Spectroscopic study of some IED´s precursors by means of laser photoacoustic spectroscopy combined with multivariate analysis

The Improvised Explosive Device (IED) is the most prevalent form of explosive device utilized by terrorists today being easy to realize and difficult to detect. These explosive devices are made by mixing different precursor substances that are generally cheap and commercially available. Thus, attention should be focused on developing fast and reliable methods able to identify such substances. In this paper we applied laser photoacoustic spectroscopy method for the spectral characterization and identification of a number of common chemicals used as precursors of IEDs: potassium sulfate, potassium nitrate, magnesium sulfate, ammonium perchlorate, ammonium nitrate, and acetone. The analyzed chemical species were classified by Principal Component Analysis applied to the collected spectral data. As conclusion of the study, the laser photoacoustic spectroscopy combined with chemometrics has confirmed to be a useful tool that could support the fight against the increased realization of modern bombs for criminal use.