Platinum, Rhodium, Palladium and Lead: Elements Linked to Vehicle Emissions. Their Simultaneous Voltammetric Determination in Superficial Water

Abstract

The present work, regarding the determination of Pt(II), Rh(III) by square-wave adsorption stripping voltammetry (SWAdSV), Pd(II) by square-wave voltammetry (SWV) and Pb(II) by square-wave anodic stripping voltammetry (SWASV) in superficial water is an interesting example of the possibility to simultaneously, or better sequentially determine each single element in real samples. The critical comparison between peak area and peak current highlights that lower limits of detection are obtained if peak area is employed as instrumental datum. 0.6 mmol/L formaldehyde+1.2 mmol/L hydrazine (formazone complex) in 0.3 mol/L HCl and ammonia-ammonium chloride buffer pH 9.6 were employed as the supporting electrolytes. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403 and Fresh Water NIST-SRM 1643d. Precision and accuracy, expressed as relative standard deviation and relative error, respectively, were generally lower than 6% in all cases. Once set up on the standard reference materials, the analytical procedure was transferred and applied to superficial water sampled in proximity to superhighway and in the Po river mouth area. A critical comparison with spectroscopic measurements is also discussed.