Surface enrichment of parts-per-million-level impurity elements duringmagnesium dissolution is of interest in the context of structural materials and battery electrodes. Particle induced X-ray emission (PIXE) measurements were performed on pure magnesium using a nuclear microprobe instrument with high sensitivity for trace elements. PIXE was capable of performing trace analysis, revealing surface enrichment of Fe, Cu, Mn, Pb, As and Zn, indicating that magnesium displays incongruent dissolution accompanied by impurity enrichment as a result of dissolution. The concentration of surface impurities was shown to appreciably increase after modest anodic dissolution corresponding to only 1.2 C/cm2. It was revealed however, that the enrichment efficiency was low, at < 1%.