Method of detecting unknown substances in body fluids of patients taking narcotic or psychoactive substances
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.
EFFECT: possibility of unique identification of chemical compounds and their fragments in arbitrary combinations while increasing accuracy and rapidness of detection.
The invention relates to gas chromatography analysis of various chemical compounds and can be used in medicine, biology, ecology and doping control.
There is a method of analysis of liquid preparations based on vegetable raw material by chromatography, which involves removing the volatiles by distillation of the original sample steam, concentrated volatiles extraction of the low-boiling solvent followed by distillation of the solvent and, finally, the actual definition of the components by the methods of gas or liquid chromatography .
The disadvantage of this technical solution is the low information content of the data received, in particular chromatographic spectra, which prevents unambiguous identification of chemical compounds and their fragments in arbitrary combinations.
There is also known a method of chromatographic identification of components of complex mixtures of organic compounds, including passing the substance through a system of series-connected columns filled with different sorbent polarity, sampling after each column, detection at the detectors of various types and identification of the analyte by calculating the sensitivity coefficient and the relative retention data of two detectors .
The disadvantages of the criminal code of the above method include the complexity of the analysis procedure, as well as the probability of obtaining inaccurate results when calculating retention values of different columns.
There is also known a method for the identification of unknown substances by gas chromatography in combination with mass spectrometry. At the specified method record the chromatogram as a function of retention time and record the mass spectrum in the period of time corresponding to the release of substances from the column, and compared with the mass spectra of known substances in the database, then define the retention index and compare it with those from the database and identify the substance by the two parameters : the mass spectrum and retention index .
The disadvantage of this method, despite the attractiveness of using the retention index is high the probability of obtaining false results of the analysis, because the retention indices of the initially bound to a specific column with defined parameters and is often either not played or played back on other equipment with distortion, which can lead to inaccurate interpretation of results.
The closest analogue to the claimed technical solution is a way of performing mass spectral analysis of multicomponent systems, which consists in registration of mass spectra of the sample, de is analucia of mass spectra and their associated chromatograms of one substance, and recognition by comparison with the reference spectrum of a substance by comparing the intensities of peaks and retention time recognized substances with predefined parameters of the required substances confirming recognition .
The disadvantage of this method is the low threshold of the definition, namely, that it is not possible to determine the analyte at low concentrations, and the resulting high probability of obtaining false results of the analysis in this two-stage recognition.
The technical result, which directed the establishment of this invention is the provision of opportunities for unambiguous identification of chemical compounds and their fragments in arbitrary combinations, while improving the accuracy and timeliness of the definition.
The technical result is achieved by the fact that prepare three samples studied sample of biological fluid first by extraction with reconstitution, second by acid hydrolysis and the third by enzymatic hydrolysis, and the first sample is subjected to GC/MS analysis mode temperature gradient 15°C/min, and the data is analyzed by comparing with the database, which identifies the characteristics of an unknown substance (HB), namely spectra with mz, coinciding with basic ions acting on the patient's drug or substance and its metabolites and the content of HB in the sample, the second sample was subjected to GC/MS analysis mode temperature gradient 25°C/min and the third sample was subjected to GC/MS analysis mode temperature gradient 15°C/min and the increase in the content of HB in the last two samples in comparison with the first, is subjected to GC/MS analysis mode temperature gradient 15°C/min operating on a patient's drug or psychoactive substance in the presence of HB, and in its absence in the base substance, check the presence of HB in intact biological fluid, for which the sample it is prepared by acid hydrolysis and subjected to GC/MS analysis mode temperature gradient 15°C/min and 25°C/min and in case of detection of HB in intact biological fluid it qualify as endogenous, and in the absence of signs - an aliquot of the first sample, is mixed with a sample of intact biological fluid, prepare the sample by acid hydrolysis of the mixture, subjecting the sample GC/MS analysis mode temperature gradient 15°C/min and 25°C/min, define the content of HB on the results of both analysis modes and compare it with the content of HB in the first sample and the matching values of the content of HB in these three samples qualify HB ka is new, previously unknown product of the metabolism of narcotic drugs or psychotropic substances.
It should be noted that the inventive method can also be carried out using analytical system HPLC-MS/MS, because the principal provisions of the proposed technical solutions are sample preparation, analyses in different modes of climate parameters on the temperature gradient, the choice of objects for analysis and subsequent identification of the designated substances by comparing the results of the analysis of baseline data of the reference substance.
As a biological fluid using blood, urine, saliva, water extracts disintegrated organs and tissues, etc.
The analytical system GC-MS can be used, for example, gas chromatography-mass spectrometer with quadrupole analyzer Agilent-5973, coupled with a gas chromatograph model Agilent-6890.
As accessories can be used:
- automatic shaker firm Glas-Col®, USA - for JJA;
- centrifuge brand Rotina 46R company Hettich, Germany) to obtain the contrast of the boundary surface between the organic and aqueous phases;
- vacuum concentrator company Barnstead Inc. (USA) for evaporation of the organic extract;
- column HP-5MS, VF-5MS for chromatographic separation.
Of course, for having realizatsii of the claimed invention can be used, and other devices with characteristics similar to the above.
As the carrier gas can be used helium, nitrogen or hydrogen.
As internal standards (SU) use diphenylamine or other suitable connection.
The ionization is carried out by electron impact in a vacuum. Detection of the detected substances is carried out in the registration mode full scan or selected ions.
Data processing is carried out with application of the automatic processing AMDIS and databases.
In principle, search, and detection should be implemented in order to find new, previously unknown metabolites, which can be potentially active and therefore be responsible for the side effects of the drug such as ketamine, or in the case of the same ketamine should be the basis for the development of new anesthetics.
With regard to the implementation of the proposed technical solution, the authors, based on their knowledge and experience, I think it advisable to search in the following sequence:
- search and discovery of the unknown substance (GC-MS analysis of the samples analyzed biological fluid at the temperature gradient of 15°C/min);
- identify the impact parameter analysis on the education of unknown substances (GC-MS analysis of the acid hydrolysate sample research which has been created biological fluid at the temperature gradient of 25°C/min);
- detection of conjugates (GC-MS analysis of enzymatic hydrolysate samples studied biological fluid at the temperature gradient of 15°C/min);
- identification of the unknown substance as an impurity or degradation product of narcotic or psychoactive substances (GC-MS analysis of samples of drugs or psychoactive substances at the temperature gradient of 15°C/min);
- identification of unknown substances in the intact liquid (GC-MS analysis of the acid hydrolysate samples of intact biological fluid at the temperature gradient of 15°C/min and 25°C/min);
confirmation of origin of an unknown substance from the study of biological fluid (GC-MS analysis of the acid hydrolysate of a mixture of samples analyzed and intact biological fluid at the temperature gradient of 15°C/min and 25°C/min).
The invention can be implemented as follows.
Previously, to create a library (database) prepare solutions of substances-standards (they are the same drugs and/or psychoactive substances) in organic solvents. Remove and register chromatographic and mass spectrometric characteristics of substances-standards (detects at least three characteristic ions of each reference substance, determine the retention time, molecular mass precursor ions, characteristic ions, the lower limit of the in detection).
Prepare the internal standard solution, then hold the sample preparation, in which a sample of biological fluid injected internal standard solution to bring the pH of the sample to 9.0 solid buffer, conduct liquid-liquid extraction with a mixture of organic solvents of different polarity, the organic layer is evaporated to dryness in a stream of nitrogen, pererastayut in ethyl acetate and then divide the sample into two analyte, the first of which is introduced into the system GC-MS. Remove and register chromatographic and mass spectrometric characteristics of the sample. The results of the analysis are compared with the database and to detect signs of unknown substances (HB). Next, prepare the second and third samples of the investigated biological fluid acid and enzymatic hydrolysis, respectively, and also enter them into the system GC-MS, shoot and record chromatographic and mass spectrometric characteristics of the samples. The results of the analysis are compared with the database, and signs HB determine its content in each sample. Then check the probability of the presence of HB in the drug or psychoactive substance, which is prepared sample of the specified substances by extraction and introduce it into the system GC-MS, shoot and record chromatographic and mass spectrometric characteristics of the sample and determine the presence of HB. Further, by acid hydrolysis to prepare a sample of intact biological fluid is injected into the system GC-MS and shoot and record chromatographic and mass spectrometric characteristics of the sample in two modes conditioning the temperature gradient, and then extracted a sample of intact biological fluid, mix it with the second analyte samples studied biological fluid mixture is subjected to acid hydrolysis and thus obtained sample is introduced into the system GC-MS, shoot and record chromatographic and mass spectrometric characteristics of the sample in two modes conditioning the temperature gradient. Next, compare, based on the results of the analyses, the HB content in all samples and is based on the ratio of the content of his qualify HB origin.
For a better understanding of the invention can be illustrated by, but is not exhausted by the following specific examples of its implementation.
The definition of the products of metabolism of ketamine.
A. Preparation of the reference sample and the analysis sample.
As an internal standard using diphenylamine, which is added to the analyzed samples to a concentration of 2 mg/DM3. To 1 ml of the investigated reference liquid add the internal standard to a concentration of 2 mg/l and extracted with 1 m is a mixture of hexane/diethyl ether 1:1. The extract evaporated, add 100 ál of ethyl acetate and 1 ál of sample injected.
The analysis is performed by gas chromatography-mass spectrometry system Agilent 6890/5973N mass-selective detector (record the mass spectrum of the quadrupole and the mass spectrum of the ion trap). The temperature of the node input of the sample - 280°C, analytical interface 240°C. the Separation is performed on silica capillary column HP-5MS length 30 m, internal diameter 0.25 mm, film thickness NF 0.25 μm. Temperature program: 70°C (1 min), 20°C/min, 280°C. the flow Rate of the carrier gas of 0.62 ml/min, the average linear velocity of carrier gas 29 cm/sec. The volume of injected sample 1 μl. The registration signal is carried out on total ion current (SCAN) in the mass range m/z 29-550 Amu Quantitative analysis is performed on the selected ions.
Fast GC program: 100°C, 1 min of exposure, (25°C/min); 300°C (15 min). The retention time of internal standard is to 4.52 min
Smooth GC program: 50°C; 0.5 min exposure; 99°C/min; 100°C (1 min); (15°C/min; 280°C (35 min). The retention time of internal standard is 9,27 minutes
B. sample Preparation and analysis of biological fluids (urine patient taking ketamine).
The urine sample (5 ml) add 5 ál of the internal standard solution containing diphenylamine (100 μg/ml), 0.1 g of the solid buffer, 5.0 g of ammonium sulfate and 5 ml of diethyl ether, the AC shall're asked for 2 minutes, further centrifuged at 1000 rpm for 5 min, the organic layer is separated, evaporated to dryness in a stream of nitrogen at 40°C and pererastayut dry residue in 50 ál of ethyl acetate, separated into four aliquots, the first of which is introduced into the system GC-MS. Remove and register chromatographic and mass spectrometric characteristics of the sample (detects at least three characteristic ions of each reference substance, determine the retention time, molecular mass precursor ions, characteristic ions, the lower limit of detection): take 5 µl of a solution and injected into the system GC-MS with ionization by electron impact in a vacuum. The analysis are as in part a smooth program (15°C/min). The results of the analysis are compared with the database (ketamine, norketamine) are presented in Table 1.
|The basic substance||Table of contents|
in the sample
|Retention time||The mass spectrum of the quadrupole||The mass spectrum of the ion trap||Molecular weight|
|Ketamine||-||11,40||237[M+]1 , 20923, 18099, 16611, 15217, 11513||238[M+H]+25, 20912, 18099, 16640, 15220, 11515,||237|
|Norketamine||-||11,10||223[M+]1, 19522, 16699, 13814, 13116, 11513, 10212||224[M+H]+50, 19520, 16699, 13132, 13816, 11518, 10240||223|
|an unknown substance||10 ng/ml||9,94||208[M+]1, 17399, 14510, 12997, 13829||209[M+H]+80, 17399, 14525, 12940, 1385, 11535||208|
Next, a second aliquot of the sample is injected hydrochloric acid, hydrolyzing the mixture, and the hydrolysate is introduced into the system GC-MS. The analysis lead for fast program (25°C/min). A third aliquot of the sample is subjected to enzymatic hydrolysis, and the hydrolysate is introduced into the system GC-MS. The analysis lead to a smooth program (15°C/min). Next, prepare a sample of a basic substance ketamine. Dissolve ketamine in ethyl acetate, 1 ml of the solution add EXT is NNI standard to a concentration of 2 mg/l and extracted with 1 ml of a mixture of hexane/diethyl ether 1:1. The extract evaporated, add 100 ál of ethyl acetate and 1 ál of sample injected. The analysis lead to a smooth program (15°C/min). Next, prepare the sample of intact biological fluids (urine man, not taking ketamine) by acid hydrolysis, as described above, the hydrolysate analyze for smooth and fast programs (15°C/min and 25°C/min). Further non-hydrolyzed sample of intact biological fluid is mixed with the fourth aliquot samples of the investigated biological fluid, hydrolyzing with hydrochloric acid, as described above, and the hydrolysate analyze for smooth and fast programs (15°C/min and 25°C/min). The results of the analyses are presented in Table 2.
|№ p/p||The object of analysis||The analysis mode Gradient t-ture (°C/min)||The content of the unknown substance (ng/ml)||Note|
|1||Reconstituted extract analyzed urine||15°C/min||10|
|2||The acid hydrolysate of the extract analyzed urine||25°C/min||1000|
|3||Enzymatic hydrolysate of the extract analyzed urine||15°C/min||1000|
|4||Sample of ketamine||15°C/min||0|
|5||The acid hydrolysate of the extract of intact urine||15°C/min||0|
|6||The acid hydrolysate of the extract of intact urine||25°C/min||0|
|7||Acid hydrolysate of a mixture of extracts analyzed and intact urine||15°C/min||10|
|8||Acid hydrolysate of a mixture of extracts analyzed and intact urine||25°C/min||10|
According to the results of benchmarking the analysis of an unknown substance in the test biological fluid is a new metabolite of ketamine.
The definition of products of the metabolism of tramadol.
The analysis is performed as described in example 1, except that analyze biological fluid (blood sample) patient taking tramadol. The results of the analysis in comparison with the basic substances are presented in Table 3.
|Substance, mol. weight||Retention time, min||Mass spectrum (ion trap)|
|Tramadol 263 u||19.01||263[M+H]+(8%); 58(100%)|
|Epoxiconazol, impurity substance (and potential metabolite) 261 u||19.26||261[M]+(8%); 202(15%); 189(50%); 135(20%); 121(35%); 73(40%); 58(100%)|
|O-desmethyl - tramadol 249 u||19.19||250[M+H]+(100%); 58(30%)|
|An unknown substance||17.55||246[M+H]+(5%); 58(100%)|
During analysis as in Example 1 non-hydrolyzed sample of intact biological fluids (blood sample of the patient not taking tramado is) is mixed with the fourth aliquot samples of the investigated biological fluid, subjected to enzymatic hydrolysis, and the hydrolysate analyze for smooth and fast programs (15°C/min and 25°C/min).
The content of the unknown substance in the analyzed samples are presented in Table 4.
|№ p/p||The object of analysis||The analysis mode|
Gradient t-ture (°C/min)
|The content of the unknown substance (ng/ml)||Note|
|1||Reconstituted extract analyzed blood||15°C/min||750|
|2||The acid hydrolysate of the extract of the investigated blood||25°C/min||0|
|3||Enzymatic hydrolysate of the extract of the investigated blood||15°C/min||750|
|5||The acid hydrolysate of the extract of intact blood||15°C/min||0|
|6||The acid hydrolysate of the extract of intact blood||25°C/min||0|
|7||enzymatic hydrolysate of a mixture of extracts analyzed and intact blood||15°C/min||750|
|8||Enzymatic hydrolysate of a mixture of extracts analyzed and intact blood||25°C/min||750|
Despite the fact that in the sample of tramadol (item 4 of Table 2) also detected an unknown substance, it, whereas the contents in each case, qualify as a new, previously unknown metabolite of tramadol.
As can be seen from the description and examples of the method of the claimed technical solution provides the ability to uniquely identify chemical compounds and their fragments in arbitrary combinations with odnovremenno improving the accuracy and timeliness of the definition.
Sources of information
1. EN 2093822 C1 Ál. G01N 30/04, publ. 1997
2. EN 2069363 C1 Ál. G01N 30/02, publ. 1996
3. WO 2004/104571, Ál. G01N 30/00, publ. 2004
4. EP 1846757 A2 Μl. G01N 30/86, publ. 2007 - the nearest equivalent.
How to identify unknown substances in biological fluids of patients taking narcotic drugs or psychotropic substances, which prepare the test sample, is subjected to its GC/MS analysis, record the mass spectra of the sample, and their associated performance and conduct recognition of the substance by comparison with a database of reference analytical characteristics of substances, characterized in that prepare three samples studied sample of biological fluid first by extraction with reconstitution, second by acid hydrolysis and the third by enzymatic hydrolysis, and the first sample is subjected to GC/MS analysis mode temperature gradient 15°C/min and data analyze by comparing with the database, which identifies the characteristics of an unknown substance (HB), namely spectra with m/z coinciding with basic ions narcotic drugs or psychotropic substances or metabolites, and content (HB) in the sample, the second sample was subjected to GC/MS analysis mode temperature gradient 25°C/min and the third sample was subjected to GC/MS analysis mode temperature gradient 15°C/min and increase with the holding NV in the last two samples in comparison with the first, subjected to GC/MS analysis mode temperature gradient 15°C/min basic drug or psychotropic substance for the presence of HB, and in its absence in the base substance, check the presence of HB in intact biological fluid, for which the sample it is prepared by acid hydrolysis and subjected to GC/MS analysis mode temperature gradient 15°C/min and 25°C/min, and in case of detection of HB in intact biological fluid it qualify as endogenous, and in the absence of signs of an aliquot of the first sample is mixed with a sample of intact biological fluid, prepare the sample by acid hydrolysis of the mixture, subjecting the sample GC/MS analysis mode temperature gradient 15°C/min and 25°C/min, determine the content of HB on the results of both analysis modes and compare it with the content of HB in the first sample and the matching values of the content of HB in these three samples qualify HB as new, previously unknown product of the metabolism of the basic narcotic drugs or psychotropic substances.
SUBSTANCE: sodium fluoride is added to an analysed sample in amount of 10% of the mass of the biological object and infused twice in 45 minutes with portions of ethyl acetate, the mass of each of which is twice higher than the mass of the biological material. Separate extractions are combined, filtered through anhydrous sodium sulphate. The solvent from the filtrate is evaporated at temperature 50-60°C. The residue is dissolved in a mixture of hexane-dioxane-propanol-2 solvents. Chromatography is performed in a column with silica gel L 40/100 µ using a hexane-dioxane-propanol-2 mobile phase. The eluate fractions which contain the analysed substance are merged. The eluate is evaporated. The residue is dissolved in a mixture of hexane-dioxane-propanol-2 solvents and the analysed substance is determined via high performance liquid chromatography (HPLC) in a 64x2 mm column filled with Silasorb 600 sorbent using a hexane-dioxane-propanol-2 mobile phase and a UV detector.
EFFECT: invention shortens the duration of detecting tetraethyl thiuram disulphide in blood and increases its sensitivity.
3 tbl, 2 ex
SUBSTANCE: biological tissue is crushed, processed twice for 30 minutes with portions of ethyl acetate, weight of each twice exceeding weight of a biological object; prepared extractions are combined, filtered through anhydrous sodium sulphate; a solvent is evaporated from the filtrate; the residue is dissolved in acetonitrile; the prepared solution is watered down in the volume ratio 1:4, extracted twice in portions of chloroform, volume of each being equal to volume of a hydrophilic layer; the chloroform extracts are combined, steamed to a dry residue; the residue is dissolved in mixed solvents hexane-dioxane-propanol-2, cleaned in a silica gel column L 40/100µ with using a mobile phase hexane-dioxane-propanol-2; eluate fractions containing an analysed substance are combined; the eluent is evaporated; the residue is dissolved in mixed solvents hexane-dioxane-propanol-2 and analysed by a HELC method in a column of dimensions 64×2 mm filled with the sorbent Silasorb 600 with using a mobile phase hexane-dioxane-propanol-2 and a UV detector.
EFFECT: invention allows higher selectivity, sensitivity and accuracy of biological material analysis for tetramethylthiuramdisulfide.
4 ex, 5 tbl
SUBSTANCE: in the method of detecting phenol in aqueous solution via reverse-phase micro-column high-performance liquid chromatography with a preliminary sample preparation step through liquid-liquid extraction with acetonitrile, extraction is carried out at temperature 263±2 K for 30 minutes with ratio of equilibrium volume of water to the organic phase equal to 1:1.
EFFECT: simple and cheap method, high degree of extracting phenol, low detection limit.
1 ex, 3 tbl
SUBSTANCE: for an assay, 5-7 cm3 of blood is taken, and before extraction the sample is pre-treated with 2 cm3 of 60% sulphuric acid; the extraction process is executed with 30 cm3 of n-hexane once, and gas chromatography is preceded with single treatment of n-hexane extract with 10 cm3 of concentrated sulphuric acid.
EFFECT: invention provides higher reliability of α-HCCH, γ-HCCH test results and twofold reduced time of sample preparation.
1 ex, 1 tbl
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
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: 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