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identified with a high degree of certainty. 200-300 g samples of back-fat were taken from freshly
slaughtered cattle, and stored at -40°C. 100 g was homogenized and a 10 g sample taken for analysis.
The samples were spiked with 13C analogs of the various dioxins being determined. The crude extract
was cleaned up, using simple column adsorption chromatography. Samples were separated on a
Hewlett-Packard 5890 Series II, high-resolution gas chromatograph, employing a DM-5ms open tubular
column, 60 m long, 0.32 mm I.D., carrying a 0.25 µm thick film of stationary phase. The initial oven
temperature was 130°C, the injector temperature 270°C, and the interface temperature 300°C. The
column was programmed at 5°C/min for one minute, then 15 min. at 6°C/min to 295°C. The Kratos
high-resolution spectrometer was used as the tandem instrument. An amazingly high sensitivity was
obtained, the actual limit of detection was found to be 0.05 ppt for the tetra-chloro-dibenzo-p-dioxins,
and 0.1 ppt for the tetra-chloro-dibenzo-furans.

Analysis of Anabolic Steroids in Biological materials

Schoene et al. [8] employed a GC/MS tandem instrument to examine the metabolism of 17a-alkyl
anabolic steroids in horses after oral administration. In an example, 100 mg of 17a-methyl testosterone
together with the deuterated analog were fed to two horses via the usual food diet. Naturally voided
urine was collected over 72 hours. 5 ml samples were extracted with ether and the solvent removed in
vacuo to give the free urine fraction. The pH of the urine was adjusted to 6.8 and then heated with E.
Coli (2000 U) at 50°C for three hours to hydrolyze the glucuronide conjugates. A solid phase extraction
cartridge, Sep-Pak C18 was washed with water and n-hexane before applying the sample.

The hydrolyzed conjugates were eluted with ether, washed with 2 mol 1-1 NaOH, dried over sodium
sulfate and the solvents again removed in vacuo. The trimethyl silane derivatives were prepared by
heating the fraction with 8% methoxyamine hydrochloride in pyridine at 80°C for 30 min, removing the
pyridine in vacuo and heating the residue in N-methyl-N (trimethylsilyl)-trufluoroacetimide at 80 °C for
1 hr. Excess reagent was also remove in vacuo and the residue dissolved in n-decane.