Sorption-photometric and test determination of lead in environmental materials

The main analytical characteristics of the reaction of hexaoxacycloazochrom with lead were determined. A method for the sorption preconcentration of lead on the Thiopan 14 sorbent was proposed. Procedures were developed for the photometric determination of lead in natural waters, air, and soil at the level of the maximum permissible concentration. A new melange gel technique for preparing silicic acid xerogels modified with hexaoxacycloazochrom was developed for the test determination of lead in environmental samples at the level of the maximum permissible concentration.     

Reaction of 4-amino-4′-methoxydiphenylamine oxidation in surfactant solutions

The kinetics of noncatalytic and catalytic oxidation reactions of 4-amino-4′-methoxydiphenylamine with different oxidants in aqueous solutions and in the presence of surfactants was studied. The catalytic activity of iridium(IV) in this reaction in weakly acidic solutions (pH = 3) was estimated. The dependences of the rates of noncatalytic and catalytic processes on the component concentrations in the reaction mixture, the acidity of solutions, and their temperature were determined. A method for the catalimetric determination of iridium(IV) was proposed and verified against model mixtures.     

Investigation of exchange reactions between alkaline earth metal oxides and some transition metal halides

DTA and the simultaneous recording of electrical conductivity were applied for the investigation of exchange reactions between alkaline earth metal oxides and some lead, copper and nickel halides. Although the possibility of the gaseous phase is not excluded for the majority of the reactions investigated, it is either the appearance of a liquid phase or the polymorphous transformation of CaO that has the decisive effect on the interaction mechanism.     

Catalymetric Determination of Rhodium Based on the Reaction of the Oxidation of Triphenylamine-4-Sulfonic Acid by Sodium Periodate

The catalytic activity of rhodium(III) was studied in the reaction of the oxidation of triphenylamine-4-sulfonic acid by sodium periodate at pH 3. The dependence of the reaction rate on the technique of catalyst preparation, the presence of activators, the concentrations of the components, and the acidity and temperature of solutions was revealed. A sensitive and selective method for the catalymetric determination of rhodium(III) is proposed and tested with synthetic mixtures.     

Sulfophenylanthranylic acid as a new reagent for palladium

The use of diphenyl reagents bearing electron-withdrawing substituents in catalymetric analysis was studied using sulfophenylanthranilic acid as an example. A selective catalytic effect of palladium(II) on the oxidation of sulfophenylanthranilic acid by cerium(IV) sulfate in a weakly acid solution was found. The reaction rate was studied as a function of component concentrations, solution acidity, and temperature. A procedure for determining palladium(II) was developed and tested using model mixtures and a KP-5 sample of complex composition.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 2, 2005, pp. 144–148. Original Russian Text Copyright © 2005 by Burmistrova, Mushtakova, Nikonorov.     

Triphenylamine-4-sulfonic acid in the catalymetric determination of platinum metals

The catalytic activity of Ir(IV), Rh(III), and Ru(IV) was studied in the reaction of the oxidation of triphenylamine-4-sulfonic acid by sodium periodate in a weakly acidic medium. The main analytical characteristics of triphenylamine-4-sulfonic acid were found out. The optimum conditions of the indicator reaction (concentrations of components, acidity, and temperature dependence) were selected. Procedures for determining Ir(IV), Rh(III), and Ru(IV) were proposed and tested with model mixtures.     

Simultaneous determination of proteins in microstructured optical fibers supported by chemometric tools

Analytical and Bioanalytical Chemistry - A new perspective on the relevant problem—creating simple, rapid, and efficient protein sensors based on microstructured optical fibers using a simple...     

Sorption recovery of platinum(II) and platinum(IV) chloro complexes with a heterochain sulfur-containing sorbent

The recovery of platinum(II) and platinum(IV) chloro complexes from hydrochloric acid and chloride solutions with a new heterochain S,N-containing sorbent, MITKhAT, was studied. The suggested mechanism of formation of platinum(II) mercapto-thio ether complexes in the course of sorption was confirmed by DFT calculations. The results of group and selective recovery of platinum metals with MITKhAT sorbent from simulated and real industrial solutions are reported.     

Immunochemical methods for the determination of mycotoxins

The state-of-the-art immunochemical methods for the determination of mycotoxins are considered. Both instrumental (enzyme-linked immunosorbent assay, polarization fluoroimmunoassay, and sensor devices) and noninstrumental methods are presented. The principles of particular methods are considered, and the examples of the use of these methods for the determination of mycotoxins from various groups in food products and animal feeds are given; the main lines of development are discussed.     

Reduction kinetics of NiO-MoO3 catalysts

Reduction kinetics of NiO–MoO₃ catalysts in H₂ at 573–723 K has been studied. Reduction activation energies E_a have been determined. The degree of NiO–MoO₃ reduction is shown to increase with increasing NiO content.

---

NiO–MoO₃ H₂ 573–723 . E NiO–MoO₃ . , NiO–MoO₃ NiO .