User:Gwmichael

Short biography of Dr. Gelana. Dr. Gelana W. Michael is An Ecotoxocologist at Adama Science and Technology University-Ethiopia. He was born in 1963 studied his primary and  secondary schools in Addis Ababa, Kasete birehan, Sibiste Negasi and Nefassilk Comprehensive S.S. School. He earned his first degree in Chemistry from Asmara university. second degree in Inorganic Chemistry from Addis Ababa University and Third degree in Ecotoxicology from University of Rostock-Germany.

'Research Articles' 1. Solar UV-Photo-oxidation as Pretreatment for Stripping-Voltammetric Trace Metal Analysis in River Water 2. Solar UV-assisted pre-treatment of river water samples for the voltammetric monitoring of nickel and cobalt ultratraces, (2012) submitted 3. Solar UV-assisted sample preparation of river water for ultra-trace determination of uranium by adsorptive stripping voltammetry, (2012) submitted Gelaneh Woldemichael a, Taffa Tulu a, Gerd-Uwe Flechsig b,*

a)	Adama Science and Technology University, School Natural Sciences, Adama, Ethiopia b)	Department of Chemistry, University of Rostock, D-18051 Rostock, Germany, and Gensoric GmbH, Schillingallee 68, D-18057 Rostock, Germany


 * Corresponding author: gerd-uwe.flechsig@uni-rostock.de, fon: +49-381-4986470, fax: +49-381-4986461

Abstract

The application of solar ultraviolet radiation as sample pretreatment or preparation step in stripping-voltammetric analysis of trace metals in presence of low levels of dissolved organic carbon (DOC) natural water samples (river water) was studied. River water samples were collected from downstream of Warnow River (Germany) and acidified to pH of 2+0.2 with ultrapure HNO3. 100 µL/L of hydrogen peroxide solution (30% H2O2) was added to the samples as photochemical reaction initiator. The samples were transferred to PET bottles and irradiated with solar radiation of UV-A intensity of 3.6 mW/m2 for six hours and the concentrations of Zn, Cd, Pb and Cu were determined by differential pulse anodic stripping-voltammetry (DPASV). The comparison of the values with the results obtained for the original untreated sample and artificial UV treated one proved that solar UV radiation can be applied to the digestion of dissolved organic carbon in trace metal analysis in natural waters like river water, lake waters, well waters etc.