Abstract Tree ring proxies are employed in dendroanalysis as a valuable tool for evaluating past anthropogenic contamination. A wide variety of analytical methods are used to quantify tree ring content for a broad spectrum of chemical elements. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) is often used to investigate element concentrations in the tree rings. However, several issues regarding the representativeness of laser ablation measurements for trace elements have to be addressed before definitive conclusions can be drawn. In this study, High Resolution (HR)-ICP-MS has been implemented to analyze the trace concentration of uranium (U) in annual growth rings of oak trees (Quercus petraea) using both laser ablation (LA) and solution modes. The three tree samples taken for the present study were located upstream (with respect to the hydrologic system) of a former uranium mine site at Rophin (Puy de Dome, France), where mining operations were performed between 1949 and 1958. According to the LA-HR-ICP-MS technique, two-dimensional quantitative (2D) mapping of uranium has developed to study the spatial distribution of uranium at the tree ring surface. A strong heterogeneity was observed, leading to an average uranium concentration with high uncertainty (50–66%). Pressed pellets of the standard reference material, NIST1570a spinach leaves and uranium doped cellulose powder were adopted as the uranium standards for quantification. No agreement was found between uranium concentrations measured after acid digestion and the values obtained by laser ablation. This comparison highlights the limitations of laser ablation technique; hence the solution mode should be preferred for quantifying uranium trace concentrations in tree rings. However, low uncertainty (

中文翻译：

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使用激光烧蚀和溶液模式下的高分辨率电感耦合等离子体质谱法对来自前铀矿开采地点的橡树年轮 (Quercus petraea) 进行铀定量

摘要 树木年轮代理作为评估过去人为污染的宝贵工具用于树状分析。各种各样的分析方法被用于量化范围广泛的化学元素的树木年轮含量。激光烧蚀电感耦合等离子体质谱 (LA-ICP-MS) 通常用于研究树木年轮中的元素浓度。然而，在得出明确结论之前，必须解决关于痕量元素激光烧蚀测量的代表性的几个问题。在本研究中，高分辨率 (HR)-ICP-MS 已用于使用激光烧蚀 (LA) 和溶液模式分析橡树 (Quercus petraea) 年轮中痕量铀 (U) 浓度。本研究采集的三棵树样本位于 Rophin（法国 Puy de Dome）前铀矿场的上游（相对于水文系统），该矿场于 1949 年至 1958 年间进行了采矿作业。 据洛杉矶报道-HR-ICP-MS 技术，铀的二维定量 (2D) 映射已经发展到研究铀在树木年轮表面的空间分布。观察到强烈的异质性，导致平均铀浓度具有高不确定性（50-66%）。采用压片的标准参考物质、NIST1570a 菠菜叶和掺铀纤维素粉末作为铀的定量标准。在酸消化后测量的铀浓度与激光烧蚀获得的值之间没有发现一致。这种比较突出了激光烧蚀技术的局限性；因此，应首选溶液模式来量化树木年轮中的痕量铀浓度。然而，低不确定性（