β Scribed by M. Fenske
No coin nor oath required. For personal study only.
For the separation of steroids, Sephadex LH-20 (1,2) or Celite (3,4) minicolumns are widely used. However, the preparation of such columns is tedious, and good separations require the repeated changes of the polarity of the eluants. With the availability of thin-layer FIG. 2. Relation between tip filling with Extrelut and the diamechromatography (TLC) aluminum sheets coated with ters of application spots. Tips were filled with 0.2-1.8 mg Extrelut silica gel, glucocorticosteroids and sex steroids can be and placed onto TLC sheets. Ten micrograms of hydrocortisone, dis-
easily separated, and they can be cut out, eluted with solved in 100 ml ethanol, was pipetted into the tips. When solutions methanol, and analyzed by radioimmunoassay, highwere drained out of the tips, the spot diameters were determined under uv light. Values are given as means { SD, n Γ 6.
π SIMILAR VOLUMES
The retention of some barbiturates and steroids on amino-bonded silica gel pre-coated plates was examined by employing high-performance thin-layer chromatography and compared with that on silica gel pre-coated plates, with respect to the pure organic solvent used as the eluent. Aqueous and non-aqueo