Gas analysis method
FIELD: test equipment.
SUBSTANCE: invention refers to analysis of the quantity of impurities in carbon dioxide during manufacturing and/or cleaning process. Measurement method of concentration of impurities during gas cleaning consists in the fact that, first, gas flow containing impurities passes through gas absorbing device during the time period at ambient temperature or higher so that impurities can be absorbed. Than gas flow movement is stopped. Then, desorption and analysis of impurities in stopped gas flow movement is performed by means of detector. At that, impurities have been chosen from the group consisting of H2S, COS, dimethyl sulphide, benzene, aldehydes, spirits with low length of carbon chain and hydrocarbons. Also, in the proposed method, gas absorbing device includes column with absorbent layer in gas chromatograph, and gas is desorbed from column with absorbent layer through gas-distributing column.
EFFECT: improving accuracy and reducing costs for measurement of concentration of impurities during gas cleaning.
9 cl, 1 dwg
The technical field to which the invention relates.
The present invention provides a method of analyzing gases. More specifically, this invention provides a method of analyzing impurities in carbon dioxide in the production process and/or cleaning.
The level of technology
Carbon dioxide has a number of industrial and domestic applications, and many of them require that carbon dioxide was clean various impurities. Unfortunately, carbon dioxide, obtained from natural sources, such as gas wells, chemical processes, fermentation processes, or produced industrially, especially carbon dioxide, produced by burning hydrocarbons, often contains impurities of sulfur compounds, such as carbondisulfide (COS) and hydrogen sulfide (H2S), oxygen-containing compounds, such as acetaldehyde and alcohols, and aromatic compounds such as benzene. When carbon dioxide is suitable for this application, which requires carbon dioxide of high purity, such as the production and purification of food products, including aeration beverages, pharmaceuticals and electronic devices, the number of sulphur compounds and other hydrocarbon impurities contained in the gas stream must be reduced before use. The level of necessary purification of the impurities varies depending on the use of carbon dioxide. For example, for use in beverages total sulfur content in carbon dioxide (CO2) should ideally be less than 0.1 parts per million (ppm), and the content of aromatic hydrocarbons should be less than 0.02 h/million To apply for the electronic clearing is necessary that the content of heavy hydrocarbons was less than 0.1 h/million
In order to ensure that cleaning methods reduce the impurity content to the desired level, the necessary methods of analysis that reliably and cost-effectively measure the content of impurities such as sulfur compounds, aldehydes, alcohols and aromatic compounds in very low concentrations (ppm and ppb - h/bn). Available a variety of ways to identify these impurities, including gas chromatographs with various detectors, analyzers, total hydrocarbons and total sulfur, GC-MS and some infrared detectors. Most of the available methods of analysis are tens of thousands of dollars and too expensive for many companies for the production and purification of carbon dioxide.
The present invention provides a simple, effective and inexpensive method for analysis of various impurities in gases, such as carbon dioxide, during production, purification and use.
The present invention offers the pic is b measuring the concentration of impurities during the purification of gas, includes: a) pass the gas stream containing impurities through the adsorbing gas unit for a period of time at ambient temperature or higher, so that impurities were adsorbed; b) stopping the flow of gas; and C) deformirovanie and analysis of the resulting gas stream using a detector.
The present invention also provides an analytical method for measuring the concentration of impurities during the production and purification of carbon dioxide comprising: a) pass the gas stream containing impurities through the adsorbing gas unit for a period of time at ambient temperature or higher, so that impurities were adsorbed; b) stopping the flow of gas; and C) deformirovanie and analysis of the resulting gas stream using a detector.
In the embodiment, the gas stream is a stream of carbon dioxide. Adsorbing gas is a column with a layer of adsorbent in the chromatograph. The chromatograph is a gas chromatograph. The detector may be a flame ionization detector (FID) and photometric ionization detector (PID) for the detection of hydrocarbon impurities and a detector such as a flame photometric detector (FPD), sirkenrobinson detector (SCD) and pulsed flame photometric detector (PFPD), for detection of sulfur compounds.
Brief description of drawing
Despite the fact that the description concludes with claims which clearly defines the object that applicants regard as their invention, the present invention can be better understood when considered together with the sole accompanying drawing, which is a detailed description of the analytical setup.
Detailed description of the invention
Carbon dioxide is usually manufactured for industrial processes, contains a number of impurities. These impurities usually present a problem for many uses of carbon dioxide, but in the production of products intended for human consumption, such as carbonated beverages, and electronics industries purity carbon dioxide is the most important, and can affect the taste, quality in accordance with the legislation of the final product.
The crude carbon dioxide gas, which can be obtained from any available source of carbon dioxide, usually contains impurities of sulfur compounds, such as carbondisulfide, hydrogen sulfide, dimethyl sulfide, sulfur dioxide, and mercaptans and hydrocarbon impurities such as aldehydes, alcohols, aromatic compounds, propane, ethylene and other impurities, such as water and carbon monoxide. The present invention describes a novel with the persons identify some impurities. The idea of the present invention is not limited to carbon dioxide and applicable for detection of impurities in other gases.
In the context of the present invention various admixtures of carbon dioxide analyzed by analyzer amounts of sulfur and analyzer number of hydrocarbons. Can be used with other detectors for the analysis of other impurities, such as galoidovodorodami, in other gases. For carbon dioxide, two of the analyzer can be a single node, such as a gas chromatograph, or they may represent a separate nodes. Before analysis of the various impurities of sulfur and hydrocarbons concentrate in order to increase their number in the sample. This stage increases the detection limits of the different analyzers. This is particularly useful for such impurities as benzene, which must be reduced to values below 20 h/bn for use in beverages. This method involves the adsorption is carried impurities within a few minutes on the adsorbent, selective with respect to the analyzed mixture. For concentration of benzene can be used such as an adsorbent, as a Poropak q After the adsorption is carried impurity adsorption column quickly heat up and send impurities in the separation column and then to the detector to determine the number. If for analysis using gas HRO shall atograph, the adsorption column can be located inside the chamber thermostat gas chromatograph or outside it. To reduce cost, it is preferable to arrange the separation column and the adsorption column inside the chamber thermostat GC.
The concentration of impurities before analysis allows to use low-cost detectors for analysis of various impurities. For example, for measuring the content of 20 hours per billion of benzene in carbon dioxide required expensive photoionization detector (PID), whereas after concentration of the sample can be used much more cheap a flame ionization detector (FID). Also for the detection of sulfur in the range from 20 to 50 h/bn required expensive gray-chemiluminescence detector (SCD), whereas after concentration of the sample can be used more cheap flame photometric detector (FPD).
Sulfur analyzer analyzes how the total sulfur content, sulfur compounds at different stages of the process. For pure for use in beverages carbon dioxide total sulfur content in the product, except for sulfur dioxide, should be below 0.1 ppm, and the content of sulfur dioxide should be less than 1 h/million For measuring total sulfur sulfur impurities are oxidized to sulfur dioxide in a catalytic reaction using resistant ser the catalyst or the ozone generator, usually based on corona discharge. Sulfur dioxide after oxidation analyzed using sensitive to sulfur detector, such as gray-chemiluminescence detector (SCD), flame photometric detector (FPD) or a pulsed flame photometric detector (PFPD). When authentication is required sulfur compounds, sulfur impurities can be further concentrated and sent directly to the separation column and the detector, bypassing oxidative node.
The content analyzer hydrocarbon analyses as total hydrocarbons (such as methane), and separate the hydrocarbons at different stages of the process. For pure for use in beverages carbon dioxide total hydrocarbons in the product should be below 50 ppm with different limits for individual compounds, such as benzene (<20 billions of shares), acetaldehyde (<0,1 ppm) and methanol (<10 ppm). For demanding high purity applications in the electronics content of heavy hydrocarbons (>C3should be below 0.1 h/million For measuring the total content of hydrocarbons, as the hub of the sample and the separation column is passed, and the sample is exposed directly to the FID to measure. For the measurement of the individual hydrocarbon components of the sample sent to the hub and in the separation to which the PMC and is directed to the FID detector for analysis.
Details of the analytical system shown in the drawing. In the drawing, the pipe 14 is a line feed sample analytical units. Pipe 16 directs a portion of the sample gas through the valve 18 and pipe 26 to a multi-way valve 28A. A carrier gas, such as nitrogen, is directed through the pipe 20 and valve 22, connecting with the pipe 26 and mixing with the gas sample.
Pipe 30 directs the gas sample in the hub 42A, the separation column 43A and then to the detector 44. Analysis data collected at the detector, proceed along the line 48 in the form of a signal on the integrator/computer, which is not shown. For analysis of hydrocarbon components can be used FID (flame ionization detector).
Another part of the sample gas is directed through the pipe 14 to the pipe 32, where it is mixed with air which enters through the pipe 34. This gas sample is directed to the optional oxidation catalyst sulfur or ozone generator 36 and through a pipe 38 to a multi-way valve 28B. Pipe 39 directs the sample 42B, the separation column 43B and the other detector 46. For detection of sulfur detector 46 may be a FPD (flame photometric detector). Line 52 extends from the detector 46 and delivers the data analysis in the form of a signal on the integrator/computer, which is not shown.
thermostat chamber gas chromatograph 65 accommodates both the detector is such as nodes detection of sulfur and hydrocarbons, but it can also include a column that hub and gas chromatographic column in one integrated node. It is preferable to reduce the total cost of the analytical system.
The valves 28A and 28B on the drawing receive samples with various attached parts of the cleaning process, and the site from which the specimen is obtained, can be tracked by computer. This allows you to monitor impurities at different stages of the process.
The signals from the detectors is converted into the concentration of various impurities using an integrator and/or computer and information can be displayed for use by the operator or transferred to the Central point. In the case of a sharp increase in the level of impurities or other data indicating that the required level of purity is not achieved, the operator can pause or stop the process of cleaning up until the deviation will not be investigated.
Setting and methods of the present invention is designed to solve problems with impurities in carbon dioxide, especially in carbon dioxide supplied in place of its use in industrial processes. By simultaneously carrying out the purification and analysis of the operator of the production equipment can be sure of a stable providing carbon dioxide guaranteed quality.
is the industry production or consumers, for which the present invention is of interest, include, but are not limited to, the production and processing of food products; manufacture of electronics, electronic components and parts; clearance of drugs; aeration soft drinks, beer and water; capping of containers and storage tanks containing flammable liquids and powders; covering substances, decaying in the air, such as vegetable oil, spices and incense.
The sample containing 1 ppm of benzene in carbon dioxide, is passed at a flow rate of 50 cm3/min through a variety of 2.0"×1/8" (5 cm × 0.3 cm) columns filled with activated alumina, silica gel, zeolite DAY and Poropak Q, respectively. The column is placed in a chamber thermostat gas chromatograph at 50°C and added to the FID detector. The traffic flow pattern continues for about 10 minutes, and for none of the columns do not see the breakthrough of benzene.
The movement of the sample flow is stopped and passed through the column with nitrogen as the carrier gas. The temperature in thermostat was raised to 150°C in less than one minute and observing the output column using the FID detector. Very little desorption of benzene observed for activated alumina, silica gel and DAY due to their high affinity for benzene is. However, with Poropak Q benzene fully desorbed less than 1 minute.
For Poropak Q concentration ratio is equal to 500 compared to 1 cm3sample. Provided that the limit of detection of benzene equal to 0.5 ppm for FID detector, the method of concentration of the sample makes it possible to measure the concentration of benzene up to 1 billion shares with the same detector. This method is suitable for other impurities, such as aldehydes and alcohols. This method is also suitable for other gases and other impurities.
The present invention is particularly suitable for detecting impurities in a partially purified product, or final product, because the lower levels of impurities in the gas stream does not require a large adsorption capacity in the hub 42A and 42B, which operate at ambient temperature or higher. In addition, the adsorbents in these hubs must be a weak adsorbents (such as Poropak Q for benzene), so that impurities are easily deformirovanii when heating thermostat GC. Strong adsorbents, such as zeolites and activated alumina, fit poorly, because they're harder to decarbonate impurities.
Although the present invention is described with reference to some embodiments of the example, numerous changes, is dopolneniya and omissions deems necessary specialist in the art, can be made without going beyond the nature and scope of the present invention.
1. The method of measuring the concentration of impurities during the purification of gas, which includes
a) pass the gas stream containing impurities through the adsorbing gas unit for a period of time at ambient temperature or higher, so that impurities were adsorbed;
b) stopping the flow of gas; and
C) deformirovanie and analysis of impurities in the stopped flow of gas through the detector.
2. The method according to claim 1, wherein the gas is carbon dioxide.
3. The method according to claim 1, wherein the impurity is selected from the group consisting of H2S, COS, dimethyl sulfide, benzene, aldehydes, alcohols of low carbon chain length and hydrocarbons.
4. The method according to claim 1, in which the adsorbing gas device includes a column with a layer of sorbent in the gas chromatograph.
5. The method according to claim 4, in which the gas is desorbed from the column with a layer of sorbent through the gas separation column.
6. The method according to claim 4, in which the gas chromatograph includes an analytical device for measuring the content of impurities of organic compounds selected from the group consisting of benzene, aldehydes, alcohols of low carbon chain length and is of glendorado.
7. The method according to claim 4, in which gas chromatograph connected to an analytical device for measuring the content of sulfur compounds.
8. The method according to claim 1, wherein the detector is selected from a flame ionization detector (FID) and photometric ionization detector (PID) for the detection of hydrocarbon impurities and flame photometric detector (FPD), gray-chemiluminescence detector (SCD) and pulsed flame photometric detector (PFPD) for the detection of sulfur compounds.
9. The method according to claim 5, further comprising increasing the temperature of the gas separation column.
SUBSTANCE: invention relates to analytical chemistry. The method is realised as follows: a sample of ground up premix is filled with a hydrochloric acid solution and put into an opaque case which is put into an ultrasonic bath. Extraction is carried out for 15-20 minutes at 38-42°C and centrifuging is then carried out for 10 minutes at 8000 rpm. The mixture is then brought up to the mark in a measurement flask. The obtained solution undergoes chromatographic separation on a column with Purospher sorbent. Chromatography conditions: eluent A - 0.005 M lithium perchlorate solution, pH=2.5; eluent B- acetonitrile; elution gradient mode - from 0 to 26% eluent B for 14 minutes.
EFFECT: high efficiency and accuracy and possibility of detecting a wider range of vitamins independent of the premix base.
2 dwg, 5 tbl, 1 ex
SUBSTANCE: method for chromatographic analysis of a substance involves exposing the separated mixture of substances carried by a carrier through a chromatographic column to acoustic oscillations. Before chromatographic analysis, a liquid nematic crystal is deposited on the wall of the chromatographic column, where the said crystal is directed across the propagation of sound oscillations.
EFFECT: high efficiency of separating an analysed mixture of substances into components using sound waves.
FIELD: oil and gas industry.
SUBSTANCE: gas chromatograph includes chamber for samples with piston position sensor, which is connected through sample valve to pipeline and through oil pump to reservoir for compensation of hydraulic oil pressure, electrical thermostat with temperature sensor and chromatograph tube located inside thermostat, which is in-series connected on one side through rotating sample injector, zeolite filter, the first return valve and isolating valve of chromatograph with connection line of sample valve and chamber for specimens, in-series connected on the other side to the second return valve, fraction detector, bottle with sample portion and the second pressure sensor. At that, rotating sample injector is in-series connected to pressure reducer, valve for transporting medium, bottle with compressed nitrogen and the first pressure sensor, bypass line with bypass valve is parallel connected to rotating sample injector, chromatograph tube and fraction detector, and circuit of electronic telemetry is connected to output of fraction detector. Method of downhole gas chromatography is proposed as well.
EFFECT: development of device allowing to perform gas chromatography for determining the type of well fluids in well in real time.
3 cl, 5 dwg
SUBSTANCE: device for chromatographic separation of substances contains three chromatographic columns connected to each other by crossover channels fitted with switching elements and extra channels fitted with switching elements which are connected to a source of the separated medium, eluent stream and system of receivers for collecting fractions. A controlled flow divider, one or more detectors and an analytical column are fitted at the output of the chromatographic separation system. Also in order to increase output and efficiency of the device for chromatographic separation of substances dissolved in supercritical fluids, the receivers for collecting fractions are fitted with level sensors and their outputs are further fitted with pilot-controlled valves which prevent diffusion of collected substances between receivers. The device also has a collector with a receiver and a flow regulator for the stream of fluids evaporated when pressure falls below the critical value. The device also has a high-pressure pump whose output is also connected to the flow regulator with pressure sensors at the input and output and a flow sensor, which guide part of the stream of formed fluids through the pilot-controlled valve into one or more spherical reactors which have an outer insulating layer and outer and inner heat chambers connected to heat or cold sources, temperature sensors, and the other part of the stream is directed to the analytical column and reactor. The reactor is connected through the pilot-controlled valve to the spherical collector of fluid solutions which is similar to the reactor whose output is connected to liquid batch collection device.
EFFECT: more accurate batching and increased output and efficiency of the disclosed device.
SUBSTANCE: method involves taking a sample, concentration of impurities, chromatographic analysis with separation of the concentrate on a capillary column and mass-selective detection while raising temperature from 35°C to 280°C, isolation of tridecane and 1-methylnaphthalene as reference compounds on the chromatogram, calculation of their concentration ratio in the sample and calculation of the time of contact between diesel fuel and water using the formula: x=0.42·y-1.8, where x is the time of contact between diesel fuel and water, h; y=Stridecane/Smethylnaphthalene; Stridecane and Smethylnaphthalene are area of peaks of tridecane and 1-methylnaphthalene on reconstructed chromatograms on selective ions with mass to charge ratio of 85 for tridecane and 145 for 1-methylnaphthalene, which correspond to concentrations of given compounds in the sample.
EFFECT: simple and reliable method with high information content.
1 ex, 1 tbl
FIELD: test equipment.
SUBSTANCE: proposed invention relates to gas chromatographic analysis and can be used in alcohol quality tests. Proposed method consists in that, additionally, water-spirit mix in the ratio of 60/40% by volume is prepared to a series of model samples based thereon to prepared by adding every component of analysed drink separately in said mix. Then model sample are analysed at the inlet assembly temperature of 180°C, 250°C and 310°C. Note that unknown substance detected in model sample is qualified as artifact formed in analysis, while is it is absent from model samples, check sample is prepared by combining the entire series of model samples to be analysed at aforesaid 180°C, 250°C and 310°C. Then mass spectra and chromatograms related therewith are analyzed and, if there is no revealed unknown substance in check sample, it is qualified as marker of nonfoods origin.
EFFECT: unambiguous identification of chemical compounds and fragments thereof as well as their origin, higher accuracy and faster identification.
4 tbl, 3 ex
SUBSTANCE: invention relates to chemistry and can be used in coke-chemical production when processing coke gas. The method involves using fractions of heavy crude pyridine bases which form during coal carbonisation as raw material, from which pyridine bases are extracted first and the obtained faction of crude quinoline bases is split into components. The fractions of crude quinoline bases are split into components through supercritical preparative chromatography, where the separated mixture is brought into contact with gas in supercritical state, which is simultaneously the mobile phase and adsorbent.
EFFECT: simpler, faster and more reliable separation.
SUBSTANCE: invention relates to a novel chemical compound - 4-(2-hydroxyethyloxy)-4'-cyanoazoxybenzene which can be used as a liquid crystal stationary phase for gas chromatography.
EFFECT: given compound has higher structural selectivity than structural isomers of lutidine.
1 ex, 1 tbl
SUBSTANCE: sample analysis device has a column for anion-exchange chromatography, as well as a buffer for elution, which contains an ion formed from a group consisting of a nitrate and a chloride. The device also includes an amperometric sensor and a spectroscopic sensor. The two sensors are placed such that, an eluate is obtained from the column.
EFFECT: provision for additional and improved methods of and systems for determining characteristics of saccharides using anion-exchange chromatography.
14 cl, 21 dwg
SUBSTANCE: method of determining content of diesel fuel in lubricating oil of an internal combustion engine involves the following stages: preparing a mixture which contains an oil sample and C5 hydrocarbon, such as C5 alkane; injecting the mixture into the injector (11) of gas chromatograph (10); obtaining chromatographs of the sample; determination of the firs parametre M, which characterises peak area related to C5 hydrocarbon, such as C5 alkane, determination the second parametre C, which characterises area of at least one peak, related to a hydrocarbon, which characterises diesel fuel; and determination of content T of diesel fuel using formula (I): where a and b are constants, which define equation y=ax+b of a calibrating straight line of the ratio of the second to the first parametres as a function of content of diesel fuel.
EFFECT: increased accuracy and reliability of analysis.
8 cl, 3 dwg
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