor nourishment, and relates to the technical field of food quality analysis and sensory evaluation, and the method comprises the following steps: S1, carrying out non-targeted analysis on the wolfberry characteristic flavor nourishment by adopting headspace solid phase microextraction in combination with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry, and obtaining original abundance data of the volatile compound. According to the quality mining and evaluation method for the Chinese wolfberry characteristic flavor nourishment, accurate identification and quantitative evaluation of key flavor substances in the Chinese wolfberry characteristic flavor nourishment are realized by establishing a flavor contribution potential index model and combining a dual verification mechanism. According to the method, the limitation that only a single chemical component is concerned or actual sensory experience is ignored is solved, and the accuracy and reliability of flavor component screening are improved by integrating multi-dimensional parameters such as instrument response intensity, human olfaction threshold and matrix release characteristics and through cross validation of a gas chromatography-olfaction technology and a standard substance addition experiment.

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 discloses a method and a device for monitoring the stability of an anaerobic digestion system in real time. The method comprises the following steps: 1, carrying out non-targeted metabonomics analysis on the anaerobic digestion mVOCs category by adopting headspace solid-phase microextraction in combination with gas chromatography-high resolution mass spectrometry; 2, screening differential mVOCs markers based on principal component analysis and orthogonal partial least squares discriminant analysis; and 3, constructing a system stability real-time monitoring system by using an electronic nose sensor array, and when the difference mVOCs marker concentration deviates from a threshold value or difference categories are continuously accumulated, triggering early warning and recommending an optimization strategy by the system. The method and the device can monitor the state of the anaerobic reactor in real time, early warn the methane production inhibition risk in advance compared with traditional parameters (pH, volatile fatty acid and the like), improve the biogas yield and reduce the operation and maintenance cost, are suitable for intelligent management of anaerobic digestion scenes of kitchen garbage, municipal sludge, agricultural waste and the like, and can also be expanded to other anaerobic biological fermentation fields.