22 results about "Mass chromatography" patented technology

A method of determining an API gravity of a crude oil includes obtaining a reservoir sample containing the crude oil, separating an aromatic fraction from the reservoir sample, analyzing the aromatic fraction using a gas chromatography mass spectrometry (GC-MS) instrument, determining peak areas and a ratio of 4-methyldibenzothiophene and 1-methyldibenzothiophene, and determining the API gravity of the crude oil in the reservoir sample using an empirical correlation between API gravity and the ratio of 4-methyldibenzothiophene to 1-methyldibenzothiophene. A method of determining productivity of a region of a reservoir includes determining an API gravity of a crude oil in the sample from the region of the reservoir using an empirical correlation between API gravity and the ratio of 4-methyldibenzothiophene to 1-methyldibenzothiophene, and based on the API gravity of the sample, determining the productivity of the region of the reservoir.

The invention discloses an FM550 in-vivo enrichment detection method and a risk monitoring method for tilapia, and relates to the technical field of ecological monitoring. The method not only can reflect the actual risk of a flame retardant in the environment, but also can be conveniently applied to aquaculture and ecological risk assessment. The detection method comprises the following steps: obtaining a liver sample and a muscle sample of a target tilapia mossambica, freeze-drying the liver sample and the muscle sample for 72 hours, and crushing and homogenizing 1 g of the liver sample and the muscle sample for later use; the target tilapia mossambica refers to tilapia mossambica which is exposed in an FM550 environment within 56 days; and carrying out solvent extraction, QuEChERS purification treatment and solvent conversion treatment on the crushed and homogenized sample, and then carrying out gas chromatography-mass spectrometry detection to obtain a detection result of FM550 in-vivo enrichment.

The present application belongs to the technical field of organic matter detection, and particularly relates to a method for extracting polycyclic aromatic hydrocarbons and halogenated polycyclic aromatic hydrocarbons by using an adsorption pen, removing water by using a pre-column, and performing gas chromatography mass spectrometry analysis, which comprises the following steps: (1) collecting a sample, placing a water sample in a headspace bottle, and inserting an adsorption pen into the headspace bottle; (2) vacuumizing the adsorption pen; (3) removing the vacuum source, and placing the sample in a shaker for oscillation extraction; (4) removing the adsorption pen, and performing preliminary water removal at low temperature; and (5) installing a pre-column and a chromatographic column II, inserting the adsorption pen into a GC sample inlet for thermal desorption, simultaneously opening a V4 valve, controlling outlet flow at 20-40 ml / min, and controlling the temperature of the pre-column and the chromatographic column II during and after desorption. The present application uses an adsorption pen to extract polycyclic aromatic hydrocarbons and halogenated polycyclic aromatic hydrocarbons in water, removes water by using a pre-column, and performs gas chromatography mass spectrometry analysis, thereby overcoming the problems of large amount of organic solvent, complex operation, poor reproducibility, and water and solvent interference in the adsorption pen extraction technology in the prior art.

The application discloses a seasoning food flavor source discrimination method, device, equipment and medium, and relates to the cross technical field of computer technology and analytical chemistry, and comprises the following steps: performing gas chromatography mass spectrometry on a seasoning food sample to obtain gas chromatography mass spectrometry flavor fingerprint data of the seasoning food; performing data enhancement processing based on the gas chromatography mass spectrometry flavor fingerprint data of the seasoning food to obtain a gas chromatography mass spectrometry flavor fingerprint enhanced data set; and combining the gas chromatography mass spectrometry flavor fingerprint enhanced data set with a flavor source discrimination model to obtain a seasoning food flavor source discrimination result. The application solves the problem of poor data comparability under different detection conditions by time retention calibration, greatly improves the discrimination accuracy by combining model analysis, simplifies the detection process, realizes efficient conversion from samples to results, is suitable for large-scale sample detection, and provides reliable technical support for food quality control and supervision.

The application discloses a method for determining the content of polychlorobenzene and polychlorobutadiene in ambient air, which comprises the following steps: (1) using a composite adsorption tube to adsorb and collect target substances in air, and then pressurizing and sealing the composite adsorption tube after the collection is completed; (2) placing the composite adsorption tube with the adsorbed target substances in a thermal desorption instrument to perform primary thermal desorption, and then introducing the target substances into a gas chromatography mass spectrometry analysis system after secondary focusing by a cold trap for analysis; the target substances are polychlorobenzene and polychlorobutadiene. The method can realize synchronous and accurate qualitative and quantitative analysis of wide-boiling-point chlorine-containing organic substances in a complex environmental matrix.

The invention discloses a VOCs spatial and temporal distribution rule analysis system and method, and relates to the technical field of air pollution detection, and the VOCs spatial and temporal distribution rule analysis method comprises the steps: laying a VOCs monitoring point network; performing multi-period sampling; component analysis is carried out by adopting a pre-concentration-gas chromatography-mass spectrometry technology; constructing a VOCs concentration space distribution model, and generating a space-time distribution map; vOCs component sources are analyzed, and main pollution source types are identified; and constructing a VOCs spatial and temporal distribution characteristic index system. A space point distribution strategy is adopted, and it is ensured that monitoring point position coverage has representativeness; a sampling time sequence and frequency arrangement are optimized, and the accuracy and integrity of component analysis are improved; an optimized spatial interpolation algorithm is introduced, so that the accuracy and reliability of a spatial distribution map are improved; a plurality of source analysis methods are integrated, and limitation of a single model is eliminated through model cross validation.

The invention provides a method for rapidly screening aroma-producing bacillus to improve the quality of cigar tobacco leaves, and belongs to the technical field of agricultural microorganisms. On the basis of bacillus 16S rDNA (ribosomal deoxyribonucleic acid) sequence analysis and fermentation liquor smell evaluation, volatile aroma components of strain fermentation liquor and fermented cigar tobacco powder are analyzed by using HS-SPME-GC-MS (headspace solid-phase microextraction-gas chromatography-mass spectrometry) and an electronic nose, and excellent aroma-producing strains are screened by combining a multivariate analysis method. And the fermentation effect on the cigar tobacco leaves is verified by simulating fermentation. Results show that seven kinds of 50 bacillus strains are identified, and the smell difference of fermentation liquor smell evaluation is large. 177 volatile components are identified in strain fermentation liquor, 7 strains have relatively high aroma producing characteristics, and 2, 3-butanedione, 2-nonyl alcohol and isoamyl alcohol are common aroma components of the strains. Two strains with the highest volatile components and large difference in the fermented tobacco powder are screened out through PCA and clustering analysis, 1-F-2 can generate high-content alcohol, pyrazine, ketone and other components, and DMMJ-4 can generate high-content alcohol, pyridine, ketone and other components. The two strains are used for fermentation, so that the content of volatile aroma components of the cigar tobacco leaves is obviously improved, and the flavor characteristics and the quality characteristics are also improved to different extents. Therefore, the invention can provide reference for screening and application of cigar tobacco leaf microbial fermentation strains.

The application relates to the technical field of analytical chemistry, and specifically discloses a method for detecting microplastics in blood plasma based on a thermal cracking-gas chromatography mass spectrometry combined technique. The method for detecting microplastics in blood plasma disclosed by the application comprises the following steps: (1) pretreatment: uniformly mixing a blood plasma sample with a Tris-HCl solution, reacting at 55-65 DEG C to obtain a cracking solution; then adding a calcium chloride solution and a protease K solution to digest, then shaking after temperature reduction to room temperature, and heating to 55-65 DEG C for heat preservation treatment to obtain a pretreatment solution; vacuum filtration on a glass fiber membrane, elution, and obtaining a sample to be measured; (2) measuring by a thermal cracking-gas chromatography mass spectrometry combined instrument. The method provided by the application solves the problems that the existing blood plasma digestion method destroys microplastics, is easy to damage the instrument and cannot be used for large batch processing, and has good quantitative applicability, and can be accurately and reliably used for quantitative analysis of various microplastics in blood plasma.

This invention discloses a wastewater source tracing detection method based on full two-dimensional gas chromatography-mass spectrometry, belonging to the field of environmental monitoring technology. The method includes: establishing a source-end transformation fingerprint chain library based on the connection relationships between parent peak clusters, associated peak clusters, and transformation peak clusters in the peak cluster families corresponding to the source-end sample sequence; obtaining a receptor peak cluster family table; performing a chain comparison between the source-end transformation fingerprint chain library and the receptor peak cluster family table to determine candidate source peak cluster families and overlapping peak cluster families; performing peak cluster family exclusion stripping to generate a confirmed source portion and a set of residual unexplained peak cluster families; merging the residual unexplained peak cluster family set for unknown sources to form an unknown transformation chain; and combining this with the confirmed source portion to output the wastewater source tracing detection results. This invention improves the completeness, specificity, and interpretability of wastewater source tracing detection results.

The invention discloses a citrus chachiensis hortorum fingerprint as well as a construction method and application thereof, and belongs to the technical field of analysis and detection. The method comprises the following steps: extracting and analyzing volatile components of the citrus chachiensis hortorum by adopting a headspace-gas chromatography-mass spectrometry method, and extracting a mass spectrum of a characteristic compound through unknown substance analysis software, so as to obtain the citrus chachiensis hortorum fingerprint spectrum. The invention also discloses a citrus chachiensis hortorum fingerprint spectrum and application thereof in citrus chachiensis hortorum identification and traceability. According to the citrus chachiensis hortorum fingerprint spectrum, a plurality of volatile substances serve as quality indexes of citrus chachiensis hortorum, and accurate and comprehensive quality control over citrus chachiensis hortorum can be achieved.

The invention discloses a biomimetic fluid-based medical equipment phthalate migration test method, which is characterized by comprising the following steps: (1) taking artificial saliva as a leaching solution; the method comprises the following steps: soaking a to-be-detected medical equipment pipeline sample in a glassware according to the ratio of the sum of the internal area and the external area (cm < 2 >) to the volume (mL) of a leaching solution of 2: 1, and standing for 24 hours at the constant temperature of 37 + / -1 DEG C; (2) transferring a proper amount of the extract liquid into a test tube, then adding n-hexane, fully oscillating for 10 minutes, then centrifuging, sucking an upper-layer n-hexane solution by using a glass dropper, and extracting by using a solid-phase extraction column to obtain an extracting solution; repeating the extraction step twice; (3) mixing the three extracting solutions, evaporating the mixed extracting solutions in a vacuum rotary evaporator until the mixed extracting solutions are nearly dry, and then adding n-hexane to dissolve the mixed extracting solutions to obtain a detection solution; and analyzing the detection liquid by using a gas chromatograph-mass spectrometer, and testing the migration volume of the phthalate.

Systems and methods for an exhaust-free GC-MS interface are described herein. The system may include a gas chromatograph. The system may include a mass spectrometer connected to a gas chromatograph through a mass spectrometer flow path. The system may include an accessory. The fitting may include a sealing surface and one or more gas purge flow paths. The accessory may be fluidly connected to the mass spectrometer. The system may include a post disposed in a ferrule.

The present invention provides a novel alcohol and a derivative thereof, which have higher industrial value than existing petrochemical raw materials and are practical. The retention time of the ethanol in gas chromatography measured by gas chromatography mass spectrometry (GC / MS) has at least one of the following peaks (A)-(D): (A) a peak of 5-25 seconds to 5-35 seconds and two peaks of 2-55-3-5 seconds, (B) a peak of 12-30 seconds to 12-40 seconds, (C) a peak of 6-36 seconds to 6-45 seconds, and (D) a peak of 15-00 seconds to 15-15 seconds.

The invention relates to a magnetic solid-phase extraction method for pyrethroid insecticides in fruits and vegetables based on a Fe3O4-coated CS-coated AA material. The magnetic solid-phase extraction method comprises the following steps: S1, synthesizing a Fe3O4-coated CS-coated AA magnetic adsorbent; s2, preparing a fruit and vegetable sample; s3, magnetic solid phase extraction; s4, determining by using a gas chromatography-mass spectrometry method; fe3O4 nano magnetic particles are embedded in chitosan gel, then acrylic acid is grafted on chitosan molecules for modification, the Fe3O4 CS AA magnetic adsorbent is prepared through glutaraldehyde curing and crosslinking, and based on the fact that the chitosan molecules contain a large number of-OH and-NH2 and-COOH active groups in acrylic acid, the Fe3O4 CS AA magnetic adsorbent and pyrethroid pesticide compounds form intermolecular hydrogen-bond interaction, so that the magnetic adsorbent can be used for adsorbing the pyrethroid pesticide compounds. Therefore, target component extraction is realized, and the method for determining deltamethrin and cyhalothrin pesticide residues in fruits and vegetables by combining magnetic solid-phase extraction with gas chromatography-mass spectrometry is established.

The present application relates to the technical field of microplastic detection, in particular to a method for quantitatively detecting trace polyethylene terephthalate microplastics. In the current research on PET microplastics based on Py-GC / MS, different masses of PET are mostly weighed by a balance to draw a standard curve, and the lowest quantification limit can only reach about 0.6 mu g. The present application combines solvent dissolution method and thermal cracking-gas chromatography mass spectrometry (Py-GCMS) technology, discloses a high-sensitivity and high-precision trace PET microplastic detection technology, reduces the quantification limit of PET microplastics from 0.6 mu g to 10 ng, shows the excellent sensitivity and potential of Py-GC / MS method in PET detection, and provides an effective analysis method for environmental tracking and monitoring of microplastic pollution.

The invention relates to a radix puerariae quality evaluation method combining multi-index quantification with an entropy weight method-TOPSIS method, which comprises the following steps: an extraction process: crushing a radix puerariae raw material, optimizing parameters such as an extraction method, an extraction solvent, extraction time and the like, and obtaining a radix puerariae extract by adopting an optimal extraction process; compound detection: optimizing mass spectrum and chromatographic parameters by adopting an ultra-high performance liquid chromatography-high resolution mass spectrometer to realize qualitative and quantitative analysis; and quality evaluation: taking the detected compound content data as a quality evaluation index, determining the weight of each quality evaluation index by using an entropy weight method, calculating the distance from each quality evaluation index to the optimal scheme and the distance from each quality evaluation index to the worst scheme based on a TOPSIS method, and obtaining the relative closeness degree of the kudzu vine roots from different producing areas to the optimal scheme as the basis of quality evaluation. By applying the method, the quality evaluation of the radix puerariae from different producing areas is realized, the data information of each quality evaluation index is fully utilized, the quality difference of different radix puerariae is accurately reflected, and the influence of subjective factors is avoided.

The invention provides a method for synchronously detecting 19 organochlorine pesticides in water based on solid phase extraction-gas chromatography-mass spectrometry, which comprises the following steps: preparing a standard solution containing 19 organochlorine pesticides and an internal standard substance, adopting a C18 solid phase extraction column, loading the standard solution, eluting a target substance adsorbed on the solid phase extraction column by using a dichloromethane / acetone eluent, and detecting the content of the 19 organochlorine pesticides. The method comprises the following steps: collecting an eluent, dissolving with n-hexane to a constant volume to obtain a to-be-detected standard solution, feeding the sample into a gas chromatography-mass spectrometer, reading response values of each target as a longitudinal axis, establishing a standard curve by taking the concentration of the standard solution as a horizontal axis, performing solid-phase extraction on a to-be-detected water sample by using the same method, performing gas chromatography-mass spectrometry detection, reading the response values of each target, and determining the concentration of the to-be-detected water sample according to the standard curve. And reading the corresponding concentration value on the working curve. The organochlorine pesticide detection method disclosed by the invention has the advantages of high recovery rate, high sensitivity, simplicity and convenience in operation and environmental friendliness, can realize simultaneous analysis of various organochlorine pesticides in a water sample, and has stable recovery rate and excellent linear variation.

Systems and methods for a ventless GC-MS interface are described herein. The system can include a gas chromatograph. The system can include a mass spectrometer connected to the gas chromatograph by a mass spectrometer flow path. The system can include a fitting. The fitting can include a sealing surface and one or more gas purge flow paths. The fitting can be fluidically connected to the mass spectrometer. The system can include a column disposed in a ferrule.

The application discloses a kind of detection methods of N-dimethyl nitrosamine in meat product, comprising: step one, cut piece of meat product, put into soaking liquid and soak, ultrasonic oscillation, clean with clean water;Step two, the meat block is crushed, add acetonitrile, anhydrous magnesium sulfate, n-hexane, drop 0.1% glacial acetic acid, ultrasonic oscillation, stand, liquid separation, take acetonitrile layer, repeat 1-3 times, combine acetonitrile layer, add extractant again, ultrasonic oscillation, centrifugal, obtain filtrate;Step three, take solid-phase extraction column activation, sample filter liquor, elution, nitrogen blowing, redissolve, filter, obtain sample to be measured;Step four, the sample to be measured is carried out qualitative and quantitative detection using gas chromatography mass spectrometry, and the content of N-dimethyl nitrosamine is obtained.The application detects N-dimethyl nitrosamine by removing grease and residual components after pretreatment of meat product, with high accuracy and precision.

This invention relates to a non-targeted identification method for mycotoxin metabolites in wine based on mass spectrometry coupled with chromatography, specifically for the detection and identification of ochratoxin A and its metabolites in wine. Through sample pretreatment, chromatographic separation, mass spectrometry detection, data screening, and fragment ion confirmation of wine samples, non-targeted detection of ochratoxin A and its metabolites can be achieved without relying on standards. In the sample pretreatment stage, the target analyte is extracted using acidified acetonitrile solution, and impurities are removed by salting out and centrifugation. Separation of ochratoxin A and its metabolites is achieved by coupling high-performance liquid chromatography with time-of-flight mass spectrometry using a reversed-phase C18 column for gradient elution. The mass spectrometry analysis uses full-scan mode and alternates between positive and negative ion modes to ensure high resolution and high sensitivity, making it suitable for the detection of mycotoxins in wine and other foods, meeting food safety regulatory requirements.

The application discloses a VOCs space-time distribution rule analysis system and method, relates to the technical field of air pollution detection, and comprises the following steps: deploying a VOCs monitoring point network; performing multi-time period sampling; adopting a pre-concentration-gas chromatography mass spectrometry combined technology to perform component analysis; constructing a VOCs concentration space distribution model to generate a space-time distribution atlas; analyzing VOCs component sources to identify main pollution source types; and constructing a VOCs space-time distribution characteristic index system. The application adopts a space point arrangement strategy to ensure that the monitoring points are representative. The sampling time sequence and frequency arrangement are optimized to improve the accuracy and integrity of component analysis. An optimized space interpolation algorithm is introduced to improve the accuracy and reliability of the space-time distribution atlas. Multiple source analysis methods are integrated to eliminate the limitations of a single model through model cross verification.

The invention discloses a method for determining the source of a natural gas stratum by using a gas chromatography-mass spectrometry method, which comprises the following steps of: 1, sampling a natural gas sample with a known stratum source and a natural gas sample with an unknown source; detecting the natural gas standard gas, the natural gas sample with the known stratum source and the natural gas sample with the unknown source through a gas chromatograph-mass spectrometer; 3, constructing a control fingerprint spectrum of C6, C7 and C8 components of a natural gas sample with a known stratum source according to a detection result, and 4, comparing the control fingerprint spectrum of a natural gas sample with an unknown source with the control fingerprint spectrum of the natural gas sample with the known stratum source and a compound ratio to judge the natural gas sample with the unknown source. Whether is from the formation of the known source natural gas sample. C6, C7 and C8 components in the natural gas are taken as detection targets, and trace components in the natural gas are taken as a bridge for connecting'gas' and'source ', so that the stratum source of the natural gas can be quickly and accurately identified.