Successful in vivo chelation treatment of iron(iii) overload pathologies requires that a significant fraction of the administered drug actually chelates the toxic metal. Increased mobilization of the iron(iii) in experiments on animals or humans, most often evaluated from urinary output, is usually used as an assessment tool for chelation therapy. Alternatively, the efficiency of a drug is estimated by calculating the complexing ability of a chelating agent towards Fe(iii). The latter is calculated by the pFe value, defined as the negative logarithm of the concentration of the free metal ion in a solution containing 10 μM total ligand and 1 μM total metal at a physiological pH of 7.4. In theory, pFe has to be calculated taking into account all the complexation equilibria involving the metal and the possible ligands. Nevertheless, complexation reactions in complex systems such as serum and urine may hardly be accurately modelled by computer software. The experimental determination of the bioavailable fraction of iron(iii) in biological fluids would therefore be of the utmost relevance in the clinical practice. The efficiency of the therapy could be more easily estimated as well as the course of overload pathologies. In this context, the aim of the present work was the development of a sensor to assess the free iron directly in biological fluids (urine) of patients under treatment with chelating agents. In the proposed device (DFO-MS), the strong iron chelator deferoxamine (DFO) is immobilized on the MCM-41 mesoporous silica. The characterization of the iron(iii) sorption on DFO-MS was undertaken, firstly in 0.1 M KNO3, then directly in urine samples, in order to identify the sorption mechanism. The stoichiometry of the reaction in the solid phase was found to be: with an exchange constant (average value) of log βex = 40(1). The application of DFO-MS to assess pFe in SPU (Simulating Pathology Urine) samples was also considered. The results obtained were very promising for a future validation and subsequent application of the sensor in samples of patients undergoing chelation therapy.

The development of a sensor based on the functionalization of common filter paper with deferoxamine (DFO) is proposed with the prospect to produce a solid phase for iron(III) and vanadium(V) sensing. The main features of this sensor are the simplicity of operation, good sensitivity and feasible applicability to real samples without the need of pre-treatment procedures. DFO was selected not only for it is easily anchored to the solid support, but also because it forms colored complexes with iron(III) and vanadium(V); hence, the developing of a simple colorimetric sensor can be considered. In particular, an innovative and economic way to perform colorimetric measurements using a desktop scanner is described. A complete characterization of the functionalized material is also reported.

A simple and rapid solid-phase spectrophotometric procedure to determine free Fe(III) in\ud environmental and biological samples is proposed. In particular, a deferoxamine (DFO) self\ud assembled monolayer on mesoporous silica (DFO SAMMS) is developed and here applied as\ud sensor for iron(III). The solid product became brownish when put in contact with iron(III)\ud solutions; so an immediate application as colorimetric sensor is considered. In order to\ud optimise the DFO SAMMS synthesis and to obtain the best product for iron(III) sensing, a\ud factorial experimental design is performed selecting the maximum absorption at 425 nm as\ud response. The robustness of the spectrophotometric method is also proved

New solid-phases for the binding, separation and extraction of perrhenate and pertechnetate (ReO(4)(-) and TcO(4)(-)) from water solutions have been developed from a selective molecular receptor. Host compounds being capable of encapsulating these oxoanions are of great interest. The azacryptand, containing two tripodal tetra-amine subunits covalently linked by p-xylyl spacers, is known to display high affinity for ReO(4)(-) and TcO(4)(-) in water. The syntheses of new solid phases, obtained by fixing the receptor on mesoporous silica MCM-41 and Amberlite CG50 supports, are here described. FT-IR, micro-Raman, elemental analysis (CHN), sorption isotherms, (29)Si MAS NMR, and SEM/EDS were employed for solids characterisation. Promising performances were found for silica derivatives, for which the amount of the receptor fixed on silica ranged from 0.2 to 0.3 mmol g(-1). The perrhenate sorption mechanism was investigated with the aim to select the conditions for application in batch and fixed bed column systems.

Research highlights • A colorimetric sensory polymer for the detection of Fe(III) was synthesized. • This polymer was prepared from a monomer derived from Kojic acid, which is a natural product. • The film-shaped polymer was cut to obtain manageable solid sensory kits. • Fe(III) was efficiently extracted, detected, discriminated and quantified from water. • UV/vis and computer vision-based techniques were used for Fe(III) analysis.