Modified method for electron capture gas-liquid chromatographic determination of diethylstilbestrol residues in urine of fattened bulls
Tirpenou, A.E.; Kilikidis, S.D.; Kamarianos, A.P.
Journal - Association of Official Analytical Chemists 66(5): 1230-1233
1983
ISSN/ISBN: 0004-5756 PMID: 6630136 Document Number: 203461
A gas-liquid chromatographic (GLC) method with electron capture (EC) detection was developed for determining diethylstilbestrol residues in the urine of fattened bulls. Diethylstilbestrol (DES) is extracted into benzene, and then into 1N sodium hydroxide. The pH of the phenolic fraction (alkaline phase) is adjusted to 10.2 and DES is extracted again into benzene. Sample extracts are cleaned up on silica gel. Trifluoroacetic anhydride (TFAA) is used as acylation reagent, and the derivatized sample is chromatographed on a 3% OV-17 column and measured with a 63Ni EC detector. The method is suitable for determining residues at levels as low as 2 ppb.