A substoichiometric radiochemical method for the determination of mercury has been developed using 1- (2 pyridylazo) -2-naphthol (PAN) as a chelating agent. The chelate was extracted at pH 9.5 (Na2CO3NaHCO3buffer) into chloroform. 15-65 μg of mercury was determined with an accuracy ±0.9%. Effects of many diverse metal ions have been studied and procedures were developed for the suppression of interference due to these ions.
Though the mechanism of201Tl accumulation in thyroid tumours is not known yet, there are some hypotheses. In order to study the mechanism, potassium contents and Na, K-ATPase, of various organs of rats and human thyroid glands were analized. The conclusion through these experiments is as follows, (1) as the potassium contents and Na, K-ATPase activity of thyroid glands are not obviously higher than those of other organs, the201Tl accumulation in thyroid is thought to be not owing to the similarity to the potassium ion, (2) pointing out high activity of Na, K-ATPase in heart and kidney, the accumulation mechanism of201Tl in these organs has high relation to this activity, (3) though there is a tendency to have higher potassium contents among thyroid tumours, the difference in potassium contents between their histopathology is small; so that the tumour specificity is not explained from the potassium contents, and (4) as for Na, K-ATPase activity of thyroid tumours, papillary adenocarcinoma and follicular adenoma, which take more in201Tl, have tendency to show higher activity; adenomatous goitre, which take less in201Tl, has tendency to show lower activity. We suggested that the factor relating to the accumulation mechanism of201Tl may be multiple, and Na, K-ATPase plays an important role in201Tl specific uptake in thyroid tumours.