“…The nail consists of a large number of chemical elements, 26 of which relate to essential and structural J of Biomedical Photonics & Eng 6 (2) 30 Jun 2020 © J-BPE 020310-2 micro-and macroelements (Cl, I, B, V, Fe, K, Ca, Co, Si, S, Li, Mg, Mn, Cu, Mo, Na, Ni, Se, P, Cr, Zn, O, N, C, H, F), the rest are toxic [10]. The 82 emission lines belonging to the atomic and ionic lines of 13 elements -Al, C, Ca, Fe, H, K, Mg, N, Na, O, Si, Sr, and Ti -can be identified in the LIBS spectrum of the nail [11][12][13][14]. LIBS analysis does not require sample extraction, as it can be performed in vivo.…”