Trennung von freien und proteingebundenen Steroiden mit Amberlite

Amberlite IRA 400-coated resin strips were tested with regard to their capability to separate free from protein-bound steroids, and as such to act as an adsorbant for the determination of testosterone by protein binding methods. Results showed

1. Tritium labelled testosterone, dihydrotestosterone, cortisol, progesterone and estradiol are adsorbed to the Amberlite in aqueous media.
2. Adsorbed are mainly the free steroids and not the steroid hormones which are bound to their specific proteins.
3. Through the quantitative determination of testosterone, results show a coefficient of variation of 1.3–3.9% in the range from 1–8 ng per sample.
4. The standard curves performed on different days fit well. The percentage error calculated for curves performed on 5 successive days was 5.7% for 8 ng of testosterone and 1.7% for 2 ng.

In contrast to other adsorbants used, the Amberlite strips are much simpler to use; therefore a greater number of samples can be processed at any one time.