Identification and determination of thyroxine using gas-liquid chromatography.

Abstract A quantitative gas-liquid chromatographic assay method has been developed for the thyroid hormone thyroxine as a bulk substance. The trimethylsilylated derivative is chromatographed with an internal standard on an OV-101 column by means of flame ionization detection. Analogs of thyroxine can be identified and quantitated as possible contaminants. Electron-capture detection of thyroxine at the picogram level has been demonstrated. Complete silylation has been confirmed.