1. Department of Chemistry and Biochemistry, University for Horticulture and Food Industry, Budapest, H-1502, P.O.B. 53, Hungary
2. Research Institute of Chemical Engineering, Hungarian Academy of Sciences, Veszprém, H-8201, P.O.B. 125, Hungary
3. REANAL Factory of Laboratory Chemicals, Budapest, H-1441, P.O.B. 54, Hungary