A method for the identification of components in complex mixtures

 

(57) Abstract:

The method of gas chromatographic analysis of multicomponent mixtures. Characterized in that the analyzed component at the outlet of the analytical column is cooled to the condensation temperature, and then the obtained condensate is subjected to intense heat. Increases the reliability of the identification. 5 Il.

The invention relates to gas chromatography and can be used in the analysis of multicomponent mixtures in different areas of technology.

Similar solutions are known. Thus, the method of chromatographic analysis, are listed in the description.with N 1160299, CL G 01 N 30/34, involves the separation of mixtures of substances in the column on the components in the stream of carrier gas, the change of the composition of the carrier gas at the outlet of the column and detection by measuring the heat flux, the change of the composition of the carrier gas is conducted and in the intervals between the output components having different thermal conductivity. The closest solution to the claimed method is the identification of the components contained in the description to the patent of Russian Federation N 2035735, CL G 01 N 50/46.

The essence of the method lies in the fact that find conditions razdenia mixture, then, the separated components are directed to the second column, which is at a constant temperature not lower than the maximum temperature of the first column with a stationary phase of the same polarity to that of the separation column, and performs the function of identification.

In the second column changes the order of the output components, which was achieved in the first column, but the temperature of the isothermal mode. This allows you to define indexes on hold and collect the Bank reproducible chromatographic data for the subsequent identification of components in complex mixtures.

The disadvantages of the method include that it does not provide high reliability of identification, because the transition of each component of the analyzed mixture from the separation column in the identification, operating under isothermal conditions, there is a blurring of the chromatographic strip component carrier gas in the line connecting the two columns.

Erosion of the band is due to the difference of the velocities of flow of the carrier gas and the analyzed component at the output of the separation column.

The invention was reduced length hromatograficheskaja solved by what components of the analyzed mixture at the outlet of the analytical column is cooled in sorption trap to a temperature of condensation, and then produce intense heat for 25-35 seconds. Thermal degradation of components subjected after heating.

The method is illustrated in an example implementation, where:

in Fig. 1 is a diagram of an apparatus that implements the method;

in Fig. 2 is a chromatogram of the analyzed mixture in the first stage of identification;

in Fig. 3 - the same for the standard sample of ethyl alcohol;

in Fig. 4 - programma analyzed component at the second stage;

in Fig. 5 - the same for the standard sample of ethyl alcohol.

The method is implemented as follows: subject to analysis, the mixture was fed to the evaporator 1, then in the separation column 2. Separated components of the mixture through the node separation of individual chromatographic strip component 3 enter the detector 8. Operation repeat with the standard sample. The obtained chromatograms identify the component of the analyzed mixture by retention time matching the retention time of the standard sample, and then proceed to further identify, which analyzed the th component identification will begin to emerge from the separation column 2 (this is evidenced by the start signal detector 8), the node separation chromatographic strip component 3 is put in the "component selection" (time selection is equal to the retention time of the component in the separation column). From site selection 3 subject identification component carrier gas serves in a sorption trap 4, where it is cooled to the dew point, where he is in this state is condensed on the sorbent. After that sorption trap injected into the heat chamber, where the condensed component is exposed to intensive heating to a temperature equal to the temperature of the separation column to be the identifying component and simultaneously begin programming the ID column 7.

The evaporated component of the sorption trap 4 serves in pyrolytic cell 6 for thermal degradation. The resulting products of thermal degradation are divided into the ID column in the programming mode and logged in as specific programme.

The above operations are performed with both the standard sample and then specific programme obtained from the analyzed component and the standard sample are compared with each other. Full match of program (Fig. Toray presumably should be the presence of ethyl alcohol. The order of operations similar to the above, the temperature concentrated analyzed sample and the standard sample of ethyl alcohol was 10oC, at the time of warm-up 150oC. Heating was carried out for 32 seconds.

The results are shown in Fig. 2-5.

Example 2. The analysis was carried out of the mixture for the presence of ephedrine. The temperature of the concentration of the analyzed sample and the standard sample ephedrine was +15oC, at the time of heating 210oC. Heating was carried out for 35 seconds. Because of the identity nature of the process of programme not given.

Thus, the proposed method allows the identification with a high degree of certainty.

A method for the identification of components in complex mixtures by component separation on the analytical column and registration according to the retention time of the analyzed component, characterized in that the analyzed component at the outlet of the analytical column is cooled to the temperature of condensation, and the resulting condensate is subjected to heat for 25 to 35, with simultaneous programming of temperature identification column, and after heating the components of the

 

Same patents:

The invention relates to the field of instrumentation and can be used in the calibration and verification of gas analyzers

The invention relates to the field of analytical instrumentation and can be used in the calibration and verification of gas analyzers

The invention relates to a device for chromatographic separation of substances chromatographic methods

The invention relates to the field of chemical analysis and can be used to determine the concentrations of o-chlorophenol and 2,6-dichlorphenol in the air when the sanitary-hygienic studies on the content of chlorophenols

The invention relates to the field of chemical analysis and can be used to determine the concentrations of o-chlorophenol and 2,6-dichlorphenol in the air when the sanitary-hygienic studies on the content of chlorophenols

The invention relates to physical chemistry, and in particular to methods and devices for determining the specific surface of powders and porous materials dynamic method of thermal desorption of gaseous adsorbates (nitrogen or argon) from a stream of a mixture of adsorbates with helium, which at various relative partial pressures of the adsorbate P/P0(P is the partial pressure of the adsorbate, mm RT

The invention relates to gas and possibly to liquid chromatography, specifically to design miniature polycapillary column chromatographic channels width from ~10-20 micrometers or more and up to several tenths of a micrometer

The invention relates to physical chemistry, and in particular to methods and devices for determination of adsorption and desorption branches of the isotherms of adsorption of nitrogen at 77 K by the dynamic method of thermal desorption

The invention relates to analytical instrumentation and can find application in devices for automatic selection and input of the fluid sample, for example, gas chromatograph

The invention relates to the field of instrumentation and can be used in the calibration and verification of gas analyzers

FIELD: analytical instrumentation engineering; chromatographic analysis of composition of substances.

SUBSTANCE: proposed method includes delivery of carrier gas to evaporation chamber through gas supply line, introduction of sample into evaporation chamber, delivery of part of gas flow from evaporation chamber to chromatographic column and discharge of remaining of gas flow to atmosphere. Delivery of carrier gas to evaporation chamber is effected in direction opposite to motion of evaporated sample to chromatographic column. Device proposed for introducing the sample into chromatograph has sample introducing line, evaporation chamber, chromatographic column, carrier gas supply and carrier gas discharge line which are connected with evaporation chamber. Carrier gas discharge line is connected with evaporation chamber in area of introduction of sample and carrier gas supply line is connected with opposite end of evaporation chamber.

EFFECT: enhanced accuracy of dosing the sample; improved quality of separation of components; enhanced reliability; simplified construction.

11 cl, 3 dwg

FIELD: chemical engineering; medical engineering.

SUBSTANCE: method involves plotting two chromatograms one of which is based on radioactivity (No 1) and the other one on ultraviolet absorption (No 2) or on radioactivity (No 1) and on fluorescence (No 2) and chromatogram specific relative to ultraviolet absorption (No 3) or relative to fluorescence (No 3). Material quality is estimated to be the more high the more close studied labeled compound peak shape is to trapezoid shape on the third chromatogram.

EFFECT: high accuracy of the method.

8 dwg

FIELD: instrument industry.

SUBSTANCE: detector comprises housing which is the cathode of the detector, devices for supplying and discharging gas to be analyzed, anode, tritium target, and insulator housed in the space between the electrodes. The working surfaces of the electrodes are parallel and mounted with a spaced relation to each other with the use of the insulator. The detector is provided with current lead and current collectors. The insulator is made of a ring made of silicate-containing material and is interposed between the electrodes.

EFFECT: enhanced stability of operation and prolonged service life.

2 cl, 1 dwg

FIELD: instrument industry.

SUBSTANCE: detector comprises housing which is the cathode of the detector, devices for supplying and discharging gas to be analyzed, anode, tritium target, and insulator housed in the space between the electrodes. The working surfaces of the electrodes are parallel and mounted with a spaced relation to each other with the use of the insulator. The detector is provided with current lead and current collectors. The insulator is made of a ring made of silicate-containing material and is interposed between the electrodes.

EFFECT: enhanced stability of operation and prolonged service life.

2 cl, 1 dwg

FIELD: medicine, biochemistry.

SUBSTANCE: at testing one should precipitate high-molecular compounds with acetonitrile and register supernatant's spectral characteristics. Supernatant should be applied onto a paper filter, dried and put into solution containing aromatic aldehyde, acetone and concentrated hydrochloric acid taken at weight ratio of 70:5:1 to be kept for 2-3 min. Then it should be once again dried up to detect qualitative and semiquantitative content of oxidized tryptophan metabolites by intensity and chromatic shades. Moreover, by chromatic shades of yellow dyeing it is possible to detect the content of hydroxylated metabolites and by chromatic shades of violet dyeing - that of unhydroxylated ones.

EFFECT: higher significance of detection.

3 ex

FIELD: investigating or analyzing materials.

SUBSTANCE: method comprises supplying of batched volumes of oil sample, standard material for comparison, and n-heptane by displacing them by the gas flow to the capillary column for chromatography. The pressure in the gas flow is higher than that at the inlet of the column. The device comprises batching cock, check valve in the gas line, and resistance in the line for discharging the gas. The valving members are made of pipes with plugs at the center and are interconnected through a gas cross-piece and vessel for batching the gas.

EFFECT: enhanced accuracy of determining hydrocarbons.

2 cl, 1 dwg, 1 tbl

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: 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: gas chromatography.

SUBSTANCE: detector has case. Burner provided with channels for supplying oxygen and air is disposed inside the case together with central channel for supplying sample inside gas-carrier. Condenser, lens, disc with interference light filters, glued prism with reflecting interference coatings, radiation receiver are mounted in series inside the case.

EFFECT: improved sensitivity; higher selectivity of detector.

2 cl, 2 dwg

Up!