RESUMEN
Hand-held, portable X-Ray fluorescence instruments (pXRF) provide a means of rapid, in-situ chemical characterisation that has considerable application as a rapid trace evidence characterisation tool in forensic geoscience. This study presents both a control test study which demonstrates optimisation of the data collection process, alongside a range of individual forensic case studies, including heavy metal contamination, conflict archaeology, forensic soil characterisation, and verification of human remains, which together validate the technique and provide some comparison between field-based and laboratory-based pXRF applications. Results highlight the time-efficiency and cost-effectiveness of in-situ, field-based pXRF analyses for material characterisation when compared with other trace evidence methods. Analytical precision of various analytes during in-situ analysis was sufficient to demonstrate considerable application of field-based pXRF as a tool for rapid identification of specific areas of interest to be further investigated. Laboratory-based pXRF analyses yielded greater accuracy which could provide an efficient compromise between field-based pXRF and traditional laboratory-based analytical techniques (e.g. WD-XRF, ICP-MS). Further studies should collect more advanced datasets in more diverse locations to further validate the techniques capability to rapidly conduct geochemical surveys in a range of environments.
Asunto(s)
Ciencias Forenses/instrumentación , Contaminantes del Suelo , Espectrometría por Rayos X/instrumentación , Crimen , Ciencias de la Tierra , Humanos , Contaminantes del Suelo/análisisRESUMEN
A 12-year-old boy presented with a 7-year history of intermittent colicky epigastric pain. Serial abdominal ultrasound studies showed a contracted gallbladder, and single and double dose oral cholecystograms demonstrated nonfunction. All other investigation results were normal. At cholecystectomy, there was a fibrotic stricture at the junction of the gallbladder neck and cystic duct. The small, thin-walled gallbladder contained white bile. Histologically, the gallbladder was lined with normal mucous secreting columnar epithelium. The area of stricture showed diffuse fibrosis with islands of heterotopic gastric mucosa containing all gastric mucosal cell types. One year postoperatively, there have been no further episodes of abdominal pain. This is the seventh reported case of heterotopic gastric mucosa in the gallbladder of a child causing symptoms necessitating cholecystectomy. We recommend that a child with abdominal pain and a nonfunctioning gallbladder be considered for cholecystectomy even in the absence of cholelithiasis.