Determination of B/Ca of natural carbonates by HR‐ICP‐MS
Determination of B/Ca of natural carbonates by HR‐ICP‐MS
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HR-ICP-MS 测定天然碳酸盐的 B/Ca
DOI：
10.1002/2013gc005049
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
H. Elderfield
中科院分区：
文献类型：
--
作者：
S. Misra;M. Greaves;R. Owen;Joanna Kerr;A. Elmore;H. Elderfield
报道了一种基于高分辨电感耦合等离子体质谱(HR-ICPMS)准确测定低质量天然碳酸盐(≤5µg CaCO_3)中B/Ca的新方法，采用混合酸基质(0.1M HNO_3和0.3M HF)和精确匹配技术。我们的程序B/Ca空白为2.0 ± 1.0µ / ，内精密度≤为1.0%，批内平均外精密度≤为4.0%(2σ)，快速样品分析(每天60个样品)使该方法非常适合常规测量。已建立的B/Ca测定方法需要≥65微克CaCO_3才能达到3.5%(2σ)的相对外部精密度。我们报告了B/Ca的检测下限为2µm o l/m o l，而以前方法的≥为10 m o l/m o l，提高了五倍。该方法可测定质量有限的样品中的B/Ca(9.0~250µm o l/m o l)，对基质匹配效率(≤±30%)有较大的容差。在含有~lt；20、∼85和∼200微克分子/摩尔的B/Ca的剑桥内部一致性标准上测量的B/Ca的长期重复性分别为±3.7%(2σ，n = 100)、±3.9%(2σ，n = 150)和±3.2%(2 S，n=180)。从含有≤5微克CaCO_3的样品中，还可以以类似的外部精密度测定许多其他微量元素与钙的比率。该方法适用于单个有孔虫贝壳的微量元素分析。
We report a new method for HR‐ICP‐MS based accurate and precise B/Ca determination from low mass natural carbonates (≤5 µg CaCO3), utilizing a mixed acid matrix (0.1 M HNO3 and 0.3 M HF) and accurate matrix matching technique. Our procedural B/Ca blank of 2.0 ± 1.0 µmol/mol, internal precision ≤1.0%, average within run external precision ≤4.0% (2σ), and rapid sample analysis (60 samples/day) make the method well suited for routine measurements. Established methods of B/Ca determination require ≥65 µg CaCO3 to achieve a comparable external precision of 3.5% (2σ). We report a B/Ca detection limit of 2 µmol/mol compared to ≥10 µmol/mol for previous methods, a fivefold improvement. The method presented here can determine a wide range of B/Ca (9.0–250 µmol/mol) in mass limited samples with considerable tolerance for matrix matching efficiency (≤±30%). The long‐term reproducibility of B/Ca measured on Cambridge in‐house consistency standards containing <20, ∼85, and ∼200 µmol/mol of B/Ca are ±3.7% (2σ, n = 100), ±3.9% (2σ, n = 150), and ±3.2% (2 s, n =180), respectively. A host of other trace element to Ca ratios can also be determined at comparable external precision from samples containing ≤5 µg CaCO3. This method is suitable for trace element analysis of single foraminifera shells.