Cleaning of extracts of cereal crop samples with aluminosilicate in the determination of pesticides by gas chromatography with mass-spectrometric detection

A procedure for the determination of 23 pesticides from different classes (organophosphorus and organochlorine compounds, synthetic pyrethroids, and triazoles) in cereal crops is proposed. It is based on sample preparation according to the QuEChERS method with the subsequent cleaning of the extract with natural aluminosilicate and the determination of analytes by gas chromatography with mass-spectrometric detection. The limits of the quantitative determination of pesticides are ~0.005 mg/kg. The relative standard deviation does not exceed 0.02. The duration of analysis is 35–40 min.     

Sorption of vapors of aromatic compounds by cross-linked polymer particles containing luminophores: A spectroscopic study

Monodispersed core-shell particles 290–315 nm in diameter were prepared by seed emulsion copolymerization of styrene with divinylbenzene in the presence of luminophore-containing comonomers. The capability of the particles obtained to sorb toluene vapor was shown by solid-state ¹H and ¹³C NMR spectroscopy.     

Thermochemical transformations of hydrolysis lignin

Conclusions on the reactivity of lignin in thermal processes are made on the basis of published data and results of thermal analysis of lignin samples from certain hydrolysis enterprises.     

Untersuchung der Orientierung der flüssig-kristallinen Domänen des Poly-γ-benzyl-L-glutamats mittels der IR-Spektroskopie

Ohne Zusammenfassung     

Role of Structural Characteristics of Aromatic Polyimides in Carbonization

The influence of the structural characteristics of polyimides belonging to four standard classification groups was analyzed. The main factors responsible for formation of ordered and/or turbostratic carbon structures in the course of carbonization were studied for the example of film and fibrous materials.     

Mechanism of low-temperature carbonization of polyacrylonitrile

Low-temperature carbonization of polyacrylonitrile was studied in relation to the synthesis procedure, heat treatment conditions, and presence of natural polymers as cocarbonization participants.     

Potential activity of hydrolytic lignin in copolymerization reactions

Structural-molecular characteristics of hydrolytic lignin samples from various factories were studied and their potential activity in copolymerization with polyacrylonitrile was determined.     

Cocarbonization of polyacrylonitrile-based composites

Structural transformations in polyacrylonitrile carbonizates and cocarbonizates were studied in the temperature range 400–600°C.     

Structural features of the ferromagnetic order formation in the Mn1<Subscript>–<Emphasis Type="Italic">x</Emphasis></Subscript>Cr<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>NiGe system

Within the phenomenological model of the interacting parameters of magnetic and structural orders, magnetic and structural transitions in magnetocaloric alloys of the Mn_1–x Cr _x NiGe system are analyzed. Based on the calculated isobaric temperature dependences of the parameters of magnetic and structural orders, a magnetic susceptibility jump in the first-order structural transition region is predicted and confirmed experimentally; the change in the magnetic ordering type during the approach of magnetic and structural transitions is justified. The change in the phase transition type during the reverse change in the temperature and magnetic field, which is observed in a number of samples of the system under study, is explained. The efficiency of the use of the transitions induced by the magnetic field in magnetocaloric applications is analyzed.