Device for preparation of a calibration gas mixture of substances
(57) Abstract:Use: for preparation of calibration gas mixture of substances and can be used in the calibration of gas analyzers. The inventive device for preparation of calibration gas mixture contains a vessel to saturate the gas vapors of a substance, a device for mixing gas with pairs of substances made in the form of a tee. One channel of the tee is connected to the atmosphere through an adjustable pneumatic resistance, another channel through the opening in the cover is introduced into the upper part of the inner volume of the vessel, and the third channel of the tee is connected with a gas line for output vapor-gas mixture. Vessel to saturate the gas pairs substances made in the form of a Dewar vessel. The lid is made of elastic insulating material and on the edge of the cover are circular protrusions covering the top edge of the Dewar vessel. The technical result of the invention consists in ensuring the constancy of the concentration of vapor in the gas when the temperature of the environment without the use of special heating and cooling devices provided with means for heat supply, measurement and control of temperature. 3 C.p. f-crystals, 1 Il. A device for the preparation of vapor-gas calibration mixtures of substances containing vessel to saturate filled with particles of a fluorinated carbon between the layers of which is placed a starting material, a gas line for supplying gas into the vessel, a gas line for output vapor-gas mixture from the vessel, a device for heating the vessel and the pump gas flow (see C-ku TU 0500938 A1, G 01 N 30/04, 1992).A disadvantage of the known device is the limited functionality. This is because the known device allows you to change the concentration of vapor of the substance in the gas in a very narrow limits, as the change in concentration is provided only by the temperature change of the vessel to saturate.In addition, the known device has a rather complicated structure due to the availability of devices for heating the vessel to saturate and maintain its temperature at a given value.Closest to the proposed device is a device for cooking kalibrovochnom, the cover overlying the neck of the vessel, a gas line for supplying gas into the vessel to saturation, gas line for output vapor-gas mixture from the vessel and a device for dilution of the gas mixture (see the company's catalog CAVKIT Ltd. (England) on the generators of gauge vapour in the air, 1997).A disadvantage of the known device, taken as a prototype, is that when changing the ambient temperature is the temperature change substance and, therefore, changes its concentration in the gas mixture. To set the previous value at which the calibration, you must perform additional configuration by adjusting pnevmoobrushenija. To maintain a constant temperature substances vessel for saturation should be placed in a special thermostat that significantly complicates the design of the device as a whole and increases its cost.The objective of the invention was to develop such a device for preparation of a calibration gas mixture of substances, which ensures the maintenance of the constancy of the concentration of the gas mixture when the temperature of the ambient air without the use of special termostatico>/P>This task is solved in that the device for preparation of a calibration gas mixture of substances containing vessel to saturate the gas pairs substances, partially filled with the substance, the lid overlying the neck of the vessel, a gas line for supplying gas into the vessel, a gas line for output vapor-gas mixture and a device for diluting the gas mixture further gas flow, which according to the invention the vessel to saturate the gas pairs substances made in the form of a Dewar vessel, and a device for dilution of the vapor-gas mixture, an additional gas flow is made in the form of a tee, one channel of which is connected with the atmosphere and it has adjustable pneumatic resistance, the other end of the tee is connected through a hole in the lid with the upper part of the inner volume of the vessel, and the third channel of the tee is connected with a gas line for output vapor-gas mixture
Another distinctive feature of the proposed device is that the cover is made of elastic insulating material.Among the differences, it should be noted that the edge of the lid is made annular projections covering the top edge of the Dewar vessel.Another>Due to the above implementation, the proposed device provides a constant temperature in the internal volume of the vessel to saturate the gas pairs substances without the use of complicated and expensive devices for temperature control.The invention is illustrated by the drawing, which shows a view of the device partially schematically and partially in section. The device comprises a vessel 1 for saturation of gas pairs substances made in the form of a Dewar vessel, partially filled with the substance 2. The substance can be used in liquid form and in the form of a solution in a suitable solvent or in the form of a sorbate, applied and evenly distributed on the sorbent. The vessel 1 is equipped with a cover 3 made of heat-insulating elastic material. The cover 3 has a hole with shrunk in a constant pneumatic resistance 4, through which the capacity of the vessel 1 hits air.The edges of the cover 3 provided with annular projections 5 and 6 covering the upper edge of the vessel 1. Between the annular projections 5 and 6 posted by annular gasket 7 of elastic material (rubber, etc.,) that performs the sealing function of the seal. The CD is th internal volume of the vessel 1. The device 8 is made in the form of a tee having three gas channel 9, 10, 11.Gas channel 9 is connected with the atmosphere through the opening 12 by an adjustable pnevmoobrushenija, the role played by changing the length of the gap between the projections of the helical surface of the screw 13 and the grooves cut in the channel 9.The upper threaded portion of the channel 10 is used for input of a solution of the substance in the vessel 1 and is sealed by the screw 17 through the elastic seal 18. In the lower part of the channel 10 plated metal tube 19, the lower section of which in the working position is at a distance of 10-15 mm from the surface of the substance 2, and the top does not cover the intersection with channel 9. Channel 11 also plated metal tube 20 connected to the gas line 14 is installed in it consumption booster 15. The internal section of the tube is at a distance from the intersection of the channels 10 and 11.Output consumption booster 15 is connected to the detector 16 for measuring the concentration of vapor in the gas, such as photoionization detector. The device operates as follows.Unscrew the ring screw 17 through the channel 10 and the tube 19 into the vessel 1 using a pipette or syringe (damn the 17, screw up it and include booster 15 gas flow. Under the action of the pump 15 of the gas flow in the internal channels of the fixture 8 vacuum is created, which in the channel 10 receives a mixture of air with pairs of substances that are in dynamic equilibrium with the solution of the substance in the vessel 1. Because the substance is in a Dewar vessel, its temperature is very weakly dependent on the ambient temperature. This provides a constant vapor pressure above the liquid surface, i.e. the constancy of the concentration of the substance in the flow of the mixture channel 10. Through the pneumatic resistance 4 in the vessel 1 is fed air to equalize the pressure in the vessel 1 with the atmospheric pressure. Although the temperature may differ from the temperature of the substance 2 in the vessel 1, it has almost no influence on the temperature of the substance 2 because of the small values of the heat capacity of air and the small flow rate. Under the action of the same vacuum gap formed by the screw threads 13 and threaded on the inner surface of the channel 9, the tee through the hole 12 receives air which mixes with the vapors of the substance flowing through the channel 10 forms a gas-vapor mixture. Gas-vapor mixture through the channel 11, the tube 20 and the gas is Concentratio vapor in the gas (air) change by regulating the depth of screwing of the screw 13 in the channel 9 of the device 8. By changing the depth of screwing of the screw 13 in the channel 9 changes the length of the gap formed by the screw threads 13 and threaded channel 9 and, therefore, the value of resistance to flow of gas (air) in the channel 9. The concentration of vapor of the substance in the gas (air) in the proposed device can be changed also by changing the concentration of the substance in the solution introduced into the vessel. This provides the possibility of changing the concentration of vapor of the substance in the gas in a very wide range (up to three orders of magnitude). For substances such as benzene and hexane, the range is from 1 to 300 mg/m3.Using the proposed device in laboratory conditions, where no sharp fluctuations in the ambient temperature, the proposed device provides for the maintenance of the concentration of substances in the gas mixture at a constant level within 8-10 hours of continuous operation.The vessel 1 when removing the device 8 may be partially pre-filled with adsorbent (e.g. activated carbon) coated and evenly distributed volatile component (or its solution). Then set the device 8 to the vessel 1, turn off the booster 15 flow fixion volatile substance and its vapor phase. After that, the generator is ready for operation. 1. Device for preparation of a calibration gas mixture of substances containing vessel to saturate the gas pairs substances, partially filled with the substance, the lid overlying the neck of the vessel, a gas line for supplying gas into the vessel, a gas line for output vapor-gas mixture and a device for diluting the gas mixture further gas flow, characterized in that the receptacle for the gas saturation pairs of substances made in the form of a Dewar vessel, and a device for dilution of the vapor-gas mixture, an additional gas flow is made in the form of a tee, one channel of which is connected with the atmosphere, and it has adjustable pneumatic resistance, the other end of the tee is connected through a hole in the lid with the upper part of the inner volume of the vessel, and the third channel of the tee is connected with a gas line for output vapor-gas mixture.2. The device under item 1, characterized in that the cover overlying the neck of the vessel is made of elastic insulating material.3. The device under item 1 or 2, characterized in that the edge of the lid is made annular projections covering the top edge of the Dewar vessel.
FIELD: chemical technology.
SUBSTANCE: invention relates to a method for synthesis of ester perfluorinated derivative by using a chemical reaction. This reaction represents the fluorination reaction of the parent compound as a raw, the reaction of chemical conversion of fragment of ester perfluorinated derivative to yield another ester perfluorinated derivative or the interaction reaction of carboxylic acid with alcohol under condition that at least one or reagent, i. e. carboxylic acid or alcohol, represents a perfluorinated compound wherein indicated perfluorinated derivative of ester represents a compound comprising a fragment of the formula (1):
with a boiling point 400°C, not above. The reaction time for carrying out abovementioned chemical reaction is sufficient to provide the required yield of ester perfluorinated derivative and wherein this yield of ester perfluorinated compound is determined by the gas chromatography method by using a nonpolar column. Also, invention relates to a method for pyrolysis of ester perfluorinated derivative with a boiling point 400°C, not above, to yield the dissociation product wherein this product represents a derivative of acyl fluoride or ketone and wherein pyrolysis time is sufficient to provide the required degree of conversion of ester perfluorinated derivative and wherein the indicated conversion degree of ester perfluorinated derivative is determined by gas chromatography method by using a nonpolar column. Also, invention relates to a method for analysis of ester perfluorinated derivative with a boiling point 400°C, not above, that involves analysis of ester perfluorinated derivative in a sample containing ester perfluorinated derivative by gas chromatography method by using a nonpolar column wherein ester perfluorinated derivative represents compound comprising a fragment of above given formula (1).
EFFECT: improved method of synthesis.
8 cl, 1 dwg, 2 ex
FIELD: instrument engineering.
SUBSTANCE: device for generating flow of vapor-gas mixture with preset concentration of vapor has vessel partially filled with fluid, second vessel provided with branch pipes for supply and removal of gas, and vapors of fluid pipeline-leak. One of vessels is connected with gas discharge forcer; fluid vapors pipeline-leak connects both vessels. Vessel, partially filled with fluid, is mounted inside second vessel. Pipeline-line, connecting both vessels, is totally placed inside second vessel. Device is also provided with additional discharge forcer for adjusting concentration of fluid vapor in second vessel. Granulated filler is introduced into vessel partially filled with fluid. Device is also provided with gas analyzer for providing gas concentration in space of second vessel.
EFFECT: higher precision of keeping of preset concentration of vapor; improved efficiency of vapor concentration control and adjustment.
FIELD: instrument engineering.
SUBSTANCE: invention is designed for calibrating gas analyser detectors, according to which there prepared is calibration substance solution with concentration A=By/k (%) as per Henry constant value k (mg/m %) at calibration temperature and as per the specified value of calibration substance mass concentration in calibration steam/gas mixture By (mg/m). After the solution has been introduced into the vessel in quantity enough for fully saturated equilibrium calibration steam/gas mixture to appear above the solution surface, the sensor calibration is carried out by means of mixture; at that, mixture concentration is changed by means of direct proportional change of solution concentration by diluting concentrated reference solution of calibration substance with analytical accuracy up to the specified concentration value A (%). There also proposed is the device for realising this method, which includes a solution point for preparing calibration solution with analytical accuracy, vessel with thermostatic device for obtaining steam/gas mixture with constant concentration corresponding to Henry law; at that, solution point includes graduated dose metre, graduated diluter, mixer with a reducer, capacity with solvent, and reference container with reference solution, which is stabilised with a gate valve meant for multiple use of container, and vessel with thermostatic device consists of thermometre and heat-insulating cover plate with an inlet branch pipe containing a normally closed return valve and a pusher for valve opening.
EFFECT: decrease of calibration substance losses; accuracy and reproducibility of metrological performance, and meeting requirements of industrial and ecological safety.
6 cl, 2 dwg
SUBSTANCE: vapour-gas mixture source has a mixer which has connecting pieces for inlet and outlet of the vapour-gas mixture. The vapour-gas mixture source also has a diffusion pipe filled with working fluid and an auxiliary pipe designed for filling the diffusion pipe with working fluid. Part of the diffusion pipe is filled with substance which retains the working fluid. The level of working fluid in the auxiliary pipe is lower than the level of substance in the diffusion pipe. The substance which retains the working fluid used can be sand, granular material with particle size between 10 and 10000 mcm, porous substances, e.g. ceramic metal etc.
EFFECT: more accurate measurement and maintenance of concentration of the vapour-gas mixture coming out of the source, provision for constant diffusion flow of vapour of working fluid into the mixer.
11 cl, 2 dwg
SUBSTANCE: invention relates to laboratory methods of analysis and deals with method of quantitative determination of manganese, lead and nickel in bile by method of atomic-absorption analysis with atomisation in flame. Essence of method lies in the following: sampling of bile is carried out during duodenal probing, after that it is frozen, and unfrozen at room temperature, homogenisation of bile by mixing being performed already at partial soft unfreezing. After that, sampling of homogenised bile is carried out for preparation for analysis, concentrated nitric acid is introduced into it with volume ratio 1:1, mixture is kept at room temperature, then heated and further mixture is kept for not less than 2.5 hours at room temperature. In order to obtain analyte, to obtained mixture added is concentrated hydrogen peroxide in volume ratio 1:1 to volume of bile sample volume, analyte is heated, after that cooled to room temperature. After that by method of atomic-absorption spectrometry, using graduated diagram, quantitative content of particular type of metal: manganese, lead and nickel is determined in analyte.
EFFECT: invention allows increasing accuracy of quantitative determination of manganese, lead and nickel in bile.
FIELD: engines and pumps.
SUBSTANCE: proposed method is based on application of simplified model of intake of admixtures into cabin which allows for only oil decomposition products in gas turbine engine. Major portion of air samples, 95-97%, required for identification and quantitative determination of oil decomposition products, is sampled on surface from device simulating oil decomposition conditions including air temperature and pressure at point of sampling from engine compressor, and oil stay time in hot zone.
EFFECT: decreased time of in-flight experiments and that of surface analysis of samples.
1 cl, 1 ex, 1 tbl, 1 dwg
SUBSTANCE: invention relates to analytical chemistry, particularly to methods of determining benzoic acid, and describes a method for quantitative determination of benzoic acid from a methyl derivative thereof - methyl ether in aqueous matrices with determination sensitivity of 5.0·10-5 mg/cm3 with determination error of not more than 25%. The method is characterised by that quantitative determination of benzoic acid is carried out using a chromatographic method with flame-ionisation detection and includes the following steps: extraction concentration of an analyte with benzene in water samples acidified with 25% sulphuric acid solution to pH 1-3 while adding sodium chloride until a saturated solution is obtained, conducting a benzoic acid methylation reaction with diazomethane to obtain a derivative - methyl ether of benzoic acid and determining the formed methyl ether of benzoic acid by a chromatographic method with flame-ionisation detection.
EFFECT: method provides high sensitivity, selectivity and easy implementation during quantitative determination of benzoic acid in aqueous media and enables use thereof in practice in factory analytical laboratories, central laboratories of chemical companies and chemical-toxicology laboratories.
1 ex, 3 tbl
SUBSTANCE: device for preparing control gas mixtures comprises a gas mixer, at least one channel for supplying target gas to the gas mixer, at least two channels for supplying the diluent gas to the gas mixer, and the channel for output of the gas mixture from the gas mixer. And in each channel for supplying gas to the gas mixer the mass flow controller of gas and a solenoid valve are mounted successively, at least in one channel for supplying the diluent gas to the gas mixer the gas humidifier and the solenoid valve are mounted successively. In each of the channels equipped with the gas humidifier at least one bypass pipeline with the additional solenoid valve is mounted. and the output of the gas flow controller of this channel is connected to the input of the additional pipeline which output is connected to the output of the last solenoid valve, and at the input of the target gas and the input of the diluent gas at least one filter is mounted, which outputs are connected to the inputs of manually operated valves.
EFFECT: possibility of operational automated obtaining the dry or moist gas mixture, and reliable obtaining of the given values of concentrations of gas mixtures at the output of the device.
SUBSTANCE: each blood sample is analysed twice. A fresh blood sample is centrifuged at 2,000 rpm for 5 min. The samples are separated in plasma fractions and formed elements. A solid-phase plasma extraction is performed by sequential passing of 100% acetonitrile, plasma, distilled water, 50% acetonitrile solution under vacuum through a cartridge with Oasis HLB 3 cc sorbent. The cartridge with the sorbent is dried under vacuum, and 100% methylene chloride is passed through the sorbent. An aliquot portion of the produced extract is chromatographed. Producing the extract of formed elements is ensured by dispersed solid-phase extraction: by adding 100% acetonitrile thereto and agitating intensively. That is followed by adding a number of QuECHeRS salts for extraction, agitating, centrifuging for 10 minutes at 2,000 rpm; that is accompanying by forming 3 layers; an upper layer is transferred to another test tube, which contains a number of QuECHeRS salts for purification; the layers are centrifuged at 2,000 rpm; the upper layer is sampled. Plasma and formed elements extracts are analysed by Agilent 1200 liquid chromatograph with a fluorimetric detector on Zorbax column 50 mm long and having an inner diameter of 4.6 mm with Eclipse PAH C18 sorbent at column temperature 27°C; a movable phase is presented by mixed acetonitrile and water at flow rate 1.5 cm3/min and optimising elution in the gradient mode (supplying the movable phase of 60 vl % to 68 vl % of acetonitrile for 1 min, increasing 60 vl % to 68 vl % of acetonitrile for 3 min, increasing 68 vl % to 70 vl % for 0.5 min, increasing acetonitrile 70 vl % to 90 vl % for 1.5 min, increasing acetonitrile 90 vl % to 100 vl % for 4.5 min, supplying 100% acetonitrile for 1.5 min, reducing acetonitrile to 60 vl % and supplying 60% acetonitrile for 4 min to balance the column). An excitation wavelength of the fluorimetric detector makes 265 nm, and an emission wavelength makes 412 nm. A calibration chart is used to quantify benz(a)pyrene in plasma and formed elements separately, while the results are summed up.
EFFECT: invention provides high sensitivity of the method and ensures selectivity in a combination with its accessibility for routine analyses.
3 cl, 6 tbl, 1 ex
SUBSTANCE: invention relates to medicine, namely to experimental pharmacology, and can be used for quantitative determination of carnosine in tissues and physiological liquids. Determination of carnosine in biological materials is carried out by highly-selective mass spectrometry method using electrospray ionization. At that, deproteinization of blood plasma should be preliminary carried out using 10 % aqueous solution of trichloroacetic acid. Then aliquot of internal standard solution of L-alanyl-carnosine is added to deproteinizated sample. And separation of extraction products is performed at reversed-phase chromatographic column 4.6×150 mm with temperature separation of 35 °C and eluent feed rate 0.7 ml/min. Used eluent is 10 mM ammonium acetate, acidified with glacial acetic acid to pH 3.7, and mixture of acetonitrile with 10 mM ammonium acetate in ratio of 90:10, taken in ratio of 10:90, respectively. Detection of carnosine is carried out by four child ions with m/z 110.0, 156.1, 180.0, 210.1, formed as result of molecular ion carnosine disintegration with m/z 227.1. Concentration of carnosine is calculated by chromatographic peak carnosine area relation to L-alanyl-carnosine internal standard peak area.
EFFECT: invention provides highly selective and sensitive gas chromatography/mass-spectrometric method for quantitative determination of carnosine in biological substrates.
1 cl, 6 dwg, 2 tbl, 1 ex