OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. The distributions of cerium and oxygen in the matrix and in graphite precipitates of a pure Fe-C-Ce cast iron sample have been studied using scanning Auger microscopy. It is shown that there is no accumulation of any element at the graphite-matrix interface. Cerium was detected in some cases in spheroidal graphite precipitates, most often associated with oxygen. Various non-spheroidal graphite precipitates proved to contain cerium and oxygen suggesting a correlation between cerium content and graphite degeneracy.