Resumen

SILVA, José A. Fracassi da; RICELLI, Nara L.; CARVALHO, Alexandre Z.  y  LAGO, Claudimir L. do. Improved separation of IA and IIA metal cations in matrices with high sodium concentration by capillary electrophoresis with contactless conductometric detection. J. Braz. Chem. Soc. [online]. 2003, vol.14, n.2, pp. 265-268. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532003000200013.

One of the most common uses of capillary electrophoresis with conductometric detection is the analysis of different samples containing alkaline and alkaline earth metals. However, the high sodium content, which is a very common occurrence, may cause loss of resolution of some peaks. In this work, the conditions and a running buffer suitable for serum and hemodialysis fluid analyses are presented. The approach basically consists in the reduction of mobilities of Ca²⁺ and Mg²⁺ by addition of methanol and lactate in the running buffer. Limits of detection in the range from 0.5 to 1.0 mmol L^-1 with molar Na⁺/Ca²⁺ ratios as high as 1000 were obtained, which are conditions that exceed the requirements of the proposed determination.

Palabras llave : capillary electrophoresis; contactless conductivity detection; human serum; hemodialysis fluid.