Optimization of separation of heavy metals by capillary electrophoresis with contactless conductivity detection.

The separation of four toxic metal ions (Cr(3+) , Pb(2+) , Hg(2+) , Ni(2+) ) was achieved by optimizing the composition of the histidine/tartaric acid background electrolyte. An on-column preconcentration technique, viz. field amplified sample injection, was performed to improve the sensitivity.