High-Precision Measurement of 187Os/188Os Isotope Ratios of Nanogram to Picogram Amounts of Os in Geological Samples by N-TIMS using Faraday Cups Equipped with 1013 Ω Amplifiers
High-Precision Measurement of 187Os/188Os Isotope Ratios of Nanogram to Picogram Amounts of Os in Geological Samples by N-TIMS using Faraday Cups Equipped with 1013 Ω Amplifiers
复制标题
使用配备 1013 Ω 放大器的法拉第杯，通过 N-TIMS 高精度测量地质样品中 Os 的纳克量与皮克量的 187Os/188Os 同位素比率
DOI：
10.1111/ggr.12269
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发表时间：
2019
影响因子：
3.8
通讯作者：
wang guiqin
中科院分区：
文献类型：
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作者：
wang guiqin
用静态法拉第杯和1013Ω放大器用N-TIMS测量了6个地质标准物质的N(187Os)/N(188Os)比值。结果表明，无论是用场效应计还是用二次电子倍增器测量，当每个样品分别加入1g~1g的BHO2和2g的Bcr-2时，重复性精度为2~3‰(2RSD，n=3)。当每个样品分别加入1g含350pg-1Os的BiR-2、493pgg-1的WGB-1或含13.3pgg-1 Os的0.5g WPR-1时，FCS测量的重复性精度为1~0.2pg(2RSD，n=3)，远好于二次电子倍增器的测量结果。而对于质量分数为4pg-1Os的~2g AGV-2，二次电子倍增器测量的重复性精度为3~4‰(相对标准偏差，n=3)，优于FCS的测量结果。在所分析的6个标准物质中，当试验部分质量为0.5-1g时，WPR-1和BIR-1a的Os同位素组成最均匀(2RSD分别为0.08%和0.23%)。
N(187Os)/N(188Os) ratios of six geological reference materials were measured using static Faraday cups (FCs) with 1013 Ω amplifiers by N-TIMS. Our results show that the repeatability precision was 2–3‰ (2 RSD, n = 3), when taking ~ 1 g of BHVO-2 with 76 pg g-1 of Os mass fraction and ~ 2 g of BCR-2 with 21 pg g-1 of Os mass fraction for each sample, whether measured by FCs or by secondary electron multiplier. The repeatability precision measured by FCs was 1–0.2‰ (2 RSD, n = 3) when taking ~ 1 g of BIR-2 with 350 pg g-1 of Os mass fraction, ~ 1 g of WGB-1 with 493 pg g-1 of Os mass fraction or ~ 0.5 g of WPR-1 with 13.3 ng g-1 of Os mass fraction for each sample, which is much better than those measured by secondary electron multiplier. Instead, when taking ~ 2 g of AGV-2 with 4 pg g-1 Os mass fraction, the repeatability precision measured by secondary electron multiplier is 3–4‰ (RSD, n = 3), which is better than those measured by FCs. Of the six reference materials analysed, WPR-1 and BIR-1a are the most homogeneous with regard to Os isotopic composition (2 RSD of 0.08% and 0.23%, respectively) when test portion masses are 0.5–1 g.