of isotopically labelled vitamin D metabolites by HPLC. Journal of Chromatography 303: 229}233. Kaspersen FM, van Acquoy J, van de Laar GLM, Wagenaars GN and Funke CW (1984) Deuterium isotope effects in mianserin. Recueil Travaux Chimique de Pay-Bas 103: 32}36. Klein PD (1966) Occurence and signiRcance of isotope fractionation during analytical separation of large molecules. Advances in Chromat...

hydrographically bolivian poopó lake is located in the basin of desaguadero river and it has over a dozen main tributary rivers and other smaller rivers with lower flow. the mine water discharge from the abandoned and current mining activities polluted these rivers by carrying heavy metals, dissolved and suspended solids which in turn polluted the poopó lake which is considered as an important ...

abstract heavy metals are the important pollution which there is in the aquatic ecosystems. today, with advances in technology have increased the pollution therefore it is important to assessment the risks. the aim of this study was acute toxicity effects of mercury chloride, lead chloride and zinc chloride in silver carp fish. in this study there were 5 treatments for lead chloride and mercury...

The northern flank of the North China Craton (NCC) hosts a linear zone gold, molybdenum, silver, lead, and zinc polymetallic ore deposits. Among these, Yingfang Pb-Zn-Ag deposit is located in central part Yanshan–Liaoxi metallogenic belt (YLMB) which extends for approximately 1000 km forms major mineralized zone. In this study, we characterize mineralization trace genesis based on new sulfur le...

The influence of experimental conditions on the formation of ZnO fibers by electrospinning has been investigated. The electrospinning of a viscous suspension containing polyvinylpyrrolidone and zinc acetate in C2H5OH/H2O produced very long fibers (several hundred μm). Upon calcination a thin deposit of precursor fibers at 400 or 500 °C for 1 h the fibers consisting of ZnO nanoparticles were obt...

Seasonal and spatial variations in metal concentrations and pH were found in a stream at a restored copper mine site located near a massive sulfide deposit in the Foothill copper-zinc belt of the Sierra Nevada, California. At the mouth of the stream, copper concentrations increased and pH decreased with increased streamflow after the onset of winter rain and, unexpectedly, reached extreme value...

An uptake of zinc (Zn), copper (Cu), and lead (Pb) from aqueous solutions by ion exchange on natural zeolitic tuff has been studied. The Croatian zeolite clinoptilolite from the Donje Jesenje deposit has been used as a natural ion exchanger. The efficiency of removal is higher for Pb and Cu than for Zn ions. Measured concentrations of Si in the liquid phase identify the detachment of the alumin...

Zinc nickel alloy was deposited from alkaline bath at a PH of 13-14 with the nickel percentage of 5-9% in our prior research. Present study dealt with the research on 10-12% of Nickel at a PH of 12-13 from Zinc – nickel alloy electrolyte and the remaining percentage of Zinc, required for corrosion resistant applications to be used for reliable alternative of cadmium. Hull cell studies was carri...