It was found by DTA and TG that [Phenyl2I][Ag(CN)2] in the solid state is chemically stable on heating in argon up to 160°C. During heating to higher temperatures it decomposes, forming volatile products such as [Phenyl]I, [Phenyl]NC and (CN)2 . After heating the sample to 500°C metallic silver resulted. The volatile and intermediate solid products were analysed by IR-spectroscopy.
A systematic study was undertaken in order to find out which of the most relevant elements can be determined in water under
normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized
water samples as well as natural water of different kind were used, brought to dryness by freeze-drying and irradiated in
quartz at a neutron flux of 1014 cm−2 s−1 for 1 day. The trace element content in quartz ampoules of different origin was determined separately. The following elements
are discussed in detail including possible interferences: As, Au, Br, Ca, Cd, Co, Cr, Cu, Eu, Fe, Hg, K, La, Mo, Na, Ni, Sb,
Sc, Se, U, Zn.
This table enables a quick estimate of the primary reaction interferences which can occur in 14-MeV neutron activation analysis
for all determinable elements throughout the periodic system. Published experimental cross-sections, and cross-sections estimated
by semiempirical formulae and systematics were used to calculate the ratio of the radioactivity produced from the element
to be determined via the principal reaction and of the radioactivity produced via the primary interference reaction for three
energy intervals between 14 MeV and 15 MeV. Also listed are the used cross-section data and abundances of the appropriate
isotopes for both the element to be determined and the interfering element, as well as the half-lives of the indicator radionuclides.
Stability and distribution constants of thallium(I) ethyl, n-propyl, isopropyl, n-butyl, isobutyl and sec-butyl xanthates have been radiometrically determined using ion-exchange and extraction methods. The length of the alkyl chain influences the distribution constant, however, it has only a small effect on the stability constant.
The theory of the double dilution method is shortly described. Critical volume of the liquid specimen has been determined. Optimal specimen concentration ratios of the sample in a given diluent have been examined. The validity and precision of the method have also been investigated. The usefulness of the method has been confirmed by analyzing a typical coin of Thailand. Good agreement with atomic absorption spectrometry (AAS) is obtained.
The procedures developed and standardised for estimation of ultra trace quantities of Pu and Am in environmental samples involve matrix dependent sample preparation, preconcentration of the nuclides by coprecipitation on iron hydroxide and or bismuth phosphate, ion exchange, electrodeposition and counting by alpha spectrometry. Isotopic analysis of Th in chicken bone using oxalate precipitation, ion exchange, electrodeposition and alpha spectrometry has indicated higher build up of228Th in chicken bone from monazite areas possibly from metabolized228Ra.
The study of physico-chemical and biotic processes in the environment is essential to understanding the behavior of transuranic nuclides and to assess their environmental impact. Dialysis, ion exchange, and co-precipitation techniques have been used to study speciation. The dissolved fraction of239,240Pu in coastal waters of Bombay harbor bay and in interstitial water from bottom sediments of the bay were found to be associated with organic matter. The desorption of Pu from sediments in coastal waters is influenced by salinity and carbonate. Studies indicate that, even from anoxic sediments, remobilization and the potential for migration is not significant.