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A new method for the determination of Pd by ion chromatography and spectrophotometric detection has been developed. The technique is based on the separation of palladium as PdCl4(2-) by anion exchange and on the detection, at a wavelength of 407 nm, of metal as PdI4(2-) after a post-column reaction with KI. The column used was an IonPac AS4 with HCl and HClO4 eluents. The eluent concentration and composition of post-column reagent were optimised in order to obtain the best separation and sensitivity for Pd. In order to reduce the detection limit, an on-line preconcentration step, has been optimised. The method, as developed, was suitable for palladium determination within a 300 ng/l D.L. value. The method applied to a BCR reference material (CRM 277, estuarine sediment) gave satisfactory results in agreement with the certified value within a D.L. value of 1.3 microg/l for the real sample.

A new method for palladium and platinum direct determination in environmental samples is proposed by coupling ion chromatography with quadrupole inductively coupled plasma MS. In order to optimise Pd and Pt separation and to minimise interference from matrix in real samples, several anionic and cationic stationary phases have been compared at different mobile phase compositions. In particular, the effect of acidity and of the addition of oxalic acid to the eluent on separation and detection performance has been studied, and the anion-exchange column AG11 turned out to be more suitable. After chromatographic and mass spectrometer parameter optimisation, several potential interferences and the main quality parameters of the method, according to the Eurachem-CITAC recommendations, were evaluated: the detection limit for Pt was 5 ng l(-1) while the value for Pd was 230 ng l(-1). The method was successfully employed in the determination of platinum group elements in urban road dust and atmospheric particulates and the complete absence of matrix spectral interferences was demonstrated.

Mesoporous silica-based materials have been synthesized and studied for applications in the environmental field. Haloacetic acids have been chosen as test compounds since they are byproducts of disinfection processes of water for human consumption. For this purpose mesoporous materials have been synthesized in acid, basic or neutral conditions. The effect of composition and synthesis conditions of mesoporous materials on their retention properties have been studied. The retention mechanism has also been elucidated in term of electrostatic interactions and as a function of the residual surfactant content in the materials.