1998 Volume 14 Issue 6 Pages 1127-1131
Separation characteristics of aminopropyl silica gels modified with copper-phthalocyanine (Cu-PCSD) were investigated in comparison with those of a pyrene stationary phase (PYE). By the use of alkylbenzenes as samples, we have found that the π-π electron interaction is dominant in the separation mode of a column packed with Cu-PCSD, while the hydrophobic interaction with alkyl groups participates in the separation mode of a PYE column. The separation factor (αn′+1) of a polyaromatic hydrocarbon (PAH) having n′+1 aromatic rings by a PAH having n′ aromatic rings is larger than that obtained from the PYE column. In particular, when n′ is 3, αn′+1 is more than 6 times that of the PYE column in the maximum value. In addition, the planar recognition ability of the Cu-PCSD column is much better than that of the PYE column. The above results indicate that the separation characteristics of Cu-PCSD are mainly due to the π-π electron interaction based on Cu-PCS bound in parallel to the surface of the aminopropyl silica gel.
