Boron filter with 500 mg/cm2 surface density has been constructed and used for epithermal neutron activation analysis of geological and biological materials.
Bare and boron-covered irradiations were performed to determine the boron activation ratios (RB) and improvement factors (IFB) for 23 nuclides. Biological and geological SRMs were also analyzed to demonstrate the practical use of this technique. Experiments
have proved that epiboron activation extends the applicability of NAA to samples with unfavorable matrices (i.e., Na, Ca,
P, Sc, etc.).
Authors:I. Sziklai-László, D. Majchrzak, I. Elmadfa, and M. Cser
The metabolic roles of vitamin E and selenium are closely related, and to a very great extent, each can compensate for the
deficiency of the other. The aim of the study was to determine and compare the Se and vitamin E (α- and γ-tocopherol) contents
of breast milk and commercially available infant formulas in Hungary. The Se content was measured by instrumental neutron
activation analysis (INAA), while the α-, and γ-tocopherol concentrations were determined by high performance liquid chromatography
(HPLC). The mean Se concentration was 17.4±2.8 μg/L in transitional and 13.8±2.3 μg/L in mature milk. It was found that, all
of the starter (ST), the follow-on (FO) and the specialized formulas (SF) had lower Se content than breast milk. Transitional
breast milk resulted in a higher Se intake (14 μg/day) than mature milk (11 μg/day). The daily Se intakes in Hungarian infants
were within the Recommended Dietary Allowance (RDA) range. The natural vitamin E contents of human milk were similar during
the early and late lactation. Mature breast milk had 3.30±1.13 mg/L α-TE concentration and this was significantly higher than
that of in ST (1.98±1.57), and FO (1.77±0.78), or in SF ready to feed preparations (1.03±0.74). The present study suggests
that the formulas for the optimal development of young infants, should contain concentrations of these antioxidants on a level
which is comparable to that of the human milk.
Authors:N. Adányi, M. Váradi, I. Sziklai-László, P. Snyder, R. D. Snyder, and M. Á. Cser
Total daily Se intake was determined by duplicate diet collection, venous blood samples were taken and urine was collected over 24 h in order to measure selenium input and output in healthy, American and Hungarian children aged 8 to 17 living in Budapest. The American children consumed not only locally processed food. Food samples were weighed, mixed, homogenised and the Se content was determined by Instrumental neutron activation analysis (INAA). The Se concentration of blood, plasma and urine samples was determined by atomic absorption spectrometry-hydride generation (AAS-HG) after wet digestion. Se intake calculated for wet weight was 62±18.5 mg/day in American children. In the Hungarian children the mean Se intake was about 35% less than in the Americans. Se concentrations in plasma were 0.84±0.16, in whole blood 1.13±0.17 mmol l-1 in the Americans, higher than those in healthy Hungarian children (0.64±0.10 and 0.83±0.12 mmol l-1, respectively) of similar age and gender. Urinary Se output calculated for creatinin was higher in the children from abroad (27.0±9.5 mg Se/day/g creatinin) compared to Hungarians (11.0±5.0 mg Se/day/g creatinin).