Gas chromatographic studies of oxide and hydroxide species of tungsten - Model experiments with respect to the physico-chemical characterization of seaborgium (Element 106)

The adsorption/desorption behavior of carrier-free W on quartz-glass surfac es in dry and moist oxygen was studied by off-line thermochromatography in the temperature range 330-1480 K. In dry oxygen W could not be volatilized. In moist oxygen the deposition temperature varies significantly with the h umidity of the carrier-gas. The transport can be described by WO2(OH)(2(g)) reversible arrow WO3(ads) + H2O(g) analogous to the lighter homologue Mo. Evaluation of the experimental data was carried out by means of the new com puter code TECPROF which allows to consider real temperature profiles. Up to an admixture of 60 mu g MoO3-carrier the formation of heteropolynucle ar complexes was not observed. However, the W was deposited at higher tempe ratures compared to experiments without a homologous carrier. Isothermal on -line gas chromatography experiments were carried out with short-lived W is otopes to model future Sg experiments and to optimize the experimental cond itions.