In various anhydrous water-immiscible organic solvents, dibenzothiophene (DBT) was removed by more than 80% by cumene hydroperoxide (alpha,alpha-dimethylbenzyl hydroperoxide) catalyzed by the immobilized cytochrome c on Celite. DBT-sulfone, the oxidation product of DBT, strongly adsorbed on Celite in highly hydrophobic organic solvents such as hexadecane, decane and n-octane. The adsorbed DBT-sulfone was desorbed from Celite by a simple washing of the Celite with a less hydrophobic solvent such as octanol.