Depth profiling of graphene with high-resolution ion beam analysis is a practical method for analysis of monolayer thicknesses of graphene. Not only is the energy resolution sufficient to resolve graphene from underlying SiC but by use of isotope labeling it is possible to tag graphene generated from reacted ethylene. Furthermore, we are able to analyze graphene supported by oxidized Si(100) substrates, allowing the study of graphene films grown by chemical vapor deposition on metal and transferred to silicon. This introduces a powerful method to explore the fundamentals of graphene formation. © 2011 American Institute of Physics.