HIGH-PERFORMANCE SEPARATION AND DETERMINATION OF CO(III) AND NI(II) CHELATES OF 4-(2-PYRIDYLAZO)RESORCINOL AT FEMTOMOLE LEVELS BY CAPILLARY ELECTROPHORESIS

Separation of 4-(2-pyridylazo)resorcinol (PAR) and its chelates of Co(III), Fc(II), Ni(II), and V(V) was accomplished within 6 min by simple capillary electrophoresis (CE) with a spectrophotometric detection. The detection limits, defined as 3sigma of base-line noise were 1.80 x 10(-7) mol dm-3 for Co(III) and 1.41 x 10(-7) mol dm-3 for Ni(II) chelates, and those on a mass basis were 1.08 fmol (63.6 fg) and 0.84 fmol (49.3 fg) in 6.0 x 10(-9) dm3 sample, respectively. A guideline on the ligand design for the CE system is also obtained from the pH dependence of the separation behavior of PAR chelates.