SR-X-ray fluorescence analysis of arsenic poisoning biopsy samples

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Synchrotron radiation induced X-ray fluorescence (SR-XRF) analysis was applied to reveal arsenic level in human hair and skin. The samples are obtained from patients of acute and chronic arsenic poisonings. The former specimens were collected from victim of arsenic curry murder occurred at Wakayama city and the latter were from China, where serious arsenic environmental problem exists and chronic poisoning is generated in a few hundred thousands person scale. The distribution of arsenic along the length of a hair was measured by one-dimensional SR-XRF analysis and that in the vertical section was measured by two-dimensional analysis utilizing X-ray microbeam in 5 μm size. The skin samples obtained by biopsy was also examined. Chemical state of arsenic is strongly related with toxicity and therefore it is another important subject of the present study.One dimensional analysis of hairs from victims of arsenic poisoning show that presence of a clear peak of arsenic and high arsenic level … More continued for 1cm length (about two weeks). On the other hand, the results for the samples of chronic poisoning show monotonous distribution of arsenic. Two dimensional analysis of hair section has revealed high accumulation of arsenic at outer rim of the hair whereas zinc and sulfur was uniformly distributed. The distribution of copper was similar to that of arsenic. It is found for the first time that the accumulation of arsenic does happen in the skin from patients of chronic arsenic poisoning. The high arsenic level was observed at a region between corium and epidermis of the skin. XANES analysis of arsenic in the hair of acute poisoning has revealed that arsenic exists in the form of inorganic trivalent state. This result suggests that the arsenic was not metabolized in the acute poisoning. The present study clearly revealed the accumulation mechanism of arsenic in both acute and chronic arsenic poisonings. This study also demonstrated that SR-XRF is a powerful nondestructive technique to reveal distribution and chemical form of trace arsenic in biopsy samples. Less