Rapid micromethod for the analysis of mitotane and its metabolite in plasma by gas chromatography with electron-capture detection.

A rapid micromethod for 50-microliter samples is described for the analysis in plasma of mitotane (o,p'-DDD) and its metabolite (o,p'-DDE), using p,p'-DDD as internal standard. The compounds are extracted with heptane without sample pretreatment, and an aliquot is directly analysed by gas chromatography with electron-capture detection. Absolute recoveries for all three compounds were ca. 87% and coefficients of variation were less than 5%. The method is being used successfully for monitoring patients with Cushing's syndrome who receive chronic oral mitotane therapy.