In order to optimize a fast and continuous gas chromatography separation system for a chemical characterization of Db,the behavior of short-lived Nb isotope which is the lighter homologue of group 5 elements was studied in this work. In order to optimize a fast and continuous gas chromatography separation system for a chemical characterization of Db, the behavior of short-lived Nb isotope which is the lighter homologue of group 5 elements was studied in this work.