The99Tc-content in99mTc-pertechnetate separated from99Mo by distillation or extraction has been studied with a plastic scintillation detector. The identification of the measured
activity was achieved by beta-spectrometry, chemical separation and half-life studies. The frequency distribution of the99Tc/99mTc-ratios in the different samples was observed to be log-normal. The most likely activity ratio was 0.4·10−6, the maximum value being 5·10−6. The specific activity of “instant” pertechnetate is approximately a factor of 60 lower than that normally recorded in pertechnetate
derived from daily eluted column generators. The low specific activity of “instant” pertechnetate is primarily explained by
the long time between separation and usage and secondly by the low yield of Tc in the distillation and extraction processes.
In several of the “instant” pertechnetate solutions the carrier concentration exceeded the reductive capacity of the stannous
ions in “kits” with small amounts of Sn(II) in usable form.
A set up forin vivo determination of nitrogen has been built. Phantoms containing different amounts of nitrogen have been measured as well as a volunteer in a pilot study. A total body protein content of 18.8 kg was calculated, to be compared with 17.0 kg estimated from potassium measurements.