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 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 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 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 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 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 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.