Method for determination of authenticity and quality of perforate st john's-wort (hypericum perforatum l.)
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention relates to method for determining quality and authenticity of medicinal raw material of St John's-wort (Hypericum perforatum L.). The method consists in the following: water-alcohol extract of Hypericum perforatum L. herb is prepared, and analysed by method of high performance liquid chromatography. After that, concentration of rutin and hyperforin (mmol/l) is determined and used as basis for calculation of their content in Hypericum perforatum L, ratio of rutin to hyperforin is determined, and its value equal to 0.8-1.2 testifies to authenticity and quality of St John's-wort (Hypericum perforatum L.).
EFFECT: invention makes it possible to increase reliability in determination of authenticity and quality of medicinal raw material.
SUBSTANCE: invention relates to nickel complex of 5,10,15,20-tetrakis [3',5'-di(2"-methylbutyloxy)phenyl]-porphin of formula
EFFECT: invention makes it possible to obtain nickel complex, demonstrating property of stationary phase for gas chromatography.
SUBSTANCE: analysed sample is simultaneously analysed three times on chromatographic columns with non-polar and polar stationary phases. The first analysis includes the initial sample and the second and third analyses include the initial sample with changed concentrations of volatile components, wherein the change of concentration of the components of the initial sample is carried out using solid-phase extraction by analysing both the gas phase at a low temperature and the condensed phase at a higher temperature. An apparatus for determining correspondence of chromatographic peaks, having an apparatus for solid-phase extraction and thermal desorption, which is in the form of a detachable temperature-controlled cartridge with a granular sorbent, which is connected on through additional flow switches instead of a headspace sampler dosing loop.
EFFECT: larger number of volatile sample components determined, high accuracy of determining concentration of volatile sample components.
2 cl, 1 dwg, 1 tbl
SUBSTANCE: first, sampling of atmospheric air is performed at rate 0.5 l/min for 30 minutes by its drawing through two successively connected absorption devices, placed on water bath with temperature +92°C and preliminarily heated for 3 minutes on water bath at temperature +92°C, each of which contains absorption solution. Said solution consists of 3-aminophenol with molar concentration 0.023 mol/dm3, hydroxylamine hydrochloride with molar concentration 0.086 mol/dm3, iron sulphate solution with weight concentration 5.6 mg/cm3, 16% water solution of sulphuric acid and distilled water with their volume ratio 10:5:1:1:3 respectively. After that, additional heating of sample is realized , located in absorbers, for 10 minutes at the same temperature, with further combination of contents from both absorbers and concentration of sample by means of vacuum concentrator at temperature +40°C and analysis on liquid chromatographer with fluorimetric detector, with application as mobile phase of mixture of water and composition, consisting of acetonitrile and methanol with their volume ratio 3:1 respectively, with their changing ratio within 10 minutes from 100:0 vol % of water and composition to 90:10 vol % of water and composition; supply of mixture of 90 vol % of water and 10 vol % of composition for 12 minutes with further reduction of volume quantity of composition in mobile phase after stopping distillation at 22 min to 0 vol % and further passing such mobile phase through column for 5 minutes. Said procedures are carried out with blank sample without air sample as well, with concentration of acrolein in air being determined by graduation graph taking into account bringing volume of air, sampled for analysis, to normal conditions, with true concentration of acrolein being determined by difference of data obtained for sample with air and blank sample.
EFFECT: increased sensitivity and selectivity with provision of extension of range of acrolein detection.
4 cl, 4 tbl
SUBSTANCE: chromatograph comprises chromatographic column with sorbent, batcher, fluid pump for forcing the eluent (solvent), carrier composed of a bundle of 0.05-0.1mm-dia wires passed from the glass flute. Besides, this chromatograph comprises evaporator, drive with speed variator, plasma-ion detector (catharometer), gas (hydrogen) feed mechanism and assemblies for gas and electricity feed to gas preparation panel detector. Detector and temperature control power supply used for supply of thermal control and programming of column temperature, thermostat, thermal regulator, programmer, electronic converter and electronic potentiometer are also incorporated therewith. Note here that chromatograph is equipped with flow divider, collector of oil product components, fluid batcher, evaporation flask, heater-thermostat, refractometric detector, refrigerator, air ejector, filters, gas batcher, gas chromatographic column and oil product discharge line.
EFFECT: increased number of simultaneously analysed characteristics of oil products, decreased number of errors, possibility for definition of mass output of oil product components, higher reliability and simple assembly.
SUBSTANCE: method includes separation with further identification of acetone and methanol on capillary chromatographic column in carrier gas flow, representing nitrogen; formation and registration of analysed ions, formed in flame by flame-ionisation detector, prepared is basic solution, which is well-preserved for 2 months, at temperature from -2°C to -5°C, intermediate solution with concentration 6.32 mg/dm3 is prepared by dilution of basic solution with purified water, calibration solutions are prepared for ranges of concentrations: acetone 0.025-6.32 mg/dm3, methanol 0.025-6.32 mg/dm3 by dilution of intermediate solution with water, chromatograph is calibrated by introduction of preliminarily sampled vapour phase of calibration solutions into it, calibration graph is built, after thermostatting of analysed solution vapour phase is sampled by vapour-phase syringe and introduced into chromatograph evaporator, data are processed by computer software ChemStation, which chromatographic complex MAESTRO 7820A is provided with.
EFFECT: increase of accuracy and reliability, and acceleration of analysis.
2 dwg, 6 tbl, 1 ex
SUBSTANCE: biological object, which contains mixture of hydroxybenzene and its monomethyl-substituted are crashed, processed twice with ethylacetate for 30 minutes with ethylacetate, ethylacetate extracts are combined, treated with ethanol solution of calcium hydroxide, solvent from combined ethylacetate extract is evaporated at 16-20°C, residue is repeatedly treated with acetone, containing hydrochloric acid in excess with respect to potassium hydroxide, present of residue, acidified acetone extracts are combined, treated with water solution of sodium hydroxide to neutralise residues of hydrochloric acid in acetone and create excess of alkaline medium, acetone is evaporated from combined extract, water-alkali residue is diluted with water, formed solution is acidified to pH 2-3, saturated with sodium sulphate, extracted with diethyl ether, extract is dehydrated, evaporated, chromatographed in column with silica gel with application of mobile phase hexane-diethyl ether with ratio 6:4 in volume, eluate fractions, containing hydroxybenzene and its monomethyl substituted, are combined, extracted with buffer solution with pH 12-13, water-alkali extract is acidified with 24% solution of hydrochloric acid to pH 2-3, saturated with sodium sulphate, extracted with dichloromethane, dichloromethane extract is dehydrated, analysed substances, contained in dichloromethane extract, are transferred into corresponding trimethylsilyl derivatives, for which purpose dichloromethane extract is treated for 20 minutes with N-methyl-N-trimethylsilyltrifluoracetamide under conditions of heating at temperature 60°C, qualitative and quantitative determination by physical-chemical method, such as chromate-mass-spectrometry, is performed in capillary column, 25 m long with internal diameter 0.2 mm with immobile phase (5%-phenyl)-methylpolysiloxane, with application of helium carrier gas, supplied at rate 0.6 ml/min, and mass-selective detector, working in electron impact mode, initial temperature of column thermostat constitutes 70°C, said temperature is maintained for 3 minutes, and then temperature is programmed from 70°C to 290°C at rate 20°C, final temperature of column is maintained for 10 minutes, injector temperature constitutes 250°C, quadrupole temperature - 150°C, temperature of ion source - 230°C, temperature of detector interface - 300°C, intensity of signal, conditioned by charged particles, formed in bombardment of analysed substance, leaving capillary column and getting into source of ions, with ionising beam of electrons with energy 70 eV, is registered, mass-spectrum is registered by full ion flow, qualitative determination of analysed substance is realised by time of exposure, set and intensity of signals of characteristic charged particles in mass-spectrum of its trimethylsilyl derivative, with quantity of determined compound being calculated by area of chromatographic peak of its trimethylsilyl derivative.
EFFECT: increasing sensitivity and reduction of determination duration.
6 tbl, 1 dwg, 5 ex
SUBSTANCE: concentration of pentaerythritol in aqueous solutions is determined using a solution with pentaerythritol content of 1-100 100 mg/dm3. The method includes determining pentaerythritol concentration therein at spectrophotometric detector wavelength of 190 nm. The eluent used is 0.0002 M sulphuric acid solution in deionised water. A column of weakly cross-linked styrene divinylbenzene resins is used.
EFFECT: shorter time for determining a chemical substance in water, simplifying the process while maintaining the quality of determination.
SUBSTANCE: invention refers to diagnostic technique in medicine and describes a laboratory diagnostic technique for Alzheimer disease by using metal-binding domain modified 1-16 forms of human beta-amyloid as Alzheimer disease pathogenesis biomarkers. The method is characterised by the fact that total peptide fraction, then beta-amyloid fraction and fragments of 1-16 beta-amyloid fraction to be further analysed after the targeted proteolysis is recovered from a denatured sample of biological fluid, urine, cerebrospinal fluid. If the biological fluid sample appears to contain a metal-binding domain modified, asparlic acid isomerised (position 7) form of beta-amyloid in the relative amount of more than 5% of the total amount of the 1-16 beta-amyloid fraction and/or a metal-binding domain modified, serine phosphorylated (position 8) form of beta-amyloid, Alzheimer disease is diagnosed.
EFFECT: invention can be used to establish a diagnosis of Alzheimer disease.
SUBSTANCE: method is implemented as follows: the biological material containing novocaine is crushed, treated three times with acetone, containing 0.2-0.4% water, the liquid extract is separated, the acetone from the liquid extract is evaporated together with water in the air stream at a temperature of 18-22°C until complete removal of the solvent, the residue obtained as a result of evaporation is repeatedly treated with acetone containing 0.2-0.4% water, the acetone extract is separated, combined, and the solvent from the combined extract is evaporated, the residue is dissolved in diethyl ether, the resulting solution is diluted in hexane in a ratio of 1:1 by volume, extracted with buffer solution with pH 1-2, the acid-water extract is separated, neutralized with 10% ammonia solution, alkalized with ammonium buffer solution to pH 9.0-9.5, the resulting aqueous alkaline solution is saturated with ammonium sulphate, extracted twice with portions of the organic extractant which is used as a 30% solution of camphor in methyl acetate, at a ratio of aqueous and organic phases as 1:1 by volume, the organic extracts are separated, combined, and the solvent from the combined extract is evaporated in a stream of air at a temperature of 18-22°C to dry residue, the residue is dissolved in a mixture of dichloromethane and ethanol taken in a volume ratio of 1:1, the resulting solution is applied to a column of silica gel CRA No. 80/120 mcm, chromatographed using two-phase movable phase dichloromethane-ethanol in a ratio of 1:1 by volume, the fractions of eluate containing the analyte, combined, the eluent is evaporated, the residue is dissolved in methanol and determining is performed by gas-liquid chromatography coupled with mass spectrometric detection in a capillary column DB-5 MS EVIDEX with the length of 25 m and an inner diameter of 0.2 mm with the stationary phase, which is 5%-phenyl-95%-methylpolysiloxane using helium carrier gas supplied at a rate of 0.6 ml/min and a mass selective detector operating in electron impact mode, the initial temperature of the column oven is 80°C, this temperature is maintained for 1 minute, then the temperature is raised from 80°C to 200°C with the rate of 40°C per minute, then from 200°C to 300°C with the rate of 12.5°C per minute, the final column temperature is maintained for 16 minutes, the temperature of the injector is 200°C, the temperature of quadrupole is 150°C, the temperature of the detector interface is 300°C, the intensity of the signal is recorded, due to charged particles produced by bombarding of the analyte emerged from the capillary column and entered into the ion source, with ionizing electron beam with energy of 70 eV, a mass spectrum is recorded on total ion current and the amount of novocaine is calculated based on the chromatogram peak area.
EFFECT: increased sensitivity of determining.
2 ex, 3 tbl
SUBSTANCE: biological material containing 3-methoxyhydroxybenzene is repeatedly (three times) treated for 45 minutes with an alkyl acetate in the form of methyl acetate; the separate extracts are combined; the solvent from the combined alkyl acetate extract is evaporated; the residue is repeatedly treated with acetone; the acetone extracts are combined, evaporated in an air current at 18-22°C, and then in an nitrogen current until complete removal of the solvent; the residue is dissolved in ether; the obtained solution is diluted with hexane in volume ratio of 1:1, extracted with a buffer solution with pH 12-13; the water-alkaline extract is separated, acidified to pH 2-3, saturated with sodium sulphate, extracted with diethyl ether; the ether extract is separated, dehydrated, evaporated in an air current at 18-22°C and then in a nitrogen current until complete removal of the solvent; the residue is dissolved in a hexane-dioxane-propanol-2 solvent mixture, taken in volume ratio of 20:5:1, subjected to chromatography in a silica gel macrocolumn L 40/100 mcm using a mobile phase of hexane-dioxane-propanol-2 in volume ratio of 20:5:1; eluate fractions containing the analyte are combined; the eluent is evaporated in an air current at 18-22°C and then in a nitrogen current until complete removal of the solvent; the residue is dissolved in dichloromethane, followed by determination using a chromatographic-mass-spectrometric technique using a capillary column with length of 25 m and internal diameter of 0.2 mm with a stationary phase with thickness (5% phenyl)-methylpolysiloxane, using a helium carrier gas, fed at a rate of 0.6 ml/min, and a mass-selective detector operating in electronic impact mode; the initial thermostat temperature of the column is 70°C; said temperature is maintained for 3 min, and the temperature is then raised from 70°C to 290°C at a rate of 20°C/min; the injector temperature is 250°C, the detector interface temperature is 300°C; the method also includes detecting the strength of the signal resulting from charged particles formed when bombarding the analyte coming from the capillary column and falling into an ion source which ionises an electron beam with energy of 70 eV; recording the mass spectrum on the full ion current and calculating the amount of 3methoxyhydroxybenzene from the area of the chromatographic peak obtained by detecting the signal from the characteristic molecular ion 124 m/Z.
EFFECT: high 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.
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