Determination of ultratrace boron concentrations in uranium oxide by isotope dilution-thermal ionization mass spectrometry using a simplified separation procedure

Boron was determined at sub-ppm levels in uranium oxide by ID-TIMS. Following nitric acid dissolution, a solvent extraction method was adapted for extraction of boron by 5% 2-ethylhexane-1,3-diol in chloroform followed by evaporation of the extractant in presence of sodium carbonate and mannitol. This procedure allowed TIMS analysis of boron by monitoring the Na₂BO ₂ ⁺ ions formed from the sodium borate salt in the ion source. Reproducibility of about 1% was obtained for boron determination in the three different uranium oxide samples containing sub-ppm amounts of boron.     

Synthesis and characterization of polyaniline: nanospheres,nanorods, and nanotubes—catalytic application for sulfoxidation reactions

The synthesis of nanostructured polyaniline (PANI) with different morphologies by simple alkali‐guided template‐free method followed by doping them with vanadium has been described. The synthesized polyaniline nanoparticles have been well characterized by various techniques. Further, the catalytic activity of the undoped and doped PANI nanostructures for selective oxidation of sulfides to sulfoxides in water has been studied. It was observed that the special morphology of nanostructures plays an important role in enhancement of catalytic activity. Vanadium‐doped PANI nanotubes and nanorods showed higher activity and selectivity than nanospheres. The catalyst has been reused for five consecutive cycles with consistent activity. Copyright © 2008 John Wiley & Sons, Ltd.