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Том 72, № 3 (2017)
- Год: 2017
- Статей: 8
- URL: https://journal-vniispk.ru/0027-1314/issue/view/9926
Article
Development and certification of the method of copper photometric determination in natural waters
Аннотация
A method for direct photometric copper determination (0.025–1.000 mg/L) in natural waters using cuprizon has been developed. Ions of accompanying elements have been masked by adding ammonium citrate. The procedure proposed has been certificated by the addition standard method and confirmed to be suitable for industry.
149-153
Effect of seasonal dynamics and chemical treatment on the quality of dissolved organic matter in water sources and potable water of Ufa
Аннотация
The structural-group composition and seasonal variations of organic matter dissolved in potable water and water sources of Ufa is studied. The efficiency of removal and destruction rate of dissolved organic matter at different technological stages of water treatment is evaluated for a surface water intake.
154-159
Evaluation of the Qy absorption band maximum in a light-harvesting complex of the bacterial photosynthetic center Thermochromatium tepidum
Аннотация
Excitation energies of the bacteriochlorophyll (BChl) chromophores embedded in the photosynthetic light-harvesting complex of the purple bacterium Thermochromatium tepidum are computed using the time-dependent density functional theory based upon the fragmental molecular orbital (FMO-TDDFT) method. The results are correlated with the empirically based estimates of the Qy absorption maximum, as well as with the observed large red shift induced by the binding of calcium.
111-114
Separation of rare earth elements in the tributyl phosphate–Ln(NO3)3–Ca(NO3)2 system in the counter current process
Аннотация
The 40-step extraction process to separate rare earth elements (RЕEs) according to the praseodymium–cerium line with the use of mixer–settler extractors in a 100% TBP–Ln(NO3)3–Ca(NO3)2 system is implemented. A lanthanum–cerium concentrate containing less than 0.03 wt % of the remaining REEs is obtained. The flow diagram of the separation process of a rare earth (RE) concentrate isolated from phosphogypsum is considered.
115-119
Polymer morphology and gas transport properties in relation to their chemical structure
Аннотация
The morphology, supramolecular structure, and gas transport properties of thin membranes of polymers with different chemical structure are studied. The relationship between the supramolecular structure of the polymers and their morphology and gas transport properties is revealed. The polymers studied represent low-permeability materials and exhibit a high degree of selectivity for different gas pairs.
120-127
Sorption kinetics of indium, iron, and zinc ions on modified montmorillonite
Аннотация
Adsorption integral kinetic curves of indium and iron(III) ions were obtained from model solutions on a montmorillonite Metosol modified with di(2-ethylhexyl)phosphoric acid. The adsorption kinetics can be reliably described with pseudofirst and pseudosecond order models. Adsorption of metal ions on a Metosol reagent occurs in a mixed diffusion mode. The rate constants of external and internal diffusion on the Metosol reagent are greater for In3+ ions than those for Fe3+ one, so that it can be used for the selective sorption of indium from complex technological solutions in zinc production.
128-134
Quantitative analysis of a multicomponent system for liquid chromatography–mass spectrometry determination of diosgenin, dioscin and protodioscin in plant extracts of Tribulus terrestris
Аннотация
An approach for the simultaneous determination of dioscin, protodioscin, and diosgenin in plant extracts by the liquid chromatography–mass spectrometry method with detection limits from 5 to 20 ng mL–1 is developed. Reversed-phase chromatography with the C18 sorbent followed by positive ion electrospray ionization and tandem mass spectrometric detection is used to analyze plant extracts. The external calibration and the quantitative analysis of multicomponent system are used to calculate the content based on peak areas in the chromatograms of the extracted ions. The difference between the results is shown to be less than 10%. The proposed approach is tested in the analysis of ethanolic and aqueous methanolic extracts of the aerial parts of Tribulus terrestris.
135-143
The study of molecular histograms of interatomic distances in organic homologs on the basis of R/S analysis
Аннотация
The spatial data based on molecular histograms of interatomic distances are studied for 25 organic homologs using a rescaled range analysis. All the spatial series are found to have a positive correlation between the previous and subsequent members. A simple linear model is proposed to explain the variation of the Hurst parameters between homolog series.
144-148