The confirmation of diethylstilbestrol residues in beff liver by gas chromatography-mass spectrometry.

A confirmatory test for the presence of the growth-promoting hormone, diethylstilbestrol (DES), in beef liver is described, Samples are subjected to a published electron capture gas chromatographic method that involves the formation and measurement of the bis-dichloroacetyl derivative of DES. The presence of the derivative is then confirmed by gas chromatography-mass spectrometry, using a repetitive scanning technique to maximize response. The isotope pattern of the tetrachlorinated molecular ion greatly facilitates the confirmation.