The method of determination of toxic substances in gas mixtures
(57) Abstract:Use: for detection of toxic substances in gas mixtures. The inventive gas mixture is passed through a polymeric adsorbent, which is the carboxyl-containing porous material, characterized by porosity 90-99,9%, and the content of carboxyl groups 1-13 mmol/g of polymer, followed by desorption by heating. The received gas flow is passed through the detector, where they perform surface ionization and analysis by plasma chromatography. The heated during desorption carried out by a sharp rise in temperature or by flash. Toxic substances definition, are narcotic, explosive substances, i.e. substances containing nitrogen-containing groups and compounds containing alkyl compounds of phosphorus or arsenic. 1 C. p. F.-ly, 2 C.p. f-crystals, 1 table. The invention relates to a developing method of analysis of various toxic substances, and the proposed method can detect them in the trace.There is a method of analysis of organic impurities in the air by use of the device containing the adsorber, which use polymer (polite the La extraction of impurities with subsequent chromatographic analysis. The method compares favorably with other well-known absence of liquid media 
The disadvantage is the limited application of the method, because it is applicable to the analysis of only hydrocarbons of aromatic character, containing no heteroatoms.Closest to the claimed method is a method of analysis of toxic substances in the air  which is as follows: the gas stream containing toxic substances, in particular light amines, is subjected to concentration by passing the mixture through a polymeric sorbent. The polymeric sorbent is a compound based on polytetrafluoroethylene. Then carry out the desorption concentrate heat stroke and analyze the resulting mixture in a stream of inert gas by passing it through physico-chemical detector. In the operation of the detector used-ionization flow with subsequent analysis of the ions.The disadvantage of this method is that the number of stages (stage ionization and subsequent) requires the use of an inert gas. Use as a polymeric sorbent (membrane in the form of a film) fluorine-containing polymer degrades the quality of the analysis, increasing the lower threshold qualitative determination of the analyzed what this also reduces the possibility of determining low concentrations of toxic volatile amines, which varies in the interval 5-1510-9g/lAn object of the invention is to provide a method allowing to determine very low concentrations similar to the closest analogue of toxic substances (volatile amines) in the analyzed stream, to determine their qualitative presence, starting with a concentration of 10-11g/l (or 10-13mol/l) and above.The method allows qualitatively and quantitatively to determine the toxic organic compounds containing other elements of the V group main-group elements of the periodic table, which are not determined in a known manner.The need of this type of analysis is constrained in some cases by the need in a short time to determine the presence of, for example, are prohibited for carriage of cargo inspection services, the occurrence of leakage from the tanks when the quality control of goods, in particular food purposes, when such substances are formed as the reaction product. The method is universal in respect of amine, amide and other nitrogen groups in any of the compounds containing them, preferably in the absence of interfering with the analysis of atoms, i.e. compounds can contain atoms of carbon, hydrogen, oxygen, metals, and prob is a date. In a series of toxic substances to be determined, in particular, are drugs and explosives. As gas mixtures can be analyzed air mixture in the premises of railway stations, manufacturing plants, etc.This object is achieved in that the working stream containing an analyte is passed through the layer of polymeric sorbent. The polymer used as the adsorbent, is a carboxyl-containing content of COOH-groups 1-13 mmol/g of dry polymer, and is characterized by porosity 90-99,9% and then for desorption using heat. It may be heat stroke, flash, quick short-time heating and other Temperature must be sufficient for desorption, it is even possible decomposition of the sorbent. After desorption stream is passed through physico-chemical detector, where the use of surface ionization with subsequent gas electrophoresis (plasma chromatography).Examples 1-7 of the method.Workflows, including air and contained impurities:
toxic compounds containing NH2group (thread 1);
toxic substances, containing hydrazine powered group (stream 2);
the Ana (stream 4);
substances containing amides (stream 5);
a stream containing alkyl derivatives of phosphorus and arsenic (threads 6 and 7, respectively),
passed through the layer of polymeric sorbent containing 1-13 mmol carboxylic groups per gram of adsorbent. As the polymer can be used, modified carboxymethylcellulose, polyvinyl alcohol, dextranase polymers and others After adsorption necessary desorption of the analyte. This is implemented by a short sharp rise in temperature. The resulting stream containing an analyte, and a background thread is subjected to surface ionization with subsequent chromatography. the presence of inert gas is not necessary.The results of the analysis are presented in the table.Thus, the proposed method against toxic substances (drugs and explosives containing volatile amines) to expand the boundaries of high-quality detection, to detect them in smaller quantities, present in the air. Furthermore, the method allows to analyze and other toxic organic compounds containing heteroatoms from the group V elements of the periodic table, i.e., to expand the scope. With the practical substances in gas mixtures by passing the gas mixture through a porous polymeric material with subsequent desorption of the adsorbed substances, ionization of the received gas flow and its analysis, characterized in that the porous material used carboxyl-containing polymeric material with a porosity of 90.0 to 99.9% and the content of carboxyl groups 1 13 mmol/g of polymer, after desorption of the resulting mixture is subjected to surface ionization with subsequent analysis of the mixture of plasma chromatography, the toxic substances identify organic compounds that contain atoms of the fifth main group elements of the periodic table.2. The method according to p. 1, characterized in that the desorption carry out a short sharp increase in temperature or by the use of fire outbreaks.3. The method according to p. 1, characterized in that toxic substances definition, are alkyl phosphorus or arsenic, compounds containing amine, amide, hydrazine powered, gidrazonami, tetrazona group.
FIELD: chemical engineering; medical engineering.
SUBSTANCE: method involves plotting two chromatograms one of which is based on radioactivity (No 1) and the other one on ultraviolet absorption (No 2) or on radioactivity (No 1) and on fluorescence (No 2) and chromatogram specific relative to ultraviolet absorption (No 3) or relative to fluorescence (No 3). Material quality is estimated to be the more high the more close studied labeled compound peak shape is to trapezoid shape on the third chromatogram.
EFFECT: high accuracy of the method.
FIELD: analytical chemistry, ecology, in particular controlling of environmental air.
SUBSTANCE: claimed method includes aspiration if air sample through chemosorbtive medium, elution of formed dimethylamine salt, eluate closure with alkali, and gas chromatography analysis of gas phase with flame-ionization detection. Dimethylamine salt elution from adsorbent is carried out with 1 cm3 of distillated water; closured with alkali eluate is held in thermostat for 5 min; and as filling in separating chromatography column chromosorb 103, containing 5 % of PEG-20000 and treated with 20 % hexamethyldisilazane solution is used.
EFFECT: method for dimethylamine detection with improved sensibility and accuracy.
FIELD: chemical industry.
SUBSTANCE: during process of taking sample from technological pipe-line, absorption of water vapors and nitrogen oxides (II) and (IV) are conducted simultaneously. For the purpose the chemical agents are used which don't absorb nitrogen oxide and don't react with it. Chromatographic measurement of volume fraction of nitrogen oxide (I) is carried out by means of industrial chromatograph having heat-conductance detector by using column of thickness of 5 m and diameter of 3 mm. The column is filled with polysorbent; temperature of column's thermostat is 20-30 C and temperature of evaporator is 100C. Hydrogen is used as a gas-carrier. Concentrations of nitrogen oxide, measured by the method, belong to range of 0, 05-0, 50% of volume fraction. Method excludes aggressive affect of corrosion-active components on sensitive parts of chromatograph. Method can be used under industrial conditions for revealing factors influencing process of forming of nitrogen oxide at the stage of catalytic oxidation of ammonia and searching for optimal conditions for minimizing effluent of ammonia into atmosphere.
EFFECT: high reproduction; simplification; improved efficiency of operation.
FIELD: oil and gas production.
SUBSTANCE: aim of invention is estimating expectations for oil and gas of oil-source rock areas. For that aim, sampled rock is treated to isolate organic substance soluble in organic solvents, after which organic substance is chromatographed to detect 4-methyldibenzothiophene and 1-methyldibenzothiophene. When ratio of 4- to 1-isomer exceeds 0.9 rock is regarded as ripened.
EFFECT: increased determination reliability and rapidity.
SUBSTANCE: in the method, hard carrier with system of narrow pores and channels is kept under temperature below height of potential barriers for movement of at least one type of separated molecules.
EFFECT: higher efficiency.
FIELD: investigating or analyzing materials.
SUBSTANCE: gas analyzer comprises chromatographic columns, detectors, unit for preparing air mounted inside the thermostat, unit for control and processing signals, member for sampling, switches of gas flows, pump for pumping gas mixture, and separating passages connected in parallel and provided with the check valve interposed between them. Each of the separating passages is made of absorbing and separating chromatographic columns connected in series, and the pump is connected to the input of the gas line through the electric valve. The gas analyzer can be made of two separating passages and low pressure chromatographic columns.
EFFECT: enhanced quality of analyzing.
2 cl, 1 dwg, 1 ex
FIELD: analytical methods.
SUBSTANCE: to determine methyl alcohol in water, sample to be assayed is preliminarily subjected to distillation with sulfuric acid added in amount required to provide its concentration in mixture to be distilled c(1/2 H2SO4) = 0.002 M, while strippings constitute 6-7% of the volume of sample. Stripped liquid is thrice rinsed with hexane or Nefras at 1:1 hexane (Nefras)-to-strippings ratio. Rinsed material is then introduced into packed column filled with diatomite modified with 1,2,3-tris(β-cyanoethoxy)propane having deposited fixed phase thereon, which phase is prepared by way of consecutively keeping glycerol each time for 4 h at ambient temperature, 100°C, 130°C, 160°C, and 200°C, and then for 8 h at 230°C and for 40 h at 200°C under nitrogen bubbling conditions. Calculation of methanol content is performed taking into consideration calibrating coefficient.
EFFECT: enabled determination of small concentrations of methyl alcohol in water with sufficient selectivity and reliability.
2 cl, 2 tbl, 6 ex
FIELD: analytical chemistry.
SUBSTANCE: invention relates to method for quantitative determination of thiotriazoline and pyracetam in complex drugs by high performance chromatography, wherein silicagel with grafted 3-(chlorodimethyl)-propyl-N-dodecylcarbamate having particle size of 5 mum is used as sorbent; and degassed 0.05 M aqueous solution of potassium dihydrophosphate is used as mobile phase. Mobile phase velocity is 1 ml/min, and column temperature is 30°C. Method of present invention makes it possible to determine content of two abovementioned active ingredients simultaneously.
EFFECT: simplified process of sample preparation.
3 ex, 3 tbl
FIELD: biotechnology, in particular content determination of polymer chitosan molecules, chitosan-chitine polymer molecules and molecules of chitosan-protein complex in finished form of chitosan.
SUBSTANCE: claimed method includes application of high performance chromatography column filled with polyvinylbenzene sorbent with refractometer detector. As eluent and for dissolving of chitosan preparation samples acetic acid aqueous solution is used. Chain-length distribution is determined on the base of first chromatography peak, and polymer molecular content is calculated on the base of area of first, second and third chromatography peaks, divided up to zero line and belonging to polymer chitosan molecules, chitosan-chitine polymer molecules and molecules of chitosan-protein complex, respectively. To calculate chain-length distribution of polymer chitosan molecules separately calibration curve is plotted using dextran polymer standards.
EFFECT: new effective method for determination of polymer chitosan molecules in chitosan preparations.
4 cl, 3 dwg
FIELD: the invention refers to laboratory chromatographic devices for conducting high-speed chromatographic analysis.
SUBSTANCE: the express-chromatron has an injector, a chromatographic column located in a thermostat, a detector, an amplifier of the signal of the detector, an analog-digital converter, a control system, a pneumatic system. The column is fulfilled either in the shape of a short capillary column or either in the shape of a polycapillary column. The injector is fulfilled with possibility of introduction of the test for the time of 5-50 ms. The detector and the amplifier of its signal are fulfilled with possibility of ensuring constant time of no worse then 10-3 sec. The analog-digital converter is fulfilled with possibility of ensuring speed of no less then 200 measurements in a second.
EFFECT: ensures conducting high-speed chromatographic analysis.
11 cl, 2 dwg