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Analytics of Substances and Materials
M. V. Gorbunova, V. V. Tolmacheva, V. V. Apyari
Sorption-spectrophotometric Determination of Catecholamines in Urine and Blood Plasma Using Hypercrosslinked Polystyrene and Gold Nanorods The possibility of combining solid-phase extraction of natural catecholamines (epinephrine, norepinephrine, and dopamine) on a microcolumn filled with hypercrosslinked polystyrene with their subsequent spectrophotometric or solid-phase spectroscopic determination in the eluate using gold nanorods or their nanocomposites with polyurethane foam was studied. The desorption of catecholamines from hypercross-linked polystyrene by various eluents was examined. Quantitative elution of all three catecholamines is achieved using 6 M acetic acid. Moreover, this eluent is compatible with the indicated determination variants. The features of dynamic sorption of catecholamines from urine and blood serum are described. It allows to reduce the influence of matrix components and increase sensitivity of the analysis due to preconcentration. The average enrichment factor is 10–56 with sample volumes of 10–300 ml. The developed methods allow to determine catecholamines in urine at the level of their normal content.
Sorption-spectrophotometric Determination of Catecholamines in Urine and Blood Plasma Using Hypercrosslinked Polystyrene and Gold Nanorods The possibility of combining solid-phase extraction of natural catecholamines (epinephrine, norepinephrine, and dopamine) on a microcolumn filled with hypercrosslinked polystyrene with their subsequent spectrophotometric or solid-phase spectroscopic determination in the eluate using gold nanorods or their nanocomposites with polyurethane foam was studied. The desorption of catecholamines from hypercross-linked polystyrene by various eluents was examined. Quantitative elution of all three catecholamines is achieved using 6 M acetic acid. Moreover, this eluent is compatible with the indicated determination variants. The features of dynamic sorption of catecholamines from urine and blood serum are described. It allows to reduce the influence of matrix components and increase sensitivity of the analysis due to preconcentration. The average enrichment factor is 10–56 with sample volumes of 10–300 ml. The developed methods allow to determine catecholamines in urine at the level of their normal content.
Tags: catecholamines nanoparticles sorption spectrophotometry urine analysis анализ мочи катехоламины наночастицы сорбция спектрофотометрия
I. S. Rudik, O. N. Katasonova, T. A. Maryutina, B. Ya. Spivakov
Comparative Analysis of Platinum (IV) and Palladium (II) Separation Under Different Gradient Elution Variants Two schemes for the extraction separation of platinum (IV) and palladium (II) from chloride solutions in rotating coiled columns (RCC) are proposed – gradient separation due to a change in the concentration of the eluent in the mobile phase and due to the creation of a gradient of the concentration of extractant in the stationary phase held in the column. A reagent of the quaternary ammonium base class, methyltrialkylammonium chloride (MTAA), was chosen as the stationary phase in the RCC. The behavior of Pd(II) and Pt(IV) with their joint presence in chloride solutions was studied depending on the concentration of chloride ion, the acidity of the solution, and the concentration of extractant. It was shown that creating a concentration gradient of the extractant in the stationary phase makes it possible to achieve complete separation of metals and to obtain separated fractions of platinum and palladium with a purity of more than 99,90%.
Comparative Analysis of Platinum (IV) and Palladium (II) Separation Under Different Gradient Elution Variants Two schemes for the extraction separation of platinum (IV) and palladium (II) from chloride solutions in rotating coiled columns (RCC) are proposed – gradient separation due to a change in the concentration of the eluent in the mobile phase and due to the creation of a gradient of the concentration of extractant in the stationary phase held in the column. A reagent of the quaternary ammonium base class, methyltrialkylammonium chloride (MTAA), was chosen as the stationary phase in the RCC. The behavior of Pd(II) and Pt(IV) with their joint presence in chloride solutions was studied depending on the concentration of chloride ion, the acidity of the solution, and the concentration of extractant. It was shown that creating a concentration gradient of the extractant in the stationary phase makes it possible to achieve complete separation of metals and to obtain separated fractions of platinum and palladium with a purity of more than 99,90%.
Tags: gradient separation methyltrialkylammonium chloride platinum metals rotating coiled columns solvent extraction вращающиеся спиральные колонки градиентное разделение платиновые металлы хлорид метилтриалкиламмония экстракция
A. Ya. Yashin
Determination of Catechins in Green Tea Samples by HPLC with an Amperometric Detector For the first time, a comparison of the catechins content in green tea samples of the main producers of this drink: China, India, Sri Lanka, Vietnam, Indonesia. Catechins are the main polyphenols-antioxidants of green tea. They provide its high antioxidant activity and a positive effect on human health. The main catechins in green tea are from six to twelve, they are usually determined by HPLC with different detection systems. The consumption of green tea with a high content of catechins reduces the risk of dangerous diseases: cardiovascular, oncological, neurodegenerative and others. Catechins suppress a dangerous bacterium, Helicobacter pylori, which causes stomach diseases, and beneficially affect the microbiota of the human intestines. The most active catechinepigallocatechin gallate inhibits even the metastases of certain cancers. Green tea catechins reduce the activity of influenza virus and other viral diseases.
Determination of Catechins in Green Tea Samples by HPLC with an Amperometric Detector For the first time, a comparison of the catechins content in green tea samples of the main producers of this drink: China, India, Sri Lanka, Vietnam, Indonesia. Catechins are the main polyphenols-antioxidants of green tea. They provide its high antioxidant activity and a positive effect on human health. The main catechins in green tea are from six to twelve, they are usually determined by HPLC with different detection systems. The consumption of green tea with a high content of catechins reduces the risk of dangerous diseases: cardiovascular, oncological, neurodegenerative and others. Catechins suppress a dangerous bacterium, Helicobacter pylori, which causes stomach diseases, and beneficially affect the microbiota of the human intestines. The most active catechinepigallocatechin gallate inhibits even the metastases of certain cancers. Green tea catechins reduce the activity of influenza virus and other viral diseases.
Tags: amperometric detector antioxidants catechins green tea hplc амперометрический детектор антиоксиданты вэжх зеленый чай катехины
Analytical Methods and Instruments
M. V. Kravchik, I. A. Novikov, T. E. Borisenko, A. M. Subbot, S. Yu. Petrov
Cluster Analysis of Elemental Micromapping Data of Trabecular Tissue in Primary Openangle Glaucoma The possibility of using cluster analysis to assess the structural and functional organization of a biological object is analyzed. For a quantitative description of cellular processes, filtering (trabecular) eye tissue was selected for unstabilized primary openangle glaucoma (POAG) in patients using the maximum possible hypotensive therapy. By chemical microanalysis based on a scanning electron microscope (SEM), data were obtained on the distribution of chemical elements in tissue. Based on the global Moran index, which describes the degree of spatial grouping of sulfur (IS) and phosphorus (IP) on the surface of the analyzed tissue block, an index of target metabolic activity loss (IL) characterizing cellular processes is proposed. A connection was established between IL and the visually observed difference in the organization of structural elements of trabecular tissue in POAG. A correlation was observed between the structural and functional status of trabecular tissue according to the IL index and intraocular pressure (IOP) on the maximum hypotensive therapy.
Cluster Analysis of Elemental Micromapping Data of Trabecular Tissue in Primary Openangle Glaucoma The possibility of using cluster analysis to assess the structural and functional organization of a biological object is analyzed. For a quantitative description of cellular processes, filtering (trabecular) eye tissue was selected for unstabilized primary openangle glaucoma (POAG) in patients using the maximum possible hypotensive therapy. By chemical microanalysis based on a scanning electron microscope (SEM), data were obtained on the distribution of chemical elements in tissue. Based on the global Moran index, which describes the degree of spatial grouping of sulfur (IS) and phosphorus (IP) on the surface of the analyzed tissue block, an index of target metabolic activity loss (IL) characterizing cellular processes is proposed. A connection was established between IL and the visually observed difference in the organization of structural elements of trabecular tissue in POAG. A correlation was observed between the structural and functional status of trabecular tissue according to the IL index and intraocular pressure (IOP) on the maximum hypotensive therapy.
Tags: cluster analysis elemental composition energy-dispersive x-ray spectroscopy moran’s i index primary openangle glaucoma trabecular meshwork индекс морана кластерный анализ первичная открытоугольная глаукома трабекулярная ткань элементный состав энергодисперсионная спектроскопия
V. S. Bashkirtsev
New Transmission Cryomicroscope for Electronic 3D-crystallography The method of electron crystallography is considered as an instrument of structural biology, an alternative to x-ray crystallography. The new CRYOARM 300 transmission microscope was tested to collect electron diffraction data for the analysis of the three-dimensional structure of protein macromolecules. The results of analysis of thin three-dimensional crystals of catalase and membrane protein complex ExbBD are presented. By filtering electrons by energy, the quality of the data has improved markedly. The features of the interaction of electrons with a biological sample embedded in thin vitreous ice cooled to low temperatures are described. The advantages of using electrons of higher energies and filtering electrons with energy losses in electronic three-dimensional crystallography are shown.
New Transmission Cryomicroscope for Electronic 3D-crystallography The method of electron crystallography is considered as an instrument of structural biology, an alternative to x-ray crystallography. The new CRYOARM 300 transmission microscope was tested to collect electron diffraction data for the analysis of the three-dimensional structure of protein macromolecules. The results of analysis of thin three-dimensional crystals of catalase and membrane protein complex ExbBD are presented. By filtering electrons by energy, the quality of the data has improved markedly. The features of the interaction of electrons with a biological sample embedded in thin vitreous ice cooled to low temperatures are described. The advantages of using electrons of higher energies and filtering electrons with energy losses in electronic three-dimensional crystallography are shown.
Tags: cryoarm electron rotation diffraction energy filter three-dimensional electron crystallography ω filter ω фильтр трехмерная электронная кристаллография электронная дифракция вращения энергетический фильтр
Z. Palacz
Measurement Evaluation of the Isotopic Composition Uranium Standards by Total Evaporation Using a Thermal Ionization Mass Spectrometer Estimation of the isotopic composition of the fuel is an important task for the nuclear industry. Several basic techniques are known for determining the isotopic composition of heavy elements, such as uranium, both more accurate and longlasting, and express. For production with a large number of samples, the method of total complete evaporation is optimal, providing a high degree of automation and acceptable accuracy of analysis. Total Full evaporation also allows to reduce the qualification level in sample preparation, thereby reducing errors in the results. In this work, standard samples of the composition NBS U010, NBL U030a, and NBL U050 were tested by the method of complete evaporation using a Phoenix thermal ionization mass spectrometer (Isotopx, UK). Statistical processing of the results of a series of experiments showed that, in comparison with others, the total complete evaporation method better meets the accuracy requirements for determining the 235 U/ 238U isotopic ratio and is consistent with published data.
Measurement Evaluation of the Isotopic Composition Uranium Standards by Total Evaporation Using a Thermal Ionization Mass Spectrometer Estimation of the isotopic composition of the fuel is an important task for the nuclear industry. Several basic techniques are known for determining the isotopic composition of heavy elements, such as uranium, both more accurate and longlasting, and express. For production with a large number of samples, the method of total complete evaporation is optimal, providing a high degree of automation and acceptable accuracy of analysis. Total Full evaporation also allows to reduce the qualification level in sample preparation, thereby reducing errors in the results. In this work, standard samples of the composition NBS U010, NBL U030a, and NBL U050 were tested by the method of complete evaporation using a Phoenix thermal ionization mass spectrometer (Isotopx, UK). Statistical processing of the results of a series of experiments showed that, in comparison with others, the total complete evaporation method better meets the accuracy requirements for determining the 235 U/ 238U isotopic ratio and is consistent with published data.
Tags: isotope ratio thermal ionization mass spectrometry total complete evaporation method uranium изотопное отношение метод полного испарения термоионизационная масс-спектрометрия уран
Laboratory Accreditation
I. V. Boldyrev
Measurement Evaluation of the Isotopic Composition Uranium Standards by Total Evaporation Using a Thermal Ionization Mass Spectrometer Estimation of the isotopic composition of the fuel is an important task for the nuclear industry. Several basic techniques are known for determining the isotopic composition of heavy elements, such as uranium, both more accurate and longlasting, and express. For production with a large number of samples, the method of total complete evaporation is optimal, providing a high degree of automation and acceptable accuracy of analysis. Total Full evaporation also allows to reduce the qualification level in sample preparation, thereby reducing errors in the results. In this work, standard samples of the composition NBS U010, NBL U030a, and NBL U050 were tested by the method of complete evaporation using a Phoenix thermal ionization mass spectrometer (Isotopx, UK). Statistical processing of the results of a series of experiments showed that, in comparison with others, the total complete evaporation method better meets the accuracy requirements for determining the 235 U/ 238U isotopic ratio and is consistent with published data.
Measurement Evaluation of the Isotopic Composition Uranium Standards by Total Evaporation Using a Thermal Ionization Mass Spectrometer Estimation of the isotopic composition of the fuel is an important task for the nuclear industry. Several basic techniques are known for determining the isotopic composition of heavy elements, such as uranium, both more accurate and longlasting, and express. For production with a large number of samples, the method of total complete evaporation is optimal, providing a high degree of automation and acceptable accuracy of analysis. Total Full evaporation also allows to reduce the qualification level in sample preparation, thereby reducing errors in the results. In this work, standard samples of the composition NBS U010, NBL U030a, and NBL U050 were tested by the method of complete evaporation using a Phoenix thermal ionization mass spectrometer (Isotopx, UK). Statistical processing of the results of a series of experiments showed that, in comparison with others, the total complete evaporation method better meets the accuracy requirements for determining the 235 U/ 238U isotopic ratio and is consistent with published data.
Tags: accreditation administrative code technical regulation testing laboratories административный кодекс аккредитация испытательные лаборатории техническое регулирование
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