A. V. Borodin, V. V. Senyuta, S. N. Bendrysheva, M. A. Proskurnin
Differential kinetic determination of cobalt
and vanadium with thermal-lens monitoring
Abstract
By the example of a
model indicator reaction of the oxidation of cobalt(II) and vanadium(IV) ions
with the complex of iron(III) with 1,10-phenanthroline resulting in the
formation of iron(II) tris-(1,10-phenanthrolinate) it is shown that
thermal-lens monitoring can be used in differential kinetic determinations. For
differential kinetic determination of mixtures of cobalt(II) and vanadium(IV)
with thermal lens monitoring (514.5 nm, 35.5 mW), the limits of detection of 2
ng/mL for both metals are achieved, which is the same as the limits of
detection for individual metals. Contrary to the spectrophotometric measurements,
the role of the synergetic effect degrading the sensitivity of determination in
this indicator system is almost negligible with thermal-lens monitoring. As a
whole, the sensitivity of differential kinetic determination of cobalt(II) and
vanadium(IV) with thermal-lens monitoring excels their determination with
spectrophotometric determination by a factor of 100.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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