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- Author or Editor: S. Kayasth x
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Abstract
A simple separation scheme for the analysis of As, Mn, Mo, Cu and Zn using neutron activation is described. It has been checked using three standard reference materials, A-11 milk powder (IAEA) and bovine liver and orchard leaves (USNBS) and found to give acceptable results. This scheme was applied for determination of these trace elements in mature human milk samples. The concentrations of As, Mn, Mo, Cu in samples obtained from two socio-economic groups—low and middle incomes—were not significantly different. However, Zn levels in samples obtained from the poor income group were significantly lower than in those obtained from the other group.
Summary
A simple pre-irradiation separation approach has been worked out for the determination of traces of tellurium in high purity selenium followed by neutron activation analysis (NAA) for the end determination of the analyte/s. The difference in volatilities of these elements has been utilized for the separation of the analyte from the matrix. The complete volatility of selenium at ~600 °C was established using neutron activation analysis and selenium radiotracer. Standard addition was used to validate the results. The proposed method of separation of selenium prior to irradiation could make the determination of tellurium possible and also improved the detection limit by several folds.
Abstract
The daily intakes of trace elements by infants showing optimal pattern of growth are used as the basis to estimate the requirements of Fe, Co and Se during infancy. Since milk is the only food and source of nutrition in the first few months of life, the requirements of these elements are calculated from their average concentrations in human milk and the volume of milk required to supply sufficient amount of energy for maintenance and healthy growth of infants. The concentrations of the three elements in human milk were determined, using the technique of neutron activation followed by radiochemical separation.
Abstract
A simple and efficient method has been developed to preconcentrate natural protactinium from large quantity of monazite (5–10 g) and thorium concentrates (5–100 g), obtained from thorium plant stream on Dowex 1X8 in acid medium. Gamma-spectrometry, a powerful determination technique, has been used for quantitative determination of protactinium and uranium. Various parameters like sample preparation, optimization of the resin and sample size for 231Pa recovery, 231Pa/235U ratio have been studied in detail and are discussed.
Abstract
Monazite (chief source of thorium) which is available in plenty in the beach sands of Kerala, India, contains uranium in the range of 0.25% to 0.35%. An attempt has been made to estimate 231Pa in monazite and the corresponding process stream samples of the thorium production cycle. This paper reports the 231Pa activity in these samples, after coprecipitation of 231Pa on MnO2 carrier and estimation by 
-ray spectrometry. The estimation shows about 1000 Bq/kg of 231Pa in monazite. This is the first reported estimate of 231Pa in monazite.
Summary
A simple ion-exchange separation procedure was developed for selective removal of antimony from synthetic cloth to facilitate determination of several trace elements frequently used to identify gunshot residues by neutron activation analysis. Radiotracers of Sb, Ba, Cu, Co, As, Zn, Hg and Ag were employed to optimize the developed procedure. The method involves the quantitative retention of the above elements, except of Sb, from 0.2M ammonium carbonate solution using Chelex 100 resin and subsequent quantitative elution of the elements of interest with 2M nitric acid for gamma-ray spectrometry. The procedure was tested by simulated gunshot residues.
