Extraction of mercury(II) ions with antipyrine and its derivatives from chloride solutions to chloroform

The extraction of 0.01 mol/L mercury(II) ions from chloride solutions to chloroform is studied in the presence of antipyrine (AP) and its condensed derivatives (diantipyrylmethane (DAM), propyldiantipyrylmethane (PDAM), and hexyldiantipyrylmethane (HDAM)). The optimal mercury extraction conditions are determined for AP and its derivatives. The composition of the extracted complexes is determined. With respect to their pH_1/2 and extraction capacities, the extractants are arranged in the following order: AP < DAM < PDAM < HDAM. The calculation of partial equilibrium constants and approximate partition constants is proposed.     

Weak combinatorial selective properties of subsets of the natural numbers

Translated from Algebra i Logika, Vol. 29, No. 4, pp. 421–429, July–August, 1990.     

Recursive-combinatorial properties of subsets of the natural numbers

Translated from Algebra i Logika, Vol. 29, No. 3, pp. 303–314, May–June, 1990.     

Foundation and development of the Perm school of analytical chemists

The steps in the development of analytical chemistry and the organization of the school of analytical chemists in the city of Perm are considered. The role of G.G. Kobyak, the first head of the Division of Analytical Chemistry, in the organization of scientific research at the division, the selection of division staff, and the subsequent continuity of the formation of the division and the school of analytical chemists at Perm State University is outlined.