Flux‐Free Fusion of Silicate Rock Preceding Acid Digestion for ICP‐MS Bulk Analysis
Flux‐Free Fusion of Silicate Rock Preceding Acid Digestion for ICP‐MS Bulk Analysis
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DOI：
10.1111/j.1751-908x.2010.00059.x
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发表时间：
2011-03
影响因子：
3.8
通讯作者：
K. Shimizu;Q. Chang;Kentaro Nakamura
中科院分区：
文献类型：
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作者：
K. Shimizu;Q. Chang;Kentaro Nakamura
我们提出了一种新的无熔剂熔融分解硅酸盐岩石的方法，用于全岩微量元素（Sc，Rb，Sr，Y，Zr，Nb，Cs，Ba，稀土元素和Hf）的测定，特别适用于含锆石的长英质岩石。通过对镁铁质岩石（JB-1a，JB-2，JGb-1）和长英质岩石（JG-3，JR-3，JSd-1，GSP-2，G-2）的RM分析，验证了该方法的正确性。称量不含助熔剂的粉末状样品的丸粒（至多500 mg），并置于干净的铂坩埚中。然后将样品在Siliconit®管式炉中熔融并淬火至室温。花岗岩熔融的最佳条件为1600 °C加热2-3 min。在Teflon®烧杯中使用HF和HClO 4分解加热后铂坩埚中的熔融玻璃。使用四极电感耦合等离子体质谱仪分析分解和稀释的样品溶液。RM的重复分析（n = 4或5）显示，JG-3中除Zr和Hf（≤ 6%）外，所有元素的分析不确定度通常< 3%。这些较高的不确定性可能归因于样本异质性。我们对RM的分析结果与推荐浓度和最近公布的浓度一致，表明我们的岩石样品在熔融过程中完全分解。
We present a new method for the decomposition of silicate rocks by flux‐free fusion in preparation for whole‐rock trace element determination (Sc, Rb, Sr, Y, Zr, Nb, Cs, Ba, rare earth elements and Hf) that is especially applicable to zircon‐bearing felsic rocks. The method was verified by analyses of RMs of mafic (JB‐1a, JB‐2, JGb‐1) and felsic rocks (JG‐3, JR‐3, JSd‐1, GSP‐2, G‐2). Pellets of powdered sample (up to 500 mg) without flux were weighed and placed in a clean platinum crucible. The samples were then fused in a Siliconit® tube furnace and quenched to room temperature. The optimum condition for the fusion of granitic rock was determined to be heating for 2–3 min at 1600 °C. The fused glass in the platinum crucible after heating was decomposed using HF and HClO4 in a Teflon® beaker. Decomposed and diluted sample solutions were analysed using a quadrupole inductively coupled plasma‐mass spectrometer. Replicate analyses (n = 4 or 5) of the RMs revealed that analytical uncertainties were generally < 3% for all elements except Zr and Hf (∼ 6%) in JG‐3. These higher uncertainties may be attributed to sample heterogeneity. Our analytical results for the RMs agreed well with recommended concentrations and recently published concentrations, indicating complete decomposition of our rock samples during fusion.