In our earlier work, we have shown that enzymes from rat brain synaptosomal membranes, Na(+)/K(+)-ATPase and Mg(2+)-ATPase, are promising biological components of a biosensor for lead detection. In this work, we represent our results of investigation with the same enzymes as biological components for the biosensor in presence of Hg(2+) ions in water. It was established that IC50 for Na(+)/K(+)-ATPase and Mg(2+)-ATPase is 6.9 and 5.5 x 10E-6 M, and the percentages of inhibition are 96% and 77% respectively. We concluded that these enzymes could be the base for developing biosensors for the presence of Hg(2+) ion in water. Since these enzymes maintain a stable activity for a longer period of time, they could be appropriate as components of biosensors for monitoring water quality.

In this investigation the applied method for lead determination in traces, from 10E-6 - 10E-10 mol/cubic dm, was Potentiometric Stripping Analysis (PSA). The main attribute of this method is possibility to detect very low metal concentrations. The investigation results of level concentration of lead into the top, natural and atmospheric water from some towns of Serbia (Yugoslavia), including city of Belgrade, are given. The investigation was carried out in some towns of Serbia (Yugoslavia), including city of Belgrade, during the 1994-1995.

As other areas on Montenegrin coast, Bokakotorska bay is also under a heavy impact of anthropogenic factors and the activities on the shore. The aim of the present work was to determine the levels of lead and cadmium in coastal surface sea water and sediment at three stations located in the inner shore waters Boka Kotor bay, and at one station located off shore Montenegrian coast considered as a reference station. The comparison of the results obtained for the inner shore stations with reference station showed that the content of this metals in some station are considerable increased in ratio to reference station.

Potentiometric stripping analysis (PSA) is highly sensitive electroanalytical method for determination of traces of heavy metals. In this paper detection limit and linearity of potentiometric stripping analysis for lead was investigated. Method was successfully used for determination of traces of lead ion (detection limit 5 microgram/cubic dm) in stream water of river Ibar, before and after joint of potential pollutant.

The aim of this study was to determine the content of heavy metals, cadmium and lead, in drinking water, spring and well water from rural part of south Serbia, as in water of river Jablanica and in the top water. The content of cadmium and lead, a very toxic metals, were studied simulataneously by potentiometric stripping analysis (PSA) in water samples using thin mercury film electrode, as a working electrode, by standard addition method in the presence of supporting electrolyte. The results of content of examined heavy metals obtained in examined water samples by PSA method, are compared with results obtained by using AAS and GF-AAS spectrometry.