1. Analytical Chemistry Laboratory, Department of Chemical Engineering, Polytechnic Faculty, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
2. Thessaloniki Water Supply & Sewerage Co S.A., 57008 Thessaloniki, Greece
3. Laboratory of Chemical & Environmental Technology, Department of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece