Iridium and lead as vehicle emission pollutants: their sequential voltammetric determination in vegetable, environmental bio-monitors

The present work regards the sequential voltammetric determination of Ir(III) and Pb(II) in vegetable environmental matrices. The analytical procedure was verified by the analysis of the standard reference materials: Tomato Leaves NIST-SRM 1573a and Olive Leaves BCR-CRM 062. Precision and accuracy, expressed as relative standard deviation and relative error, respectively, were generally lower than 6 % in all cases, while the limits of detection for each element were lower than 5.23 g kg-1. Once set up on the standard reference materials, the analytical procedure was transferred and applied to laurel leaves sampled in three sites differently influenced by vehicle traffic. A critical comparison with spectroscopic measurements is discussed.