Ład korporacyjny na Ukrainie we współczesnych warunkach: aspekty regionalne

Article is devoted to the development of corporate sector in the Zaporozhye region. Consider the financial state of joint-stock companies, influence on their financial situation and legal principles of their operation. Defined the range of problems that adversely affect on the level of corporate management

Whole-cell conductometric biosensor for determination of toxicity of heavy metals in water

internationa

Alkaline phosphatase conductometric biosensor for heavy-metal ions determination

Berezhetskyy, A. L. Sosovska, O. F. Durrieu, C. Chovelon, J. -M. Dzyadevych, S. V. Tran-Minh, C.Alkaline phosphatase conductometric biosensors consisting of interdigitated gold electrodes and enzyme membranes have been used for assessment of heavy-metal ions in water. These analytes act as enzyme inhibitors. Enzyme residual activity has been measured in Tris-nitrate buffer without metal preincubation in the presence of Mg2+ ions as activator. The results indicate that the toxicity of the various metals tested toward immobilized phosphatase is ranged as follows: Cd2+ > Co2+ > Zn2+ > Ni2+ > Pb2+. Detection limits were about 0.5 ppm for Cd2+, 2 ppm for both Zn2+ and Co2+, 5 ppm for Ni2+ and 40 ppm for lead ions. In addition, the responses during 10 h were stable (RSD 4%) and a drift of about 7% per day was observed. The storage stability in buffer solution at 4 degrees C remained stable for more than one month. (C) 2008 Elsevier Masson SAS. All rights reserved