π-Electron interaction of PAHs with anion-exchange silica gels modified with anionic metal-porphine and -phthalocyanine derivatives as HPLC stationary phase for preparative column in organic solvents

To develop easy-to-prepare stationary phases for HPLC, we investigated anion-exchange silica gels, Nucleosil 5SB (Nuc), modified with metal-porphines and -phthalocyanines (M-P). The modified silica gels (M-P-N) were evaluated for the availability as a stationary phase of HPLC for the separation of pi-electron-rich polyaromatic hydrocarbons (PAHs) in polar and non-polar eluents. Separation ability of silica gels modified with Cu-phthalocyanine derivative (CU-PCSN) was comparable to that of the silica gets binding Cu-PCS through sulfonamide bonds; however, the latter requires troublesome procedures for the preparation. The PAHs tested interact with CU-PCSN in non-polar organic eluents through their pi-electrons similarly as in the case of the PYE column(R), in which interaction with PAHs was reported to be only the pi-pi-electron interaction. (C) 2004 Elsevier B.V. All rights reserved.