AbstractThe capabilities of a preparative chromatograph assembled at moderate cost from commercially available components are examined in relation to the purification of β‐lactam derivatives. It is shown that high efficiency separations can be achieved rapidly, economically, and on a scale sufficient to provide adequate quantities of material for spectroscopic identification and biological testing. In the synthesis of a large batch of aminopropyl silica for preparative HPLC purification of an impure sample of cephacetrile, three different grades of silica were investigated. The material giving the best performance was prepared on a 100 g scale and baseline separations for 0.5 g loadings of the impure cephacetrile were obtained on a 30 cm × 2.2 cm i.d. column. The pure cephalosporin was recovered in high yield by freeze drying of the elu