In situ determination of trace elements in melt inclusions using laser ablation inductively coupled plasma sector field mass spectrometry
In situ determination of trace elements in melt inclusions using laser ablation inductively coupled plasma sector field mass spectrometry
复制标题
激光烧蚀电感耦合等离子体扇形场质谱原位测定熔体夹杂物中的微量元素
DOI：
10.1002/rcm.8359
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发表时间：
2019
影响因子：
2
通讯作者：
Wu Dan
中科院分区：
文献类型：
--
作者：
Zhang Le;Ren Zhong Yuan;Xia Xiao Ping;Yang Qing;Hong Lu Bing;Wu Dan
激光烧蚀电感耦合等离子体质谱（LA-ICP-MS）原位分析熔融包裹体中的微量元素提供了重要的地球化学信息。然而，该技术的精密度和准确度受到许多因素的影响，如基质效应、激光条件和校准方法。此外，许多先前的LA-ICP-MS研究都是将整个熔融包裹体沿着其寄主矿物一起烧蚀，并通过对混合烧蚀信号进行去卷积来获得微量元素组成，这可能会导致很多不确定性。（ICP‐SF‐MS）用于研究基质效应、激光条件、外部校准标准品的选择，六种常用硅酸盐标准玻璃中36种主量和微量元素的原位分析数据处理策略。通过测量橄榄石熔融包裹体中的微量元素，证明了本文所述方案的有效性。熔融包裹体被抛光到表面，而不是沿着消融整个熔融包裹体及其宿主矿物，以避免激光消融矿物host.ResultsThe校准线计算的校准标准应交叉坐标原点，特别是对于低浓度的元素（<10 ppm）。当激光凹坑尺寸从17 μ m增加到33 μm时，精密度从<20%提高到<8%（2 RSD），准确度从±20%提高到优于± 10%。大理熔融包裹体中微量元素的测定结果与寄主岩石基本一致。熔融包裹体中的移动的元素（Ba，Sr，Pb）的变化远小于其寄主岩石。结论建立了一种简单而准确的熔融包裹体中微量元素的LA-ICP-SF-MS原位分析方法，这将极大地促进原位微量元素地球化学在熔融包裹体研究中的广泛应用。
RationaleIn situtrace element analysis of melt inclusions by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) provides important geochemistry information. However, the precision and accuracy of this technique are affected by many factors, such as matrix effect, laser conditions, and calibration method. In addition, many previous LA‐ICP‐MS studies ablated entire melt inclusions along with their host minerals and obtained trace element composition by deconvoluting the mixed ablation signal, which may induce much uncertainty.MethodsA 193 nm ArF laser ablation system combined with inductively coupled plasma sector field mass spectrometry (ICP‐SF‐MS) was used to investigate matrix effect, laser conditions, choice of external calibration standards, and data reduction strategy forin situanalysis of 36 major and trace elements in six common silicate reference glasses. The validity of the protocol presented here was demonstrated by measuring trace elements in olivine‐hosted melt inclusions. Instead of ablating entire melt inclusions along with their host minerals, melt inclusions were polished to the surface to avoid laser ablating the mineral host.ResultsThe calibration lines calculated from the calibration standards should cross the coordinate origin, especially for low‐concentration elements (<10 ppm). As the laser crater size increased from 17 to 33 μm, the precision was improved from <20% to <8% (2RSD), and accuracy was improved from ±20% to better than ±10%. Most measured trace elements in Dali melt inclusions are consistent with those in their host rocks. For mobile elements (Ba, Sr, Pb), melt inclusions display much smaller variations than their host rocks.ConclusionsA simple but accurate approach forin situanalysis of trace elements in melt inclusions by LA‐ICP‐SF‐MS has been established, which should greatly facilitate the wider application ofin situtrace element geochemistry to melt inclusion studies.