Extraction of steroid diconjugates using Amberlite XAD-2 resin

Sensitive multi-residue method for detection of anabolics in urine and in tisssues of slaughtered animals

A routine procedure is described for the dependable detection of various anabolic residues in tissues or urine contaminated at levels as low as 0.5-10 ppb (10 parts per 10(9)). A suitable extraction and clean-up procedure was developed, permitting adequate recovery (60-80%) of various anabolics from tissue samples (50 g) or urine (50 ml). Following two-dimensional thin-layer chromatography, the presence of the anabolic residues are detected by sulphuric acid-induced fluorescence. The detection limit of most anabolics is of the order of 1-10 ng.

Steady-state urinary excretion method for determining bioequivalence of conjugated estrogen products

The steady-state excretion of conjugated estrogens in the urine of postmenopausal women dosed with conjugated estrogens tablets was studied using a modification of a previously published method. The procedure was used to quantitate the estrogens both before and during conjugated estrogens replacement therapy. The method, which is relatively specific, involves enzyme hydrolysis of urine samples a number of classical extraction and purification steps, and analysis of the silylated estrogens on a 2.7-m, 1.7% diethylene glycol succinate column using flame-ionization detection. The results indicate that steady-state urinary estrogen excretion levels were obtained within 17 days of dosing. Furthermore, the urinary estrogen excretion profile was significantly different from the composition of the estrogens in the dosage form.