title: Trace analysis of estradiol in animal chow by electron-capture gas chromatography.
abstract: A gas chromatographic method is described for trace analysis of the natural steroidal hormone estradiol in animal chow at levels as low as 3 ppb. Salient elements of the method include extraction of the estradiol with methanol, an initial clean-up on a column of Sepadex LH-20, liquid-liquid partitioning at pH 14 and 10.2, additional cleanup on a slilica gel column, conversion of the estradiol to the pentafluoropropionly (PFP) derivative and analysis by electron-capture gas chromatography on a column of OV-25. Samples containing less than ppb of estradiol are subjected to further clean-up on silica gel after derivatization and prior to analysis.
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D002849:Chromatography, Gas; D004958:Estradiol / Q000032:analysis*
chemical_list: D004958:Estradiol