CAPILLARY ELECTROPHORETIC ESTIMATION OF SULFATE STABILITY-CONSTANTS OF METAL-IONS AND DETERMINATION OF ALKALI AND ALKALINE-EARTH METALS IN WATERS

We studied the influence of sulfate concentration on the effective mob ilities of mono-, di- and tervalent ions and developed a method for th e determination of sulfate stability constants. Relative migration tim es of several cations were determined. Capillary electrophoresis with indirect detection using 4 mmol/l copper(II) sulfate, 18-crown-6 and f ormic acid in background electrolyte was then applied to the determina tion of the metal ions in mineral and tap waters samples. The results were compared with those of ion chromatography. The CE detection limit s were estimated [signal/noise ratio (S/N)=3] in the range from 0.59 ( for Li) to 12.9 mg/l (for Ba).