| Summary: | 博士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 103 === Lead (Pb) isotopic fingerprinting is a robust means in environmental forensic and new to Taiwan. In this study, the analytical procedure of high-precision Pb isotopic characterization in environmental materials through chromatographic separation with Sr-Spec resin and MC-ICP-MS was developed and applied to agro-environmental system in Taiwan. Besides, other reported values from literatures were also collected for built-up the database of Taiwan’s Pb isotopic ratios. The phenomenon of isotopic anomaly in soil-rice system was first found and raised. The above isotopic variation occurred within rice plants during uptake and translocation in each growing periods for both pot and field experiments. Whereas, crops grown in Pb-tainted farms exhibit Pb isotopic characteristics of the pollutant. That anomaly was interrupted at the paddy fields suffering from seriously anthropogenic heavy metal contamination. Observation from varios study sites around Taiwan suggest that the Pb isotopic ratios of Taiwan’s non-polluted soils are ~2.472 for 208Pb/207Pb, ~1.170 for 206Pb/207Pb, ~18.47 for 206Pb/204Pb, ~15.66 for 207Pb/207Pb and ~38.7 for 208Pb/204Pb; while those values of soils collected at anthropogenic contaminated sites show distinctive lower in 208Pb/207Pb and 206Pb/207Pb ratios. Lead isotopic characterization helps precise evaluation and identification of contamination sources, then, the liability of the contaminated site could be revealed, but is expensive for set-up and maintaining costs of the novel instrument and the high technology training.
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