Special aspects of the uncertainty quantification in k0-NAA are discussed and applied in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM), on a model
case. The uncertainty budget is calculated highlighting the contribution and the importance of the different parameters to
be taken into account. The importance of the nuclide-specific and neutron fluence-specific approach in estimating individual
uncertainty contributions is emphasized and demonstrated by examples of Au, Cr, Rb, and Sb determinations.
Authors:V. Valenčič, M. Bučar-Miklavčič, and T. Golob
Table olives are prepared from the sound fruits of varieties of the cultivated olive tree (
L.) that are chosen for their production of olives whose volume, shape, flesh-to-stone ratio, fine flesh, taste, firmness and ease of detachment from the stone make them particularly suitable for processing. The world production in the crop year 2006/2007 is estimated at 1.8 million tons of table olives and in the last fifteen years it has constantly increased. Most of the Slovenian Istria table olive production is based on a modification of the Spanish style. Results of qualitative and quantitative sensory assessments of two olive cultivars, ‘Storta’ and ‘Istrska belica’, are presented. Sensory characteristics were determined after four and six months of fermentation. Texture differences between the two production systems were revealed. Significant decrease in hardness was determined after six months of fermentation with initial alkaline treatment. The effect of cultivar type was also evident. After four and six months, the bitterness of table olives produced by the traditional technology decreased and the olives were appropriate for consumption.
Authors:T. Bučar, B. Smodiš, P. Pelicon, J. Simčič, and R. Jaćimović
Cellulose cylinders and circular filter papers spiked with known amounts of standard element solutions were prepared for studying
some aspects of assessing measurement uncertainty of NAA and the elemental distribution measured by micro-PIXE analysis. Results
for the cylinders showed strongly non-homogeneous distribution of the elements, both in radial and vertical directions, dominantly
caused by osmosis driven transport of added liquid solution from the centre to the edges. Results for the thin cellulose filter
paper disks exhibited weaker peaking of the standard element concentrations at the edges in comparison with the thick cylinders.
Authors:R. Jaćimović, B. Smodiš, T. Bučar, and P. Stegnar
A suite of natural matrix reference materials (RMs) were used to assess the quality of analytical results obtained by k0-instrumental neutron activation analysis (k0-INAA) at the Joef Stefan Institute (IJS). Five certified reference materials (CRMs) from the Institute for Reference Materials and Measurements (IRMM), two standard reference materials (SRMs) from the National Institute of Standards and Technology (NIST), three RMs from the International Atomic Energy Agency (IAEA) and one RM from IJS were analyzed. Altogether, results for twenty-four elements in inorganic matrices and twenty-nine elements in organic matrices, obtained by k0-INAA, were compared to certified values. Results obtained show good agreement with certified or assigned values except for Fe, La, Nd, Sm and U in inorganic matrices, and Ag, Al and Cr in organic matrices.