Inorganic arsenic, MMA, DMA and arsenobetaine (As) were separated by the use of cation and anion exchange chromatography combined with neutron activation. Two complementary approaches were used: firstly, authentic, non-irradiated arsenic compounds, either singly or in mixtures, were separated and NAA of the fractions used as an element specific detection method. Secondly, the arsenic compounds were neutron irradiated under different conditions and for different times and the products separated and quantified. The76As labeled species (mono-, di and trimethylated) were then additionally used to calibrate and improve the column separations. Using the separations developed, arsenic species in samples of shrimps and the standard reference material DORM-1 were determined, after an extraction step, using ion exchange chromatography followed by INAA of the fractions collected.
Authors:M. Dermelj, Z. Šlejkovec, M. Šorak-Pokrajac, and M. Rossbach
The concentration levels of total iodine obtained by RNAA in different sorts of tobacco, including the reference sample Kentucky Tobacco 2RI, two new candidate reference materials, Oriental Tobacco Leaves /CTA-OTL-1/ and Virginia Tobacco Leaves /CTA-VTL-2/ prepared in the Institute of Nuclear Chemistry and Technology, Warsaw, and some biological SRMs, are presented and discussed.
Authors:M. Dermelj, Z. Šlejkovec, P. Stegnar, V. Čoh, K. Čujes, and M. Novič
On the basis of tracer experiments, a simple and rapid radiochemical separation method for simultaneous determination of I–, Br– and Cl– in one aliquot of a water sample (only 2–4 ml) has been developed. The method is based on short irradiation of the water sample and separation of the halogens using sequential ion exchange columns filled with Dowex 1×8, 100–200 mesh anionic resin prepared in I–/I2, Br–/Br2 and Cl– form. After washing the columns with an appropriate volume of 2% NaCl solution, the resins were transferred to vials and activities of the isolated radionuclides128I,82Br and38Cl measured together with standards in a well type or on a coaxial Ge detector connected to a Canberra 90 multichannel analyzer. Besides high chemical yields, from the -spectra of the isolated radionuclides, it is evident that high decontamination fac-