Determination of three anabolic compounds in calf urine by

Abstract

A method for the determination of three anabolic hormones (diethylstilbestrol, dienestrol and trenbolone) in calf urine is described. After enzymatic hydrolysis, the samples were cleaned up by C₁₈ solid-phase extraction. Drugs were extracted with hexane and analyzed by isocratic elution on a Discovery RP-Amide C₁₆ 5 μm column with photodiode-array detection at 240 and 347 nm. Both retention time and UV spectra were used for identification. Detection limits for the HPLC system were calculated to be 0.3 ng injected for all analytes in the standard mixture. However, for urine samples these limits increased because of the presence of unidentified matrix components. After extraction from urine, the limits of detection for the whole analytical procedure were 5 and 10 ng injected for trenbolone and stilbenes, respectively. The average recoveries of the hormones from spiked samples were in the range 53.1–56.7% with RSD between 11.3 and 14.5% for the whole procedure in the concentration range 25–2.5 ng ml⁻¹.