Method of authenticating medicinal plant raw material and apparatus for realising said method
SUBSTANCE: sample of medicinal plant raw material is held for 40 minutes at 100°C. Components of the equilibrium vapour phase are analysed on a standard column. Interpolation characteristics of sorbates are then determined, and the input of equilibrium vapour phase samples and n-alkanes is synchronised based on a signal from the detector on part of the discharge line of the divider of the sample input unit. The apparatus has a sampling valve, a heated vessel for analysed samples and a sample input unit with a flow divider. The apparatus also has a capillary column, a detector connected through a constant fluidic resistor with the discharge line of the divider, an analysis programming unit and an additional amplifier for the detector signal, which generates a start command for the analysis programming unit.
EFFECT: high accuracy while standardising and improving precision of measurements under repeatability conditions.
2 cl, 1 dwg
The invention relates to gas chromatography and can be used to standardize and evaluate the authenticity of various pharmaceutical raw materials in medicine, pharmacology, health care, food, perfumery and other industries.
Known methods and devices for standardization of medicinal plants (herbal drugs and phytopharmaceuticals (AF) based on them, based on the determination of biologically active compounds (BASS) and standard samples comparison (WITH) using various types of chromatography and UV spectroscopy. These methods allow you to quickly and reliably assess the quality of raw materials on top of the BASS. In this case, as a rule, do not use the additional stage of treatment, which increases the analysis time and leading to an inevitable loss of part of the investigated substances (see: the Industry standard of Ministry of health of the Russian Federation OST. 91500.05.001-00. The quality standards of medicines. The main provisions. - An introd. 01.01.01. - 2000. - 12 S.).
Known as methods of standardization of herbal drugs, biologically active additives (BAA) and various OP (see: Kurkin V.A. Pharmacognosy. The tutorial. 2nd ed., added; and extra - Samara LLC "Etching". GOU VPO Samara state medical University, 2007 - 1239 S.).
To determine the authenticity of the LRS and the OP also use so-called "fingerprints", in which the chromatogram appreciate not separate classes and the individual is property of matter, and the totality of the BASS (see, for example, Tereshina NS, Abramov A.A., Margaryan A. Analysis of homeopathic medicines barberry chromatographic methods. // Vestnik MGU. Ser. 2. Chemistry, 2006. - 47 so. No. 5. - S-349.)
However, the known methods of determining the authenticity LRS do not provide a direct analysis of the BASS directly into the LRS, and require pre-cooked preparations, for example, essential oils, tinctures, extracts, teas, etc.
The closest to the invention by the combination of essential features is the way of standardization of polymers "fingerprint" in the form of a set of program products of their pyrolysis, in which a fixed number of crushed analyzed raw material is placed in a heated sealed vessel is maintained at a given temperature, the pyrolysis products are batched in a chromatographic column, measured value signal and the retention time for identification and standardization of polymers (see: Berezkin V.G., Eliseev V.R., Nemirovskaya IN Gas chromatography in chemistry of polymers. - M.: Nauka, 1972 - 283 S.)
The disadvantages of this method is the low reliability in the standardization of herbal drugs and the bad convergence of the analysis.
The closest to the invention by the combination of essential features is a gas chromatograph Color-100, provided the pyrolytic console tap-dispenser, the node of the input samples with the evaporator and the flow divider, the capillary column and a flame ionization detector (see: Eliseev V.R., V.G. Berezkin, pancakes A.S., Kolmanovskii placing V.N., Yashin YA and other Pyrolytic device for gas chromatography. Auth. mon. The USSR №284418 from 14.10.1970. // Bull. Fig. No. 32, 1970, see also: Technical description and operating instructions on the chromatograph series Color-100". Specifications TO).
A disadvantage of the known device for evaluating the authenticity of herbal drugs is the increased accuracy in the determination of the interpolation characteristics for qualitative and quantitative analysis of the components of the RPF, as the external standard homologues of n-alkanes is injected by syringe into the node of input samples with the evaporator, and the components RPF in line with the carrier gas tap-dispenser, resulting in the beginning of the two analyses, a fixed torque input samples differ from each other.
The objective of the invention is to increase the reliability in the standardization of herbal drugs and the improvement of the convergence analysis in terms of the frequency of occurrence.
This problem is solved due to the fact that the way to assess the authenticity of medicinal plants, in which a fixed number of investigated sample is placed in a sealed vessel, maintained at a given temperature, the components of the equilibrium vapor phase on serout in a chromatographic column, measured value signal and the retention time, wherein the sample is kept in a sealed vessel at 100°C for 40 minutes, the components of the equilibrium vapor phase will be analyzed by standard capillary column with a node of the input samples with a flow divider in a linear programming temperature, the output signals of the components of the equilibrium vapor phase compared with the signals of external standards homologues of n-alkanes to calculate the interpolation characteristics of the solutes, and the synchronization time of the input of the analyzed samples are carried out by the signal detector to a fixed part of the flow from the discharge line of the divider node of the input samples.
This problem can be solved also due to the fact that the device for evaluating the authenticity of medicinal plant raw materials containing preparation unit gas, tap-dispenser, heated sealed vessel for the studied samples, the node input samples with flow divider, capillary column, detector and software analysis, characterized in that the input of the detector is connected with the tee as with the exit of the capillary column and the vent line of the flow divider node of the input samples through a permanent pneumatic resistance and the measuring circuit of the detector is provided with an additional amplifier connected to the programmer analysis.
When the solution set is military tasks created technical result which are as follows:
1. Higher confidence in the standardization of herbal drugs by creating a reference data banks in the form of a "fingerprint" for different LRS. Reference banks contain a set of retention indices in linear programming temperature columnand quantitative information in the form of concentrations of components RPF (Cicalculated according to the relative output signals using the dual internal standard. Standardization and evaluation of the authenticity of the investigated LRS is to confirm together receivedand Ciaccording to published data Bank.
2. Improving the precision of analysis results in terms of repeatability (precision of measurement), which is achieved by use of the interpolation output signals for qualitative and quantitative analysis of herbal drugs.
This allows us to conclude that the claimed invention are connected by a single inventive concept.
The invention is illustrated in the drawing. Figure 1 schematically shows a device for evaluating the authenticity of medicinal plants, which includes the preparation unit gas 1, tap-dispenser 2, the pressurized heated vessel for samples 3, node of the input samples with flow divider 4, the capillary quartz is the third column 5 firm Varian type VF-1 (length 30 m, the internal diameter 0.32 mm, film thickness of 0.5 µl), the detector 6, an additional amplifier 7, programmer analysis of 8 and a constant pneumatic resistance 9.
The system for assessing the authenticity of medicinal plants is as follows: 5 g of crushed LRS put heated in a sealed vessel 3 and heated to 100°C. Crane dispenser 2 at this time is set to "analysis" (solid lines), and the carrier gas is nitrogen supplied to the input node of the sample 4, column 5 and the detector 6. LRS is kept in a vessel 340 minutes and crane dispenser switch to "set" (dotted line), the carrier gas sweeps the components of the RPF from the vessel 3 in column 5. The operation time is set to 30 seconds, after which faucet-spout again switch to position "analysis". The separation of components of the RPF carried out in the regime of linear temperature programming of the column. The initial column temperature of 40°C, heating rate 5°C/min Final temperature of 180°C. the Total analysis time of 40 minutes. The division of the flow at the inlet to column 1:40, the flow of carrier gas in the column of 1 cm3/min. the Beginning of each analysis is synchronized programmer analysis 8 by the signal detector 6 via the auxiliary amplifier from a fixed portion of the flow from the discharge line of the flow divider node of input sample 4.
To determine the interpolation output signals in the qualitative and the quantitative analysis of the components of the RPF as the external standards used homologues of n-alkanes (from hexane to hexadecane), the mixture which is metered by microprism 0.5 ál to the input node of the sample 4, the evaporator temperature 250°C.
According to the results of gas chromatographic analysis of the components of the RPF and mixtures of n-alkanes expect the following characteristics:
1. The retention times of the solutes RPF and homologues of n-alkanesandrespectively, where z is the number of carbon atoms in the molecule n-alkane.
2. The retention indices of the components of the RPF in linear programming the temperature of the column.
3. The normalized output signals to components RPFand for homologues of n-alkanes.
where yCR- chromatographic output signal from the discharge line of the flow divider is proportional to the sample volume; yiand yz- output signals of the components of the RPF and n-alkanes, respectively.
4. The concentration of the components RPF using the dual internal standard.
where Czand Cz+1the concentration of n-alkanes in the analyzed mixture.
5. Root mean square deviation (RMS) average of the measurements.
wherefor the proposed method;
x=yi- proceed. of the STN method;
n - number of measurements.
6. The relative standard deviation of the arithmetic mean of the measurements in %.
7. Limit of confidence interval in %.
8. The accuracy of measuring the concentration of a model mixture in %.
where Ciis measured by the equation (3) concentration using the output signal, yi(for a known way) and(the proposed method); (CEastthe true concentration in the mixture model, calculated by the procedure of preparation by weighing the components of the mixture on an analytical balance.
In the known method a portion of powdered herbal drugs are placed in a pyrolytic console, maintained at a temperature of 800°C, and the products of pyrolysis chromatographic and get a set of output signals (- retention time and Qi- the area of the chromatographic peak) in the form of a "fingerprint".
The experiments were conducted using the following LRS: peppermint leaves, grass, tarragon, St. John's wort herb and fruit, milk Thistle.
The correctness and precision of the measurements was assessed by the results of the analysis of model binary mixture of n-alkanes (decane - 35 wt.%, and undecane - 65 wt.%). The number of measurements n=5. The mixture is hotovely gravimetric method by weighing components on an analytical balance of POWER-200.
The results of the experiments are summarized in table Comparative data experimental verification of known and proposed methods.
|Comparative data experimental verification of known and proposed methods|
|№ p/p||Name||The known method||The proposed method|
|1.||The average value of the output signal, (2)|
|- absolute, yimV·||720||1275||-||-|
|2.||The relative standard deviation, Sr, %, (5)||a 3.9||4,1||1,6||1,7|
|3.||Limit of confidence interval, ±Δ, %, (6)||10,8||11,4||4,4||the 4.7|
|4.||The accuracy of measuring the concentration of the mixture model, δ, %, (7)||6,1||5,8||2,5||2,4|
|5.||Analysis of the LRS for the standardization and evaluation of authenticity||The combination of the output signals "fingerprints"|
|Retention time, min||Index holding, (1)|
|5.1.||Peppermint leaves||20,251±3,1||935, 968,1015,1026, 1059,1083, 1142, 1167 Δ=±2 units index|
|5.2.||Herb tarragon||593, 655, 665, 709, 804, 1145, 1504, 1512 Δ=±2 units index|
|5.3.||St. John's wort herb||11,972±1,8||601,633,660, 686, 793,923|
Δ=±2 units index
|5.4.||Fruits, milk Thistle||9,055±1,4|
|540, 568, 580, 711, 869, 907, 998|
Δ=±2 units index
As can be seen from the data in table 1, the proposed method provides a significant increase in the reliability in the standardization of herbal drugs in comparison with the known method. Thus, the set of output signals for all samples LRS (item 5, table 1) is not less than six signals with different indexes retention and limit of confidence interval does not exceed ±2 units of the index or 2%, while for known way herb tarragon generally not identified, and peppermint leaves and herbs St. John's wort is only one reference substance, and the bound of the confidence interval of the absolute retention time in the mode of pyrolysis is ±15%.
The precision or repeatability of measurement in the output signals in terms of repeatability and accuracy of measurement of the concentration of mixture model for the proposed method is more than two times higher than for known (see PP, 3, 4 of table 1).
The use of the proposed method of assessing the authenticity of medicinal plant materials and devices for its implementation allows you to:
1. To create a reference data Bank on the combination of the output signals of the components RPF (retention indices in linear programming the temperature of the column and the quantitative content of the individual components of the RPF normalized output signals using the dual internal standard).
2. Check the standardization and evaluation of the authenticity of the LRS using the reference of the Bank.
3. To conduct rapid analysis of the quality and facilities of various BAD and the OP of this LSR.
1. The way to assess the authenticity of medicinal plants, in which a fixed number of investigated sample is placed in a sealed vessel, maintained at a given temperature, the components of the equilibrium vapor phase is metered into the chromatographic column, measured value signal and the retention time, wherein the sample is kept in a sealed vessel at 100°C for 40 min, the components of the equilibrium vapor phase will be analyzed by standard capillary column with a node of the input samples with a flow divider in a linear programming temperature, the output signals of the components is tov equilibrium vapor phase compared with the signals of external standards homologues of n-alkanes to calculate interpolation characteristics of the solutes, and synchronizing the moment you enter the analyzed samples are carried out by the signal detector to a fixed part of the flow from the discharge line of the divider node of the input samples.
2. The system for assessing the authenticity of medicinal plant raw materials containing preparation unit gas, tap-dispenser, heated sealed vessel for the studied samples, the node input samples with flow divider, capillary column, detector and software analysis, characterized in that the input of the detector is connected with the tee as with the exit of the capillary column and the vent line of the flow divider node of the input samples through a permanent pneumatic resistance and the measuring circuit of the detector is provided with an additional amplifier connected to the programmer analysis.
SUBSTANCE: present invention relates to versions of a method of purifying terbinafine from nonmetallic impurities, primarily a substance A of formula
, as well as to use of said methods to obtain purified terbinafine. One of the versions of the method involves molecular distillation of crude terbinafine in form of a free base and extraction the obtained purified terbinafine in form of a free base or acid-addition salt (method A). In another version (method B), crude terbinafine in form a free base undergoes molecular distillation combined with formation of a salt of the obtained product with simultaneous deposition of a purified trans-isomer, and the obtained highly pure terbinafine is extracted in form of a free base or acid addition salt.
EFFECT: method enables to obtain terbinafine containing less than approximately 5 ppm of substance A.
13 cl, 2 dwg, 6 ex
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
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
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
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.
EFFECT: method enables efficient separation of methionine and glycine by combining sorption and desorption processes while excluding the sorbent regeneration step, and reduce the volume of wash water without using considerable amount of auxiliary reactants.
2 dwg, 2 tbl, 1 ex
SUBSTANCE: analysed sample is infused with an organic insulating agent. The obtained extract is purified through chromatography on a column of silica gel L 40/100 µ, while performing elution with a mixture of organic solvents. The analysed substance is determined using a chromatographic technique using a mobile phase which contains hexane, dioxane and propanol-2. The organic insulating agent is toluene. The toluene extract is dehydrated with anhydrous sodium sulphate. During the purification process, hexane is first passed through the column and elution is then carried out with a hexane-dioxane-propanol-2 solvent mixture (8:3:0.6 by volume). Eluate fractions containing the analysed substance are merged. The eluent is evaporated. The residue is dissolved in the hexane-dioxane-propanol-2 solvent mixture (15:5:1 by volume) and detection is carried out using high-performance liquid chromatography (HPLC) in a 64×2 mm column filled with Silasorb-600 sorbent using a hexane-dioxane-propanol-2 mobile phase (15:5:1 by volume) and a UV detector.
EFFECT: high accuracy and sensitivity of analysis.
3 ex, 4 tbl
SUBSTANCE: there is described a method of quantitative cyclosporine A evaluation in patients' blood involving blood protein precipitation by adding an aqueous solution of zinc sulphate and methanol, mixing, centrifuging and sampling a centrifugate; separating the centrifugate ingredients by reverse phase high-yield liquid chromatography, mass-spectrometre detecting cyclosporine A and evaluating the cyclosporine A concentration with plotting a calibration curve; blood protein are precipitated with using whole blood; blood protein precipitation is followed by additional salt impurity precipitation by adding methanol to the centrifugate to the general concentration not less than 90 vol. %, mixing again, centrifuging and sampling the centrifugate; separating the centrifugate ingredients, detecting and evaluating the cyclosporine A concentration.
EFFECT: method allows facilitating analysis simplicity and universality with providing adequate sensitivity and selectivity ensured by the absence of necessity for the internal standard and online extraction and lower requirements to specification of the used mass spectrometre by conducting preliminary impurity precipitation.
SUBSTANCE: proposed method comprises forcing analysed product into chromatograph first circuit to define carbon sulphide at its concentration exceeding 0.1 wt % and, at a time, into second circuit at carbon sulphide concentration lower than 0.1 wt %. First circuit comprises piston-type metering valve and packed columns arranged in heated temperature-controlled cabinet and filled with polymer adsorbent, 0.1-1.5 m-long precolumn and 0.5-5 m-long main column, and heat conductivity detector. Second circuit comprises piston-type metering valve, packed capillary columns arranged in heated temperature-controlled cabinet and filled with polymer adsorbent, 0.1-1.5 m-long precolumn and 15-50 m-long main column with their ID making 0.23-0.32 mm, and sulfur-selective detector. Metering valves are arranged sequentially in both circuits along sample feed direction.
EFFECT: shorter easier process.
5 cl, 1 dwg, 2 tbl, 1 ex
SUBSTANCE: urine is sampled, centrifuged that is followed by solid-phase extraction with Oasis HLB sorbent with using 100% acetonitrile as an extraction fluid for dimethyl terephthalate extraction. Said solid-phase extraction is conducted by consequent passing 100% acetonitrile, distilled water, the urine sample after centrifugation, distilled water, 20% aqueous acetonitrile and 100% acetonitrile as the extraction fluid through the sorbent; then the prepared extract is analysed by liquid chromatography with using as a mobile phase mixed acetonitrile and water in the at the varying ratio 25:75 vol. % to 90:10 vol. % respectively in a gradient mode which is enabled with combining chromatography by supplying at first the mobile phase containing mixed acetonitrile and water in the ratio 25:75 vol. % for 10 minutes. Then increasing the acetonitrile concentration in the mobile phase to 90 vol. % for 5 minutes and passing such mobile phase for another 5 minutes is followed by decreasing a volume amount of acetonitrile to 25 vol. % for 5 minutes and passing such mobile phase through a column for 10 minutes, while an amount of dimethyl terephthalate is determined by a calibration chart.
EFFECT: high sensitivity of the method combined with selectivity and availability for routine analyses.
5 cl, 6 tbl
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: 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