The method has been developed of simultaneous
determination of active ingredients of different kinds
of pesticides in biological tissues (fish liver) by
applying HPLC with ultra-violet detection and the
rapid method of QuEChERS sample preparation. We
defined optimum volume and composition of the
reagents for the extraction, time of centrifugation and
ultrasound treatment, the origin and composition of
sorbents that ensure maximum extraction of the
substances studied and further cleanup of interfering
substances. Acetonitrile was used as a solvent. The
extraction was carried out in the presence of a
buffering mixture - trisodium citrate dihydrate and
disodium citrate hemihydrate. Bondesil PSA bulk
sorbents (alkylated amine containing two amine
functional groups - secondary and primary) and C18E
(reversed-phase sorbent based on silica gel with
grafted octadecylsilane groups were used to purify the
extract from coextractable substances (fats, proteins,
sugars, organic and fatty acids, pigments and other
impurities). The degree of extraction of the analyzed
active ingredients of pesticides from the liver of fish
was 79%. The detectable pesticide concentrations
ranged from 0,4 to 0,97 mg/kg. The relative standard
deviation of the analysis results amounted to 0,01-0,14
Macrodeficiency of polymeric materials, including the
pervasive one, is a consequence of the development of
initial microdefects which appear in polymers both
due to external factors and during their processing.
This article solves the task of identification the
interrelation and interdependence of structural
microdefects of various polymeric materials,
consisting in the estimation of the structural
parameters under uniaxial deformation. It is
experimentally shown that the process of changing
microdefects in the material bulk begins to flow more
intensely during deformation of the material, having
anisotropic structures in the bulk. Change of the
parameters of microdefects is not observed compared
to the starting material at small quantities of the
deformation. In the area of deformation corresponding
to the transition of the material from isotropic to
anisotropic state parameters of microdefects do not
depend on the degree of deformation of the sample,
and abrupt changes of the parameters of microdefects
are observed after completing the formation of
anisotropic patterns. It is shown experimentally the
identity of the parameters of microdefects in the bulk
material (rubber-based natural caoutchouc) during
deformation with the quantities of local deformations
at the edge of the artificially created macrodefects.
Under uniaxial deformation more than 280-300% and
the growth of the quantities of local deformations
come out at the edge of the artificially created
macrodefects and normalized linear dimension k and
decrease the total number n of microdefects
Macrodeficiency of polymeric materials, including the
pervasive one, is a consequence of the development of
initial microdefects which appear in polymers both
due to external factors and during their processing. In
the article, the problem of the detection of structural
microdeficiency of various polymeric materials
through an assessment of their structural parameters is
solved. The considered materials possess
approximately identical degree of crystallinity (60 –
66%), but different density. The express assessment
technique of polymeric materials microdeficiency by
the sorption method with the use of the academician
M. M. Dubinin’s theory of volumetric micropore
filling is developed and evaluated. On the basis of a
quantitative assessment of sorption processes in
polymeric materials, including elastomeric
compositions – rubbers and rubberized fabrics, the
existence of the initial local microdefects arising in
the course of synthesis is established. In real
polymeric materials, including elastomeric
compositions – rubbers and rubberized fabrics, the
existence of the initial local microdefects arising in
the course of synthesis is established (the number of
microdefects n varies from 1x1017 sm-3 to 6x1019 sm-3
,
and the rated linear size k – from 2 nm to 7 nm). The
general reduction of microdeficiency in rubberized
fabrics in comparison with initial rubber is revealed
and rationalized
Article is devoted to the research and working out of calculation method of thermodynamic data and phase diagrams of ternary alloy materials of low-melt metals with the use of data bases known in literature.
The article is devoted to the research and working out of calculation method of thermodynamic data and phase diagrams of pentonary alloy materials of low-melt
The article is devoted to the application of method of differential-scanning microcalorimetry for research of phase-transitive materials on the base of inorganic and organic substances.
In the article the mathematical model of the space charge region in the bipolar membrane is considered. The structure of the space charge region under passing of electric current, and without electric current is discussed. The results of experimental studies of water dissociation in the bipolar membrane in the presence of chromium(III) are discussed
The results of investigation of melanoidin’s formation
early stages in acidic ethanolic D-glucose – p-toluidine
model system are presented. Based on the elemental
analysis, IR- and UV-spectroscopy data obtained we
have shown, that in system studied Amadori
rearrangement product undergo the aryl amine
elimination during browning to form a nonnitrogenous
reductons with antioxidative activity in
processes of linoleic acid oxidation. It is also noted,
that in system studied inhibition of carbohydrate’s
destruction occurs because of non-reactive O-ethylglycosides
formation. The data obtained may be useful
for technology of carbohydrate-containing raw
material
Since the industrial revolution a huge amount of pollutants
emitted annually into the water most of which is
occupied by toxic metals. These metals widely distributed
in the environment and of accumulation of a
threat to human health. It is known, that cadmium and
zinc at high concentrations have a negative impact on
nature. In modern wastewater treatment technology we
widely use polymeric sorbents with chelating properties.
The use of polymeric chelating sorbents (PCS)
usage allows separating individual or group trace elements
from large volumes of solutions of complex
composition, lowering the limit of detection, eliminating
or reducing significantly the impact of macrocomponents
which increases the cleaning efficiency.
The article presents the results of a study of conditions
of interaction of zinc (II) ions and cadmium (II) with
PCT - polystyrene-azo-o-phenol-azo-rhodanine. We
found the optimal values of the conditions for zinc (II)
ions and cadmium (II) sorption. We investigated the
effect of interfering of the macro- and micro- water
components with the sorption of the ions studied.
Maximum desorption of metal ions is achieved by
washing the concentrate with 10 ml of 2M hydrochloric
acid. The data indicate availability of the investigated
sorbent for concentration and separation of zinc
(II) ions and cadmium (II)
Surface energy of polymers determines such
important properties of polymers like wetability,
adhesion, ability adsorption of low molecular weight
substances. Inner organization, the structure of the
polymer and the dynamics of interaction between
macromolecular chains are shown at last. At the same
time, the micro-defects (inhomogeneity) of polymers,
which is an integral part of the structure are changed
during deformation and must contribute to changing
of the surface energy and its components.
This article solves the task of detecting changes in the
parameters of surface energy of polymers under
uniaxial deformation. Data for the quantitative
indicators of the surface properties total surface
energy and its dispersive and polar components are
presented. The calculations showed that the disperse
and polar components of all the samples of polymer
materials are about 98% of the total and, therefore, is
crucial. For the first time experimental data,
illustrating the change of surface energy of polymeric
materials had been obtained, including elastomeric
compositions, when uniaxial deformation. The
relative changes of the surface energy vary from 54.5
per cent to 125 %. A decrease of total surface energy
and its dispersion component is observed during
deformation of polymer samples of different structure
and chemical nature