57 results about "Discharge ionization detector" patented technology

The invention discloses a gas chromatography valve path system for analyzing multiple high-purity fluorine-containing electronic gases and a using method of the system. The system comprises 2 four-way valves, 2 ten-way valves, 1 eight-way valve, 1 quantitative ring, 4 chromatographic columns, 14 pressure balance regulation valves and 1 discharge ionization detector; and the carrier gas of the system is high-purity helium. According to the invention, a five-valve four-column valve path system is adopted, and the measurement of multiple gas-phase impurities can be finished by once sample introduction. The valve path system is convenient to operate and applicable to the industrial production in the field of high-purity fluorine-containing electronic gases.

The invention relates to a field gas chromatograph with flame ionization for the analysis of a gaseous mixture of hydrocarbons, extracted, in particular, from oil drilling mud. Said mixture consists of a fraction of heavy hydrocarbons (beyond pentane) dissolved in mud in gaseous form. Said field gas chromatograph is made up of two independent analysis circuits, dephased by half a cycle and synchronised one with the other. Said analysis circuits are comprised of at least one sampling cell in a preferred design layout, at least one capillary separation chromatography column, at least one flame ionization detector, and at least one electrometer for the conversion of an electrical current, collected by the flame ionization detector, into a voltage signal describing a chromatogram.

Provided is a discharge ionization current detector. To reduce the cost of a high-voltage power supply unit by reducing the discharge starting voltage for a low-frequency dielectric barrier discharge. Light from light source unit (20) located externally to cylindrical tube (2) through which a plasma gas (He) flows is irradiated through the wall surface of the cylindrical tube (2) onto a plasma generation region (the region between plasma generation electrodes (6 and 7) located in gas flow path (4). The light energy excites the He molecules or the minute quantities of impurity gas molecules present in the He gas, causing photo-ionization. This causes a discharge to start, and a plasma to be formed, when a low-frequency voltage of a voltage that is less than the usual discharge starting voltage is applied across electrode (5) and electrodes (6, 7). Once the discharge starts, the discharge is sustained when the usual discharge sustaining voltage is applied across electrode (5) and electrodes (6, 7). This means that the light source unit (20) has to be on only for a short duration when discharging is started.

A gas chromatography-quadrupole time-of-flight mass spectrometry/flame ionization detection method of flavor components in cigarette mainstream smoke comprises the following steps: collecting the flavor components in the cigarette mainstream smoke through adopting a Cambridge filter, extracting the flavor components with dichloromethane or n-hexane, taking the obtained extract liquid, analyzing the extract liquid, and allowing the obtained sample to undergo chromatographic column separation and to enter a quadrupole time-of-flight mass spectrometer (QTOF MS) and a flame ionization detector (FID) for determination in order to realize accurate qualitative diagnosis and quantification of the flavor components in cigarette mainstream smoke. The gas chromatography-quadrupole time-of-flight mass spectrometry/flame ionization detection method is applied to determination of the flavor components in cigarette mainstream smoke for the first time, and a QTOF MS spectrogram and an FID spectrogram can be simultaneously obtained only through one-shot sample introduction; and the components of a complex sample can be accurately characterized through the QTOF MS, a sample with very wide concentration range can be accurately quantified, and the retention times of the two spectrograms are completely same, so accurate qualitative diagnosis and quantification of the flavor components in cigarette mainstream smoke can be realized.

A discharge ionization current detector is provided with a dielectric tube through which plasma generating gas flows, a plasma generating unit formed from one section of the dielectric tube in a flow direction of the plasma generating gas, a casing connected to a lower end portion, in the flow direction of the plasma generating gas, of the dielectric tube, a sample ionization unit provided inside the casing, and an ion current detection unit for detecting a sample component ionized by the sample ionization unit. The lower end, in the flow direction of the plasma generating gas, of the dielectric tube protrudes into the space inside the casing.

A pulsed discharge helium ionization detector for gas chromatography with multiple combined bias/collecting electrodes.

The invention discloses a cooling oil content measuring method. The cooling oil content measuring method comprises a step of qualitative and quantitative analysis on one or more ingredients of menthol, camphor, eucalyptol and eugenol. The method comprises the following specific steps: (1) taking the menthol, the camphor, the eucalyptol and the eugenol as reference objects; (2) treating a cooling oil sample by using a solvent, and then detecting the cooling oil sample by using a GC (Gas Chromatography) method; (3) a GC measuring method is as follows: a chromatographic column and a detector are used, wherein the chromatographic column is an HP-INNO WAX capillary column; the detector is a flame ionization detector; the temperature of the detector is 250-300 DEG C, the temperature of a sample inlet is 220-270 DEG C, the temperature of the column is increased in a programmed manner from an initial temperature of 60-110 DEG C to 220-280 DEG C, the temperature is increased by 5-15 DEG C every minute and kept for 8-20 minutes; sampling mode: split sampling is adopted, and the split ratio is 20:1. The method is scientific, reasonable, simple, convenient, easy to implement and suitable for quality control of volatile components including the menthol, the camphor and the like of the cooling oil and relevant extractives.

The invention provides a method for analyzing contents of trace arsine and phosphine in gas-phase propylene by a gas chromatograph. A detector of the gas chromatograph is a helium discharge ionization detector. The method comprises the steps as follows: 1) setting the parameters of a gas purifier and the gas chromatograph; 2) preparing standard gas with the content of arsine or phosphine being Cs and measuring the peak area As which corresponds to arsine or phosphine in the standard gas by the gas chromatograph; 3) taking the propylene to be detected, preparing gas to be detected, and measuring the peak area Ai which corresponds to arsine or phosphine in the gas to be detected by the gas chromatograph; and 4) determining the content Ci of arsine or phosphine in the gas to be detected, in accordance with the formula that Ci is equal to Cs*Ai/As. By the combination of the gas chromatograph and the helium discharge ionization detector, the component changing of a sample can be sensitively, rapidly, correctly and continuously reflected, arsine and phosphine can be detected simultaneously, the amount of the needed samples is small, and other toxic and harmful chemical agents are not needed. Therefore the method is safe and sanitary and can timely and effectively guide technological production.

The flame ionization detector consists of sample port, hydrogen port, nozzle, air port, igniting coil and collector electrode, as well as nozzle cap, spring and shaft. Of the flame ionization detector, the shaft with flange is connected to the negative high voltage power source, the nozzle with nozzle cap possessing through hole constitutes the polarizing electrode, the spring has one end contacting the nozzle cap and the other end contacting the flange, and the igniting coil is mounted over the collector electrode. The present invention has high signal collecting efficiency of the collector electrode, lowered noise interference, and high sensitivity.

Disclosed is a gas chromatography-quadrupole time-of-flight mass spectrometry/ flame ionization detection method for tobacco essence perfume. The method includes subjecting the tobacco essence perfume to organic solvent extraction and centrifugation, taking an organic solvent layer to analyze, regulating tail-end distribution of a chromatographic column through a capillary flow technology after the sample is subjected to chromatographic column separation, and determining by a QTOF MS (quadrupole time-of-flight mass spectrometer) and FID (flame ionization detector) to achieve accurate qualitativeness and quantitativeness of the tobacco essence perfume. The gas chromatography-quadrupole time-of-flight mass spectrometry/ flame ionization detection method is put forward for the first time and is applied to determination of the tobacco essence perfume, QTOF MS and FID spectrograms can be obtained simultaneously only by one-needle sample injection, QTOF MS can determine components of complicated samples accurately, the FID is capable of qualifying the sample with wide concentration range accurately, and the retention time of the QTOF MS spectrogram and the retention time of the FID spectrogram are the same, so that accurate qualitativeness and quantitativeness of complicated tobacco essence perfume samples can be achieved.

The invention discloses a high-purity nitrogen trifluoride analysis oxygen-free adsorption gas chromatography valve path system and a use method thereof. The valve path system using four valves and four posts comprises two four-way valves, two ten-way valves, two quantitative rings, four chromatographic columns, 11 pressure balance regulating valves and one discharging ionization detector. The system carrier gas is high-purity helium with the purity higher than 99.9999 percent. The system has the advantages that simplicity is realized; the operation is convenient; the analysis is accurate.

To suppress baseline current other than baseline current derived from the ionization of impurities, and to achieve the enhancement of the SN ratio of a detection signal and the improvement of the lower limit of detection, the inner diameter of a bias electrode for collecting an ion derived from a sample component is made smaller than the inner diameter of an insulating member separating the bias electrode and a collector electrode. Light emitted from plasma formed by dielectric barrier discharge is shielded by the bias electrode, so that the light is not cast directly on the surface of the insulating member. Therefore, the photoelectric effect caused by casting light of high energy does not occur on the surface of the insulating member, whereby a decrease in electric resistance of the surface can be prevented.

The present invention refers to a surface ionization detector comprises an emitter, a heating rod, a collecting electrode, a reducing liner and a housing. The emitter is made of molybdenum, platinum or alloy, and in the form of cylinder or a wire spiral. The heating rod heats and supports the metal emitter. When the heating rod is heated to 300-500° C., organic amine compounds collide with the surface of the emitter, generating positive ions through surface thermal ionization and thus are detected. The lowest detecting limit value of tertiary amine by the detector in the present invention can achieve to 10⁻¹⁴ g/s. The response to other hydrocarbons, ketones, etc., is 5-6 orders of magnitude lower than that of organic amines. The detector can selectively detect amines, hydrazines and their derivatives, and so on. The detector can be used as a detector for a gas chromatography system adopting capillary column or packed column, or alternatively be used alone as a sensor.

The invention provides a method for testing oxynitride in the environment. The test method comprises the following steps: nitric oxides in a standard sample are sent to a chromatographic test column by a discharge ionization detector and through steps of isolation and cutting reverse blowing, and standard chromatograms of all the nitric oxides in the standard sample are obtained; peak areas of all the nitric oxides in the standard sample are obtained according to the standard chromatograms, and correction factors of all the nitric oxides are calculated according to the peak areas of all the nitric oxides in the standard sample and the concentration of all the nitric oxides in the standard sample; to-be-tested gas is tested with gas chromatography test conditions which are same with the standard sample, test chromatograms of nitric oxides in to-be-tested air are obtained, and the concentration of each nitric oxide which is equal to the correction factor multiplying the peak area of the corresponding nitric oxide in the to-be-tested gas is calculated according to the peak areas of all the nitric oxides in the test chromatograms. The test method has the advantages that the sampling process is simple and rapid, the accuracy and the sensitivity are high, the detection limit is low and the like.

A dielectric barrier discharge ionization detector Includes: a dielectric tube; a high-voltage electrode connected to an AC power source and circumferentially formed on the outer wall of the dielectric tube; upstream-side and downstream-side ground electrodes and circumferentially formed above and below the high-voltage electrode; a discharging section for generating electric discharge to create plasma, from a gas containing argon; and a charge-collecting section for ionizing sample-gas components by the plasma and detecting an ion current formed by the ionized components. The detector also satisfies one or both of the following conditions: the upstream-side ground electrode is longer than a creeping discharge initiation distance between a tube-line tip member at the upper end of the dielectric tube and the high-voltage electrode; or the downstream-side ground electrode is longer than a creeping discharge initiation distance between the high-voltage electrode and the charge-collecting section.

The invention discloses a fireproof and anti-blocking structure of a combustion chamber of a hydrogen flame ionization detector, which comprises a combustion chamber gas inlet, a hydrogen gas inlet and a sampling gas inlet; a combustion chamber, which also includes a combustion chamber base and a cavity; an ignition system, which also includes thermocouples and ignition coils; and combustion chamber gas vents; also includes fireproof and anti-blocking structures. The fire-proof structure includes the fire-proof structure body and the fire-blocking sheet. The fire-blocking sheet is a mesh ventilation sheet installed on the main channel of the combustion chamber gas discharge port; the anti-blocking structure includes the anti-blocking structure body and the bypass of the combustion chamber gas discharge port The channel, the bypass channel of the gas discharge port of the combustion chamber is to increase N through holes on the side of the main channel of the gas discharge port of the combustion chamber, preferably N is taken from 2-4. The invention is simple in structure and easy to use, ensures that the FID combustion chamber can fully burn without extinguishing the flame, and at the same time isolates the communication between the flame and the outside world, prevents the flame from escaping from the combustion chamber, and avoids safety problems such as fire and explosion.

A discharge ionization current detector of the present invention is used for a detector for a gas chromatograph and suitable for analyzing high-boiling components. A discharge ionization current detector 10 is mainly constituted by a plasma generating section 20 and an ion collecting section 30. Regarding the ion collecting section 30, an ion collecting electrode 31 and a bias electrode 32 are arranged, and furthermore, an insulating member made of sapphire or aluminum oxide having a purity equal to or greater than 99.5% is arranged between the ion collecting electrode 31 and the bias electrode 32.