[en] Fibrous material disks filled with a weakly basic anion exchanger immobilized by Arsenazo 1 (IMARS) are suggested to be used as a sensitive elements of optical sensors for uranium (6). The IMARS disks are applicable to rapid direct determination of uranium (6) under dynamic conditions by reflection spectrometry. The limit of detection of uranium (6) is equal to 3 · 10 ^-8 mol/l at a solution passing time of 10 min. The use of IMARS provides an increase in the determination sensitivity and selectivity as well as a wide range of determinable concentrations compared with aqueous solutions of Arsenazo 1

[en] Methods of synthesis of chelating agent sorbents (CAS) on the basis of different polymeric matrices, physico-chemical and analytical properties of sorbents are presented along with the fields of CAS applicaton in the analytical chemistry. All known CAS are systematized according to polymeric matrices and chelating groups. Peculiarities of CAS application for selective element concentration and separation are considered. Procedures based on CAS application for microelement (Be, Cd, Ce, La, Sc, Y, Yb, Zr, Hf, V, Nb, Ta, Mo, V) determination in natural waters, natural, and industrial substances, and in element (Th, U, Pu, Am, Cm, Zr, REE) separation are described. Bbliography contains 507 references

[en] A new type of carrier for immobilization of reagent-fibrous materials of polyacrylonitrile fiber filled with fine-dispersed ion exchanger during formation- was suggested when creating sensitive element of optical sensor for lead (2) and thorium(4). The highest sensitivity and contrast are achieved in color reactions with xylenol orange, immobilized on weak-base anion-exchanger. Detection limits are decreased down to 2x10^-8M, the range of determined concentrations -5x10^-8-1x10^-6 M, reproducibility Sr 0.05-0.10, the response forms during 1-10 minutes

[en] The influence of substituents on the electronic structure of anions of salicyclic acid and its complexes with beryllium was studied by the CNDO/2 method. The influence of the substituents on the dissociation energy of the complexes was examined. The mechanisms of the influence of the substituents in the ligand on the strength of the complexes are discussed

[en] A test-method of thorium determination based on sorption from a solution of oxalic acid on a disk made of filamentous material filled with anionite and subsequent reaction with arsenazo 3 in 6 M HCl is proposed. A color-scale is used in the range of thorium concentration 0.01-0.08 mg/liter. The error of determination is <= ± 50 %. 7 refs.; 2 figs

[en] A visual methods of U(6) and Th(4) determination with arsenazo(3) immobilized on the fiber material filled with anion exchanger is proposed. The method makes it possible to determine the total U and Th content and Th content from the single sample using two color scales within the concentration range of 0.02-0.24 mg/liter (total) and 0.01-0.12 mg/liter of Th at their ratio from 1:3 to 3:1. The error of analysis is no more than ±50%

[en] Data on real possibilities of applying NMR spectroscopy when solving inorganic analysis problems are generalized for the girst time in the world literature NMR-spectroscopy method for identification of chemically related metals (including alkal, alkaline-earth, rare earth ones, actinides, Zn-Cd, Al-In pairs) in a solution is proposed. Metals are determined in the form of complexes with specially selected polydentate ligands. Structural reguirements to ligands and common limits of the method applicability are discussed. 1078 refs.; 14 figs.; 8 tabs

[en] Possibilities of organic reagents application in analysis of high purity substances including Zr, V, Nb, Ta, rare earth compounds as well as in determination of impurities of Be, B, Cd, Sr, Sc, Re, Ru, Th et al. elements are considered. It is shown that organic reagents may be used directly in photometric, luminescent and kinetic methods of analysis if sensitivity of these methods satisfy the required one. On the opposite, preconcentration of microimpurities using organic reagents and subsequent their determination by appropriate methods are applied

[en] The properties of certain chelating sorbents of POLIORGS type and their analytic application for the concentrating and separation of rare metals (rare earth, platinum ones, actinides, as well as Zr, Hf, Nb, Mo, Sc, etc.) are considered. The sorbents contain chemically active groups with donor atoms of oxygen, sulfur and nitrogen, able of complexing with rare metal ions in solutions. Aminopolystyrene of linear structure, copolymer of styrene and divinylbenzene, polyvinylene fibre, etc. are used as polymer matrices

[en] Spectrophotometric methods of analysis of boron, indium, alkaline-earth, rare-earth, and transition metal compounds with an application of organic reagents in the modern chemistry are discussed. Some new organic reagents synthesized in the last few years are presented. New methodical techniques of spectrophotometric analysis and its equipment potentialities are discussed. Progress in the field of development of theoretical grounds of organic reagent action is described; and the new approach to the problem of explanation of organic compounds reactivity is suggested