Comparison of high-performance liquid chromatographic detection methods for thyronine and tyrosine residues in toxicological studies of the thyroid.

Four high-performance liquid chromatographic methods for the detection of thyroid hormones (iodinated thyronines) and precursors (iodinated tyrosines) have been developed and evaluated. Two methods consist of direct determination of the parent compounds with detection at ultraviolet wavelength (230 nm) and with electrochemical detection. The two other methods consist of a pre-column derivatization (with fluorenylmethyl chloroformate and dabsyl chloride) prior to high-performance liquid chromatographic analysis. The various methods were evaluated based on their practical use and sensitivity. The method with direct ultraviolet detection turned out to be the most practical method. With this method analyses of thyroid homogenates have been performed from rats from a toxicological experiment.