35 results about "Mass chromatography" patented technology

The invention discloses a method for detecting zinc stearate in a stabilizer, and belongs to the technical field of heat stabilizer component detection. The detection method comprises the following steps: carrying out ethanol Soxhlet extraction on a part of a stabilizer to be detected to obtain an extracting solution; freezing the extracting solution, and if a precipitate is obtained, carrying out qualitative test on the precipitate by adopting FTIR (Fourier transform infrared spectroscopy) and / or GCMS (gas chromatography mass spectrometry) to determine whether the stabilizer to be tested contains zinc stearate or not; and when FTIR and / or GCMS test results prove that the stabilizer to be tested contains zinc stearate, carrying out zinc quantitative test on the stabilizer to be tested by adopting a titration method or an ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer) method. According to the method, rapid screening, selective separation and high-precision quantification of zinc stearate in the stabilizer can be realized, and a reliable analysis means is provided for quality control of the PVC heat stabilizer.

The present invention provides a method and application for calibrating hydrogen isotope gas sensitivity. The provided method comprises: (1) detecting a gas to be tested based on mass spectrometry-chromatography to determine the sample components and content contained in the gas to be tested, which is counted as a first detection result; (2) using the hydrogen isotope gas percentage in the gas to be tested obtained from the first detection result to determine the positive calibration sensitivity; (3) based on the positive calibration sensitivity, using a high-resolution mass spectrometer to measure the sample components and content contained in the gas to be tested, which is counted as a second detection result; (4) using the hydrogen isotope gas percentage in the gas to be tested obtained from the second detection result to determine the recalibration sensitivity. The provided method can calibrate hydrogen isotope sensitivity without using national standard substances, thereby ensuring the accuracy of hydrogen isotope abundance determination.

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 invention belongs to the technical field of organic base detection and analysis, and particularly relates to application of 2-(2-pyrrolyl) pyridine as an internal standard substance for gas chromatography-mass spectrometry detection of nornicotine in cigarette mainstream smoke and a detection method. The 2-(2-pyrrolyl) pyridine provided by the invention is used as an internal standard substance for gas chromatography-mass spectrometry detection of nornicotine in cigarette mainstream smoke. Based on the closeness of the molecular polar surface area PSA, the hydrophobicity LogP and the retention index RI of the internal standard substance and the target alkaloid, the selected 2-(2-pyrrolyl) pyridine and nornicotine have similar structures and similar physicochemical properties, and can be highly matched with the target alkaloid in the aspects of pretreatment recovery rate, chromatographic retention behavior and mass spectrum response characteristics; the quantitative precision of a detection result is improved and the cost of an internal standard substance is reduced.

The invention relates to a quantitative analysis method of nicotinic acid and nicotinamide in tobacco leaves, which comprises the following steps: 1) sample pretreatment: accurately weighing a tobacco leaf sample, adding a mixed solvent of methanol, water and dichloromethane, carrying out oscillation extraction and centrifugal treatment, taking supernatant liquid, and carrying out freeze drying treatment to obtain freeze-dried residues; adding pyridine and BSTFA into the freeze-dried residues to carry out silanization derivation reaction to form a nicotinic acid derivative and a nicotinamide derivative, namely a sample to be detected; 2) preparing a standard solution and drawing a standard curve; 3) sample analysis: performing gas chromatography-mass spectrometry analysis on the to-be-detected sample to obtain chromatographic peaks and mass spectrum peaks of the derivatives of nicotinic acid and nicotinamide; and according to the retention time of the chromatographic peak and mass spectrum characteristic ion peak qualitative analysis, the content of nicotinic acid and nicotinamide in the tobacco leaf sample is calculated through external standard method quantitative analysis. The quantitative analysis method is simple, convenient, efficient and high in sensitivity and accuracy.

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 provides a compound, a polymer containing the structure of the compound and a rock debris mark detection method. The structural formula of the compound provided by the invention is as shown in formula I: # imgabs0 #, the compound is reacted with acrylamide and N, N-methylene bisacrylamide under the action of an initiator to obtain the polymer, namely the water-in-oil polymer nanoparticle dispersion liquid, and the water-in-oil polymer nanoparticle dispersion liquid can be used as a tracer to adsorb and mark rock debris without purification. The rock debris marking detection method comprises the following steps: injecting the water-in-oil polymer nanoparticle dispersion liquid and drilling fluid into a stratum during rock debris logging, adsorbing and marking the generated rock debris, extracting the marked rock debris by using tetrahydrofuran, collecting an extracting solution, concentrating and drying, and thus obtaining the water-in-oil polymer nanoparticle. And detecting the polymer nanoparticles by using a thermal cracking-gas chromatograph-mass spectrometer.

The invention provides a high-sensitivity detection method for quinclorac in grains and honey. The high-sensitivity detection method comprises the following steps: S1, extracting; S2, deriving; S3, redissolving and on-machine analysis of GCMSMS (Gas Chromatography Mass Spectrometry) and LCMSMS (Liquid Chromatography Mass Spectrometry). According to the technical scheme, iodoethane is adopted to react with quinclorac under the alkaline condition to generate a new compound 3, 7-dichloro-8-quinoline carboxylic acid ethyl ester, the derivation reaction speed is high, and the reaction can be completed within 60 minutes; and the used derivatization reagent is safe to use and low in cost. According to the method, the derivative 3, 7-dichloro-8-quinoline carboxylic acid ethyl ester of quinclorac is quantitatively detected through GCMSMS, the sensitivity is high, the quantification limit is far lower than that in an existing literature method, and the harsh requirement of the market for quinclorac detection in food can be met.

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.

The application discloses a method for rapidly detecting butyric acid and isomers thereof in liquor, which does not need any pretreatment process and a large amount of organic solvents, directly takes 0.5-3ml of a liquor sample and adds the sample into a sample bottle of a rapid gas chromatography-PTR photochemical ionization source-time of flight mass spectrometer, selects appropriate rapid gas chromatography mass spectrometry conditions, and utilizes the rapid gas chromatography-PTR photochemical ionization source-time of flight mass spectrometer to rapidly complete detection of butyric acid and isomers thereof in the liquor. The method established by the application does not need any pretreatment process and a large amount of organic solvents, can rapidly detect butyric acid and isomers thereof in the liquor within five minutes, and provides a strong means for acidity and taste adjustment of the liquor.

The invention relates to a method for determining an atosiban acetate polymer. The method is carried out by adopting high performance liquid chromatography-liquid mass spectrometry chromatography, and comprises the following steps: (1) preparing a polymer-containing test solution of atosiban acetate; (2) injecting the solution obtained in the step (1) into a high performance liquid chromatography and liquid chromatograph-mass spectrometer, and recording a chromatogram; wherein the chromatographic conditions of the liquid chromatography are as follows: the chromatographic column is TSK-GEL G2000SWXL, 7.8 mm * 300 mm * 5 [mu] m, and the mobile phase is prepared from trifluoroacetic acid-water-acetonitrile (0.05: 70: 30); the liquid and mass conditions are as follows: the chromatographic column is ACQUITY UPLC BEH C18 Column, 100 mm * 2.1 mm, 1.7 [mu] m; a mobile phase A is a 0.1% formic acid solution, and a mobile phase B is acetonitrile; an ESI ion source is adopted, and the detection mode is positive ions. The method can be used for measuring the content of high-molecular polymers and identifying the molecular weight of multiple polymers, so that the total amount of the polymers can be measured and controlled more accurately and effectively, and the detection method is simple and convenient to operate and high in specificity.

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.

A masterbatch composition comprises 30-98% by weight of an aromatic vinyl polymer containing at least one aromatic vinyl polymer block, and 2-70% by weight of a hydrocarbon compound group containing a plurality of hydrocarbon compounds having different numbers of carbon atoms from 12 to 60. When the hydrocarbon compound group is measured by gas chromatography mass spectrometry to determine ratios of detected areas of the hydrocarbon compound components having different numbers of carbon atoms to the total peak area of the components having 12-60 carbon atoms, where the total peak area of components having 12-60 carbon atoms is regarded as 100%, each of the total peak areas of components having 24-27 carbon atoms, components having 27-30 carbon atoms, components having 30-33 carbon atoms, and components having 33-36 carbon atoms is 5% or more, and the total peak area of components having 12-27 carbon atoms is 45% or less.

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 application discloses a kind of oil sand pitch ring bridge island molecular structure model construction method, it is related to model construction technical field, the method with same target oil sand pitch sample as modeling object, based on the results obtained element composition parameter, carbon skeleton structure parameter, functional group parameter, heteroatom occurrence parameter and pyrolysis product parameter of elemental analysis, nuclear magnetic resonance, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermal cracking-gas chromatography mass spectrometry, and accordingly establish structure quantity table;After correction to two-dimensional ring bridge island molecular structure model, in succession execution spatialization processing, geometric optimization, annealing treatment and energy minimization, under the premise of keeping the two-dimensional connection relationship between each unit unchanged, the method can improve the consistency of the conversion of multi-source parameters to molecular model, retain pyrolysis active site, and improve the explanation ability of model to pyrolysis product source structure.

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 discloses a macrolide antibiotic silyl ether derivatization GCMS (Gas Chromatography Mass Spectrometry) analysis method, which adopts silyl ether derivatization and a gas chromatography-mass spectrometry analysis method to determine macrolide antibiotics (MA) and determine characteristic fragments of a macrolide antibiotic silyl ether derivatization product. The method is wide in linear range, high in analysis speed and low in cost; meanwhile, besides MA determination, the analysis method identifies and determines an intermediate degradation product similar to MA in structure, and can better meet the requirements of scientific research and environmental management and control on MA analysis.

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.