What Can DC Polarography Offer Today
Petr Zuman*
Department of Chemistry, Box 5810, Clarkson
University, Potsdam, NY 13699-5810, USA
*Corresponding author: Tel. +1-315-268-2340, fax
1-315-268-6610
*Corresponding author: E-mail:
zumanp@clarkson.edu
Abstract
Advantages of uses of DC polarography in determination of inorganic and organic
species (such as speed of analyzes, highly reproducible and reliable results,
good theoretical background, establishment of the degree of conjugation in
organic species, possibility to determine the oxidation states in metal ions,
lower costs, no use of organic solvents, wide range of heavy metal ions and of
reducible organic compounds that can be determined) as well as limitations (lack
of qualified supervising personnel, fewer species undergoing oxidations) are
stated. Examples of recent successful applications are given: (1) analyses of
drugs containing a single physiologically active and electroactive species; (2)
investigations in non-homogeneous systems, such as of binding of heavy metal
ions, N-nitrosamines and various pesticides in suspensions of lignin; or of
formation of slightly soluble small aggregates and well soluble large aggregates
in interactions of heavy metal ions with bile salts; (3) determination of
equilibrium and rate constants for equilibria occurring in the bulk of the
solution and of rate constants of establishment of acid-base and hydration
dehydration equilibria that are perturbed by electrolysis in the vicinity of the
electrode. It is possible to follow this type of fast reactions, with rate
constants in the range between 1 × 104 L mol–1 s–1 and 1 ×
1010 L mol–1 s–1.
Keywords: DC polarography, metal ions, drugs, kinetics rate constants