Photolytic degradation of chlorpyrifos induced by an artificial light source

Chlorpyrifos dissolved in methanol was illuminated by the Xe polychromatic light source, which is commonly used as artificial solar radiation source. Photolytic degradation of the parent compound was followed by UV/Vis spectrophotometry and GC/MS technique. GC/MS measurementsindicated that very few pyridine containing intermediates are formed during the degradation process. After 2 hours of illumination almost no chlorpyrifos could be observed and significant mineralization (formation of carbon dioxide, water, alkyl phosphates and sulfates) was achieved.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Voltammetric determination of lutetium

Half wave potential of lutetium was determined by anodic stripping voltammetry using various electrolyte solutions at the mercury electrode. The influence of electrolyte pH on the value of peak current was also observed. The results show that the choice of the supporting electrolyte and the electrolyte pH strongly influence the voltammetric behaviour of lutetium.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Determination of copper and nickel by ion chromatography and voltammetry

Simultaneous determination of copper(II) and nickel(II) by ion chromatography (IC) has been optimized and the detection limits of the new method were compared to stripping voltammetry. The best eluent enabling fast end efficient separation of Cu(II) and Ni(II) is a mixture of 8 mM citric and 0.3 mM oxalic acid using a Metrosep C2 (Metrohm) IC column. The detection limits are significantly lower using stripping voltammetry, while IC is considerably faster.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Targeted alpha therapy in vivo: direct evidence for single cancer cell kill using 149Tb-rituximab

This study demonstrates high-efficiency sterilisation of single cancer cells in a SCID mouse model of leukaemia using rituximab, a monoclonal antibody that targets CD20, labelled with terbium-149, an alpha-emitting radionuclide. Radio-immunotherapy with 5.5MBq labelled antibody conjugate (1.11GBq/mg) 2 days after an intravenous graft of 5·106 Daudi cells resulted in tumour-free survival for >120 days in 89% of treated animals. In contrast, all control mice (no treatment or treated with 5 or 300µg unlabelled rituximab) developed lymphoma disease. At the end of the study period, 28.4%±4% of the long-lived daughter activity remained in the body, of which 91.1% was located in bone tissue and 6.3% in the liver. A relatively high daughter radioactivity concentration was found in the spleen (12%±2%/g), suggesting that the killed cancer cells are mainly eliminated through the spleen. This promising preliminary in vivo study suggests that targeted alpha therapy with 149Tb is worthy of consideration as a new-generation radio-immunotherapeutic approac

Colloidal-chemistry based synthesis of quantized CuInS2/Se2 nanoparticles

Ternary chalcogenide nanoparticles, CuInS2 and CuInSe2, were synthesized in high- temperature boiling organic non-polar solvent. The X-ray diffraction analysis revealed that both materials have tetragonal (chalcopyrite) crystal structure. Morphology of the obtained materials was revealed by using transmission electron microscopy. Agglomerated spherical CuInS2 nanoparticles with broad size distribution in the range from 2 to 20 nm were obtained. In the case of CuInSe2, isolated particles with spherical or prismatic shape in the size range from 10 to 25 nm were obtained, as well as agglomerates consisting of much smaller particles with diameter of about 2-5 nm. The particles with the smallest diameters of both materials exhibit quantum size effect

Indirect determination of lutetium by differential pulse anodic stripping voltammetry at a hanging mercury drop electrode

Lutetium has been determined by differential pulse anodic stripping voltammetry in an acidic solution containing Zn-EDTA. Lutetium (III) ions liberated zinc (II), which was preconcentrated on a hanging mercury drop electrode and stripped anodically, resulting in peak current linearly dependent on lutetium (III) concentration. Less than 0.4 ng mL(-1) lutetium could be detected after a 2 min deposition

Synthesis and Characterization of Rutile TiO2Nanopowders Doped with Iron Ions

Titanium dioxide nanopowders doped with different amounts of Fe ions were prepared by coprecipitation method. Obtained materials were characterized by structural (XRD), morphological (TEM and SEM), optical (UV/vis reflection and photoluminescence, and Raman), and analytical techniques (XPS and ICP-OES). XRD analysis revealed rutile crystalline phase for doped and undoped titanium dioxide obtained in the same manner. Diameter of the particles was 5–7 nm. The presence of iron ions was confirmed by XPS and ICP-OES. Doping process moved absorption threshold of TiO2into visible spectrum range. Photocatalytic activity was also checked. Doped nanopowders showed normal and up-converted photoluminescence

Extraction of uranyl nitrate, sulphate and chloride with tri-n-octyl amine (TOA) from aqueous solutions

Extraction of uranyl nitrate, chloride and sulphate with tri-n-octyl amine (TOA) in benzene as a function of the TOA concentration has been studied. The concentration based extraction equilibrium constants were calculated from the distribution data of the uranyl salts, fitting the parameters of a chemical model to the experimentally obtained extraction isotherms. The calculated equilibrium constants are 46.5, 89.4 and 4.2x 10(4) for uranyl nitrate, chloride and sulphate, respectively. These values are in good agreement with the previously reported extraction equilibrium constants calculated by the inflection point method

Self-association and association of tri-n-butyl phosphate (TBP) in different diluents

The interact ion of tri-n-butyl phosphate (TBP) with diluents and its self-association have been investigated. The corresponding equilibrium constants were determined and used to calculate the concentration of TBP monomer. The calculated TBP monomer concentrations correspond to the TBP activities published in the literature

Extraction of thallium with butyl acetate

Experimentally obtained extraction isotherms of the system thallium-sulfuric acid-sodium chloride-butyl acetate are presented. The influence of the sulfuric acid and chloride anion concentrations on the extraction equilibria of thallium was investigated. An increase in the acidity of the aqueous phase results in steeper extraction isotherms, and the amount of thallium extracted generally increases. The influence of chloride anions on the equilibrium is more complex. It was found that the extraction equilibria is not influenced by the chloride ion concentration, provided that the Cl/Tl ratio in the aqueous phase is greater than or equal to 4. If this ratio is less than 4, the concentration of chloride anions significantly influences the extraction isotherms. The results obtained are discussed in terms of the composition of the complex in the organic phase. An apparent reaction constant equation is proposed for the prediction of the extraction equilibria