Experiments with TT can also help to understand gold VS atomization
when taking into account hydride atomization mechanism in this
atomizer: a cloud of H radicals, filling only a small portion of the volume
of the atomizer, is formed at the beginning of the hot zone of the atomizer
by reactions between hydrogen and traces of oxygen (always present
in sample, reagent solutions and gases) [4]. Hydrides are, under
optimum conditions, fully atomized in the cloud by reactions with H
radicals analogously as in the case of FIGS atomizer even though the
density of H radicals in the cloud is much lower than in FIGS [4]. Analogously
as in the case of DF and FIGS, the relatively intensive gold signal
(Fig. 8) does not correspond to thermodynamic equilibrium calculations:
fraction of gold free atoms at the actual temperature of 900 °C
should be negligible (Fig. 9). This indicates an equal mechanism as for
hydrides: atomization of the nanoparticles in the cloud of H radicals situated
at beginning of the hot zone of the atomizer. It should be
highlightedmuch higher sensitivity is observed in TT than in FIGS (compare
Figs. 8 and 5) even though FIGS produces much higher H radical
density than TT [4]. This again points to the key role of temperature in
volatilization/atomization of the nanoparticles: the higher temperature
in TT compared to FIGS can accelerate vaporization of nanoparticles in
the form of AuH and, subsequently, AuH can be atomized much faster
in the H radical cloud than in “low-temperature” FIGS.
Experiments with TT can also help to understand gold VS atomizationwhen taking into account hydride atomization mechanism in thisatomizer: a cloud of H radicals, filling only a small portion of the volumeof the atomizer, is formed at the beginning of the hot zone of the atomizerby reactions between hydrogen and traces of oxygen (always presentin sample, reagent solutions and gases) [4]. Hydrides are, underoptimum conditions, fully atomized in the cloud by reactions with Hradicals analogously as in the case of FIGS atomizer even though thedensity of H radicals in the cloud is much lower than in FIGS [4]. Analogouslyas in the case of DF and FIGS, the relatively intensive gold signal(Fig. 8) does not correspond to thermodynamic equilibrium calculations:fraction of gold free atoms at the actual temperature of 900 °Cshould be negligible (Fig. 9). This indicates an equal mechanism as forhydrides: atomization of the nanoparticles in the cloud of H radicals situatedat beginning of the hot zone of the atomizer. It should behighlightedmuch higher sensitivity is observed in TT than in FIGS (compareFigs. 8 and 5) even though FIGS produces much higher H radicaldensity than TT [4]. This again points to the key role of temperature involatilization/atomization of the nanoparticles: the higher temperaturein TT compared to FIGS can accelerate vaporization of nanoparticles inthe form of AuH and, subsequently, AuH can be atomized much fasterin the H radical cloud than in “low-temperature” FIGS.
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