title: Trace analysis of diethylstilbestrol [DES] in animal chow by parallel high-speed liquid chromatography, electron-capture gas chromatography, and radioassays.
abstract: An analytical method is described for determining residues of the synthetic estrogen diethylstilbestrol (DES) in animal chow at levels as low as 1 ppb. A methanol extract of the chow is subjected to a 3-step cleanup procedure including a Sephadex LH-20 column, liquid-liquid partitioning at pH 14 and 10.2, and a silica gel column. Residues of DES in the cleaned-up extract are analyzed directly by high-speed liquid chromatography or derivatized to pentafluoropropionyl-DES and assayed by electron-capture gas chromatography. Tests with 14C-DES were used to develop and validate the procedure. Ancillary data concerning extraction efficiencies of various solvents, comparisons of various derivatizing reagents, rates of trans-cis isomerization in two solvents, P-values of DES in various solvent-systems and thin-layer chromatographic behavior i
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004054:Diethylstilbestrol / Q000031:analogs & derivatives / Q000032:analysis* / Q000138:chemical synthesis; D007536:Isomerism; D008722:Methods
chemical_list: D004054:Diethylstilbestrol