Extraction of a synthetic androgen from fish muscle and quantitation by high performance liquid chromatography.

A rapid, reproducible extraction procedure was developed to recover the synthetic androgen 17 alpha-methyltestosterone (MT) from fish muscle. A single extraction with chloroform-methanol (2:1 V/V), followed by elution from mini-columns with various methanol concentrations, yielded an extraction efficiency of greater than 70%. Resolution of MT from testosterone was complete and reliable quantitation was achieved utilizing reversed-phase high performance liquid chromatography. Endogenous testosterone was not detectable in 1-g muscle samples, but MT was detected in fish muscle 6 h after adult Tilapia aurea were fed a diet containing the steroid.