Refining Boron Isotopic Measurements of Silicate Samples by Multi-Collector-Inductively Coupled Plasma-Mass Spectrometry ( MC-ICP-MS )
Refining Boron Isotopic Measurements of Silicate Samples by Multi-Collector-Inductively Coupled Plasma-Mass Spectrometry ( MC-ICP-MS )
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通过多收集器电感耦合等离子体质谱 (MC-ICP-MS) 精炼硅酸盐样品的硼同位素测量
DOI：
10.1111/ggr.12527
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发表时间：
2023
影响因子：
3.8
通讯作者：
Paul A
中科院分区：
文献类型：
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作者：
Paul A
溶液MC-ICP-MS是碳酸盐岩中高精度硼同位素测量结果（δ11BSRM 951）的成熟技术，但其在硅酸盐岩石中的应用受到限制。障碍包括硅酸盐溶解过程中的挥发和化学纯化过程中的污染。为了解决这一问题，我们提出了一种低空白样品制备程序，该程序将氢氟酸消化和低温蒸发（无甘露醇）与使用B特异性Amberlite伊拉743树脂进行化学纯化后建立的MC-ICP-MS测量程序相结合。我们获得了硼酸（BAM ERM‐ AE 121 19.65 ± 0.14‰）和碳酸盐（NIST RM 8301（Coral）24.24 ± 0.11‰）标准物质的准确δ 11 BSRM 951值（中间精密度±0.2‰）。对于涵盖镁铁质到长英质成分的硅酸盐标准物质，我们获得δ 11 BSRM 951，中间精度< ±0.6‰（2s），即JB-2 6.9 ± 0.4‰; IAEA-B-5 - 6.0 ± 0.6‰; IAEA-B-6 - 3.9 ± 0.5‰（2s）。此外，通过替代融合和纯化程序处理这些相同参比物质的片段。我们发现使用两种样品处理技术通过MC-ICP-MS对参比物质的δ 11 BSRM 951测量结果之间具有极好的一致性。这些测量结果表明，我们的样品处理和MC-ICP-MS方法为低B-质量分数样品提供了一致的δ 11 BSRM 951值。我们提供了来自大洋中脊玄武岩（MORB）玻璃的新数据，记录了δ11BSRM 951的范围从-5.6 ± 0.3‰到-8.8 ± 0.5‰（2s），这意味着上地幔δ11BSRM 951存在一定的不均匀性。
Solution MC‐ICP‐MS is an established technique for high precision boron isotope measurement results (δ11BSRM 951) in carbonates, yet its application to silicate rocks has been limited. Impediments include volatilisation during silicate dissolution and contamination during chemical purification. To address this, we present a low‐blank sample preparation procedure that couples hydrofluoric acid‐digestion and low‐temperature evaporation (mannitol‐free), to an established MC‐ICP‐MS measurement procedure following chemical purification using B‐specific Amberlite IRA 743 resin. We obtain accurate δ11BSRM 951values (intermediate precision ±0.2‰) for boric acid (BAM ERM‐AE121 19.65 ± 0.14‰) and carbonate (NIST RM 8301 (Coral) 24.24 ± 0.11‰) reference materials. For silicate reference materials covering mafic to felsic compositions we obtain δ11BSRM 951with intermediate precision < ±0.6‰ (2s), namely JB‐2 6.9 ± 0.4‰; IAEA‐B‐5 ‐6.0 ± 0.6‰; IAEA‐B‐6 ‐3.9 ± 0.5‰ (2s). Furthermore, splits of these same reference materials were processed by an alternative fusion and purification procedure. We find excellent agreement between δ11BSRM 951measurement results by MC‐ICP‐MS of the reference materials using both sample processing techniques. These measurement results show that our sample processing and MC‐ICP‐MS methods provide consistent δ11BSRM 951values for low B‐mass fraction samples. We present new data from Mid Ocean Ridge Basalt (MORB) glass, documenting a range in δ11BSRM 951from ‐5.6 ± 0.3‰ to ‐8.8 ± 0.5‰ (2s), implying some upper mantle δ11BSRM 951heterogeneity.