1. Mass Spectrometry Laboratory; National Institute for Research and Development in Electrochemistry and Condensed Matter; Plautius Andronescu Str. 1 RO-300224 Timisoara Romania
2. Faculty of Physics; West University of Timisoara; Blvd. Vasile Parvan 4 RO-300223 Timisoara Romania
3. Department of Gastroentero-, Hepato-, and Endocrinology I3; Hannover Medical School; EB2/R3110, Carl-Neuberg-Str. 1 D-30625 Hannover Germany
4. Department of Chemical and Biological Sciences; “Aurel Vlaicu” University of Arad; Revolutiei Blvd. 77 RO-310130 Arad Romania