Fluorocarbon lubricants are of great interest in many applications where they are used in very thin layers. Control of the lubricant presence is easily performed by a surface analysis technique such as x-ray photoelectron spectroscopy. However, the interpretation of the spectra is not straightforward. A simple electronegativity description of the charge shifts is developed from the group electronegativity and the Sanderson equalization approaches. It is applied to two types of high molecular weight molecules, and allows us to assign the experimental photoelectron spectra of the two fluorocarbon lubricants under study.