PREPARATION AND COMPARISON OF A PENTAFLUOROPHENYL STATIONARY PHASE FOR REVERSED-PHASE LIQUID-CHROMATOGRAPHY

A pentafluorophenyl stationaryphase was prepared for reversed-phase liquid chromatography. The amount of organic moiety bonded on a silica support was determined from thermogravimetric curves of modified silica gel. The specific surface area of the gel was obtained from nitrogren sorption measurements at 77 K. The retention behaviour of solutes on a column packed with this gel was examined and compared with that on a commercially available phenylmethyl column. The capacity factors of the solutes were normalized to unit surface area of the support (k'/SBET) and compared with the k'/SBET values for 52 different solutes in an isoeluotropic system. It was observed that the pentafluorophenyl stationary phase exhibited specific fluorine-fluorine interactions and showed enhanced retention not only of fluorine-containing compounds but also of some other halogen-containing solutes. © 1990.