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.

Simultaneous determination of inorganic anions and cations in waters by capillary electrophoresis.

The applicability of a recently proposed capillary electrophoresis technique based on the electromigrative sample introduction from both ends of the capillary was further investigated for the simultaneous determination of inorganic anions and cations in real water samples. The optimized separations were carried out in 5.0 mmol l-1 copper(II)-ethylenediaminehydroxide and 2.0 mmol l-1 triethanolamine electrolyte neutralized with chromic acid to pH 8.0, using indirect UV detection at 254 nm. Nine inorganic ions (Cl-, NO3-, SO4(2-), HCO3-, K+, NH4+, Na+, Ca2+ and Mg2+) were well separated in less than 5 min. The analytical performance of the method is discussed in terms of migration time, peak area and corrected peak area repeatability, linearity of response and detection limits. To evaluate this system, the determination of anions and cations was examined for mineral water, tap water and river water samples using Li+ as the internal standard. The comparison of the results with ion chromatography and conventional capillary electrophoresis is presented.