Method to reveal and determine origin of unknown substances in alcoholic drinks
FIELD: test equipment.
SUBSTANCE: proposed invention relates to gas chromatographic analysis and can be used in alcohol quality tests. Proposed method consists in that, additionally, water-spirit mix in the ratio of 60/40% by volume is prepared to a series of model samples based thereon to prepared by adding every component of analysed drink separately in said mix. Then model sample are analysed at the inlet assembly temperature of 180°C, 250°C and 310°C. Note that unknown substance detected in model sample is qualified as artifact formed in analysis, while is it is absent from model samples, check sample is prepared by combining the entire series of model samples to be analysed at aforesaid 180°C, 250°C and 310°C. Then mass spectra and chromatograms related therewith are analyzed and, if there is no revealed unknown substance in check sample, it is qualified as marker of nonfoods origin.
EFFECT: unambiguous identification of chemical compounds and fragments thereof as well as their origin, higher accuracy and faster identification.
4 tbl, 3 ex
The invention relates to gas chromatography analysis of various chemical compounds and can be used in the control of alcoholic beverages.
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 vapor, the concentration of volatile substances by extraction with a 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 this method sleduyuschi complexity analysis procedures, 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 index retention is a high 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 decks is nwalozie of mass spectra and their associated chromatograms of one substance and recognition by comparison with the reference spectrum of the 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 and determining the origin of these chemical compounds while increasing the accuracy and timeliness of the definition.
The technical result is achieved in that, in addition, prepare a water-alcohol mixture of 60/40 % by volume, based on it, develop a set of model samples by introducing a water-alcohol mixture each component of the investigated drink separately model and analyze the samples at the temperature of inlet node 180°C, 250°C and 310°C, and detection in the model sample of an unknown substance qualify as an artifact formed during the analysis, and in the absence of it in modelin the x samples prepared control sample by combining the total number of model samples analyze it when the temperature of the inlet node 180°C, 250°C and 310°C, recorded mass spectra and associated chromatogram and in the absence in the sample found an unknown substance it qualify as a marker of non-food origin.
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 the study of alcohol beverage can be used the full range of alcohol-containing liquids.
The analytical system GC-MS can be used such as 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;
- VAK the smart hub firm Barnstead Inc.(CLUA) for evaporation of the organic extract;
- column type FFAP for chromatographic separation.
Of course, carrying out 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 cyclohexanol 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, the detection and determination of unknown substances should be implemented in order to find new, previously unknown tokens, which may be responsible for the quality of alcoholic beverages or can be a witnesses of falsification liquor.
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 liquor at the temperature gradient of 10°C/min);
- yavlenie unknown substances as a product of decomposition of component(s) studied liquor (GC-MS analysis of a number of model samples of water-alcohol mixture + component investigated drink at the temperature of inlet node 180°C, 250°C and 310°C);
- identification of the unknown substance as an impurity or degradation product of components of the control sample (GC-MS analysis of the control sample at the temperature of inlet node 180°C, 250°C and 310°C).
The invention can be implemented as follows.
Previously, to create a database prepared samples of known beverage standards. Remove and register chromatographic and mass spectrometric characteristics of their (detects at least three characteristic ions of each component, determine the retention time, molecular mass precursor ions, characteristic ions, the lower limit of detection). From the data obtained form the base. Separately form the database laboratory background contamination and instrument background.
Prepare the internal standard solution, then hold the sample preparation, in which the sample liquor enter the 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 the sample is introduced into the system GC-MS. Remove and register chromatographic and mass spectrometric characteristics of the sample. The results of the analysis comparing the database and identify the characteristics of an unknown substance (HB). Then check the probability of the presence of HB in each component analyzed liquor, which prepare a water-alcohol mixture of 60/40% vol. and on its basis the number of model samples of the composition of the water-alcohol mixture component analyzed alcoholic drink. Each sample is introduced into the system GC-MS, shoot and record chromatographic and mass spectrometric characteristics of the sample at the temperature of inlet node 180°C, 250°C and 310°C and determine the presence of HB. Next, mix the whole number of model samples and thus obtained control sample is introduced into the system GC-MS, shoot and record chromatographic and mass spectrometric characteristics of the control sample when the temperature of the inlet node 180°C, 250°C and 310°C. In the absence of the control sample was found an unknown substance it qualify as a marker of non-food 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 identification of unknown substances in cognac.
A. Preparation and analysis of samples of the reference and the sample for the presence of volatile compounds.
As an internal standard using a solution of cyclohexanol in ethanol with a concentration of 0.1 vol.%. To 1 ml of the reference cognac add 30 µl of the internal art is ngarta to a concentration of 28 mg/l and the sample is introduced into the system GC-MS with FFAP column.
Similarly prepare and analyze the sample studied brandy.
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 process is conducted with the following parameters: temperature node of the input sample - 180°C, analytical interface 190°C. the Separation is performed on silica capillary column with a stationary phase (NP) HP-FFAP length 50 m, inner diameter 0.32 mm, film thickness of stationary phase 0.5 µm. The flow rate of the carrier gas at 1.2 ml/min, the average linear velocity of carrier gas 32 cm/sec. The volume of injected sample 1 ál dividing stream 1/10. Temperature program: 60°C (4 min), 10°C/min, 190°C (40 min). The registration signal is carried out on total ion current (SCAN) in the mass range m/z 29 - 300 Amu retention Time of internal standard is to 4.52 minutes When using the GC-FID analysis is carried out in similar conditions. The retention time of internal standard is 9,27 min carrier Gas is nitrogen. Quantitative analysis is performed on the selected ions.
B. Preparation and analysis of samples of the reference and the sample for the presence of markers of age.
The sample reference brandy (3 ml) add 100 ál of internal standard solution orthovision in ethanol, 2 mg/l), extracted with 3 ml of a mixture of hexane/diethyl the fir 1:1. The extract evaporated, add 100 ál of ethyl acetate and 1 ál of sample is introduced into the system GC-MS with column HP-5MS.
Similarly prepare and analyze the sample studied cognac. Remove and register chromatographic and mass spectrometric characteristics of the samples (detects at least three characteristic ions of each reference substance, determine the retention time, molecular mass precursor ions, characteristic ions, the lower the detection limit).
The results of analysis in the study brandy (see Table 1) found two substances identified as not characteristic of brandy.
|Retention time||Mass spectrum||Content||Estimated substance*|
|24,56 min||103, 116, 145||8 ng/µl||triacetin|
|26,75 min||31, 43, 60, 172||6 ng/ál|
|* - was found in the database|
Next, prepare a water-alcohol (cognac alcohol relevant excerpts) a mixture of SOS is ava 60/40% vol. and on the basis of the above-mentioned mixture to prepare a number of samples of the individual components of the reference brandy, including:
water-alcohol mixture + ethylhexenal
water-alcohol mixture + diethylcarbamoyl
water-alcohol mixture + ethyllactate
water-alcohol mixture + vanilla
water-alcohol mixture + sucrose
water-alcohol mixture + eugenol
Each sample is introduced into the system GC-MS, shoot and record chromatographic and mass spectrometric characteristics of the sample at the temperature of inlet node 180°C, 250°C and 310°C.
When analyzing samples of water-alcohol mixture + sucrose found an unknown substance with the following parameters: retention time 26,75 min; characteristic ions 31, 43, 60, 172. Specified substance, therefore, is a product of thermal decomposition of sucrose in the injector of the chromatograph. Database substance defined as a dimer of 1,3-dihydroxyacetone. A full analysis of the components of the reference brandy individually and in the aggregate, have not revealed the presence of the other unknown substances. On the basis of the data determined that the specified substance is triacetin. It is known that triacetin is an indispensable component of artificial flavorings. According to the analysis of triacetin is regarded as a marker of non-food origin.
The identification of unknown substances in the vodka.
Preparation of reference samples and analyzed vodkas are as in Example 1. Analysis of lead, as in part B of Example 1.
Resolutionality presented in Table 2.
|Retention time||Mass spectrum||Content||Estimated substance*|
|33,85||122, 105, 77||13,0|
|40,76||212, 194, 167, 105||8,5|
|45,02||234, 120, 86||7,6|
Next, prepare the reference water-alcohol mixture of 60/40% vol. (in accordance with the formulation of the investigational vodka) and analyze the sample, as in example 1. In the control sample of unknown substances were not detected. On the basis of data found in the study vodka unknown substances are benzoic acid, benzoyl benzoate and lidocaine, respectively, and are the products of thermal decomposition of bitrex - denaturing additives to alcohols and qualify the results of the analysis as markers of non-food origin.
The identification of unknown substances in the vodka.
Preparation of reference samples and analyzed vodkas are, as the Example 2. Analysis of lead, as in part B of Example 1.
The results of the analysis are presented in Table 3.
|Retention time||Mass spectrum||Content||Estimated substance*|
|39,45||222, 177, 149||34,7|
In the control sample of an unknown substance was found. On the basis of data found in the study vodka unknown substance is diethylphthalate.
At the same time, diethylphthalate and other esters of phthalic acid are typical representatives of laboratory contamination (injectors, dishes, etc. and therefore qualified for the determination of origin found dimethylphthalate required to carry out an audit of determining the level of laboratory contamination. The analysis is conducted at the following parameters: 100°C (1 min), 35°C/min, 300°C (20 min), column HP-5MS.
The results of the laboratory analysis of contaminants are presented in Table 4.
The results of the analysis to qualify detected in the studied vodka unknown substance - dimethylphthalate - qualify as a marker of episunago origin, denaturing additive to alcohol.
As can be seen from the description and examples of the method, the proposed solution provides the ability to uniquely identify chemical compounds and their fragments, allows you to set the origin of these chemical compounds while increasing the accuracy and timeliness of the definition.
Sources of information
1. EN 2093822 C1, MCL G01N 30/04, publ. 1997
2. EN 2069363 C1, MCL G01N 30/02, publ. 1996
3. WO 2004/104571, MCL G01N 30/00, publ. 2004
4. EP 1846757 A2, MCL G01N 30/86, publ. 2007 - the nearest equivalent.
The method of detection and origin identification of unknown substances in alcoholic beverages, which prepare the sample studied drink, put her GC/MS analysis, record mass spectra and their associated performance and conduct recognition components are compared with a database of reference analytical characteristics of the beverage, characterized in that it additionally prepare a water-alcohol mixture of 60/40% by volume, based on it, develop a set of model samples by introducing a water-alcohol mixture each component of the investigated drink separately model and analyze the samples at the temperature of inlet node 180°C, 250°C and 310°With, and if it is detected in the model sample of an unknown substance qualify as an artifact, is resouses in the analysis, in the absence of it in the model samples are prepared control sample by combining the total number of model samples, analyze it when the temperature of the inlet node 180°C, 250°C and 310°C, recorded mass spectra and associated chromatogram and in the absence in the sample found an unknown substance it qualify as a marker of non-food origin.
SUBSTANCE: invention relates to chemistry and can be used in coke-chemical production when processing coke gas. The method involves using fractions of heavy crude pyridine bases which form during coal carbonisation as raw material, from which pyridine bases are extracted first and the obtained faction of crude quinoline bases is split into components. The fractions of crude quinoline bases are split into components through supercritical preparative chromatography, where the separated mixture is brought into contact with gas in supercritical state, which is simultaneously the mobile phase and adsorbent.
EFFECT: simpler, faster and more reliable separation.
SUBSTANCE: invention relates to a novel chemical compound - 4-(2-hydroxyethyloxy)-4'-cyanoazoxybenzene which can be used as a liquid crystal stationary phase for gas chromatography.
EFFECT: given compound has higher structural selectivity than structural isomers of lutidine.
1 ex, 1 tbl
SUBSTANCE: sample analysis device has a column for anion-exchange chromatography, as well as a buffer for elution, which contains an ion formed from a group consisting of a nitrate and a chloride. The device also includes an amperometric sensor and a spectroscopic sensor. The two sensors are placed such that, an eluate is obtained from the column.
EFFECT: provision for additional and improved methods of and systems for determining characteristics of saccharides using anion-exchange chromatography.
14 cl, 21 dwg
SUBSTANCE: method of determining content of diesel fuel in lubricating oil of an internal combustion engine involves the following stages: preparing a mixture which contains an oil sample and C5 hydrocarbon, such as C5 alkane; injecting the mixture into the injector (11) of gas chromatograph (10); obtaining chromatographs of the sample; determination of the firs parametre M, which characterises peak area related to C5 hydrocarbon, such as C5 alkane, determination the second parametre C, which characterises area of at least one peak, related to a hydrocarbon, which characterises diesel fuel; and determination of content T of diesel fuel using formula (I): where a and b are constants, which define equation y=ax+b of a calibrating straight line of the ratio of the second to the first parametres as a function of content of diesel fuel.
EFFECT: increased accuracy and reliability of analysis.
8 cl, 3 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to process engineering and can be used in deeper conversion of hydrocarbons, their cracking and reforming. Proposed device comprises three chromatographic columns, one for sorbent layer regeneration from the mix heavy fraction and the other two for mix separation and release of light fraction. Aforesaid columns are divided into sections, each filled with sorbent that moves forced by carrier gas. The latter is fed from the first section and withdrawn from the third section, via transition channels incorporating controlled switching elements. Each column communicates with the system of preparation of introduction of the mix to be separated and with fraction collectors. There is a sorption-desorption activator arranged in sample preparation and introduction line to destruct complex organic molecules and distill separated substance.
EFFECT: higher efficiency.
FIELD: physics, measurement.
SUBSTANCE: invention is related to chromatograph intended for analysis of gaseous substance. Device comprises supplying system for sample supply, open tubular capillary column for separation of sample components, device for temperature control for adjustment of column temperature, detector for detection of separated sample components. Specified column comprises bundle of open tubular capillaries. Besides specified capillaries have gas permeable walls that comprise polymer membrane.
EFFECT: improved chemical specificity of detector, improved strength of structure.
22 cl, 3 dwg
FIELD: physics, measurements.
SUBSTANCE: proposed method can be used in chemical, petrochemical, medical and other industries to analyse compound mixes of various substances. It differs from known techniques in that as chyral smectic decyloxi-benzylidenamino-2-methyl-butyl-ether of aminocinnamic acid vapor is used as a fixed nematic phase.
EFFECT: higher selectivity of analysis.
FIELD: physics, measurements.
SUBSTANCE: proposed method can be used in chemical, petrochemical, medical and other industries to analyse rapidly the compound mixes of various substances of natural and technogenic origin. The proposed method differs in that immobile liquid-phase film is formed on a solid carrier dynamically pre-applied by periodic metering out of the portion of aerosol of liquid-phase solution in inert gas. The proposed device incorporates a spray gun to produce mist of liquid-phase fluid solution in inert gas and an adjustable air drag bubbler.
EFFECT: higher efficiency of proposed method.
2 cl, 1 dwg
FIELD: physics, measurements.
SUBSTANCE: invention can be used in gas chromatography for quantitative analysis of compound mixes of harmful organic and inorganic substances generated by automotive ICE gas engines. The proposed gas chromatographic system incorporates the device to feed in the pre-concentrated sample, two analytical modules with flame ionisation detector and heat conductivity detector, capillary column to isolate the sample hydrocarbon components, three filled columns, methanator and reactor to reduce nitrogen oxides to total nitrogen in the presence of carbon dioxide.
EFFECT: faster analysis.
FIELD: physics; measurement.
SUBSTANCE: present invention relates to devices for separating a mixture of gases and vapours using gas chromatography method. The device has a carrier gas channel with a pressure regulator, which connects, through a control valve-switch, the reservoir of separated liquid with an intermediate measuring tank, from which a pre-set dose is forced out by the gas-carrier on another channel through a return valve fitted on its outlet and an atomiser into an evaporator. The intermediate measuring tank has concave walls for linearisation of the scale. Inside the reservoir, there is a rotating pipe with an actuator and means of moving in several degrees of freedom. The inlet opening of the rotating pipe can change its level relative the upper level of liquid in the intermediate measuring tank. A batcher, with friction members, stabilises the operational parametres of the device. The evaporation process is controlled and monitored using temperature and pressure sensors, placed in the atomiser and evaporator.
EFFECT: increased efficiency and output of the device.
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