Forensic analyst, Forensic Science Laboratory, Pretoria,
Chris Pistorius, P
Associate professor, University of Pretoria, Pretoria,
(Received 4 August 1995; accepted 18 March 1996)
The debris produced by abrasive and oxygen-acetylene cutting of mild steel has been examined by scanning electron microscopy, energy-dispersive X-ray analysis, inductively coupled plasma atomic emission spectrometry, and X-ray diffraction, to establish which of these techniques are useful to test whether debris originated from a given source. Because of its poor sensitivity to trace amounts of elements, energy-dispersive X-ray analysis cannot be used for this purpose. However, when analyzed by inductively coupled plasma atomic emission spectrometry, the line intensities from chromium, nickel, cadmium, zinc, and copper in debris were mostly within 30% of the intensities for the source of the debris (with the intensities expressed relative to that from manganese). It was found that the morphology of the debris (as studied by scanning electron microscopy) did not give an unambiguous indication of the cutting technique, although X-ray diffraction did reveal that the debris from oxygen-acetylene cutting was oxidized to a greater degree than that from abrasive cutting.
Paper ID: JFS14037J