Possible interference in the sequential voltammetric determination at trace and ultratrace concentration level of platinum group metals (PGMs) and lead. Application to environmental matrices

The present work describes a procedure for the sequential determination of Pd(II), Pt(II), Rh(III), by square wave adsorption stripping voltammetry (SWAdSV) and Pb(II) by square wave anodic stripping voltammetry (SWASV) in environmental matrices (sediments, soils and superficial water) in the presence of possible metal interferences, including high concentration ratios. In the presence of reciprocal interference, the standard addition method considerably improved the resolution of the voltammetric technique, even in the case of very high element concentration ratios. Once set up on the standard reference materials, the analytical procedure was transferred and applied to sediments, soils and superficial waters sampled in proximity of superhighway and in the Po River mouth area. A critical comparison with spectroscopic measurements is also discussed.