It is possible to volatilize about 95% (at temperatures between 200°C and 600°C) of the iodine, which has been produced by
irradiating solid UCl4 with thermal neutrons. The delay times for iodine are decreasing from 2 hrs (at 200°C) to 7 sec (at 600°C). The release of
the iodine is improved by using an inert carrier gas. When adding AgCl to the UCl4 before irradiation is carried out, the release of iodine is suppressed at temperatures lower than 400°C. The adding of KI
leads to a more rapid release of iodine at low temperatures.
Using an aniline sulfur resin for the selective enrichment of mercurials from surface waters it is possible to determine ppb
amounts of mercury by INAA within less than three days after irradiation. Interferences from other elements, especially Na,
Se, U and Au, can be avoided by following defined preconcentration and elution conditions.
Authors:B. Neidhart, K. Kringe, and P. Deutschmann
A critical investigation of the separation of free noradrenaline and adrenaline from urine samples revealed serious errors
during sample pretreatment using Al2O3 as adsorbant. An exact and rapid pH adjustment of the sample, using thymol-blue as indicator, proved to be the chief prerequisite
for precise and accurate results. Increasing temperature and pH favour the oxidative decomposition of the catecholamines during
routine analysis. This was examined, using the radiotracer method and liquid scintillation counting.