Authors:H. Polkowska-Motrenko, R. Dybczyński, B. Danko, and D. Becker
A very accurate and sensitive method for the simultaneous determination of trace amounts of Co and Ni in biological materials has been elaborated. The method is based on radiochemical neutron activation. Irradiation of samples in Cd-shielded channel of a nuclear reactor assures balanced activity ratio of58Co and60Co isotopes and favourable detection limits for both nickel and cobalt. Column chromatography (ion exchange and extraction) has been used for the quantitative and selective isolation of the determined radionuclides. High accuracy of the method has been demonstrated by the analysis of several certified reference materials.
Authors:S⦊. Sterliński, H. Maleszewska, Z. Szopa, and R. Dybczyński
Trace amounts of Ir, Au, Ag, Pt, Zn, Mn, and Cu were determined in high purity palladium by destructive and instrumental neutron
activation analysis (NAA). The latter version of NAA was employed for the determination of Ir, Au and Ag. Special attention
was paid to a new non-destructive method for the determination of silver traces in palladium. The results obtained by both
versions of NAA are critically discussed and compared.
Authors:R. Dybczyński, B. Danko, K. Kulisa, E. Maleszewska, H. Polkowska- Motrenko, Z. Samczyński, and Z. Szopa
Preparation and characterization of two new reference materials of biological origin, namely: Tea Leaves (INCT-TL-1) and Mixed
Polish Herbs (INCT-MPH-2) is described. The raw materials were ground in an agate ball mill, sieved through a nylon sieve,
collecting fraction of particle size: Æ£67 ·m, and carefully homogenized. Preliminary homogeneity testing by XRF method and
final checking of homogeneity by NAA after distribution of the materials into containers revealed that they are sufficiently
homogeneous at least for sample size ≥100 mg. Both materials were prepared in amounts exceeding 40 kg and certified on the
basis of a worldwide interlaboratory comparison, in which 109 laboratories from 19 countries participated. The method of data
evaluation leading to assignment of certified values was essentially the same as that used previously in this Laboratory,
but supplemented by additional data from the analysis of a CRM which was sent to the participants and analyzed by them along
with the candidate reference materials. In addition the results for a few elements by very accurate developed methods in this
Laboratory were obtained and used to support the certification process. Analytical uncertainties and stability uncertainties
were quantified to arrive at combined uncertainties of the certified values. So far 18 elements in INCT-TL-1 and 21 in INCT-MPH-2
could be certified.