Trace detection of explosive compounds by different laser-based techniques at the ENEA Laboratories

摘要

The ENEA Laser Application Section has participated to the European project ISOTREX (Integrated system for on-line trace explosives detection in solid and vapor state), funded in the frame of the PASR 2006 with the main aim to exploit different laser based techniques. Standard explosive compounds and their precursors have been investigated through an atomic technique (LIBS; Laser-Induced Breakdown Spectroscopy), an absorption technique (LPAS; Laser Photoacoustic Spectroscopy) and vibrational techniques (Laser Raman and SERS; Surface-Enhanced Raman Spectroscopy). LIBS and SERS reached a sub ng level of detection, supported by a high rank of discrimination of the components via chemometric analysis. This selectivity skill is also quite evident in the LPAS technique. These results assume particular relevance due to the inclusion of interferents, such as dust, fingerprint oil and lubricant oil, into the investigated compounds. The results of the measurements are presented in view of the possible integration of the three techniques in a single device for trace detection, might contribute also to drastically limit the number of false positives.