The use of portable XRF as a forensic geoscience non-destructive trace evidence tool for environmental and criminal investigations

Portable X-ray fluorescence (pXRF) analysis of heavy metal contamination in church graveyards with contrasting soil types

“…The sample was then mixed with 1.5 mL of polyvinylpyrrolidone-methylcellulose binding agent and mechanically pressed under 10-tn pressure (Fig S1 ) into a homogenous flat-cylinder pellet, before being oven-dried for a further 24 h at 105 °C to remove any soil water influence on signal strength (Kalnicky and Singhvi 2001). Each pellet (Fig S1 ) was then analysed using the NITON XL3t 900 pXRF Analyzer in its laboratory holder, using a 5-min measurement time, chosen as a compromise between analytical time and instrumental precision (see Pringle et al 2022 ). The instrument employs four sub-filters (Main, Low, High, Light), each targeting a specific range of elements.…”

“…To create the pressed powder pellet, surface soil samples were oven-dried for 24 h at 105 °C before being hand-ground using a pestle and mortar to pass through a 63-μm sieve. The sample was then mixed with 1.5 mL of polyvinylpyrrolidone-methylcellulose binding agent and mechanically pressed under 10-tn pressure (Fig S1 ) into a homogenous flat-cylinder pellet, before being oven-dried for pXRF Analyzer in its laboratory holder, using a 5-min measurement time, chosen as a compromise between analytical time and instrumental precision (see Pringle et al 2022). The instrument employs four sub-filters (Main, Low, High, Light), each targeting a specific range of elements.…”

In situ measurements using hand-held XRF spectrometers: a tutorial review

“…Originally, these spectrometers were large, oor standing instruments requiring specialist operators, the use of extensive safety precautions to avoid X-ray hazards, and careful preparation of test samples from materials submitted to the XRF laboratory. For many years, basic spectrometer design comprised an X-ray tube excitation source (similar to those used in medical X-ray devices), a sample chamber that ensured excitation and 28 Examples include an index of the soil types in Japan to allow mud on shoes at crime scenes to be identied, the analysis of paint akes from automobile accidents and the detection of various counterfeit objects 17…”

Portable x‐ray fluorescence as a tool for assessing electric marks in forensic evaluation

“…17 In recent reports, 18,19 XRF has proven to be a good technique for various forensic investigations, including analyses of human remains. [20][21][22] Its potential applications in forensic practice can be very useful anytime a medium-high Z element has to be detected in a light matrix, as reported by several applications in other fields. [23][24][25][26] Given this great versatility and enormous potential, we experimentally used a portable XRF spectrometer in a real forensic case in which a man died from a highvoltage electric shock.…”

“…Despite all this, the use of XRF has been proposed only in one forensic case where it was possible to correctly assess a suspected electrical death 17 . In recent reports, 18,19 XRF has proven to be a good technique for various forensic investigations, including analyses of human remains 20–22 . Its potential applications in forensic practice can be very useful anytime a medium‐high Z element has to be detected in a light matrix, as reported by several applications in other fields 23–26 …”