Method of detection and identifying of chemical substances in the mixture by their characteristics

FIELD: analytic chemistry.

SUBSTANCE: invention relates to analytical chemistry and can be used to detect and identify chemical substances in the mixture by their characteristics. Method of detection and identification of components of chemical mixtures by their characteristics include a preliminary identification of indicators traits components to detect and identify these indicators and depending on the operating parameters in the whole range of changes in these parameters. Also method includes measuring of the operating parameters and preliminary identification of indicators of response variations in calibration of measuring devices in the whole range of possible changes in operating parameters. In addition the method includes defining critical limits values of the intensity variations in the subsets of values or ranges of characters in the absence of any of the parts. Then selects a subset of values or characteristic ranges of any of the intensity distribution in excess of the modulus of the critical border of intensity data subsets or ranges of values of attributes. Next, determine the center group parameters and the variation of the intensity distribution observed in selected subsets of values or ranges characteristics. Then the component identification is performed by comparing the values of clustering center of the intensity distributions and values of characteristics in the measured values of operating parameters and values variation of the intensity distributions and values of variations at an incorrect response that measured in operating parameters. In this first in the whole range of possible changes of operating parameters and intensities of the parameter definition of line segments approximating the contour or contour segments gauge responses measuring device. Then determine the relationship between the parameters of these segments and the type of gauge responses contour, and before identification determine sites selected subsets of values or ranges characteristics that can be approximated by line segments with a given deviation. From the values of the parameters of these segments separate the contours of the mixture components are successively subtracted from the subsets of values or ranges of characteristics.

EFFECT: improving the reliability of detection and identification of mixture components.

15 cl, 7 dwg

 

The invention relates to analytical chemistry and can be used for detection and identification of chemical substances in a mixture by their marks.

Known how to identify the signs in the indexed data, including selecting a subset of the indices, with start and end indices, the calculation of the estimated variance of the subset of indices that have a subset of responses corresponding to the subset of indices as the histogram of frequencies, compare the value of the dispersion with the dispersion critical value [U.S. patents: No. 6253162, publ. 26.06.2001; No. 6366870, publ. 02.04.2002; No. 6487523, publ. 26.11.2002].

The main disadvantage of these technical solutions is the inability to identify the indexed data with similar characteristic values.

There are also known methods of detection and identification of chemical components of a mixture by their marks, for example, ion mobility component in a gas under the action of an electric field, including a preliminary determination of the mobility of the ions of components that are subject to detection and identification, and dependencies of these parameters on the operating parameters over the entire range of possible changes of these parameters, the variation and the measurement of operating parameters, check the distributions of the intensity of the ion current for different values of operating parameters, determine the bookmark indicators of the Central grouping of the distributions of the intensity of the ion current, identification of components by comparing the dependencies of the indicators of the Central grouping of the distributions of the intensity of the ion current for different values of operating parameters and corresponding dependencies of the mobility of the ions of components [U.S. patents: No. 7005632, publ. 28.02.2006, No. 7045776, publ. 16.05.2006, No. 7119328, publ. 10.10.2006, No. 7129482, publ. 31.10.2006, No. 7605367, publ. 17.07.2007. Article: Tomilov A.V., Kalinin B.A., Alexandrov PU, Seleznev V.D. Mathematical processing mass spectrum is not fully resolved peaks. // Analysis and control. 2008. Vol.12. No. 3-4, S-112].

The main disadvantages of these technical solutions are: the inability to detect and identify components of chemical mixtures with close values of ion mobility; low reliability of the identification of the components due to small differences for different components of the dependency of the performance characteristic of operational parameters.

Closest to the proposed method is a method of detection and identification of chemical components of a mixture by such a sign of these components, as the dependence of the ion mobility of the components in the gas of the electric field, including a preliminary determination of such rate characteristic components, such as the location of their ion peaks in the spectrum, the determination of such rate VA is eacii calibration of the response of the measuring device, as the width of the peak at half height, and dependencies of these parameters on such operating parameters as the amplitude of the high-voltage generator and the intensity of the ion current in the whole range of possible changes of these parameters, the measurement of operating parameters, the registration of the spectrum with the intensity distribution of ion currents of any component, selects peaks in the spectrum of the ion current with regard to instrument calibration dependence, identification of components with matching indicators the location of the peaks in the spectrum with parameters characteristic components [Kapustin VI RF Patent №2354963, publ. 10.05.2009].

The main disadvantage of this technical solution is the inability or small the detection and identification of mixture components with close values of the characteristic components and comparable values of the intensities.

This disadvantage is due to the fact that if the components have similar values characteristic and comparable values of the intensities, the distribution of the mixture of these components can be false indicators of Central grouping that using a known method can be detected and identified as components that are not actually present in the mixture.

The technical task of the present is subramania is to provide a method for detection and identification of chemical components of a mixture by their marks, it enables to improve the reliability of detection and identification of the components of the mixture.

The specified technical task is solved in that in the method of detection and identification of chemical components of a mixture by their features, including a preliminary determination of the performance characteristics of the components that are subject to detection and identification, and dependencies of these parameters on the operating parameters over the entire range of possible changes of these parameters, the measurement of operating parameters, a preliminary measurement of variation of the calibration response of the measuring device in the whole range of possible changes in the operating parameters, determining the values of the critical limits of the rate of intensity variation in the subset of the values or intervals of signs in the absence of any components, selection of subsets of values or intervals of the signs having any intensity distribution, exceeding the value of the module of the critical limits of the intensity data subsets of values or intervals of signs, indicators of the Central group and the variation of the intensity distributions observed on the selected subset of the values or intervals of signs, identification of components by comparing the performance of the Central grouping of the distributions of intensity and Zn the values of performance characteristics for the measured values of the operating parameters, and indicators of variation of the distributions of intensity and indicators of variation of the calibration response of the measured values of the operating parameters according to the claimed technical solution previously in the whole range of possible changes in the operating parameters and intensities determine the parameters of the segment, approximating paths or segments of the contours of the calibration response of the measuring device, determine the relationship between the parameters of these lines and the outline of the calibration response and identification define the regions of the selected subset of the values or intervals of signs, which are approximated by segments of straight with a given variance, the values of the parameters of these sections highlight the contours of mixture components, which are sequentially subtracted from subsets of values or intervals of signs.

The parameters of the segment described by the equation y=A+BX, are constants a, b and boundaries of the segment.

Constants a, b and border segment is chosen so that the deviation values of the intensities calculated for the parameters of the segment, from the intensities of these plots of subsets of values or intervals of signs does not exceed the value equal to the product of the coefficient of confidence on pre-determined the initial indicator of the intensity variations of the calibration response data values performance characteristics and intensities.

The measure of the intensity variation of the calibration response is a function of the variations of the intensity in the absence of any components, intensity variations caused by fluctuations in the operating parameters, and intensity variations due to grabovym effect.

Determine areas selected subset of the values or intervals of signs, approximated by segments of straight lines, should preferably be near the boundaries of these subsets of values or intervals of signs.

Pre-determine the deviation of the performance characteristics of the components and indicators of variation of the calibration response over the entire range of possible changes of all operating parameters, and a positive decision about the identity is accepted if the difference between the indices of the Central grouping of the intensity distributions and the values of the performance characteristics for the measured values of the operating parameters and/or the difference between the variations of the distributions of the intensity and rates of variation of the calibration response of the measured values of the operating parameters does not exceed half of the deviation value corresponding indicators.

Performance center grouping may be the mathematical expectation, median, and/or fashion, and performance variations of the initial and/or Central moments of k-th order (k=2, 3 4, ...), variations, variations at half intensity, simple or weighted average linear deviation, coefficient of oscillation, the linear coefficient of variation, coefficient of variation.

Performance center grouping may be a voltage offset drift of the ion component in the gas, resulting from the dependence of ion mobility on electric field intensity. In this case, the operating parameters may be the compensation voltage and its rate of change, temperature, pressure and gas composition, flow rate and fluctuations of the flow rate of the drift gas, the amplitude and waveform of the AC periodic asymmetric polarity of the voltage.

Performance center grouping can be a time drift of the ion component in the gas, which occurs under the influence of an electric field. In this case, the operating parameters may be temperature, pressure and composition of the gas, the voltage drop along the drift space, the type of ions in the drift space, the flow velocity and fluctuations of the flow rate of the drift gas.

Performance center grouping can be a time of chromatographic retention component. In this case, the operating parameters may be temperature, pressure and gas composition, flow rate and fluctuations of the flow rate GA is as a carrier.

Performance center grouping may be the ratio of the mass of the ion component to his charge. In this case, the operating parameters may be accelerating voltage, the supply voltage of the electromagnet.

Approximation of the intensity distribution lines direct from the set deviation, the selection of the parameters of these sections outline the components of the mixture, serial subtraction circuits components of the intensity distribution of the subsets of values or intervals of signs, identification of components by comparing the performance of the Central grouping of the selected paths and parameters indication when the measured values of the operating parameters, and performance variations of the selected paths and performance variations of the calibration response of the measured values of the operating parameters can improve the accuracy of detection and identification of the components of the mixture.

The advantages of the present invention are described in detail below with reference to the accompanying certi where:

figure 1 - total intensity distribution, including the density function of the normal distribution with the same average standard deviations: (A) one function and balance, B) are two functions, In) - three functions;

figure 2 - drift-range air containing vapors of 2,4,6-trinitrotoluene (TNT), organic is islote, allocated person, and not controlled trace.

Consider, for example, the intensity distribution, which is the sum of two density functions the normal distribution with the same average quadratic deviations and intensities and close values of the center of the grouping. In figure 1 this distribution is specified as the total intensity distribution. For detection and identification of components in the prototype identify indicators of Central grouping intensity distribution, such as local maxima, local maxima and previously measured values of the variation of the calibration response (in this case is the mean square deviation) in the measured values of the operating parameters distinguish the contours of the components of the mixture. On figa of the total intensity distribution in the manner described in the prototype, the selected path component. The remainder of the intensity distribution after subtraction circuit component of the total intensity distribution is a two loop with indicators of variation is substantially less than the rate of variation of a selected path component, i.e. the paths may not be the contours of any component. Therefore, identification of components using izvestno the way in this total intensity distribution is impossible.

On figb on the parameters of the segment, i.e. the proposed method, two circuit components. While the remainder of the intensity distribution does not exceed the error.

On FIGU brute force identified three circuit components with the same average standard deviations. It is obvious that the total intensity distribution can be distinguished and a greater number of circuits in the limit to infinity. This shows that the proposed method has a limit.

On figa shows the drift spectrum of air containing ions of 2,4,6-trinitrotoluene (TNT), organic acids secreted by the person, and the concentration of background emissions. Previously, it was determined that: the contours of the distributions of the calibration response of the measuring device do not significantly differ from the density function of the normal distribution with average standard deviations σ; lateral segments of these contours are approximated by segments of straight lines in the range 0.85 σ; base path, which is defined as a segment between points of intersection of lines described by the equation y=A+Bx, and x-axis is equal to 4σ; mean, median and fashion calibration responses coincide and are in the middle of this segment; σ calibration response varies from 0.32 In when Uwith=5 V to 0.54 In when Uwith=10th Century using the m pre-existing data near the boundaries of the drift spectrum (figa) were selected component outlines and subtracted from the drift spectrum (figb). Next, from residue 1 near the borders were allocated and deducted the contours of the components (pigv). Then rest 2 were selected paths of the two components (high). With pre-defined values of voltage adjustment ion components in the gas, resulting from the dependence of ion mobility on the electric field intensity, selected paths were identified as TNT, organic acid and trace amounts of background substances.

Implementation of the proposed technical solution is a simple technical problem, as it can be performed on the equipment used in the prototype. You only need modernization program processing intensity distribution.

1. The method of detection and identification of chemical components of a mixture by their features, including a preliminary determination of the performance characteristics of the components that are subject to detection and identification, and dependencies of these parameters on the operating parameters over the entire range of possible changes of these parameters, the measurement of operating parameters, a preliminary measurement of variation of the calibration response of the measuring device in the whole range of possible changes in the operating parameters, determining the values of the critical limits measure intensity variations in subsets of Zn the values or intervals of signs in the absence of any components, selecting a subset of the values or intervals of the signs having any intensity distribution exceeds the value of the module of the critical limits of the intensity data subsets of values or intervals of signs, indicators of the Central group and the variation of the intensity distributions observed on the selected subset of the values or intervals of signs, identification of components by comparing the performance of the Central grouping of intensity distributions and parameters indication when the measured values of the operating parameters, and indicators of variation of the distributions of intensity and indicators of variation of the calibration response of the measured values of the operating parameters, wherein the pre in the whole range of possible changes in the operating parameters and intensities determine the parameters of the segment, approximating paths or segments of the contours of the calibration response of the measuring device, determine the relationship between the parameters of these lines and the outline of the calibration response and identification define the regions of the selected subset of the values or intervals of signs, which are approximated by segments of straight with a given variance, the values of the parameters of these sections highlight the contours of the components of the mixture, to which were successively subtracted from subsets of values or intervals of signs.

2. The method according to claim 1, characterized in that the parameters of the segment described by the equation y=A+Bx, are constants a, b and boundaries of the segment.

3. The method according to claim 2, characterized in that the constants a, b and border segment is chosen so that the deviation values of the intensities calculated for the parameters of the segment, from the intensities of these plots of subsets of values or intervals of signs does not exceed the value equal to the product of the coefficient of confidence on pre-defined indicator of the intensity variation of the calibration response data values of the performance characteristics and intensities.

4. The method according to claim 3, characterized in that the rate of variation of the intensity of the calibration response is a function of the variations of the intensity in the absence of any components, intensity variations caused by fluctuations in the operating parameters, and intensity variations due to grabovym effect.

5. The method according to claim 1, characterized in that the determination of the areas selected subset of the values or intervals of signs, approximated by segments of straight lines, should preferably be near the borders of subsets of values or intervals of signs.

6. The method according to claim 1, wherein the pre-determined deviation indicators is Reznikov components and indicators of variation of the calibration response over the entire range of possible changes of all operating parameters, and a positive decision about the identity is accepted if the difference between the indices of the Central grouping of the intensity distributions and the values of the performance characteristics for the measured values of the operating parameters and/or the difference between the variations of the distributions of the intensity and rates of variation of the calibration response of the measured values of the operating parameters does not exceed half of the deviation value corresponding indicators.

7. The method according to claim 1, characterized in that the indexes of the center of the grouping may be the mean, median and/or fashion, and performance variations of the initial and/or Central moments of k-th order (k=2, 3, 4, ...), variations, variations at half intensity, simple or weighted average linear deviation, coefficient of oscillation, the linear coefficient of variation, coefficient of variation.

8. The method according to claim 1, characterized in that the indexes of the center of the grouping may be a voltage offset drift of the ion component in the gas, resulting from the dependence of ion mobility on the electric field.

9. The method according to claim 8, characterized in that the operating parameters can be the compensation voltage and its rate of change, temperature, pressure and gas composition, flow rate and fluctuations soon the minute flow of drift gas, the amplitude and waveform of the AC periodic asymmetric polarity of the voltage.

10. The method according to claim 1, characterized in that the indexes of the center of the grouping may be a time drift of the ion component in the gas, which occurs under the influence of an electric field.

11. The method according to claim 10, characterized in that the operating parameters can be temperature, pressure and composition of the gas, the voltage drop along the drift space, the type of ions in the drift space, the flow velocity and fluctuations of the flow rate of the drift gas.

12. The method according to claim 1, characterized in that a measure of center grouping can be a time of chromatographic retention component.

13. The method according to item 12, wherein the operating parameters may be temperature, pressure and gas composition, flow rate and fluctuations of the flow rate of the carrier gas.

14. The method according to claim 1, characterized in that the indexes of the center of the grouping may be the ratio of the mass of the ion component to his charge.

15. The method according to 14, characterized in that the operating parameters depending on the type of mass spectrometer can be accelerating voltage, the supply voltage of the electromagnet.



 

Same patents:

FIELD: medicine.

SUBSTANCE: biological tissue is crushed, twice for 1 hour is drawn with portions of dioxane, each of which by weight is two times the amount of biomaterial, separate extracts are combined, filtered, filtrate is evaporated in air flow at temperature 18-22°C to small volume, diluted 5 times with water, extracted with ethyl acetate, ethyl acetate extract is separated, dehydrated, evaporated at 18-22°C in air flow to small volume, after which in nitrogen flow until solvent is removed completely, residue is dissolved in mixture of solvents hexane-dioxane-propanol-2 (150:5:1), purified by method of column chromatography in column with size 490×11 mm, filled with 10 g of silica gel L 40/100 mc, with application of mobile phase solvents hexane-dioxane-propanol-2 (150:5:1), eluate fraction, which contain analysed substance, combined, eluate is evaporated in air flow at temperature 18-22°C to small volume, then in nitrogen flow until solvent is removed completely, residue is dissolved in hexane and detection is carried out by method of gas-liquid chromatography with application of capillary column DB-1701, 30 m long, with internal diameter 0.25 mm with stationary phase 0.25 mcm thick, which contains polysiloxane and polyethylene glycol, with application of helium as carrier gas, supplied with velocity 1 ml/min and mass-spectrometric detector, working in mode of electron impact, with registration of mass-spectrum by full ion flow, amount of esphen valerate is calculated by data of chromatogram, obtained by registering intensity of signal induced by charged particles formed during bombardment of analysed substance, which comes from capillary column and gets into source of ions, by ionising beam of electrons with energy 70eV.

EFFECT: increase of detection sensitivity.

3 ex, 4 tbl

FIELD: medicine.

SUBSTANCE: invention describes a method of determination of ethanol and other metabolites content in human blood by liquid phase chromatography, including preparation of blood distillates by vapour straight distillation and blood component analyis, characterised by the fact that it is combined with one-stage quantitative determination of ethanol, diethyl ester, acetaldehyde, acetone, methylacetate, ethylacetate, propyl alcohol, isobutyl alcohol, butyl alcohol, isoamyl alcohol with the use of capillary chromatographic columns; the concentration of the determined blood components is calculated by formula: where a is chromatographic study results, mg/dm3; V is a distillate volume, cm3; m is a whole blood weight, g.

EFFECT: method can be used in clinical laboratory diagnostics in studies of metabolic disorders caused by alcohol poisoning, and in judicial medical activity for diagnosing of a degree of intoxication of live persons.

1 ex, 1 tbl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method for ion-exchange separation of methionine and glycine and can be used in biochemistry, pharmaceutical and food industry. The method involves separation of methionine and glycine in two steps. At the first step amino acids undergo sorption with enrichment of the sorbent phase with glycine, and the solution at the output enriched with methionine. For this purpose, polyampholyte Purolite S950 in H-form is prepared. The mixture of two aliphatic amino acids undergoes sorption in a countercurrent column with a fixed sorbent layer. For this purpose, a solution containing a mixture of glycine and methionine is fed from below and glycine is undergoes sorption on polyampholyte Purolite S950. Methionine, appears at the output, the aqueous solution of which is sorbed in a receiver at the output of the column and after a certain time - the amino acids. Sorption is stopped. During sorption, samples are collected at defined time intervals. Total concentration of amino acids is controlled using an iodimetric method, and concentration of methionine is controlled using a spectrophotometric method, while glycine concentration is controlled based on concentration difference: between total concentration and methionine concentration. The degree of separation of the initial solution is equal to 60%. At the second step, glycine is eluted with hydrochloric acid solution at pH 1.2 from the sorbent while feeding glycine-containing eluate from the top, and sorbed in the receiver. Concentration of glycine is equal to 70%. After desorption of glycine, the mixture of amino acids undergoes complete desorption. Polyampholyte takes the initial shape and is ready for operation. Samples are collected at defined time intervals and each sample is analysed using iodometric and spectrophotometric methods. For complete separation of glycine from methionine, the two-step process of separating the mixture of amino acids obtained at the output of the column is repeated.

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2 dwg, 2 tbl, 1 ex

FIELD: chemistry.

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EFFECT: high accuracy and sensitivity of analysis.

3 ex, 4 tbl

FIELD: medicine.

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1 ex

FIELD: physics.

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EFFECT: shorter easier process.

5 cl, 1 dwg, 2 tbl, 1 ex

FIELD: medicine.

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5 cl, 6 tbl

FIELD: medicine.

SUBSTANCE: invention describes a method of quantitative evaluation of blood acetic, propionic, isobutyric, butyric, valeric, isocapronic and capronic acids by gas chromatography analysis wherein a blood sample is acidified with 1 % sulphuric acid to pH 2-3, evaluated acids are extracted with isobutyl alcohol volume of which is related to the blood sample volume as 1:1. The protein separation is enabled by centrifugation. 2-3 drops of 0.4 % alkali is added, and the extract is evaporated dry, further the solid residue is added consistently with 1 % sulphuric acid and isobutyl alcohol that is followed with gas chromatography separation of the mixed acids in a capillary column with a flame ionisation detector, and the amount of each acid is evaluated by a calibration diagram.

EFFECT: higher sensitivity and accuracy of the method of quantitative evaluation of acetic, propionic, isobutyric, butyric, valeric, isocapronic and capronic acids if found in blood together.

5 cl, 1 ex, 4 tbl

FIELD: chemistry.

SUBSTANCE: disclosed is a method of detecting unknown substances in body fluids of patients taking narcotic or psychoactive substances. The method involves preparation of three body fluid samples - the first through extraction with re-solution, the second through acid hydrolysis and the third through enzymatic hydrolysis. The first sample undergoes GC/MS analysis at temperature gradient of 15°C/min and data are analysed by comparing with a data base from which features of the unknown substance are detected, specifically spectra with m/z values which coincide with basic ions of the narcotic or psychoactive substance or metabolites and content of the unknown substance in the sample. The second sample undergoes GC/MS analysis at temperature gradient of 25°C/min and the third sample undergoes GC/MS analysis also at temperature gradient of 15°C/min and, if content of the unknown substances in the last two samples is higher than the in the first, the narcotic or psychoactive substance undergoes GC/MS analysis for presence of the unknown substance also at temperature gradient of 15°C/min, and if also not present in the basic substance. Presence of the unknown substance in intact body fluid is also checked, for which a sample of the intact body fluid is prepared via acid hydrolysis and undergoes GC/MS analysis at temperature gradient of 15°C/min and 25°C/min, and if the unknown substance is detected in the intact body fluid, the substance is classified as endogenous, and in the absence of features, an aliquot of the first sample is mixed with the sample of intact body fluid. The sample is prepared via acid hydrolysis of the mixture. The sample undergoes GC/MS analysis at temperature gradient of 15°C/min and 25°C/min. Further, content of the unknown substance is determined from results of both analysis modes and then compared with content of the known substance in the first sample. If content values of the unknown substance in the said three samples coincide, the unknown substance is classified as a new, previously unknown product of metabolism of the basic narcotic or psychoactive substance.

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4 tbl

FIELD: chemistry.

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EFFECT: invention shortens the duration of detecting tetraethyl thiuram disulphide in blood and increases its sensitivity.

3 tbl, 2 ex

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.

8 dwg

FIELD: analytical chemistry, ecology, in particular controlling of environmental air.

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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.

3 ex

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.

2 tbl

FIELD: physics.

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.

4 dwg

Gas analyzer // 2267123

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

Express-chromatron // 2300764

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

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