Method for determining content of polycyclic aromatic hydrocarbons in rubbers and tires

FIELD: chemistry.

SUBSTANCE: invention relates to the determination of individual polycyclic aromatic hydrocarbons (PAH) in rubbers (vulcanized and non-vulcanized) and tires produced from the rubber compounds. The claimed method for determining the content of polycyclic aromatic hydrocarbons in rubbers and tires consists in extracting a rubber or tire sample with toluene and then purifying the resulting extract from the interfering substances and concentrating the polycyclic aromatic hydrocarbons using silica gel column chromatography deactivated by water and then quantifying the content of the polycyclic aromatic hydrocarbons in the purified sample by gas chromatography with mass selective detection. In the column chromatography of the extract, the interfering substances are eluted with n-hexane previously equilibrated with water.

EFFECT: increasing the accuracy due to the separation of polycyclic aromatic hydrocarbons from the interfering components contained in the extract and shortening the determination time.

1 tbl

 



 

Same patents:

FIELD: instrumentation.

SUBSTANCE: invention relates to forecast of ageing processes of the synthetic polymer materials (SPM) depending on duration of their operation or storage. Analysis of the volatile organic compounds (VOC) migrating from SPM is performed by active sampling for sorbent, with further thermal desorption and gas chromatographic analysis. Forecast of the ageing processes of the material and estimation of toxicity of the gas discharge are performed as per dynamic of the qualitative and quantitative composition of gas discharge components in SPM initial state, and during artificial climatic thermal-humidity ageing. Dynamics analysis of the total gas discharge (ΣT) from each material is performed for all substances migrating from studied SPMs. Change of toxicity is estimated and forecast of the material ageing is performed as per developed indices of total gas discharge (ΣT) and as per hygienic index P=(ΣTinitial/ΣTn)/V, where Tinitial and Tn are indices of toxicity of gas discharge of each substance in initial state and after ageing, respectively, and ΣTinitial and ΣTn are total indices of toxicity of gas discharge of all components of SPM in initial state and after ageing, V is duration of ageing (year, month).

EFFECT: invention ensures high accuracy of the method of VOC qualitative and quantitative composition determination in gas discharge during materials ageing and the analysis results repeatability.

3 tbl

FIELD: chemistry.

SUBSTANCE: method includes preparing a 1% solution of engine oil in hexane for full extraction of zinc dithiophosphates from engine oil and purity of the obtained samples; adding the obtained solution to an extraction cartridge filled with hydroxylated silica gel in amount of not more than 2 ml of the 1% solution of the oil in hexane per 1 g sorbent; successively passing a hexane:acetone mixture taken in volume ratio of 9:1, respectively; passing an isopropanol:water:phosphoric acid:acetonitrile mixture, taken in ratio of 4:2:0.4:1, respectively. Each mixture is taken in amount of not less than 1.5 times the volume of the oil solution in hexane. An aliquot of the obtained solution is analysed by RP HPLC.

EFFECT: high accuracy and reliability of determination.

1 tbl, 7 dwg

FIELD: chemistry.

SUBSTANCE: method involves extraction of drilling fluid in an extractor in order to continuously obtain a stream of extracted gases at the output of the extractor, containing the analysed hydrocarbons and at least one spurious compound which is not water and is more polar than the analysed hydrocarbons. The gas stream is then carried from the extractor over a transfer line into a separation column to separate the analysed hydrocarbons depending on their elution time in the separation column. Further, successive detection and/or determination of the amount of each analysed hydrocarbon is carried in a detector located at the output of the separation column. One or each spurious compound can have elution time in the separation column ranging from the elution time of the first analysed hydrocarbon in the separation column to the elution time of the last analysed hydrocarbon in the separation column. The method also involves passing the gas stream through a surface for chemical and/or physical interaction with the spurious compound which is in contact with gases between the output of the extractor and the input of the separation column, for selectively holding said spurious compounds without delaying the analysed hydrocarbons and so as to prevent washing-off of the spurious compounds in the separation column.

EFFECT: high accuracy of qualitative and quantitative evaluation of analysed hydrocarbons, and high rate of analysis.

FIELD: chemistry.

SUBSTANCE: invention refers to drinking, natural and waste water, precipitation sanitary-hygienic control and analysis for phenol content. Method includes chemical phenol modification in 2,4,6-tribromphenol, extraction concentration of 2,4,6- tribromphenol and gas chromatography testing. Herewith chemical modification is preceded with humic acid removal on aluminium oxide from aqueous medium sample with copper sulphate in amount 0.05-0.25% of aqueous medium sample weight.

EFFECT: higher analysis reliability.

7 ex, 2 tbl, 7 dwg

FIELD: silicon compounds technology.

SUBSTANCE: tetrafluorosilane production process comprises following stages: (1) hexafluorosilicate heating; (2-1) reaction of tetrafluorosilane gas containing hexafluorodisiloxane formed in stage (1) with fluorine gas; (2-2) reaction of tetrafluorosilane gas containing hexafluorodisiloxane formed in stage (1) with fluorine-polyvalent metal compound; (2-3) reaction of tetrafluorosilane gas obtained in stage (2-1) with fluorine-polyvalent metal compound. Finally, high-purity tetrafluorosilane with 0.1 ppm by volume of hexafluorodisiloxane is obtained, which is applicable in manufacture of optical fiber, semiconductors, and sun battery elements.

EFFECT: reduced content of impurities in product.

24 cl, 1 dwg, 1 tbl, 9 ex

FIELD: silicon compounds technology.

SUBSTANCE: tetrafluorosilane production process comprises following stages: (1) hexafluorosilicate heating; (2-1) reaction of tetrafluorosilane gas containing hexafluorodisiloxane formed in stage (1) with fluorine gas; (2-2) reaction of tetrafluorosilane gas containing hexafluorodisiloxane formed in stage (1) with fluorine-polyvalent metal compound; (2-3) reaction of tetrafluorosilane gas obtained in stage (2-1) with fluorine-polyvalent metal compound. Finally, high-purity tetrafluorosilane with 0.1 ppm by volume of hexafluorodisiloxane is obtained, which is applicable in manufacture of optical fiber, semiconductors, and sun battery elements.

EFFECT: reduced content of impurities in product.

24 cl, 1 dwg, 1 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention refers to drinking, natural and waste water, precipitation sanitary-hygienic control and analysis for phenol content. Method includes chemical phenol modification in 2,4,6-tribromphenol, extraction concentration of 2,4,6- tribromphenol and gas chromatography testing. Herewith chemical modification is preceded with humic acid removal on aluminium oxide from aqueous medium sample with copper sulphate in amount 0.05-0.25% of aqueous medium sample weight.

EFFECT: higher analysis reliability.

7 ex, 2 tbl, 7 dwg

FIELD: chemistry.

SUBSTANCE: method involves extraction of drilling fluid in an extractor in order to continuously obtain a stream of extracted gases at the output of the extractor, containing the analysed hydrocarbons and at least one spurious compound which is not water and is more polar than the analysed hydrocarbons. The gas stream is then carried from the extractor over a transfer line into a separation column to separate the analysed hydrocarbons depending on their elution time in the separation column. Further, successive detection and/or determination of the amount of each analysed hydrocarbon is carried in a detector located at the output of the separation column. One or each spurious compound can have elution time in the separation column ranging from the elution time of the first analysed hydrocarbon in the separation column to the elution time of the last analysed hydrocarbon in the separation column. The method also involves passing the gas stream through a surface for chemical and/or physical interaction with the spurious compound which is in contact with gases between the output of the extractor and the input of the separation column, for selectively holding said spurious compounds without delaying the analysed hydrocarbons and so as to prevent washing-off of the spurious compounds in the separation column.

EFFECT: high accuracy of qualitative and quantitative evaluation of analysed hydrocarbons, and high rate of analysis.

FIELD: chemistry.

SUBSTANCE: method includes preparing a 1% solution of engine oil in hexane for full extraction of zinc dithiophosphates from engine oil and purity of the obtained samples; adding the obtained solution to an extraction cartridge filled with hydroxylated silica gel in amount of not more than 2 ml of the 1% solution of the oil in hexane per 1 g sorbent; successively passing a hexane:acetone mixture taken in volume ratio of 9:1, respectively; passing an isopropanol:water:phosphoric acid:acetonitrile mixture, taken in ratio of 4:2:0.4:1, respectively. Each mixture is taken in amount of not less than 1.5 times the volume of the oil solution in hexane. An aliquot of the obtained solution is analysed by RP HPLC.

EFFECT: high accuracy and reliability of determination.

1 tbl, 7 dwg

FIELD: instrumentation.

SUBSTANCE: invention relates to forecast of ageing processes of the synthetic polymer materials (SPM) depending on duration of their operation or storage. Analysis of the volatile organic compounds (VOC) migrating from SPM is performed by active sampling for sorbent, with further thermal desorption and gas chromatographic analysis. Forecast of the ageing processes of the material and estimation of toxicity of the gas discharge are performed as per dynamic of the qualitative and quantitative composition of gas discharge components in SPM initial state, and during artificial climatic thermal-humidity ageing. Dynamics analysis of the total gas discharge (ΣT) from each material is performed for all substances migrating from studied SPMs. Change of toxicity is estimated and forecast of the material ageing is performed as per developed indices of total gas discharge (ΣT) and as per hygienic index P=(ΣTinitial/ΣTn)/V, where Tinitial and Tn are indices of toxicity of gas discharge of each substance in initial state and after ageing, respectively, and ΣTinitial and ΣTn are total indices of toxicity of gas discharge of all components of SPM in initial state and after ageing, V is duration of ageing (year, month).

EFFECT: invention ensures high accuracy of the method of VOC qualitative and quantitative composition determination in gas discharge during materials ageing and the analysis results repeatability.

3 tbl

FIELD: chemistry.

SUBSTANCE: method for determining the content of polycyclic aromatic hydrocarbons in oil-plasticizers is to purify from interfering substances, and to concentrate the polycyclic aromatic hydrocarbons using column chromatography on silica gel, deactivated with water, using gradient elution, and then quantifying the content of polycyclic aromatic hydrocarbons in a purified sample by gas chromatography with mass-selective detection. The interfering components of the sample in the first stage of column chromatography are eluted with n-hexane, previously equilibrated with water.

EFFECT: expanding the list of analyzed polycyclic aromatic hydrocarbons to 23 individual and, in particular, to light polycyclic aromatic hydrocarbons in oil-plasticizers with high accuracy.

1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to the determination of individual polycyclic aromatic hydrocarbons (PAH) in rubbers (vulcanized and non-vulcanized) and tires produced from the rubber compounds. The claimed method for determining the content of polycyclic aromatic hydrocarbons in rubbers and tires consists in extracting a rubber or tire sample with toluene and then purifying the resulting extract from the interfering substances and concentrating the polycyclic aromatic hydrocarbons using silica gel column chromatography deactivated by water and then quantifying the content of the polycyclic aromatic hydrocarbons in the purified sample by gas chromatography with mass selective detection. In the column chromatography of the extract, the interfering substances are eluted with n-hexane previously equilibrated with water.

EFFECT: increasing the accuracy due to the separation of polycyclic aromatic hydrocarbons from the interfering components contained in the extract and shortening the determination time.

1 tbl

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