Trace Element Analysis of Selected Elements and Speciation

3 Trace Element Analysis of Selected Elements and Speciation 

One of the most famous applications in forensic science is the analysis of Napoleon s hair by ICP-MS after mineralization in concentrated nitric acid whereby an arsenic concentration about 40 times higher than normal (about 40p,gg 1) was measured (see Section 9.5). Ingested arsenic is known to be stored in sulfydryl rich tissue, like hair, nails or skin. ETV-ICP-MS combined with isotope dilution has been employed to measure thallium in human scalp hair from a person poisoned by thallium compared to control subjects, whereby several longitudinal concentration gradients for the analyzed segments (length 10 mm) were obtained.28 

In Stingeder s group the unique capabilities of sector field ICP-MS and LA-ICP-MS were employed to reconstruct details of a homicide by thallium poisoning, which took place about 40 years ago in Austria.29 Thallium was determined in several human bone samples after acid digestion in a microwave oven. The thallium concentration measured by ICP-MS and GF-AAS varied from 1.07-2.63 p,gg 1, which was up to 170 times higher compared to the concentration found in persons who died due of natural causes. LA-ICP-MS was employed to analyze a thumbnail from the poisoned person compared to a control person. Thallium peaks were detected in the nail of the victim at a distance of 2.5 mm from the younger edge of nail.29 

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