Authors:Concetta De Stefano, Antonio Gianguzza, Alberto Pettignano, Daniela Piazzese, and Silvio Sammartano
Stability data on the formation of dioxouranium(VI) species with polyacrylic (PAA) and fulvic acids (FA) are reported with
the aim to define quantitatively the sequestering capacity of these high molecular weight synthetic and naturally occurring
ligands toward uranium(VI), in aqueous solution. Investigations were carried out at t = 25 °C in NaCl medium at different ionic strengths and in absence of supporting electrolyte for uranyl–fulvate (
–polyacrylate. By using the stability data obtained for all the complex species formed, the uranium(VI) sequestration by PAA
and FA was expressed by the pL50 parameter [i.e. the −log(total ligand concentration) necessary to bind 50% of uranyl ion] at different pH values. A comparison
between pL50 values of FA and PAA and some low molecular weight carboxylic ligands toward uranyl ion is also given.
Authors:Paola Cardiano, S. Sergi, Concetta De Stefano, S. Ioppolo, and P. Piraino
The ancient mortars of the monastery of San Filippo di Fragalà in Frazzanò, the first Basilian-Norman center in Sicily, have
been studied and classified by means of ICP, HPLC, TG-DTA, XRD and thin sections analysis. A new very simple method to evaluate
the hydraulic properties of the mortars, based on the combination of analytical and thermogravimetric data, is also reported.
The HPLC investigations indicate that the monastery is only partially involved in decay phenomena due to the action of soluble