Detection of PETN on Latent Fingerprint by Laser Confocal Micro-Raman Spectroscopy

Pentaerythritoltetranitrate (PETN) particles on latent fingerprint were examined by laser confocal micro-Raman spectroscopy.PETN explosive powder was dipped with a finger and the fingerprint was pressed on the surface of aluminum foil tape and treated by vacuum carbon deposition. Then the fingerprint image was collected by 10 times objective lens under white light of the laser confocal micro-Raman spectroscope, and the image of a fraction (4.0 mm×4.0 mm) of the fingerprint was collected using a 50 times long focal length objective lens with laser light. According to the characteristic Raman scattering peaks of PETN, the distribution information of PETN particles on the fingerprint was obtained. The results were confirmed by LC-MS/MS method.