SE306627

1,054,576. Alumina adsorbent. E. MERCK, A. G. Oct. 29. 1964 [Dec. 14. 1963], No. 44225/64. Heading C1A. [Also in Division B1] A chromatographic adsorbent comprises 1- 25% hydrated aluminium oxide or hydroxide of particle size below 1 micron, preferably 0À001-0À1 micron, and a balance of adsorbent alumina of particle size at least 1 micron. The fine material may be the amorphous hydroxide gel obtained by precipitation from Al salt solutions with NH 3 or NaOH, or a transition alumina obtained by heating the gel at 50- 1250‹ C. The adsorbent alumina may have a surface area of 50-400 m2/g. It may be basic (pH 8-11 in suspension), neutral (pH 6-8) or acidic (pH 3-6), and the pH of the fine aluminium oxide or hydroxide may be adjusted to the same value, e.g. by acid washing. Fluorescent substances, e.g. Mn-activated Zn silicate, Mg tungstate, or Cd halogen phosphate, Sn-activated Ca phosphate, Mn- or Mn/Pbactivated Ca silicate, Sb- or Sb/Mn-activated Ca halogen phosphate, Na 3-hydroxy-pyrene- 5, 8, 10-trisulphonate, Na3,5-dihydroxypyrene- 8, 10-disulphonate, or morin, may be added. The adsorbent is used in thin layer chromatography and for preparative separations using layers 0À5-5 mm. thick.