The study of adsorption of squalene onto fumed silica samples having nitrogen specific surface areas varying from 50 to 380 m(2)/g, was led using inverse liquid chromatography frontal analysis in anhydrous heptane. Their monolayer capacities of adsorption, the Langmuir's and Henry constants were determined from the desorption isotherms. A complex evolution of their surface properties with the specific surface area was evidenced, showing that the fumed silica can be classified in four different categories according to their specific surface areas. A mechanism of formation of the primary particles is proposed that explains the differences observed in surface properties. According to this mechanism these differences are related to the flame temperature : at high temperature fumed silica having a low specific area are formed that exhibit a regular surface on both the surface functionality and the surface geometry. Lowering the flame temperature lead to fumed silica having a rough surface and correlatively, a non-random distribution of the silanol groups on the silica surface.