This study describes the simultaneous determination of phosphonate, phosphate, and diphosphate by CE with direct UV detection, based on in-capillary complexation with Mo(VI). When a mixture of phosphonate, phosphate, and diphosphate was injected into a capillary containing 3.0 mM Mo(VI), 0.05 M malonate buffer (pH 3.0) and 45% v/v CH3CN, three well-defined peaks, due to the migration of the corresponding polyoxomolybdate anions, were separated. The respective calibration graphs were linear in the concentration range of 2 x 10(-6)-2 x 10(-4) M for phosphonate, 1 x 10(-6)-5 x 10(-5) M for phosphate, and 1 x 10(-6)-2 x 10(-4) M for diphosphate; the correlation coefficients were better than 0.9990. The present CE method is successfully applied to the simultaneous determination of phosphonate, phosphate, and diphosphate in tap water.

The cyclic voltammetric behavior of [FeIIICl(salen)] complexes has been investigated in CH3CN and compared to that obtained with [CoII(salen)] analogues. Details of the mechanism associated with iron- and cobalt-salen complex reduction in the presence of the lithium cation have been elucidated by comparison of simulated and experimental voltammograms. Electrogenerated [FeICl(salen)]²⁻ and [FeICl(salophen)]²⁻ complexes catalyze the dehalogenation of halo-alkyl compounds as is the case with [CoI(salen)]⁻ complexes, even in the presence of the lithium cation which allows the reduction to occur at a less negative potential.