Chromatographic patterns of prostaglandins using different lots of silicic acid

The chromatographic patterns of prostaglandin E2 chromatographed on various lots of silicic acid are presented. Two lots of Mallinckrodt silicic acid tested give totally unsatisfactory separation of PGE2. Sigma silicic acid SIL-R gives better separation than any of the Mallinckrodt lots tested. Increasing the size of the "E" fraction of solvent can give satisfactory separation on Mallinckrodt silicic acid.