Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: Gabriele Wallner x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

All commercially available mineral waters of Austrian origin were investigated with regard to the natural radionuclides 228Ra, 226Ra, 210Pb, 210Po, 238U and 234U. From 1 to 1.5 L of sample the nuclides were extracted and measured sequentially: the radium isotopes as well as 210Pb were measured by liquid scintillation counting after separation on a membrane loaded with element-selective particles (Empore Radium Disks), 210Po was determined by α-particle spectroscopy after spontaneous deposition onto a copper planchette and uranium was determined also by α-particle spectroscopy after anion separation and microprecipitation with NdF3. The calculated committed effective doses for adults, teens and babies were compared to the total indicative dose of 0.1 mSv/year given in the EC Drinking Water Directive. The dominant portion of the committed effective dose was due to 228Ra. Highly mineralised waters showed also higher 226Ra and 228Ra levels.

Restricted access

Abstract  

The specific activities of the naturally occurring radionuclides 238U, 232Th, and 40K were measured in rock samples from the Hetaunda area, central Nepal, using gamma spectrometry. The specific activities were found to be in the range of 17–95 Bq kg−1 for 238U, 24–260 Bq kg−1 for 232Th and 32–541 Bq kg−1 for 40K. From these data absorbed dose rates in air and annual effective doses were calculated and compared with respective data from the UNSCEAR compilation. The results from our study open the door to the safe applicability of most of the investigated materials as a cheep building material.

Restricted access

Abstract  

This work describes a procedure for the isolation of 90Sr and 210Pb from deer bones by anion exchange methods and their sequential measurement by LSC. To prevent collection of Pb on the Sr·Spec® resin we first separated Pb on a Dowex anion exchange column. Sr, which is not held back on the Dowex column, was then purified using Sr·Spec® resin: first Ca and the Ra isotopes were eluted with 3 M HNO3 and then Sr was eluted with distilled water. With this 2-steps procedure pure 210Pb and 90Sr spectra can be achieved. The chemical yield of both steps was determined by ICP-MS. Our 90Sr results show satisfying agreement with data obtained by a shorter Sr·Spec® method and also by the “classical” 90Sr determination using fuming nitric acid. Also 210Pb results were checked by re-measuring bone samples with already known 210Pb activities. Further our method was verified on the reference sample IAEA-A-12.

Restricted access