Dete rmin ing electron energy losses is of great in teres t for basic studies of in te rac t ion of low energetic electrons wi th solid surfaces as well as for the in te rp re ta t ion of Auger electron spect ra . The p r i m a r y eilergies wi thin the range of 100--2000 eV are realizable in commercia l Auger electron spectrometers and, therefore , it is possible to measure s t ructures based on electron energy loss processes, i . e . surface and vo lume-p la smon exci ta t ion s imultaneously to Auger electron spect roscopy. The appl icabi l i ty of this me thod is demons t r a t ed on Al and Al-oxide as well as on Ti and Ti-oxide. Consequent ly , s t a t emen t s on concen t ra t ion gradients were possible b y choosing the p r i m a r y energy and t h e r e b y the in format ion depth .