Rapid analysis of cation constituents of urine by capillary electrophoresis.

Capillary electrophoresis was applied for the simultaneous determination of K(+), NH(4)(+), Na(+), Ca(2+) and Mg(2+) cations in urine. The separations were carried out in electrolyte containing 7. 5 mmol/l copper(II) acetate, 15 mmol/l ethylenediamine and 2 mmol/l triethanolamine at pH 8.0, with indirect UV detection at 230 nm. All cations were well separated in less than 4 min. The results obtained by this method were comparable with ion chromatography. The proposed system is simple, rapid and does not require any preliminary treatment of the urine samples except diluting.