Forensic applications of X-ray fluorescence microscopy

The development of highly efficient X-ray optics has allowed the development of bench-top XRF systems which have high intensity X-ray beams with diameters ranging from 10 micrometres through to a few millimetres. Coupled with integrated high magnification optical cameras, these systems are ideally suited to the needs of the forensic scientist. A microscopic particle from a crime scene can be analysed without any sample preparation, simply located using optical cameras and motorised sample stages, and subsequently characterised for elemental content. Furthermore XRF mapping creates detailed element distribution maps of heterogeneous materials. This article presents an overview of the use of micro-XRF for forensic analysis, and shows analysis results of typical samples. However, it can in no way be considered a comprehensive survey, since over a matter of years almost every possible type of sample is likely to pass its way through a forensic laboratory.