The method of obtaining chromatographic spectrum and device for its implementation

 

(57) Abstract:

Use: for identification of individual compounds or individual components of complex mixtures in various industries: chemical, oil, gas, petrochemical, oil refining, metallurgy, medicine, biology, ecology, etc. of the invention: test substance simultaneously dispense two or more parallel connected chromatographic column with different molecular structure and nature vzaimodeystviya with the analyzed substances stationary liquid phases, register the signals from the detector on the same chromatogram as a spectrum peaks of the analyte, shifted in time proportional to the value of the holding in each column. The dispenser is equipped with a number of different doses, fixed volume, and the entrance of each of the columns is connected to a fixed dose and a line of carrier gas through the locking elements of the dispenser. The absolute value of the chromatographic signal detector output columns judge toiletries each peak of the spectrum sootvestvuyushie column. 2 S. p. f-crystals, 2 Il.

The invention relates to chromatography and can be used for identifydata: chemical, oil, gas, petrochemical, oil refining, metallurgy, medicine, biology, ecology, etc.

The known method and device for chromatographic spectra of individual compounds or individual components of complex mixtures in series-connected columns Packed with different molecular structure and the nature of the interaction with the analyzed substance stationary liquid phases [1], in which register the signals of each detector column on the same chromatogram as a spectrum peaks of the sorbate. While the sample analyte is introduced to the input of the first column, and the output of each column is connected to the detector through the capillaries of different cross-section for submission to the detector minor part of the flow from each column.

However, the known method and apparatus do not provide the necessary reproducibility in obtaining chromatographic spectra, so as not possible with sufficient accuracy to determine the flow rate and pressure of carrier gas in each column.

Closest to the invention, the set of essential characteristics is a method for the chromatographic spectra, which identificirebulia United columns with different stationary liquid phases, and detector signals are registered on the same chromatogram as a spectrum peaks sorbate, shifted in time in proportion to their retention values in each column [2]. A device for implementing the known method comprises a source of carrier gas, dispenser, two or more parallel connected chromatographic column, a detector, a recorder, and the inputs and outputs of the columns are connected by capillaries of different cross-section, respectively, with the output of the metering device and the input of the detector [2].

The disadvantages of the known method and device: low reproducibility in obtaining chromatographic spectra due to the low accuracy of definition and installation of flow of carrier gas in each column, the lack of representation of the chromatographic spectra in the form of a set of universal retention indices of the partial loss of information due to overlapping chromatographic zones, eluruumid from different speakers, and possible errors associated with determining the origin of each peak of the spectrum of the corresponding column.

The objective of the invention is to improve the reproducibility and reliability of the decoding when receiving chromatographic spectra of the studied substances.

This problem can be solved also due to the fact that the device for receiving the chromatographic spectrum that contains one United source of carrier gas, the first line of the carrier gas, the metering device, at least two parallel connected chromatographic column, a detector and recorder further comprises at least one line of the carrier gas, and the additional lines parallel to each other and the first line of the carrier gas, a dispenser with a dispensing volumes of various sizes, and the entrance of each of the columns is connected to one of the dosing volumes and one of the lines of carrier gas through the locking elements of the dispenser.

In Fig. 1 shows the chromatographic spectra: a - ethanol, b - benzene; Fig. 2 schematically images and device for its implementation.

Chromatographic spectra get two columns, made of stainless steel tube (length 1 m, inner diameter 3 mm). As one of sorbent columns use apiezon L incurred in the amount of 15 wt.% on chromaton N-AW graining of 0.16 to 0.2 mm, the Second column is filled 15 wt.% etilenglikolevye on chromaton N-AW graining also of 0.16 to 0.2 mm, the Flow of carrier gas - nitrogen in each column set equal to 30 cm3/min. Pressure carrier gas inlet of the column is 0.8 kg/cm2. The amount of dose for the chromatography was carried out identifiable substance in the first column set to 0.12 ál, the second μl of 0.18, i.e., 1.5 times more than the first column. The temperature of thermostat columns 120aboutC. the Output of each column is connected with the tee with a flame ionization detector. Detector signals recorded by the electronic potentiometer in the form of a chromatogram. Identifiable substance with a fixed volume of the sample simultaneously dosed, respectively, in each column and the absolute value of the chromatographic peaks of the spectrum on the chromatogram determine the identity of each peak corresponding column. A smaller value of the maximum chromatography is etilenglikolevye, the amount of dose of 0.18 mm. The universal value of the calculated retention indices respectively for column 1: ethanol - 281, benzene - 571; for column 2: ethanol - 457, benzene - 499. The obtained values of retention indices are in good agreement with the available literature data on the retention of ethanol and benzene on selected stationary liquid phases. Error in the determination in the case of conversion of indexes Kovac not exceed 1.0 to 1.5 I. E. for benzene and 2.0-2.5 I. E. for ethanol.

Device for chromatographic spectrum contains (Fig.2) United source 1 carrier gas, two regulators of flow 2, two pressure gauge 3 one on the appropriate line a, B of the carrier gas, parallel to each other, the dispenser 4 with two doses of 5 different fixed volume, the two channels 6 to the carrier gas supply when the set of samples and two locking elements 7, two parallel connected chromatographic column 8 with different stationary liquid phases, with the inputs of each column is connected to one of the fixed doses of 5 and lines a, B of carrier gas through the locking elements 7 of the dispenser 4, the detector 9, the recorder 10, line 11 of the analyte.

The device operates as follows.

IAMI 5 is advanced to the right (Fig.2 is shown by the dotted line). While the carrier gas from source 1 by the two lines a And B, each of which has a knob 2 flow rate and pressure gauge 3, entered in the appropriate columns 8 through the locking elements 7 and the channels 6 of the dispenser 4. Upon completion of the cycle of the set of samples in a dose of 5 dispenser 4 switch in position I, shown in Fig.2 by solid lines, and inputs each of the columns 8 are simultaneously connected with the corresponding fixed dose of 5 and line a, B of the carrier gas through the locking elements 7 of the dispenser 4. The sample is identifiable substance is washed away in the flow of carrier gas from 5 doses in column 8 and in accordance with the values of the retention eluted from columns 8, entering the detector 9 and the Registrar 10. Detector signals are recorded on the same chromatogram as a spectrum peaks identifiable substance and the absolute value of the chromatographic peak is proportional to the volume of the dose, determine the identity of each peak of the spectrum of the corresponding column.

Using the proposed method to obtain the chromatographic spectrum and device for its implementation can improve the reproducibility and reliability of the decoding of the chromatographic spectra of individual compounds when they are received on Provo and equality of the values of the flow at a certain pressure of carrier gas in the separation columns), and by simultaneously metering in each column different, fixed quantities of samples of the substance, accurately determine the identity of the investigated substances to the groups of compounds defined molecular structure, comparing the obtained chromatographic spectra with the Atlas of spectra of individual compounds to determine chromatographic value retention of the studied substances on the basis of the measured universal retention indices.

1. The method of obtaining chromatographic spectrum, in which identifiable substance at the same time miss at least two chromatographic columns filled with different stationary liquid phases, register the signals of the detector on the same chromatogram as a spectrum peaks of the analyte, wherein the identifiable substance is metered into each chromatographic column with different amounts of injected sample and the absolute value of the chromatographic signal detector output columns judge toiletries each peak of the spectrum of the corresponding column.

2. Device for chromatographic spectrum containing connected in series and tographically column, detector and recorder, characterized in that it additionally contains at least one line of the carrier gas, and an extra line of carrier gas connected in parallel to one another and the first line of the carrier gas, a dispenser with a dispensing volumes of various sizes, and the entrance of each of the columns is connected to one of the dosing volumes and one of the lines of carrier gas through the locking elements of the dispenser.

 

Same patents:

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.

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.

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

FIELD: chemical technology.

SUBSTANCE: invention relates to a method for synthesis of ester perfluorinated derivative by using a chemical reaction. This reaction represents the fluorination reaction of the parent compound as a raw, the reaction of chemical conversion of fragment of ester perfluorinated derivative to yield another ester perfluorinated derivative or the interaction reaction of carboxylic acid with alcohol under condition that at least one or reagent, i. e. carboxylic acid or alcohol, represents a perfluorinated compound wherein indicated perfluorinated derivative of ester represents a compound comprising a fragment of the formula (1):

with a boiling point 400°C, not above. The reaction time for carrying out abovementioned chemical reaction is sufficient to provide the required yield of ester perfluorinated derivative and wherein this yield of ester perfluorinated compound is determined by the gas chromatography method by using a nonpolar column. Also, invention relates to a method for pyrolysis of ester perfluorinated derivative with a boiling point 400°C, not above, to yield the dissociation product wherein this product represents a derivative of acyl fluoride or ketone and wherein pyrolysis time is sufficient to provide the required degree of conversion of ester perfluorinated derivative and wherein the indicated conversion degree of ester perfluorinated derivative is determined by gas chromatography method by using a nonpolar column. Also, invention relates to a method for analysis of ester perfluorinated derivative with a boiling point 400°C, not above, that involves analysis of ester perfluorinated derivative in a sample containing ester perfluorinated derivative by gas chromatography method by using a nonpolar column wherein ester perfluorinated derivative represents compound comprising a fragment of above given formula (1).

EFFECT: improved method of synthesis.

8 cl, 1 dwg, 2 ex

FIELD: physics.

SUBSTANCE: method is proposed for identifying narcotic and psychoactive substances in biological fluids, where two aliquot samples of the analysed specimen are prepared - native and derived. Each of the two aliquot samples is passed through a column in at least two modes of conditioning parametres of temperature gradient variation. Each of the said aliquots is additionally passed through the column with division of the stream in the same conditioning modes. Further, detector signals are picked up on chromatograms. Peaks with asymmetry values on 0.1; 0.5 and 0.6 the height of the peak from the base ≤1.05 are selected on the chromatograms as best corresponding to binomial distribution of probability density and undeformed by effect of background components. Further, detected substances are identified on the selected peaks by comparing with standard analytical characteristics of the detected substances.

EFFECT: increased efficiency and accuracy of detection, possibility of unique identification of chemical compounds and their fragments in arbitrary combinations.

26 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to biology and toxicological chemistry and can be used in chemical-toxicology, expert forensic and clinical laboratories. The method includes: crushing a biological object containing N-(4-nitro-2-phenoxyphenyl)-methanesulphonamide, settling twice for 45 minutes with portions of an organic isolating agent which is methyl acetate, combining the obtained extracts, evaporating the solvent from the resultant extract, treating the residue with acetone, separating the acetone extract, evaporating the solvent from resultant extract, dissolving the residue in diethyl ether, extracting the ether solution with a buffer solution at pH 9-10, acidifying the aqueous alkaline extract with 24% hydrochloric acid to pH 2-3, saturating the obtained solution with sodium bromide, extracting with ethyl acetate, evaporating the obtained extract in an air current at 20-22°C until a dry residue is obtained, dissolving the residue in a mixture of hexane and acetone taken in volume ratio of 8:2, performing chromatography on a macrocolumn with silica gel L 40/100 mcm using a hexane-acetone mobile phase in volume ratio of 8:2, combining eluate fractions containing the analysed substance, evaporating the eluent in an air current at 20-22°C until complete removal of the solvent, dissolving the residue in methanol and performing determination via a combined physical-chemical method in the form of chromatography-mass spectrometry, using a DB-5 MS EVIDEX capillary column with a mobile phase which is 5% phenyl-95% methylpolysiloxane, using a mass-selective detector operating in electron impact mode, the initial thermostat temperature of the column is 70°C, maintaining said temperature for 3 minutes, further raising the temperature from 70°C to 290°C at a rate of 20°C per minute, maintaining the final temperature of the column for 16 minutes, the temperature of the injector is 250°C, the temperature of the quadrupole is 150°C, the temperature of the detector interface is 300°C, detecting strength of the signal resulting from charged particles formed when bombarding the analysed substance coming from the capillary column and falling into an ion source with an ionising electron beam with energy of 70 eV, recording the mass spectrum on the full ion current, while calculating the amount of N-(4-nitro-2-phenoxyphenyl)-methanesulphonamide from the area of the chromatographic peak.

EFFECT: high sensitivity of analysis.

2 ex, 3 tbl

FIELD: chemistry.

SUBSTANCE: method includes transforming a compound with an asymmetrical structure into two compounds with a symmetrical structure relative to a selected centre of symmetry and determining the retention index as the half sum of retention indices of compounds with a symmetrical structure, characterised by that the centre of symmetry of an O-alkylalkylfluorophosphonate compound is the carbon atom in the O-alkyl radical at the branching of which two different alkyl fragments or an alkyl fragment and a hydrogen atom are located; further, the method includes structural transformation of the compound into two compounds of the same class of O-alkylalkylfluorophosphonates with a symmetrical structure relative to the selected carbon atom using only said fragments and without structural change of the rest of the molecule.

EFFECT: novel method of predicting gas-chromatographic indices with improved reliability and objectivity.

1 ex, 2 tbl, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to identification of unknown compounds and, in particular, but not exclusively, to methods and systems for unknown compounds identification by gas chromatography - mass spectrometry using a retention index as the second parameter for identification. The computer method for creation of a standard compounds database with associated retention indices for unknown compounds identification using gas chromatography - mass spectrometry, GC-MS, includes assessment of the predicted retention index for a standard compound from the mass spectrometric GC-MS standard library on the basis of standard compound atomic structure. Also, the computer method includes assigning of the predicted retention index to a standard compound to create a record in the database, identifying the standard compound and the predicted retention index.

EFFECT: increased reliability and efficiency of unknown compounds identification.

15 cl 3 dwg

Up!