Abstract
Methods were examined for measuring 14C and for simultaneous measuring of 3H and 14C in biological samples. A lyophilized organ material was pulverized and about 20 mg of the powder was burnt in an oxygen flask. Scintillator containing ethanolamine was used for radioactive carbon dixoide and a scintillator containg dnioxan and ethanolamine was used for simultaneous measurement of 3H and 14C. Recovery of 14C was 96.3% and its standard deviation was 1.4%. Reproducibility of the assay was further examined with the same liver of a rat given 14C-ephedrine with satisfactory results, i.e. the standard deviation was 0.8%. Recoveries of 3H and 14C were 99.8 and 99.3% respectively in the simultaneous measurement, and their standard deviation was 1.3 and 1.5%.
