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Ye. A. Osipova, D. S. Shishmarev, N. K. Zaitsev
Comparative
Charactrization of Two Techniques of Selenium(IV) Accumulation at the Mercury
Film Electrode Using an Automated Medium Exchange System without the Circuit
Disconnection
Abstract
Two
procedures of selenium(IV) accumulation and determination at the mercury film
electrode (MFE) by cathodic stripping voltammetry have been compared – in the
presence of copper and at the MFE with preliminary accumulated copper. It has been established that
the calibrating curves are the same for both techniques and demonstrate linear
behavior in the ranges from 2.5 till 20 and from 50 till 250 мg/l of selenium concentration under
optimal conditions (0.1 M HCl, accumulation potential (–350)…(–400) mV,
electrolysis time 180…300 s). In both cases selenium peak heights are quite
well reproduced (Sr. is 0.02…0.05 in the investigated concentration interval). The
technique with successive accumulations of copper and selenium is more convenient
from the practical point of view as in this case there is no need to add copper
to each analyzed solution, and it enables to optimize the conditions of
selenium accumulation (composition of the solution, electrolysis potential and
time).
Copyright (C) Chemistry Dept., Moscow State University, 2002
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