Semi-automated determination of hormonal iodine without incineration

A sensitive semi automated technique for the determination of hormonal iodine is described. The thyroid hormones are isolated by means of a cation exchange resin (Dowex 50 Wx2). The iodine atoms are liberated from the organic molecules with bromine, without prior incineration or destruction (moidified Pileggi's method). Then, mineral iodine is measured colorimetrically with a Technicon autoanalyzer. This technique seems particularly adapted to a programme of standardisation because of its sensitivity and reproductibility. It is well adapted to the determination of circulating hormonal iodine of the ruminants, in which the concentration is lower than in man.