55 results about "Purge and trap" patented technology

Novel metal organic framework (MOF) molecules and methods of synthesizing them are described. MOFs are organometallic crystalline structures that have high sorption capacity due to high surface area, tailorable selectivity, an inert nature, and thermal stability at high temperatures. MOFs may be used as sorbents in preconcentrators for analytical devices to provide orders of magnitude of improved sensitivity in analyte detection. MOFs are also useful as sorbents in new compact and portable micropreconcentrator designs such as a modified purge and trap system and a multi-valve microelectromechanical system (MEMS) to achieve high gain in analyte detection. Further, MOFs may be used as coatings for novel microstructure arrays in micropreconcentrators where the microstructures are designed to increase the surface area to volume ratio inside the micropreconcentrator while minimizing the pressure drop across the micropreconcentrator.

Novel metal organic framework (MOF) molecules and methods of synthesizing them are described. MOFs are organometallic crystalline structures that have high sorption capacity due to high surface area, tailorable selectivity, an inert nature, and thermal stability at high temperatures. MOFs may be used as sorbents in preconcentrators for analytical devices to provide orders of magnitude of improved sensitivity in analyte detection. MOFs are also useful as sorbents in new compact and portable micropreconcentrator designs such as a modified purge and trap system and a multi-valve microelectromechanical system (MEMS) to achieve high gain in analyte detection. Further, MOFs may be used as coatings for novel microstructure arrays in micropreconcentrators where the microstructures are designed to increase the surface area to volume ratio inside the micropreconcentrator while minimizing the pressure drop across the micropreconcentrator.

The invention discloses decompressed purge-and-trap processing equipment for a non-volatile organic compound in a water sample and a processing method thereof. The invention is characterized in that the equipment is formed by sequentially connecting a sample heater (1), a purge bottle (2), a trapper (3), a pressure controller (4) and a pump (5), wherein purge gas (6) is connected with the purge bottle (2) through a purge gas inlet (7); the purge bottle is connected with the trapper (3) through a purge gas outlet (8); the trapper (3) is connected with the pump (5) through the pressure controller (4); the gas trapped by the trapper (3) is taken out and then placed into a heater (13) of the trapper; chromatographic carrier gas (14) is connected with a chromatographic injection port (12) in a column oven (11) through the trapper (3) and a transmission pipeline (15); and the chromatographic injection port is connected with a chromatographic detector (9) through a chromatographic column (10). The processing method comprises the following steps: forming a negative pressure environment around a test sample under the action of the pump, and increasing the vapor pressure of the non-volatile organic compound under the negative pressure environment; purging the bottom of the sample by utilizing inert gas so that the target compound can be trapped by the trapper after being blown out from the sample; and finally, resolving the target compound at high temperature and then carrying out chromatographic analysis.

The invention relates to a purging and trapping thermal desorption device for switching a desorption flow path without using a valve and switching a gas flow path by using a normal temperature valve. The device is suitable for adsorption and enrichment of volatile organic compounds in liquid, solid samples or gas samples. The principle of the method comprises that: the volatile components in a sample enter an adsorption column filled with an adsorption stationary phase under the drive of a purging gas, the volatile components are adsorbed by the adsorption stationary phase, the adsorbed components are desorbed by a thermal desorption or solvent desorption method after the adsorption is finished, and the desorbed components are analyzed in a chromatographic instrument or other analysis system. The basic device comprises a steady pressure or temperature flow valve, a gas damper, a normal temperature six-way two-station valve, a purging pool, a micro tee joint with different inside diameters, an adsorption column, a heating and heat preservation box of an adsorption and enrichment column and a desorbed component sample transmission pipe.

The invention relates to an analysis method for detecting ten high-toxic disinfection byproducts in drinking water. The method comprises the steps of pretreating a sample with a purging and trapping device (P&T), then allowing the sample to enter a gas chromatograph-mass spectrometer (GC / MS) for analysis, and determining contents of the ten disinfection byproducts in the sample according to an analysis chromatogram of the sample and standard working curves of the ten disinfection byproducts. Compared with the prior art, the method adopts the purging and trapping device to gather the disinfection byproducts (DBPs) in the water, and determines instrument parameter conditions; reagents such as salt and an extraction agent are not required to be used; an experimenter is prevented from being directly contacted with toxic and harmful organic solvents; simultaneously, the sample detection time is saved; the sample detection cost is lowered; the GC / MS is adopted for measurement, and the detailed instrument parameter conditions are determined, so that phenomena such as peaking and trailing of the ten DBPs can be avoided; the normal peaking of the DBPs is ensured; and a maximum detection limit (MDL) and a smaller relative standard deviation (RSD) can be obtained.

The invention belongs to the technical field of natural environment water quality monitoring and discloses a method for determining eight kinds of common odorous substances in water simultaneously through use of a method of combining purge-and-trap and gas chromatography / mass spectrometry. The method can be adopted to determine eight kinds of common odorous substances such as dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), 2-isopropyl-3-methoxy pyrazine (IPMP), 2-isobutyl-3-methoxy pyrazine (IBMP), 2-methyl isobornyl (MIB), beta-cyclocitral, geosmin (GSM) and beta-ionone in water simultaneously. Any report on the method for determining the eight kinds of substances in one step is not present yet. The method disclosed by the invention fills the gap and can be used for quantitatively analyzing the eight kinds of odorous substances in water in one step, so that the detection efficiency is greatly increased.

The invention relates to a refrigeration-type purge and trap instrument being applicable to nitric oxide, comprising an inert gas steel cylinder, a mass flow controller, a seawater sample bottle, a gas stripping chamber, an adsorption tube, a trapping device, a control circuit board and a gas circuit formed by connecting a pipeline and an electromagnetic valve. Under the control of the mass flow controller, inert gas in the inert gas steel cylinder is filled into the seawater sample bottle, and water sample in the sample bottle enters into the gas stripping chamber under the action of pressure; the inert gas purges N2O in water body sample from the bottom of the gas stripping chamber, inert gas carrier gas carrying the N2O enters into the adsorption tube from the gas stripping chamber, and moisture and impurity of the carrier gas are absorbed and removed inside the adsorption tube; the carrier gas carrying the N2O then enters into a trapping tube of the trapping device and is used for trapping at the low temperature; after trapping, stop valves at the two ends of the trapping tube are closed, and the N2O is resolved out when the temperature of the trapping tube raises; after resolution, the stop valves at the two ends of the trapping tube are opened, and the carrier gas enters into the trapping tube and brings the N2O into gas chromatogram to be analyzed and detected.

The invention relates to a purge and trap device which comprises a U-shaped purge tube, a stainless steel tube line, a trap tube, electromagnetic valves and conversion valves. The carrier gas tube line is connected with the carrier gas inlet of the purge tube, and the carrier gas outlet, the stainless steel tube line, the first electromagnetic valve, the first conversion valve, the trap tube, the second conversion valve, the second electromagnetic valve and the air outlet at the other end of the purge tube are connected in sequence. The first conversion valve is further connected with the inlet of a chromatographic instrument, and the second conversion valve is further connected with the carrier gas tube line. The purge tube is provided with beams of quartz glass tubes with diameter of 0.175 micron, and the quartz glass tubes are sintered to a porous quartz tube sieve plate on which water sample to be tested is placed. The trap tube is filled with an adsorbent and externally sleeved with quartz tubes and spiral heating assemblies. The invention has the advantages of providing a concentration device which has simple structure and convenient use and can be directly used for chromatographic analysis to analyze trace volatile organic matters in the water sample.

A purge and trap concentrator system that includes a sparge vessel, and includes a variable gas flow valve for controlling the gas pressure in an analytic trap or the sparge vessel; a sensor that detects both a foaming sample state and a high liquid level in the sparge vessel, using one optical sensor; a control scheme that re-directs the purge gases to a second inlet of the sparge vessel during a foaming condition; a control scheme that uses a split flow to enhance the quantity of sample gases passed from an analytic trap; an electrically powered thermal energy source with a fan raising the sparge vessel temperature via thermal convection.

The invention relates to a heat purge and trap instrument, comprising a heating furnace, a sample furnace, a high-purity nitrogen gas cylinder, a transmission pipe sealably connected with the air outlet of the sample furnace, a trapping pipe sealably connected with the other end of the transmission pipe and a cooling cold trap with the trapping pipe sleeved therein. The invention also relates to a heat purge and trap method. The method successively comprises the following steps of 1. putting a to-be-tested sample in the sample furnace; 2. adsorbing materials with 80-mesh granular Tenax TA; 3. heating the sample furnace to a temperature of 180 DEG C-600 DEG C; 4. opening the high-purity nitrogen gas cylinder and the cooling cold trap, wherein the flow rate of the high-purity nitrogen gas is 20 mL / 80 min; the collecting time lasts for 30-60 minutes; and the cooling cold trap is kept at a temperature of -1.0 DEG C-15.0 DEG C. The heat purge and trap instrument and the heat purge and trap method are in no need of organic reagents and post-enrichment processes, and are suitable for the determination of volatile organic components in solid samples such as rocks, soils, coals and the like. Combined with GC / MS, the sensitivity for detecting alkane organic components is superior to 0.1 ng / g.

The invention relates to an on-line analyzer for aquatic VOCs (Volatile Organic Chemicals) based on a purge and trap-gas chromatography principle, in particular to an instrument combined with functions of automatic sampling, purge and trap pretreatment and gas chromatography. After quantitative sampling of a water sample through an automatic sampling device, the water sample is purged through controlling purge gas, a water matrix is separated and trapped by a trap after the aquatic VOCs are purged; a flow path is switched through a switch valve, so that carrier gas of a gas chromatograph passes through the trap, the trap is instantly heated to analyze absorbed organic matters, and then the carrier gas carrying the analyzed organic matters is separated and analyzed after entering a gas chromatograph analysis module. Each module is synchronously controlled by a microprocessor of the on-line analyzer for the aquatic VOCs, control software synchronously has functions of instrument operation control, and data acquisition and processing, the uniform control is realized, and the delay and the function conflict are reduced. The on-line analyzer has the advantages of simple structure, simplicity in operation, and capability of synchronously realizing sampling, pretreatment and on-line analysis of the aquatic VOCs.

The invention belongs to the technical field of analysis and detection, and relates to a detection method for volatile organic compounds in water source pollution, which is mainly used for detection of volatile organic pollutants with peculiar smell in water. The present invention establishes a purge-and-trap-GC-MS method for the determination of multi-component trace VOCs in drinking water, including steps such as sample collection, sample storage, sample measurement, standard curve formulation, and result calculation. The detection conditions of the instrument in the determination step are described in detail, providing a rapid early warning and emergency monitoring technology for sudden accidents of organic polluted water sources.

The invention discloses a method for detecting components of a flavor substance in milk, mainly comprising the following steps of: sampling a milk sample; placing the sample in a bottle; adding with NaCl, sufficiently and uniformly shaking so as to saturate the sample; sealing the bottle by a cover; purging top part volatile flavor substance by an automatic purge and trap concentrator; adsorbing the volatile flavor substance into a capillary trap which is filled with Tenax adsorbing material; stirring and heating the sample; introducing helium gas in the sample; and finally performing thermal analysis to analyze the volatile flavor substance, and automatically assaying by starting gas chromatograph-mass spectrometer (GC-MS) collecting data. The detecting method is a quick qualitative assaying method which is convenient, fast, excellent in reproducibility, short in using time and the like.

A purge and trap concentrator system that includes a sparge vessel, and includes a variable gas flow valve for controlling the gas pressure in an analytic trap or the sparge vessel; a sensor that detects both a foaming sample state and a high liquid level in the sparge vessel, using one optical sensor; a control scheme that re-directs the purge gases to a second inlet of the sparge vessel during a foaming condition; a control scheme that uses a split flow to enhance the quantity of sample gases passed from an analytic trap; an electrically powered thermal energy source with a fan raising the sparge vessel temperature via thermal convection.

The invention discloses a method for determining the migration quantity of volatile organic compounds in an adhesive sticker for a food label in a water-based food simulating object. The method comprises the following steps: performing a direct or indirect migration test on the adhesive sticker for the food label through a water-based food simulating solution; sampling the water-based food simulating solution through purging and trapping; separating 10 volatile organic compounds through HP-5ms or chromatographic columns with similar properties; performing detection through a mass spectrometry detector; performing quantification through an external standard method, wherein the 10 volatile organic compounds include nonene, 2-ethylhexanol, 1,2,4,5-tetramethylbenzene, camphor, 1-dodecene, naphthalene, 2-ethylhexyl acrylate, 1-methylnaphthalene, 1-undecanol and dodecyl aldehyde. The method is accurate in test, easy to operate, high in efficiency, quick, high in sensitivity and high in practicality, is applicable to qualitative and quantitative determination on the volatile organic compounds in the adhesive sticker for the food label through a manufacturing enterprise of the adhesive sticker for the food label and relevant government supervision departments, and can be used for avoiding harm to the physical health of a consumer caused by over-large migration quantity of the volatile organic compounds.

The invention provides a method for analyzing hexachloroethane in soil or sediment by purge-and-trap gas chromatography- mass spectrometry. The method comprises the following steps of performing purge-and-trap extraction on the hexachloroethane in the soil or sediment to obtain extracted hexachloroethane; and analyzing the extracted hexachloroethane by a gas chromatography-mass spectrometry device. The invention provides simple, high-efficient and accurate method for analyzing the hexachloroethane in the soil or sediment, purge-and-trap can be performed on the hexachloroethane in the soil or sediment, the pre-processing is simple and rapid, the semi-volatile organic compound in the soil or sediment can be effectively purged, no organic solvent is needed for extraction, so that the enrichment efficiency is high, and the method is a high-efficiency pre-processing method. The hyxachloroethane in the coil or sediment is analyzed by the gas chromatography-mass spectrometry device, and the method has the characteristics of low detection limit, high accuracy, rapidness and sensitivity.

The invention discloses a volatile fragrant component detection and analysis method and application. The method comprises the following steps: sample pretreatment: carrying out purging and trapping onsamples; carrying out separation and qualitative analysis on the samples, obtained after pretreatment, through GC-MS; and carrying out identification and confirmation on the samples, obtained after pretreatment, through GC-O. The method not only can effectively avoid interference of a high boiling point solvent, but also can obtain sensory information of components which have important contribution to aroma; the detection method is simple to operate and requires few samples; detection cycle is within 16min, and match degree of each component is higher than 80%; and the method is a fast and accurate analysis method for detecting and analyzing the aroma components in cigarette filter capsule, and meanwhile, provides good technical guidance and data support for preparation of essence of thecigarette filter capsule.

A purge and trap concentrator system that includes a sparge vessel, and includes a variable gas flow valve for controlling the gas pressure in an analytic trap or the sparge vessel; a sensor that detects both a foaming sample state and a high liquid level in the sparge vessel, using one optical sensor; a control scheme that re-directs the purge gases to a second inlet of the sparge vessel during a foaming condition; a control scheme that uses a split flow to enhance the quantity of sample gases passed from an analytic trap; an electrically powered thermal energy source with a fan raising the sparge vessel temperature via thermal convection.

The invention discloses a purging and trapping device of VOCs (volatile organic chemicals) in water and a purging and trapping method using the purging and trapping device. The purging and trapping device comprises a mixed gas carrying gas inlet, a purging pipe, a pure gas carrying gas inlet, a dehydration device, a cyclone separator and an enrichment separation device, wherein the mixed gas carrying gas inlet is connected with one end of the purging pipe; the other end of the purging pipe is connected with a water sample inlet and outlet and a purging gas outlet and is connected with the puregas carrying gas inlet and the dehydration device through a three-way valve; the cyclone separator is arranged between the dehydration device and the enrichment separation device; the tail end of theenrichment separation device is connected with a detector. The purging and trapping device has the advantages that the purging and trapping efficiency can be improved; the gas carrying consumption isreduced; the time is shortened. The mixed gas is used for purging, the mass transferring speed of the VOCs between liquid and gas is accelerated; the purging and trapping rate on the VOCs in water isincreased; the detection limit of the VOCs is improved; the evaporation quantity of water vapor can be reduced; the next water removal, trapping and detection is facilitated.

The invention relates to a method for determining volatile flavor substance of an egg yolk. In the method, an egg yolk is pretreated, and volatile flavor substance in the egg yolk is collected by a purge-and-trap method and then is determined. The volatile flavor substance is determined by adopting a thermal desorption-gas chromatography-mass spectrometer (TCT-GC-MS). By understanding the components of the volatile flavor substance in the egg yolk, feeds can be prepared or a breeding means can be adopted by people as required to make laying hens produce eggs with different flavors so as to produce the eggs with unique flavor and the egg products thereof by a simpler and safer method.

The invention discloses a purge-and-trap detection method of volatile flavor substances in a sour-dough steamed bun. The method comprises the steps as follows: after the sour-dough steamed bun is cooled and diced, a purge-and-trap device is adopted to collect the volatile flavor substances; and a gas chromatography-mass spectrometry technology is adopted to evaluate the volatile flavor substances. According to the method, an organic solvent is not required, the sampling quantity is small, the enrichment efficiency is high, matrix interference is little, trace component loss can be effectively reduced, and the detection rate of trace components is increased.

The invention discloses a method for measuring the migration quantity of benzene series in a food processing electric appliance on the basis of a dynamic headspace-gas chromatgraphy mass spectrometrometry technology. The method comprises the following steps that food simulation liquid is subjected to migration when a stirring machine is in a normal work state; migration liquid is obtained; the migration liquid is subjected to dynamic headspace purge and trap sampling; the gas chromatography-mass spectrometrometry detection is used; an external standard method is used for quantification. The method for measuring the migration quantity of the benzene series in the food processing electric appliance on the basis of dynamic headspace has the advantages that the operation is simple; the speed is high; the environment is protected; the sensitivity is high; the method can be used for the migration quantity detection of the benzene series in a domestic blender.

The invention relates to a method for detecting benzene series in a biological sample blood. The method for detecting benzene series in a biological sample blood is a method for simultaneously detecting the content of six benzene series in the blood by a purging and trapping / gas chromatography / mass spectrometry technology. Purging and trapping experiment conditions are optimized to enrich and desorb the six benzene series in the blood, and qualitative and quantitative analysis is carried out by gas chromatography / mass spectrometry and isotope internal standard method selected characteristic ions. The method has the advantages of simplicity in operation, short analysis period, good separation degree, and high accuracy and precision meeting the requirements of analysis and testing, and is suitable for the simultaneous detection and analysis of the benzene series in the biological sample blood.

The invention relates to an environmental protection technology, and provides a volatile gas collecting trap and a volatile gas purging and trapping device. The volatile gas collecting trap comprises a trapping tube, a heat conduction layer and a heating layer; the trapping tube internally comprises an adsorbent, the trapping tube is U-shaped, the heat conduction layer wraps the trapping tube, the heating layer comprises an electric heating wire, and the heat generated by the electric heating wire is conducted to the trapping tube through the heat conduction layer; the electric heating wire comprises an electric heating wire body, an insulating heat conduction film and a tube shell; the tube shell comprises an inner tube cavity, the electric heating wire body penetrates through the inner tube cavity, and the insulating heat conduction film wraps the electric heating wire body and is located between the tube shell and the electric heating wire body. According to the trapping trap of a novel structure, the novel electric heating tube is adopted, rapid heating can be achieved, the actually measured heating rate can reach 30 DEG C / s, and the desorption efficiency of the trapping trap can be remarkably improved.

The invention discloses a method for detecting myrcene in soil by combining purging and trapping with GC-MS. The method comprises the following steps: firstly, collecting a soil or sediment sample, removing foreign matters, and adding 5.0 g of the sample into 5mL of ultrapure water; then placing the obtained sample in a purging and trapping sample injector, setting purging and trapping conditions to perform purging and trapping on the sample, purging myrcene in the sample out and entering a gas chromatograph-mass spectrometer, and setting chromatographic conditions of the gas chromatograph-mass spectrometer to analyze myrcene. According to the method, purging and trapping are combined with GC-MS, the detection efficiency is improved, the detection precision is greatly improved, the method is low in detection limit and good in repeatability, and myrcene in soil or sediment can be independently detected with high precision.

The invention discloses a method for analysis of thiophene in water by purge and trap coupled with GC-MS, the method is as follows: firstly, adding a proper amount of methanol as a preservative into a collected water sample, taking 20ml of the water sample into a sample bottle, adding 0.2g of sodium chloride, gently shaking to dissolve the sodium chloride, adding an internal standard solution, and sealing the sample bottle; putting the sample bottle into a purge and trap sample injector, setting purge and trap conditions, and performing purge and trap on the sample bottle to purge the thiophene out of the water to enter a gas chromatograph-mass spectrometer GC-MS; setting conditions of gas chromatography and mass spectrometry conditions of the gas chromatograph-mass spectrometer, analyzing the thiophene according to the set conditions, qualitatively analyzing the thiophene in the water sample according to retention time and ion fragments, and quantitatively analyzing the response value of the thiophene in the water sample by an internal standard method. By the purge and trap coupled with GC-MS, the thiophene is separated from the water, and quantitative and qualitative detection of the thiophene in the water are realized. The detection efficiency is improved, the experimental process is simplified, and the detection accuracy is improved.

The invention discloses a method for measuring trace chlorobenzene in hydrogen chloride gas, and a pretreatment method thereof. The pretreatment method comprises the following steps: dissolving a hydrogen chloride gas sample into an alkaline water solution, and evenly mixing the alkaline water solution with acetone so as to obtain an absorption liquid; wherein the alkaline contains enough moles of alkaline substances to totally neutralize the hydrogen chloride in the hydrogen chloride gas, and the volume of acetone is more than or equal to 0.1 mL for each 300 mL of the alkaline water solution. The method comprises the following steps: subjecting the absorption liquid to a purge and trap treatment, and then carrying out gas chromatography-mass analysis. The method is harmless to detection instrument, and the detection limit can reach a ppb grade.

The invention relates to a method for rapidly determining the content of phenol in wastewater by purge and trap-gas chromatography-mass spectrometry, which comprises the following steps: 1) collecting a wastewater sample, adding phosphoric acid, and adjusting the pH value of the wastewater sample to weak acidity; (2) purging phenol in the wastewater sample by using a purging and trapping sample injector, trapping the phenol by using a trapping trap, and then analyzing the phenol to enter a gas chromatograph-mass spectrometer; and (3) carrying out qualitative and quantitative analysis on the phenol trapped by the trapping trap by using a gas chromatograph-mass spectrometer. Compared with the prior art, the method for measuring the phenol content in the industrial wastewater is simple, rapid, efficient and accurate, the wastewater with complex components and high organic matter concentration can be directly purged, the pretreatment processes such as separation and purification are omitted, an organic solvent is not needed for extraction, the detection cost is reduced, and the method is suitable for large-scale popularization and application. The time for detecting a group of water samples is shortened from two hours to about 30 minutes, and the detection limit is 0.01-1 mg / L.

The invention discloses a purge and trap method for aroma components in tobacco and tobacco products. A sample is subjected to ultrasonic water bath extraction to obtain an extract liquid, and then issubjected to purge and trap under a salting out condition. The method specifically includes the following steps: performing shearing treatment on a tobacco treatment; performing high temperature ultrasonic extraction in water; adding salt to the extract liquid; performing the purge and trap; performing desorption on the aroma components through thermal analysis; and detecting by utilizing a gas chromatography / mass spectrometer, thereby achieving qualitative and quantitative analysis of the aroma components. Compared with the prior art, in the purge and trap method of the invention, organic reagents are not utilized in an extraction process of the aroma components, thus preventing loss of a part of the aroma components and environmental pollution. The purge and trap method achieves fast and accurate analysis of a plurality of aroma components, and has the advantages of multiple detection components, high sensitivity, accurate quantification, simple and rapid operation, and the like.

The invention discloses a method for detecting lead tetraethyl in water, which comprises the following steps: (1) preparing a lead tetraethyl standard solution, and putting the lead tetraethyl standard solution in a sample bottle; (2) firstly adding methanol into the sample bottle, and then adding a water sample to obtain a detection water sample; (3) analyzing the standard solution obtained in the step (1) by using purge and trap-gas chromatography / mass spectrometry, and obtaining a linear regression equation y = b*x + a according to the concentration of the standard solution and the peak area generated by the instrument, where x is the concentration of lead tetraethyl, and y is the peak area; and (4) analyzing the detection water sample in the step (2) by using purge and trap-gas chromatography / mass spectrometry, and calculating the concentration of lead tetraethyl in the sample by using the regression equation in the step (3). The problems of tedious operation steps and low precision and sensitivity of a detection method in the prior art are solved.