Raman hyperspectral imaging in conjunction with independent component analysis as a forensic tool for explosive analysis: The case of an ATM explosion

Abstract

In this work, Raman hyperspectral imaging, in conjunction with independent component analysis, was employed as an analytical methodology to detect an ammonium nitrate fuel oil (ANFO) explosive in banknotes after an ATM explosion experiment. The proposed methodology allows for the identification of the ANFO explosive without sample preparation or destroying the sample, at quantities as small as 70μgcm. The explosive was identified following ICA data decomposition by the characteristic nitrate band at 1044cm. The use of Raman hyperspectral imaging and independent component analysis shows great potential for identifying forensic samples by providing chemical and spatial information.

Independent components analysis (ICA) at the “cocktail-party” in analytical chemistry

“…It is clear that the range of applications of ICA to different types of chromatographic profiles should increase in the near future similarly to the alternative technique, MCR-ALS, which is widely used in chromatographic data analysis [45][46][47][48][49][50][51][52][53][54][55][56][57].…”

“…The combination of Raman imaging and ICA has shown great potential for investigating biological and forensic samples, and pharmaceuticals. The combination of Raman imaging and ICA was used to detect ammonium nitrate/fuel oil explosives on banknotes with a limit of detection of 70 μg/cm 2 after an ATM explosion experiment [45] and to detect differences in pen inks [46]. The capability of Raman spectroscopy together with ICA as a diagnostic tool for oral cancer was demonstrated in Ref.…”

Vibrational Spectroscopy and Chemometrics in Forensic Chemistry: Critical Review, Current Trends and Challenges

“…Poppi and co-workers 157,158 published two studies for the identification of explosive traces in banknotes using the same Raman imaging instrument (laser excitation 785 nm). In the first, 157 they developed the methodology for the identification of pre-blast traces of eight explosives (three military, four commercial and one propellant) on banknotes.…”

A three-dimensional discriminant analysis approach for hyperspectral images

“…[2][3][4][5] One of these imaging techniques that has found increasing application is Raman hyperspectral imaging, 6 which is a generally non-destructive technique where a spectral response is obtained based on molecular polarizability changes. 7 Raman hyperspectral imaging has been used in a wide range of applications, such as, pharmaceutical analysis, 8 food quality control, 9 forensic studies, 10 and to investigate biological materials. 11 Some advantages of using Raman hyperspectral imaging to analyze biological samples include its relative low-cost, minimal or no sample preparation, high sensitivity to chemically-relevant information, and minimum water interference.…”