Detonation nanodiamonds are sp3 carbon nanomaterials with narrow diameter distribution. They have high potential of application in various fields like nanomedecine, advanced composites and lubricants, photocatalysis. Detonation nanodiamonds unfortunately contain metallic and inorganic impurities of diverse nature which can act as “Trojan horses” and even at weak content, they can significantly impact the nanodiamonds efficiency and the searched performances. Detection and quantification as well as subsequent removal of these impurities is highly difficult due to the lack of tools available by scholars. In this work, we propose a useful approach to detect and identify the inorganic impurities in detonation nanodiamonds. Our method which consists in a selective combustion of the nanodiamonds results in concentrating these impurities is a one-step and simple method. This approach, transferable to other kinds of carbon nanomaterials, is proved to be a valuable way allowing analysis of detonation nanodiamonds by standard characterization techniques such as X-ray Photoelectron Spectroscopy, Fourier Transform Infra-Red and Raman spectroscopies or Powder X-Ray Diffraction, available in any material science laboratory.