L. Bolundut

Manganese(III) Porphyrin-based Potentiometric Sensors for Diclofenac Assay in Pharmaceutical Preparations

Two manganese(III) porphyrins: manganese(III) tetraphenylporphyrin chloride and manganese(III)-tetrakis(3-hydroxyphenyl)porphyrin chloride were tested as ionophores for the construction of new diclofenac–selective electrodes. The electroactive material was incorporated either in PVC or a sol–gel matrix. The effect of different plasticizers and additives (anionic and cationic) on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10−6 – 1 × 10−2 M with a slope of −59.7 mV/dec diclofenac, a detection limit of 1.5 × 10−6 M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.

Characterization of the Structural Properties of Zinc Phosphate Glass Ceramics Doped with Manganese Ions Following Thermal Treatment

ABSTRACT Glasses of the MnOxu2009·u2009(P2O5)40u2009·u2009(ZnO)60−x system were prepared by the melt-quenching technique and thermally treated for 2u2009h at 650°C. To describe the influence of thermal treatment on zinc phosphate glass matrix doped with manganese ions, X-ray diffraction and infrared spectroscopy were used. The X-ray diffraction patterns revealed that the degree of crystallinity gradually decreased with increasing MnO content in the samples up to 5u2009mol% of MnO2. The manganese ions were also shown to be captured in the vitreous phase. The infrared spectra confirmed that the glass network underwent changes following thermal treatment. The spectra of thermally treated samples contained new peaks and the infrared bands become narrower compared to those of the untreated samples.

Ozonation Influence on Aluminum Ions in an Aqueous Solution, in Different Temperature Conditions

Metal waste disposed in the environment outside the landfills is a persistent type of polutant both for water and soil. The percolation of rainwater in the mass of waste determines the release of toxic substances in soil and groundwater. Using water polluted with such contaminants for food preparation has negative effects on human health. This study presents comparative experiments conducted on standard samples (artificially contaminated) with alumnium sulphate [Al2(SO4)3·18H2O]. These samples have been ozonated at different temperatures and timeframes. The effect of ozone treatment on metal ions concentration reduction was investigated using the cyclic voltammetry. It has been observed that for a considerable decrease of metal ions concentration from the contaminated samples, a longer ozonation time is needed at low temperatures.