Nataša Gros,* Andrej Nemarnik
University of
Ljubljana, Faculty of Chemistry and Chemical Technology, Aškerčeva 5, SI-1000
Ljubljana, Slovenia.Tel.:+386 1 2419 164;
Fax:+386 1 2419 220,
E-mail: natasa.gros@fkkt.uni-lj.si.
Abstract
The first
objective of our investigation was to find an experimental procedure and
conditions under which ion-exclusion chromatography gives reliable results for
determining the concentration of hydrogen carbonate in model solutions: results
that are comparable with other traditional methods, e.g., potentiometric
titration and direct potentiometry with a CO2-responsive electrode.
Our second aim was to estimate the effect of anions of carboxylic acid on the
hydrogen carbonate determination with different analytical methods. The extent
of the possible interferences was evaluated afterwards with ion-exclusion
chromatography for real samples, i.e., surface waters. The analyses of the
Slovenian river waters and waste water from a paper-production plant are
represented as a pilot study for the method comparison for real life
applications. Ion-exclusion chromatography was recognised as the method of
choice for a reliable determination of the concentration of hydrogen carbonate
in water samples containing anions of carboxylic acids.
Keywords: hydrogen carbonate/bicarbonate, ion-exclusion chromatography, potentiometric titration, direct potentiometry, river water, waste water