抄録
1. Thyroxine shows in alkaline solution (pH12.30) ultraviolet absorption maximum at 227mμ. and 327mμ. The linear relationship between the concentration and absorbance was found in the limited concentration range.
2. The polarogram of thyroxine in ammoniumhydroxide and ammoniumchloride adding hcxamethonium bromide solution shows three waves having halfwave potentials of about-0.8, -1.0 and 1.2v. The height of the second wave found to be proportional to the ammount of thyroxine in the limited concentration range.
3. The ammount of thyroxine in the presence of 3, 5-diiodotyrosine was determined by means of polarographic analysis.
4. Free iodines in thyroxine solution were determined in potassium nitrate electrolyte at the half-wave potential of-0.03v.
5. It is proved that thyroxine is decomposed by ultraviolet irradiation in alkaline solution.
