136 results about "Electron capture detector" patented technology

Disclosed herein are detectable refrigerant compositions, comprising from about 0.001 to about 5 weight percent tracer compositions, which are useful to identify leaking in a vapor compression refrigeration and / or air conditioning system. The presence of the tracers make the refrigerant compositions detectable by chemo / electro-active array, corona discharge, heated diode, electrochemical, photoionization, infra red, ultrasonic and electron capture detectors.

The invention belongs to the technical field of physicochemical testing of residual pesticide in tobacco and a tobacco product and in particular to a method for mensurating the residual amounts of six classes of dinitraniline pesticides, The method is to extract residual pesticides in an accelerated solvent extraction instrument (ASE), and use a gas chromatograph (matched with electron capture detector (ECD) to directly mensurate the residual amounts of six classes of the dinitraniline pesticides in the tobacco and the tobacco product, namely, butralin, flumetralin, isopropalin, pendimethalin, benfluralin and trifluralin. The method overcomes the disadvantages of a sample treatment method in the prior art and optimizes a sample pretreatment method and the instrument detecting conditions aiming at a tobacco sample. Compared with the prior art, the method has the advantages of simple pretreatment process, reduction of the interference of pigment and other impurities in the tobacco, high automation degree of the whole operation, accurate operation, high sensitivity and good repeatability.

Belonging to the technical field of soil and sediment pollution detection, the invention relates to a dispersive solid-phase extraction gas chromatography method for polychlorinated biphenyls (PCBs) in soil and sediment. The method includes: adding n-hexane into a soil or sediment sample to conduct ultrasonic extraction, when the extraction liquid is basically colorless and transparent, subjecting the extraction liquid to rotary evaporation till dry, adding n-hexane, then adding 50-200mg of a N-propylethylenediamine solid phase adsorption agent to carry out dispersive solid-phase extraction, performing centrifugal layering, and introducing 1microliter of the supernatant into a gas chromatography-electron capture detector to conduct detection, otherwise adding a concentrated sulfuric acid purification step after ultrasonic extraction. The detection limit of 7 polychlorinated biphenyls is 0.02-0.03 microgram / kg, the recovery rate is 72-115%, and the relative standard deviation (n=5) is 3.5-6.9%. The method provided by the invention is simple and sensitive, and can quickly realize batch detection of PCBs in soil and sediment.

The invention provides an analyzing method for simultaneously determining residues of organophosphorus pesticides and pyrethriods pesticides in soil. The analyzing method is characterized by comprising the following steps: carrying out ultrasonic extraction on a soil test sample by using an acetonitrile solution containing 1% of acetic acid by volume percent; purifying by using a suitable amount of PSA and C18 mixed fillers; blowing liquid supernatant by nitrogen and concentrating until the liquid supernatant is nearly dried; respectively dissolving by acetone and n-hexane and enabling the volume to be constant; raising the temperature by using DB-1701 and HP-5 quartz capillary columns and separating; carrying out GC / FPD (Gas Chromatograph / Flame Photometric Detector) detection and GC / micro ECD (Electron Capture Detector) detection; and finally, quantifying by using a base material external standard method. A test confirms that the method has a wide linear range; the technical indexes including detection sensitivity, accuracy and precision meet the requirements of a residue analysis; the pre-treatment operation is simple, convenient and rapid and a reliable manner is provided for analytical researches for simultaneously determining the residues of ths pesticides and the pyrethriods pesticides in the soil.e organophosphoru.

The invention belongs to the field of analytical chemistry, and specifically relates to a method for determining short-chain chlorinated paraffins in plastics, rubber, and textile materials. (2) purification by sulfonation with concentrated sulfuric acid; and (3) detection step (2) using gas chromatography-electron capture detector or gas chromatography-negative chemical ionization (NCI) mass spectrometry detector The content of short-chain chlorinated paraffins in the obtained purified samples. Beneficial effects of the present invention: Utilize concentrated sulfuric acid sulfonation purification method, can effectively remove interference, use gas chromatography-electron capture detector and NCI mass spectrometry detector to detect medium and short-chain chlorinated paraffins in plastics, rubber, textile materials, can realize Accurate quantification; according to the specific mass spectrum of short-chain chlorinated paraffins, the interference of medium and long-chain chlorinated paraffins can be effectively eliminated, making the qualitative more accurate, the selectivity stronger, and the sensitivity higher.

The invention discloses a method for simultaneously measuring residual quantity of three types of herbicide in vega soil, belonging to the technical field of physicochemical detection of pesticide residue in vega soil. Specifically, acetonitrile is used for extraction, Florisil is carried out with solid phase extraction, a gas chromatograph is matched with an electron capture detector to directly measure the residual quantity of three types of herbicide, such as propanil, Rimsulfuron, quizalofop-p-ethyl and the like in vega soil. The invention overcomes the restriction of the defect and the condition of the prior art to optimize the pretreatment method and the instrument detection condition of vega soil samples. Compared with the prior art, the invention has the following favorable advantages that the invention can detect three types of herbicide all at once and has the advantages of simple pretreatment process, high detection sensitivity and good accuracy and reproducibility.

The present invention relates to a method for analyzing N2O, CO, CH4 and CO2 in atmosphere with one injection by gas chromatography. According to the method, a carrier gas with the purity less than 10-5% passes through a purifier under the output pressure of 0.20-0.60 Mpa, such that the purity of the purified carrier gas is less than 10-6% or 10-7%; the purified carrier gas is introduced into a chromatographic column loaded with a sample requiring detection in a gas chromatograph, after an adsorption effect and a desorption effect, N2O, CO, CH4 and CO2 in the sample requiring detection sequentially enter an electron capture detector, a methane converter and a hydrogen flame ionization detector perform detections at the temperature of 90-350 DEG C; finally the data from the electron capture detector and the hydrogen flame ionization detector are concurrently input to a chromatographic work station in the gas chromatograph to obtain the analysis result chromatogram. The method of the present invention is simple, and is easy to operate. With the method of the present invention, the data accuracy error can be effectively reduced, and the sample measurement period can be shortened.

The present invention relates to a solid phase membrane extraction-gas chromatography detection method for chlorobenzene compounds in water body. The method comprises the steps of gathering 500 mL of a water sample with a pH value of 2.5 by flowing through a C18 solid phase extraction membrane at a flow rate of 5-50 mL / min; then eluting with 5 mL of acetone and 3*5 mL of dichloromethane; drying an elution by rotary evaporation; dissolving by n-hexane; diluting to 1 mL; introducing 1 [mu]L of the product into a gas chromatography-electron capture detector for the detection. A detection limit of eleven chlorobenzene compounds ranges from 0.05 ng / L to 4 ng / L; recovery rate ranges from 91% to 115%; and relative standard deviation (n=5) is 3.6-7.6%. The detection method is simple and sensitive, has wide linearity range, good repeatability and high recovery rate, and can rapidly determine concentrations of the chlorobenzene compounds in the water body.

The invention relates to a method for analyzing nitrous oxide, methane and carbon dioxide in atmosphere by injecting a sample once, comprising the following steps of: firstly, passing a carrier gas at a purity of 10-5% below through a purifier with 0.20-0.60 MPa of output pressure so that the purity of the purified carrier gas is 10-6% or 10-7% below; secondly, charging the purified carrier gas in a chromatographic column with a to-be-tested sample in a gas chromatograph, after an adsorption-desorption function, orderly conveying the nitrous oxide, methane and carbon dioxide in the to-be-tested sample into a thermal conductivity cell detector, an electron capture detector and a hydrogen flame ionization, then detecting at 90-350 DEG C; and finally, simultaneously inputting the data obtained by the thermal conductivity cell detector, the electron capture detector and the hydrogen flame ionization into the chromatographic working station of the gas chromatograph to obtain an analysis result chromatogram. The method in the invention is simple, easy to operate, and capable of efficiently decreasing data precision error and shorting sample measurement period.

The invention discloses a method for detecting free hydrolysis formaldehyde in a textile. A technical procedure for detecting the free hydrolysis formaldehyde in a water extract turbid or colored textile is established; after being derived, a target compound is extracted and purified, and a gas chromatograph (with an electron capture detector) is used for quantitative and quantitive analysis; and the method can be suitable for measurement of the free hydrolysis formaldehyde in various types of textiles, such as water extract turbid or colored customs, fiber fillings, yarns, custom materials, family decorative products and the like. According to the method, the using amount of organic solvents is small, the impurity interference is low, and the sample recycling rate is high.

The invention relates to a water polychlorinated biphenyl dispersive solid-phase extraction gas chromatography detection method and belongs to the technical field of water pollution detection. The method comprises adding 30g of common salt into a water sample, wherein if the water sample is a seawater sample, the salt addition process is avoided, carrying out automatic liquid-liquid extraction twice by 30-50mL of n-hexane, merging the extract, carrying out rotary evaporation on the extract until drying, adding 1mL of n-hexane into the extract for dissolution, transferring the solution into an injection tube filled with 100-200mg of an N-propylethylenediamine adsorbent, carrying out dispersion solid phase extraction, carrying out filtration after vortex treatment for 30-60s, taking 1 microliter of the filtrate, feeding the filtrate into a gas chromatography-electron capture detector and carrying out detection. The method has seven polychlorinated biphenyl detection limits of 0.0002-0.0003 micrograms per liter, has a recovery rate of 71-107% and has relative standard deviation (n=5) of 3.1-6.2%. The method is simple and sensitive and can realize fast batch detection polychlorinated biphenyl in water.

The invention relates to a method for enriching and separating a trace amount of polychlorinated biphenyls (PCBs). According to the method, a trace amount of the PCBs in an environmental sample are enriched by a modified solid-phase microextraction column by a combining a method that a trace amount of the PCBs are subjected to linkage separation by a double column gas chromatography-electron capture detector, and then are eluted and detected. Compared with the prior art, the method has the advantages that: a macromolecule fixed phase of the solid-phase microextraction column is modified, a solid-phase microextraction technology is combined with the gas chromatography-electron capture detector, sampling, extraction, concentration, sample separation, and detection are combined into a simpleprocess, automaton is easy to realized, the amount of the pre-enriched samples and the detection time are reduced, and the effect of enriching the PCBs is improved; the nature is determined by a double chromatographic column, and PCB monomers with different polarities and structures are separated; the method has the advantages of high analysis speed, low manufacturing cost, and high detection sensitivity and specificity and the like, and is easy to operate; instruments are portable; and the detection limit of the coplanar PCB monomers in water can reach 10<-8> to 10<-7> mol / L, and the field test of residues of toxication forms of six kinds of main PCBs can be realized.

The invention relates to a quantitative determination method for general chlorantraniliprole residual quantity. The method is characterized in that residual chlorantraniliprole in a test sample is subjected to ultrasonic extraction by an acetonitrile solvent, a proper amount of MWCNTS and PSA adsorbents are used for removing impurity, a supernatant is subject to nitrogen blowing and concentrating until nearly dry; volume metering is carried out by using an acetone-hexane mixed solvent with volume ratio of 1:1, a HP-5 chromatographic column program is used for heating and separating, electron capture detector ECD detection is carried out, and a matrix external standard method is used for quantification. Through test, the method has the advantages of simple, fast and accurate operation, easy popularization and grasping, low cost, is the rapid and reliable method for detecting the residual chlorantraniliprole in different samples, and can satisfy the quality and progress requirement by analysis of large-batch samples.

The invention discloses a method for simultaneously and rapidly determining contents of various organic chlorine pesticides in water, and belongs to the field of organic chlorine pesticide detection. The method comprises the steps of series-connection solid-phase extraction column extraction, solvent elution, concentration to a definite volume, and qualitative and quantitative detection performed on a sample to be tested by means of a gas chromatography-electronic capture detector. By building and optimizing series-connection solid-phase extraction column extraction enrichment purification and conditions detected by the gas chromatography-electronic capture detector, 25 kinds of organic chlorine pesticides can be rapidly and accurately determined at the same time, and the method has the excellent precision and sensitivity and overcomes the technical detects in the field.

The invention relates to an isotope dilution high resolution chromaticness combination method for simultaneously detecting organic chlorine pesticides and polychlorinated biphenyl in a biological sample. The method can realize simultaneous purification of the two targets of the organic chlorine pesticides and the polychlorinated biphenyl in a pre-treatment process, and a detection process can be carried out simultaneously. The sample pretreatment employs a method combining gel permeation chromatography with Florisil silica column (or silica gel column) purification. A gold standard method using an isotope dilution high resolution GC-MS is employed for the detection. Compared with a traditional low resolution mass spectrum and an electron capture detector (ECD) method, the interference and false positive results are reduced, and the indexes such as the method deletion limit and the quantitative result accuracy are greatly improved. The method can save more than 50% of labour amount, time and consumables such as solvents, and filler materials in comparison with a method for respective and step by step measurement of the organic chlorine and the polychlorinated biphenyl, and has important meaning for research and monitor of the organic chlorine pesticides and the polychlorinated biphenyl.

The invention relates to the technical field of seafood pollution detection, and especially relates to a method for detecting polychlorinated biphenyls in a seafood. The method comprises the followingsteps: (1) sample collection, and sample preparation; (2) sampling and ultrasonic extraction; (3) concentrating, and fat content detection; (4) concentrated sulfuric acid purification, and concentrating; (5) dispersion, solid phase extraction and purification; (6) gas chromatography-electron capture detector detection; (7) standard curve drawing; and (8) detection of the content and the recoveryrate of the polychlorinated biphenyls. The method adopts ultrasonic extraction, dispersion, solid phase extraction and purification, and gas chromatography-electron capture detection technologies to detect the polychlorinated biphenyls in the seafood, has the advantages of simplicity in operation, high efficiency, and flexibility in selection of one-step purification and two-step purification, allows the dispersion, solid phase extraction and purification process to only take 1 min, the result to be accurate, the detection limit of seven polychlorinated biphenyls to be 0.025-0.038 [mu]g / kg, the recovery rate to be 73-110% and the relative standard deviation (n=5) to be 3.3-6.3%, and has a high sensitivity, a satisfactory recovery rate and a satisfactory reproducibility.

The invention provides a method for determining residual quantity of myclobutanil by SPE-GC / ECD (Solid Phase Extraction-Gas Chromatography-Electron Capture Detector). The method comprises the following steps of: (1) preparation of a standard liquid: weighing a myclobutanil standard substance and dissolving by an organic solvent to set volume so as to prepare a standard storage liquid; stepwise diluting the myclobutanil standard storage liquid to prepare standard working liquid with series of concentrations; (2) extracting residue in a sample; (3) purification: dissolving by an acetone-normal hexane mixed liquid, then, transferring to a Florisil solid phase column pre-sprayed by the acetone-normal hexane mixed liquid and spraying by the acetone-normal hexane mixed liquid; (4) detecting the residual quantity of myclobutanil in the sample by gas chromatography; (5) establishing a standard curve; and (6) calculating the residual quantity of myclobutanil. The detection method provided by the invention has the characteristics of simpleness and rapidness, and accuracy and reliability, and is of significant value to control the residual quantity of myclobutanil in tobacco for guiding safe and reasonable use of myclobutanil in tobacco.

The present invention provides a detection method for -2,3,4,7,8-PeCDF in incinerator fly ash and flue gas, wherein quantitative analysis is performed by adopting a multi-dimensional gas chromatography and mass spectrometry combined method. According to the detection method, a purified sample is subjected to primary separation through one-dimensional gas chromatography to achieve the one-step purification purpose, wherein the separation column is quartz capillary chromatographic column DB-5, and the detector is an electron capture detector; and the peak at which the target object exist is cut through a cutting device arranged inside a one-dimensional chromatographic column incubator and then enters second dimensional chromatography to carry out further separation detection, and mass spectrometry detection is performed, wherein the ion source is negative chemical ionization (NCI), and the mass analyzer is a quadrupole mass analyzer. According to the present invention, the isotope internal standard method is adopted to perform quantification; the quantification on the dioxin toxicity indicator -2,3,4,7,8-PeCDF is achieved based on the multi-dimensional gas chromatography and mass spectrometry series connection method; and the rapid analysis on the dioxin content in incinerator fly ash and flue gas is achieved, the analytical instrument is simple, the spectrum and the quantitative method are simple, and the detection result is accurate.

The invention discloses a measuring system and a method of N2O concentration in air. The system is characterized in that: an injection port of a part of analysis and detection and a constant pipe are respectively connected with a first pneumatic valve, and a first chromatographic column is connected with the first pneumatic valve; a second chromatographic column is connected with the first and a second pneumatic valve; two ports of a three-way connection in a part of buffer gas are respectively communicated with an electron capture detector and the second pneumatic valve; another port of the three-way connection is connected with an exit end of a gas switch globe valve to allow the electron capture detector to connect with the buffer gas; the gas switch globe valve is provided with an inlet and an outlet, the inlet of the gas switch globe valve is connected with an outlet of a gas flow control valve, the outlet of the gas flow control valve is connected with an outlet of a pressure-reducing valve, and the inlet of the pressure-reducing valve is connected with a buffer gas steel cylinder. The method is characterized in that: the gas switch globe valve is opened, the gas flow control valve is adjusted to put a buffer gas CO2 with the concentration of 10% in the buffer gas steel cylinder into the electron capture detector with the flow velocity of 2ml / min, and when the detection system turns stable, the sample is analyzed.

The invention discloses a system for monitoring volatile organic contaminants in a water source. The system comprises a water sample acquisition device, a geographic information determining device, a blowing and arresting device, a concentration device and a gas chromatography-mass spectrometry-flame ionization detector (FID)-electron capture detector (ECD) combined instrument, wherein the geographic information determining device is connected with the water sample acquisition device and is used for determining the geographic position information when the water sample acquisition operation iscarried out by the water sample acquisition device; the blowing and arresting device is connected with the water sample acquisition device, and is used for blowing the collected water samples, and arresting volatile organic contaminant gas in the collected water samples; the concentration device is connected with the blowing and arresting device, and is used for concentrating the arrested volatile organic contaminant gas; and the gas chromatography-mass spectrometry-FID-ECD combined instrument is connected with the blowing and arresting device, and is used for receiving the concentrated volatile organic contaminant gas, and carrying out qualitative and qualitative detection on the concentrated volatile organic contaminant gas. The invention also comprises a control device which is used for carrying out statistics and analysis on the detection results, thus the detection becomes more scientific and accurate.

The invention discloses a separation analysis method of the residual amount of chloroform in meclizine dihydrochloride. The separation analysis method is characterized in that a gas chromatographic (GC) method and an electron capture detector (ECD) are used for the separation analysis of the residual amount of the chloroform in the meclizine dihydrochloride. The separation analysis method can be used for overcoming the shortcoming that when a gas chromatographic method of a conventional flame ionization detector (FID) is used for detection, the response value of the chloroform is low, has the advantages that the response value of the chloroform is high, the sensitivity is high, and the operation is simple and convenient, and provides technical reference for the establishment of the quality standard for the residual amount of chloroform in medicinal raw materials.

The invention relates to a gas chromatography for analyzing methane and nitrous oxide in air by one sample injection, which is characterized by comprising the following steps: enabling a carrier gas, of which the purity is lower than 10-5%, to pass through a purifier under the output pressure of 0.20-0.60 MPa, so that the purity of the purified carrier gas is lower than 10-6%; introducing the purified carrier gas into a chromatographic column of a gas chromatograph, in which a sample to be detected is placed, at the flow rate of 15-85 ml / min at the temperature of 15-40 DEG C, absorbing and desorbing at 20-90 DEG C, and after nitrous oxide and methane in the sample to be detected orderly enter an electron capture detector and a hydrogen flame ionization detector, carrying out detection at 110-350 DEG C; and finally, simultaneously inputting the data obtained by the electron capture detector and the hydrogen flame ionization detector into a chromatogram work station of the gas chromatograph, thereby obtaining the analytic result chromatogram. The invention is simple and easy to operate, can effectively lower the data accuracy error, and shortens the sample measurement period.

The invention relates to the technical field of detection and discloses a sensitivity automatic detection method and device of an electron capture detector. The automatic detection method comprises detecting current basic frequency of a voltage pulse in an electron capture detector, determining whether the detected current basic frequency exceeds a predetermined basic frequency range of the voltage pulse, outputting a judgment result, producing an adjustment command for adjusting a target current of the electron capture detector if the result shows that the detected current basic frequency exceeds the predetermined basic frequency range, and adjusting the magnitude of the target current in accordance with the adjustment instruction so that the electronic capture detector can adjust the basic frequency of the voltage pulse according to the adjusted target current. The method and device can automatically adjust the magnitude of the target current of the electron capture detector so that the signal-to-noise ratio of the measured chromatogram is not affected when the electron capture detector cavity is polluted or influenced by other factors so that high sensitivity of the electron capture detector is kept.

The invention relates to an extraction method for residual pyrethroid pesticides in a water environment, which is characterized by pretreating a low-density polyethylene extraction membrane bag placed into normal hexane and acetone mixture liquor; adding sodium chloride into a sample to be detected until saturated concentration and placing a saturated liquor sample in a headspace sample injectionbottle; fixing the pretreated membrane bag into the headspace sample injection bottle added with the saturated liquor sample, adding extraction solvents into the membrane bag, sealing the headspace sample injection bottle and placing the headspace sample injection bottle in an oscillator to obtain extraction liquor; and transferring the extraction liquor to a small sample injection bottle and measuring the concentration of the pyrethroid pesticides in the extraction liquor by the aid of a GC-ECD (gas chromatography-electron capture detector) or a GC-MS (gas chromatography-mass spectrometer). Compared with the prior art, a membrane-assisted extraction system obtained by means of research and development can be applied to separating and purifying the residual pyrethroid pesticides such as cypermethrin, deltamethrin, fluralinate, bifenthrin, phenothrin, fenvalerate and the like in the water environment sample. Compared with common liquid-liquid extraction and solid extraction methods, the extraction method is higher in separation speed and more efficient in enrichment of the pyrethroid pesticides.

The invention relates to a method for analyzing nitrous oxide and carbon dioxide in atmosphere by adopting gas chromatography through one sampling, which is characterized by firstly purifying the carrier gas with purity being less than 10-3% in a purifier under the output pressure of 0.20-0.60MPa to ensure the purity of the purified carrier gas to be less than 10-4%; secondly pumping the purifiedcarrier gas into a chromatographic column with samples to be detected in a gas chromatograph under the conditions of flow of 15-75ml / min and temperature of 15-40 DEG C and the nitrous oxide and carbon dioxide in the samples to be detected entering into an electron capture detector and a thermal conductivity cell detector in sequence after adsorption and desorption at 25-50 DEG C to be detected at90-350 DEG C; and finally simultaneously inputting the data obtained by the electron capture detector and the thermal conductivity cell detector into a chromatographic working station in the gas chromatograph, thus obtaining the analysis result chromatogram. The method is simple and easy to operate and can effectively reduce the data accuracy error and shorten the sample measuring period.

The invention discloses a method for rapidly detecting residual forchlorfenuron in cucumbers. The method comprises the first step of instrument and reagent selection, the second step of plant sample extraction, the third step of soil sample selection, the fourth step of purification and the fifth step of gas chromatography detection, wherein instruments adopt an electron capture detector and a full-automatic accelerated solvent extraction instrument, and reagents adopt acetone, dichloromethane, anhydrous sodium sulfate, sodium chloride, ethyl acetate, n-hexane and diatomaceous earth. According to the method for rapidly detecting the residual forchlorfenuron in the cucumbers, a gas chromatography detection method of a plant growth regulator forchlorfenuron in the cucumbers and soil is established, and the method has the advantages of being simple and convenient in pretreatment step, wide in use of instruments, high in recovery rate and low in minimum detection limit.

The invention discloses a method for determining the content of bromomethane in occupational health. The determination method comprises the following steps: 1, preparing a bromomethane standard curve; 2, collecting bromomethane in air to active carbon through a sampling device; 3, disposing the bromomethane-enriched active carbon under closed conditions overnight to balance bromomethane; 4, desorbing bromomethane adsorbed in the active carbon with 1ml of an organic solvent; and 5, quantitatively analyzing bromomethane in the organic solvent by using a gas chromatograph. The determination method has the following advantages: the desorption efficiency is high; an active carbon tube has a small size and is easy to carry and store, and the sampling volume changes as needed; the storage time is long, and reaches up to 5-7d; a desorbed solvent desorption bottle can be disposed on an automatic sampler, so large-scale automatic sample introduction analysis can be easily realized; and a detector is changed to an electron capture detector, so the sensitivity is improved by several orders of magnitudes, and the analysis reliability is improved.

The invention discloses a preparation method of a pyrethroid pesticide type molecularly imprinted membrane. The preparation method is characterized by comprising the following steps: firstly performing ultrasonic washing on an LDPE (low-density polyethylene) membrane with anhydrous ethanol, acetone and distilled water respectively, performing vacuum drying, placing into a reaction chamber of a plasma treatment instrument, introducing argon gas and performing surface activation treatment; then placing the LDPE membrane after activation treatment into a molecular imprinting grafting solution to graft under nitrogen production conditions; taking out the molecularly imprinted membrane after the grafting reaction, and eluting with an organic solvent to remove template molecules till the template molecules can not be detected by GC-ECD (gas chromatography with an electron capture detector); and finally performing vacuum drying on the molecularly imprinted membrane after removal of the template molecules. The preparation method has the advantages that the pyrethroid pesticide type molecularly imprinted membrane has relatively high selective permeability against pyrethroid pesticide residues, can be applied to selective separation and efficient enrichment of pyrethroid pesticides in aquatic products and other complex biological samples, and has relatively high application values.