M. Pantsarkallio et Pkg. Manninen, DETERMINATION OF SODIUM, POTASSIUM, CALCIUM AND MAGNESIUM CATIONS BY CAPILLARY ELECTROPHORESIS COMPARED WITH ION CHROMATOGRAPHY, Analytica chimica acta, 314(1-2), 1995, pp. 67-75
Capillary ion analysis (CIA) is a young analytical methodology adapted
to analysis for inorganic ions, and has some remarkable advantages ov
er ion chromatography (IC). In this paper a CIA method used for analys
is for K+, Ca2+, Na+ and Mg2+ in water samples is presented, and the f
actors affecting the separation - such as electrolyte ion, complexing
or chelating agents - are discussed. Also the repeatabilities of the m
ethod, linearities and the detection limits are compared with those ob
tained by IC. Sufficient separation of the four ions is achieved with
an electrolyte solution of 5 mM imidazole/6.5 mM alpha-hydroxyisobutyr
ic acid/2 mM 18-crown-6 ether, pH 4.1. Detection is by 'reverse' absor
bance measurements.