Detection of anabolica in meat (administration sites) by three-dimensional HPLC/HPTLC

Simultaneous determination, in calf urine, of twelve anabolic agents as heptafluorobutyryl derivatives by capillary gas chromatography-mass spectrometry

A method to determine twelve anabolic hormones (diethylstilbestrol, hexestrol, dienestrol, 17 beta-estradiol, 19-nortestosterone, testosterone, 1-dehydrotestosterone, 17 alpha-methyltestosterone, progesterone, estrone, 17 alpha-ethynilestradiol, and trenbolone) is presented. Urine samples were extracted with octadecylsilica columns and clean-up was performed in two steps with basic alumina and silica solid-phase extraction cartridges. The extracts obtained were derivatized with heptafluorobutyric anhydride and analyzed by GC-MS. Stability of derivatives was good and compounds having keto groups produced enol derivatives that were stable also. SIM mode was applied to increase the sensitivity and, when possible, the higher m/z ions were selected to improve identification. Repeatability of the chromatographic analysis was evaluated on the basis of area repeatability, and the coefficient of variation obtained was lower than 13%. Absolute recoveries were in the range 35-60% (dehydrotestosterone and estrone < 20%) with coefficients of variation between 14 and 37% for the whole procedure. [2H3]Testosterone and [2H8]diethylstilbestrol were evaluated to improve quantitative data. The recovery of [2H3]testosterone was found to be equal to or slightly higher than that of the other hormones, but the recovery of [2H8]diethylstilbestrol was lower than any other. [2H3]Testosterone was the most suitable for use as an internal standard, as its addition at the beginning of analytical procedure, corrected recovery results and greatly improved precision. Corrected recoveries from urine ranged from 72-110%, and coefficients of variation ranged from 6-15%, except for testosterone which yielded slightly higher values. The limit of detection was 0.5 ng/ml for all the compounds studied.

The development and application of coupled HPLC-TLC for pharmaceutical analysis

Successful coupling of high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) facilitates correlation of the retention factor (Rf) of a component in a TLC separation with a peak observed in HPLC, thus eliminating the need for isolation of the component. Experiments were designed to optimize flow and spotting rates for typical HPLC mobile phases, evaluating such parameters as band broadening and on-plate loading. Also investigated were the application of flow splitting and semi-microbore HPLC columns. The problems encountered with the development of TLC plates upon which the HPLC eluent has been applied as a linear streak were studied, as were detection methods for the resulting spots. This paper describes the successful development of the technique, using model compounds of pharmaceutical interest.

Thin-layer chromatographic detection of zeranol and estradiol in fortified plasma and tissue extracts with Fast Corinth V

In an attempt to improve sensitivity of thin-layer chromatographic (TLC) analysis and selectivity of visualizing agents for detection of estrogenic anabolic hormones, several dyes were screened for their chromogenic interactions with estrone, estradiol, diethylstilbestrol (DES), zeranol (zearalanol), zearalanone, and mycotoxins, zearalenone and zearalenol. Fast Corinth V salt was selected for its relatively high sensitivity. These anabolic compounds were separated by TLC and visualized with Corinth V and the results compared to iodine and starch visualization. Fortified bovine plasma and tissues (kidney, liver and muscle) and chicken muscles were analyzed after a clean-up procedure using solid-phase dual columns of alumina and anion-exchange resin. Iodine-starch clearly detected 4 ng of estradiol and DES while zeranol and zearalenone were detected at higher levels (10 ng). Fast Corinth V showed distinct spots with 2 ng of zeranol and 4 ng of zearalenone while faint spots were observed with estradiol and estrone standards. DES was not detectable at these levels. Less background interference was observed with Corinth V than with iodine-starch. The former confirmed spots detected by iodine-starch. This study suggests its selectivity for detection of zeranol and its metabolite, zearalanone, in the presence of steroidal compounds.