A method for charged-particle activation analysis and its application to fluorine determination by the19F(p, αγ)16O reaction

A simple method for calculating the sensitivity for detecting a nuclide distributed uniformly in any given matrix through charged particle activation is described. This method takes into account the actual values of the reaction cross section at different energies as the beam traverses through a thick target and the corresponding stopping power values. The detection sensitivity for fluorine in a number of matrices through the¹⁹F(p, αγ)¹⁶O reaction have been calculated as a function of the energy from threshold to 4.16 MeV using this method and the sensitivity curves plotted. The sensitivity values (dps/ppm/μA) for a thick or thin target and even for a layer of known thickness at a particular depth within a sample can be directly read from these curves for known bombarding conditions. The comparator methods for charged particle activation analysis of RICCI¹ and of CHAUDHRI,² especially when the matrices of the sample and standard are different, have been compared in the case of F determination through the¹⁹F(p, αγ)¹⁶O reaction. It has been found that the errors are reduced by almost a factor of two when the latter method is used compared to the former one. The fluorine concentration in animal bones and teeth, apatite crystal, and rocks have been determined through the¹⁹F(p, αγ)¹⁶O reaction using the Melbourne University Pelletron.     

A note on the distillation of permanganic acid from sulphuric acid solutions

1. If solutions which contain XXX periodic acid and sulphuric acid are boiled, permanganic acid is found in the XXX concentration of permanganate in the steam is negligibly small until the sulphuric acid concentration of the solution exceeds about 6 M. It is at a maximum when the sulphuric acid is to M and then rapidly decreases as the sulphuric acid concentration further increases. 2.The'distillation of permanganic acid from nitric acid solutions is inappreciable even from the concentrated acid. 3. A brief account is given of the analytical application of the distillation from IoM sulphuric acid.     

The interaction of hydrogen and carbon monoxide on Cu-Ni (110) single-crystal surfaces

The co-adsorption of H₂ and CO on a Cu-Ni (110) surface was studied by thermal desorption spectroscopy (TDS) and ultraviolet photoemission spectroscopy (UPS). Strong interactions between adsorbed CO and hydrogen observed in the CO desorption spectrum and CO valence emissions were attributed to a blockage of certain CO adsorption sites by hydrogen.     

Mo(Tm(Me))(O)2Cl]: an alternative functional model of sulfite oxidase

The hydrotris(methimazolyl)borate anion (TmMe) has been used to synthesize an alternative functional model ([Mo(TmMe)(O)2Cl]) of the metalloenzyme sulfite oxidase. It has been shown that the complex undergoes oxygen atom transfer chemistry and that it performs the primary function of the enzyme, sulfite oxidation. A method using ion chromatography has been developed to definitively prove that sulfite is oxidized to sulfate. Employment of a soft tripodal ligand has allowed us to tune the redox potentials of our complex so that they are significantly closer to those reported for sulfite oxidase.