The potential of using laser ablation inductively coupled plasma time of flight mass spectrometry (LA-ICP-TOF-MS) in the forensic analysis of micro debris

The ability to rapidly determine and match the elemental distribution patterns of debris collected from crime scenes to those recovered from persons of interest is essential in ensuring successful prosecution. Traditionally, relatively large amounts of sample (up to several milligrams) have been required to obtain a reliable elemental fingerprint of this type of material [R.J. Walting , B.F. Lynch, D. Herring, J. Anal. At. Spectrom. 12 (1997) 195]. However, this quantity of material is unlikely to be recovered from a POI. This paper describes the development and application of laser ablation inductively coupled plasma time of flight mass spectrometry (LA-ICP-TOF-MS), as an analytical protocol, which can be applied more appropriately to the analysis of micro-debris than conventional quadrupole based mass spectrometry. The resulting data, for debris as small as 70 μm in diameter, was unambiguously matched between a single spherule recovered from a POI and a spherule recovered from the scene of crime, in an analytical procedure taking less than 5 min.