Backscattering spectroscopy using 7.6 MeV He 4 e ions was performed for depth profiling of light elements in heavy matrices consisting of gold, silver and copper. The specimens were produced and modified with different etching techniques to reproduce in laboratory ancient gilding recipes of mesoamerican goldsmiths. Due to the special etching treatments, different oxygen and carbon contaminations are detected close to the specimens surfaces. In addition, high energy backscattering measurements were performed with 10 and 12 MeV He 4 e ions in order to investigate further advantages and disadvantages when using ion energies above 9 MeV.