2849 results about "Gas liquid chromatographic" patented technology

A high-sensitivity, separation microcolumn assembly for a microgas chromatograph and the like is provided. The assembly has an ultra-low mass complete with integrated heaters. The assembly uses multiple zones for temperature control, and microstructures that permit very rapid heating and cooling of the microcolumn.

The basic structure of a PTV (programmed temperature vaporizer) injector has been considerably modified so that is can be used for the direct coupling of liquid chromatography in normal phase or reverse phase, and gas chromatography and also for the introduction of high volumes in gas chromatography. The glass tube of the injector is filled with an adsorbent. By means of a system of valves and tubes or capillary tubes, the previously selected fraction of liquid chromatography is transferred to the injector, said fraction coming in through the same extremity for introducing the gas chromatography column. The eluent is entrained by a gas stream through the adsorbent, wherein are retained the solutes, and the solvent is removed through a tube or capillary tube introduced in the injector through the opposite extremity. Thereafter, the solutes are desorbed thermally passing to the chromatography column.

A system for testing thermal performance of a vehicle power battery belongs to the field of electric vehicle batteries. The system includes a high-temperature explosion-proof box; a pressure sensor, a temperature sensor, a heating and cooling device, a battery module and a circulating fan are arranged in the high temperature explosion-proof box; the circulating fan is connected with a circulating motor; the high temperature explosion-proof box is provided with an exhaust hole; the exhaust hole, a ball valve, a sampling port, a cut-off valve and a gas chromatograph are connected in sequence; the ball valve is connected to a gas collecting bag through an air exhaust pipe; the pressure sensor and the temperature sensor are connected to the computer through a data collector; a charge-discharge machine is connected to the battery module through a socket; the high temperature explosion-proof box is provided with an observation window; and the observation window is connected to a camera through an endoscope. The system can perform thermal property test of the battery, battery discharge analysis and thermal runaway test of the battery. The system has the advantages of simple structure and low cost, can carry out test on multiple functions of the lithium ion battery, so as to realize design optimization on the structure of the battery pack; and the system has broad market prospects.

The invention relates to a method for measuring alkaloid in tobacco and tobacco products, which is characterized by dissociating alkaloid from the tobacco and tobacco products by using sodium hydroxide solution, extracting the alkaloid from samples by using triethylamine/trichloromethane solution, and detecting content of five kinds of alkaloid with GC-MS ( Gas Chromatograph-Mass Spectrum) quantitative analysis. Compared with other methods for analyzing the alkaloid, the invention has the advantages that alkaloid is separated from the tobacco by DB-35MS chromatographic columns so as to separate nornicotine and myosmine in the tobacco and accurately quantify target matters; batch sampling is carried out on the separation of nicotinamide and other alkaloid so as to detect the nicotinamide with high content in the tobacco and meet the quantitative analysis of other alkaloid with low content; the standard working curves of standard matters are separately compounded so as to avoid influence on quantization of other alkaloid by alkaloid catabolite existing in the standard samples. The method is simple and convenient and has the advantages of good repeatability, high analyzing and measuring sensitivity, and accurate quantization.

A fluidic switching device is particularly for use in chromatography is described. The device allows a rapid switching between chromatographic columns; particularly, in gas chromatography.

Provided is an electrophotographic photosensitive member in which an undercoat layer is a layer of which at least one selected from the group consisting of a compound represented by the formula (1), a compound represented by the formula (2), a compound represented by the formula (3) and a compound represented by the formula (4) can be detected by gas chromatography analysis when the undercoat layer is heated at 150° C. for 60 minutes by headspace method.

The invention relates to a sample application device for a gas chromatograph, having an evaporator (1) which can be cooled, can be heated in a temperature-controlled manner, is provided with a carrier-gas feed and has a valve head (11) for holding an exchangeable sampling tube (27), a receiving chamber (4) for the sampling tube (27), a column exit (18) and, if appropriate, a splitter exit (31). In this device, a pyrolyser tube (20), which is coupled to the carrier-gas feed and is held by the valve head (11), is arranged in the receiving chamber (4), in which there is a heating coil (26) into which the sampling tube (27) can be fitted and to which current can be applied by means of a heating conductor (25) which is guided outwards through the valve head (11).

The invention relates to a gas chromatograph for the analysis of gas samples. It has a feed arrangement for feeding the sample, an open tubular capillary column for separating the components of the sample, temperature control means for controlling the temperature of the column, and a detector for detecting the separated components of the sample. The efficiency has been improved and a convenient hand-held version has been made possible by constructing the column of a bundle of open tubular capillaries having a gas permeable wall comprising a polymer membrane. The invention also relates to the use of such a column together with a detector for identifying gaseous samples.

The invention discloses a chiral analysis method for nicotine in tobacco juice of an electronic cigarette. The chiral analysis method comprises the steps of diluting the tobacco juice of the electronic cigarette by a methyl alcohol/methyl tertiary-butyl ether solution, analyzing S-(-)-nicotine and R-(+)-nicotine in the tobacco juice of the electronic cigarette by using a chiral stationary phase capillary column mthrough a gas chromatograph-mass spectrometer, performing chiral analysis on the S-(-)-nicotine and the R-(+)-nicotine by comparing the retention time of a chromatographic peak and characteristic ions of nicotine in a standard sample with the retention time of a chromatographic peak and characteristic ions of nicotine in an electronic cigarette tobacco juice sample, and normalizing areas of quantitative ion peaks of the S-(-)-nicotine and the R-(+)-nicotine to quantify the proportions of the S-(-)-nicotine and the R-(+)-nicotine to the total nicotine. The chiral analysis method has the advantages that the nicotine in the tobacco juice of the electronic cigarette is separated by a chiral stationary phase capillary column, so that the S-(-)-nicotine and the R-(+)-nicotine in the nicotine can be better separated, and accurate and quantitative analysis on the nicotine can be realized. The sample treatment is simple and convenient; the chiral analysis method is low in detection limit, high in sensitivity, high in reproducibility, accurate in quantification and suitable for chiral analysis on the nicotine in a large batch of electronic cigarette tobacco juice samples.

A self-contained micro-scale gas chromatography system that includes a plurality of gas chromatography components arranged on a micro-fluidic platform with nearly zero dead volume “tubeless” fluidic connections for the gas chromatography components. The micro-fluidic platform includes a plurality of flow channels that provide fluid flow paths for a sample, carrier gas and waste gas through and among the micro-fluidic platform and the plurality of gas chromatography components. The system may also include an on-board supply of carrier gas and on-board waste management, as well as a thermal management scheme making the system suitable for use in oil and gas wells and also other remote environments.

The invention discloses a test method and device of the air permeability of a membrane electrode of a fuel cell, which can be used for testing the air permeability of the membrane electrode of the fuel cell under actual running conditions. The method comprises the following steps of: assembling the membrane electrode in a testing pool, wherein a gas inlet and outlet channel is arranged at one side of the test pool and a test channel is formed at the other side of the test pool; and respectively introducing tested gas and carrier gas to two sides of the test pool, introducing a gas outlet at the carrier gas side of the test pool into a gas chromatography, and calculating the air permeability of the membrane electrode through testing the content of the tested gas in the tested carrier gas through the gas chromatography. The test device of the air permeability of the membrane electrode mainly comprises the test pool and an air permeability test system. The test pool consists of two plate clamps and corresponding sealing materials, wherein each plate clamp is provided with a gas inlet and a gas outlet. The invention provides an intrinsic test method for testing the air permeability of the membrane electrode of the fuel cell accurately and effectively; and the test pool and the test device have the advantages of simple structure, easiness in control and low cost and can be used for accurately representing the intrinsic air permeability of the membrane electrode under offline or online state.

Disclosed are a method of determining the components of a fluoroolefin composition, a method of recharging a fluid system in which the composition is used, and sensors used therefor. In particular, the composition may be a fluoroolefin refrigerant composition used within a vapor compression system, where the refrigerant composition is useful in cooling systems as replacements for existing refrigerants with higher global warming potential. Such fluoroolefin refrigerant compositions have double bond structures which make them particularly well suited with sensing technologies, including: infrared sensors, UV/vis sensors, NIR sensors, ion mobility or plasma chromatographs, gas chromatography, refractometry, mass spectroscopy, high temperature thick film sensors, thin film field effect sensors, pellistor sensors, Taguchi sensors and quartz microbalance sensors.

The method for analyzing diesel hydrocarbon composition by using solid phase extraction and mass spectrography includes the following steps: using solid phase extraction process to separate saturated hydrocarbon and aromatic hydrocarbon in diesel sample, collecting all the saturated hydrocarbon solution and aromatic hydrocarbon solution, respectively adding equivalent internal standard material, then respectively sampling and making gas chromatography and mass spectrography; utilizing gas chromatomap of aromatic hydrocarbon and saturated hydrocarbon to calculate relative content of both them, and utilizing mass spectrogram to obtain hydrocarbon composition of aromatic hydrocarbon and saturated hydrocarbon; according to the relative content of saturated hydrocarbon and aromatic hydrocarbon using normalization-calculation method to obtain the hydrocarbon composition of diesel.

The invention relates to electronic cigarette liquid and a quality detecting method. The raw materials of the electronic cigarette liquid are cigarette industry finished cigarette tobacco supercritical fluid extracting substances, other components are added, even mixing is carried out according to weight percentage, and then the liquid is prepared. According to the formula, the liquid comprises 10%-30% of finished cigarette tobacco extracting substances, 5%-15% of tobacco flavor, 2%-10% of deionized water and 10%-30% of glycerine, and the rest is propylene glycol. A gas chromatography-mass spectrography method is used for analyzing the extracting substances, a chromatographic peak area normalization method is used for determining the relative content of various volatile components, and according to the key chemical components which determine characteristic aroma style and the magnitude of the relative content, the quality of the electronic cigarette liquid is evaluated. According to the electronic cigarette liquid, the cigarette finished cigarette tobacco supercritical fluid extracting substances are used as main components, the aroma and the taste of an electronic cigarette are made similar to the taste and sense judgment of a traditional cigarette to the maximum degree, and the problem that single cigarette regulated cigarette liquid taste is single and is not harmonious is solved. Meanwhile, cigarette liquid flavor component evaluation is objective and accurate through the gas chromatography-mass spectrography method.

The invention relates to a sampling device and method of gas chromatographic online analysis transformer dissolved gas, which comprises sampling probe, temperature sensor, multi-ported valve, sample quantitative pipe, marginal gas quantitative pipe, cutoff valve and marginal gas regulating system. The method directly inserts sampling probe into transformer oil and presses marginal gas into sampling probe by switching of multi-ported valve; the transformer oil is circulated by oil pump so that the dissolved gas of transformer oil can spill into marginal gas and then it achieves gas-liquid equilibrium in probe.

The invention relates to a method for analyzing carbon isotopes of micro single hydrocarbons in natural gas. The method is characterized by utilizing a divinyl benzene/carbon molecular sieve/polydimethylsiloxane (DVB/CAR/PDMS) composite adsorbing material to enrich the microcomponents in the hydrocarbons, carrying out thermal desorption at the gas chromatography injection port and carrying out separation through gas chromatography and analyzing the carbon isotopes of the single hydrocarbons by isotope ratio mass spectrometry. The method has the following beneficial effects: the method has the advantages of high carbon isotope testing precision and good repeatability, conforms to the research needs, is simple to operate and has good use and popularization values.

The invention provides a thermal desorption-gas chromatography-mass spectrometry fingerprint analysis method of fragrance and flavor for tobacco, comprising the following steps: using the thermal desorption technique during pre-processing the fragrance and flavor for tobacco; using a gas chromatography-mass spectrometry to analyze; establishing a digital fingerprint of sample; judging the similarity of the sample and standard sample by the cosine and euclidean distance method. The thermal desorption technique greatly simplifies the pre-processing operation process and ensures the reliability and stability of the experiment result, and introduces the volatile components into the gas chromatography, in order to conquer the defect of the prior technique that: all the components dissolved in the extraction solvent are introduced into the gas chromatography and the pollution on the instrument is reduced and the service life of the instrument and chromatographic column is prolonged. The analysis method provides a reliable, stable, quick and new method for controlling the quality of the fragrance and flavor for tobacco.

The present invention discloses filter paper sheet gas chromatography-mass spectrum analysis process of organic acid/amino acid metabolic product in urine. The process includes elution of urine collected with filter paper, oximation reaction, extraction, methyl silane derivation, and united detection with chromatographic instrument and mass spectrograph. The process of the present invention is superior in that the filter paper collection of urine favors remote analysis of genetic metabolic diseases; the oximation reaction processing favors alpha-ketonic acid detection for diagnosis of branched chain ketonic acid metabolic disorder; the extraction has high recovery rate of organic acid/amino acid metabolic product, high repeatability, less chromatographic impurity peaks and no pollution to chromatographic capillary column and mass spectrographic ion source; and the united detection is suitable for screening analysis of great amount of samples.

The invention relates to a method for simultaneously detecting multiple residual solvents in ceftriaxone sodium, which adopts a gas chromatographic analysis process to simultaneously detect six organic solvents in medicines, including methanol, ethanol, acetonitrile, acetone, ethyl acetate and triethylamine. The gas chromatographic process is adopted to simultaneously detect the contents of the six organic solvents, and has the advantages of high sensitivity, favorable repetitiveness and high precision; by using a standard addition process, the method does not need any additional standard substance as an internal standard, only needs a pure substance for predicting components, can counteract the matrix effect, and is simple to operate; by using a headspace sampling process, the method prevents the direct solution sample from interfering with detection and from polluting the chromatographic column; and a programmed heating process is adopted to effectively separate low-boiling-point organic solvents from high-boiling-point organic solvents.

A step (1) of heating a fluoronickel compound to release a fluorine gas, a step (2) of allowing a fluorine gas to be occluded into a fluorinated compound, and a step (3) of heating the fluoronickel compound and reducing an inner pressure are conducted in a container, respectively, at least once, and thereafter a high-purity fluorine gas is obtained in the step (1). Also, a step (5) of heating a fluoronickel compound and reducing an inner pressure and a step (6) of allowing a fluorine gas reduced in a hydrogen fluoride content to be occluded into the fluoronickel compound are conducted in a container having a fluorinated layer formed on its surface, respectively, at least once, the step (5) is further conducted, and thereafter a fluorine gas containing impurity gases is contacted with the fluoronickel compound to fix and remove the fluorine gas, and the impurities are analyzed by gas chromatography.

A thermal conductivity detector includes separate sample gas and reference gas chambers. Each chamber has a gas inlet and a gas outlet and a sensor. The chambers are connected by at least one passageway. For example, a passageway can extend from the sample gas chamber to the reference gas chamber adjacent the gas inlets. As a further example, a passageway can be provided adjacent the gas outlets. More specifically, an exhaust passageway extends from the first passageway to the additional passageway and there is an exhaust outlet connected to the additional passageway.

The invention discloses a gas sensor calibration device which is convenient to calibrate, high in precision and good in using effect and a method. A constant-volume gas preparation device is designed for the problems that an existing high-precision gas preparation system is complex and high in cost, and an existing gas sensor is low in calibration precision; the gas concentration in the device is increased by precisely controlling the valve switching-on time, and then gases with the different concentrations are sequentially prepared; the gas preparation method is easy to operate and high in precision. In addition, the gas concentrations under different concentrations are detected by gas chromatograph or a calibrated sensor to serve as true concentrations, and then the sensor calibration precision is further improved. Due to the fact that the sensor has the nonlinearity, the calibration mode of the sensor is different from that of a traditional sensor, precise sensor calibration is achieved by acquiring sensor detection values and true concentration values under the different concentrations for curve fitting, and errors which are influenced by the sensor characteristics and caused by single concentration calibration are avoided.

The solid phase capillary miniature extractor includes mainly one four-way valve and one six-way valve connected via gas path; one capillary extracting column made of elastic hollow quartz capillary, stainless steel capillary or stainless steel capillary with inside quartz lining, connected to the six-way valve and with cross-linking coated fixing phase in the inside wall; one heater outside the extracting column for heating; one miniature three-way pipe connected to the extracting column, the six-way valve and conveying gas path for the desorption sample; and one conveying pipe inserted into the gas chromatographic sample injector. The liquid sample pushed by the auxiliary carrier gas enters first to the extracting column via the four-way valve and the six-way valve; the four-way valve is then turned and the extracting column is heated; and the six-way valve is finally turned for the desorbed component to enter the gas chromatographic sample injector.