Comparison of photoacoustic spectroscopy, conventional absorption spectroscopy, and potentiometry as probes of lanthanide speciation

Abstract

erators are fed with air ( 31)) that its effect on ozone measurements can be neglected.For these reasons, the sensor here described appears to be well suited for ozone monitoring in general applications of this reagent, such as chemical syntheses or disinfection and preservation procedures. ACKNOWLEDGMENTWe thank S. Sitran of CNR-IPELP (Padova) for skillful experimental assistance.

High-temperature spectroscopy for nuclear waste applications

“…This behaviour has been 7,14 previously observed in other studies with Pr at room temperature. For the Am(III)-OH series, increasing hydrolysis was manifest as decreasing absorbance in the 503-nm peak.…”

Coordination chemistry of two heavy metals: I, Ligand preferences in lead(II) complexation, toward the development of therapeutic agents for lead poisoning: II, Plutonium solubility and speciation relevant to the environment

“…Environmentally, waters include numerous ligands (in addition to hydroxide) present at significant concentrations ; among them are carbonate, bicarbonate, phosphate, and the organic acids, fulvates and humates. 2 Plutonium hydrolysis and carbonate equilibria alone consistute a complex aqueous system which is being researched extensively.9· 14 · 19 - 22 The speciation (oxidation state, formula, structure) of plutonium in a relatively carbonate-rich solution, which is a model for a specific groundwater, will be discussed in the second section of Part ll.…”

“…22 Titration curves for the ligand alone and in the presence oflead(II) are shown in Figure 13. A species distribution curve for theNmethylthioformohydroxamate/lead(II) system is shown in Figure 14 Lead ( Apparently there are species interconversions with small, but significant equilibrium constants, which we were unable to extract from the available data.…”

Development of High-Temperature Uv-Vis-Nir Spectroscopy for the Measurement of Free Energies of Complexation at Elevated Temperatures

“…From small shifts in wavelength and optical absorption as a function of complexation, metalligand stability constants (free energies of reaction) can be calculated under suitable experimental conditions. [3] We report stability-constant measurements for the Pr-digly complexes at temperatures of 23, 50, 65, 80, and 95"C. The Pr-digly system does not have any direct relevance in modeling the environment of a nuclear repository, but some comparison of the present variable-temperature results with conventional techniques [4,5] After a Pr-digly solution was introduced into a quartz optical cell, the unit was closed to the environment. Temperature and pressure settings were adjusted, and the solution was allowed to equilibrate for one hour.…”