Beyond low-level activity: on a "non-radioactive" gas mantle.

Gas mantles for camping gas lanterns sometimes contain thorium compounds. During the last years, the use of thorium-free gas mantles has become more and more popular due to the avoidance of a radioactive heavy metal. We investigated a gas mantle type that is declared to be "non-radioactive" and that can be bought in Austria at the moment.

Trace elements in rock salt and their bioavailability estimated from solubility in acid.

In this study, 18 partly commercially available samples of rock salt from Austria, Germany, Pakistan, Poland, Switzerland, and Ukraine were investigated with respect to their content of trace elements using instrumental neutron activation analysis. Elements detected were Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, La, Mn, Na, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, and Zn, some of them only in individual cases. An estimation of the bioavailability of these trace elements was performed by dissolving an equivalent of the sodium chloride samples in diluted hydrochloric acid (simulating stomach acid), filtering off the insoluble components, and analyzing the evaporated filtrate.

[Synthesis of radioactively labelled tetroxoprim (author's transl)].

Synthesis of radioactively labelled 2,4-diamino-5-[3,5,-dimethoxy-4-(2-methoxyethoxy)]-benzylpyrimidine (tetroxoprim) as needed for pharmacokinetic studies, is described. Commercial [14C]-guanidine hydrochloride was used as radioactive label.

[Determination of the integral dose with a body phantom using Fricke's system and an evaluation by means of potentiometric analysis (author's transl)].

The concept of the integral dose, being correlated with the system of immunity, has got an increased bearing on radiation therapy. Experimental determination of integral doses in a tissue-equivalent body-phantom by means of ferrosulfate dosimetry and potentiometric analysis is described. The results are discussed and compared considering X and Y irradiation techniques and different units for irradiation.