Evaluation of cyano bonded phases for the fractionation of bioactive complex mixtures

Cyanopropyl bonded-phase sorbents are investigated for the liquid chromatographic (LC) fractionation of complex mixtures with the goal of extending routine sample fractionation to samples containing highly polar biologically active components. Separations based both on gravity-flow column chromatography and on high performance liquid chromatography (HPLC) are evaluated for efficiency and resolving power. Typical gravity-flow column separations of neutral to moderately polar mixtures are found to be less effective than those employing traditional sorbents; however, HPLC methods could be called upon to provide the resolving power necessary for satisfactory separations of these mixtures. For mixtures of polar reference compounds, cyano bonded phases provide good separations and are very efficient, permitting the elution of components too polar to be recovered from traditional sorbents. A scheme combining gravity-flow chromatography with HPLC is developed for the fractionation of complex mixtures into compound classes. It is based on the chromatographic behavior of reference compounds covering a wide polarity range utilizing cyanopropyl sorbents exclusively. Results are presented for the fractionation of two air particulate reference samples containing highly polar components.