Magnetic alumina sorbent was used in the separation of aromatic compounds from gasoline by a pi-complexation mechanism. Magnetic alumina sorbents can effectively adsorb polycyclic aromatics and polycyclic aromatic sulfur compounds from model gasoline, and the amounts adsorbed were up to 0.12 mmol.(g of sorbent)(-1). The interactions between various aromatics and sorbents of different acidities were studied. The results showed that the amounts adsorbed are related to the capability of forming pi-complexation interactions, and the magnetic alumina sorbent used was found to have the following order of adsorptive ability for aromatics: pyrene > naphthalene > DBT approximate to fluorene. Al3+ and its oxide are Lewis pi-acids, and aromatic compounds are Lewis pi-bases; thus, they can form pi-complexes with each other. The pi-complexation was verified by fluorescence spectrum. The quenching of the fluorescence of pyrene by Al3+ was due to partial pi-electron transfer from pyrene to the cation according to Lewis theory and fluorescence quenching theory.