Xu Jingyao et al. AC: Accurate and efficient "online" matrix effect correction Sims white cloudstone oxygen isotope analysis method

Baiyun Stone is widely seen in various geological samples, such as carbonate rocks, marble rocks and thermal veins. It is worth noting that Baiyun Stone is also a common mineral of high -temperature rocks such as Kingsley rock and carbonate rocks from the mantle sources. These mantle source rocks carry the information of deep mantles, and often accompanied by important economic value mineral resources (such as diamond ore, rare earth, rare earth Mine, etc.). According to research, Baiyun Ebo in my country, Mountain Pass in the United States, and Australia

Mount Weld, mostly economic value, and other economic value are closely related to fire carbonate. Therefore, the oxygen isotonophyllin of white cloudstone can demonstrate the characteristics of the mantle source area of ​​the magma, the evolution of magma, and the later thermal fluid process to restrict important scientific issues such as crustal dive and recycling, mantle explanation, and rare earth mineral mining process. However, Bai Yunshi often has the characteristics of multiple causes and multiple times. Traditional full analysis methods may obtain the result of multi -stage mixed.

Ion probe (SIMS) provides a new dimension for studying oxygen -containing in situ -content isotopes of oxygen -containing minerals, but using SIMS to perform high -quality oxygen isotope analysis of ingredient mines is extremely challenging. For minerals with great changes in the FE-MG ratio of Baiyun Stone, traditionally need to develop a series of label samples of the changing range of cover components (Fe#= Fe/(Fe+Mg)) to fit the correction curve. After the electronic probe is determined, the ion probe analysis is required before the electronic probe is determined, and the ion probe analysis is performed in the same area to correct the aluminopen distillation (matrix effect) analyzed by the ion probe caused by the component change. On the one hand, this traditional offline process is time -consuming and is essentially inaccessible, because the two instruments of electronic probes (EPMA) and SIMS are difficult to match (involving analysis of the size, depth, shape and location of the analysis of the beam spots) Essence On the other hand, for minerals with large changes in ingredients, the standard samples with different series of ingredients are very time -consuming and laborious processes. Therefore, evaluation and improvement of traditional offline methods are essential for the accurate and effective SIMS oxygen isotope of ingredients.

中国科学院地质与地球物理研究所岩石圈演化国家重点实验室许晶瑶博士后、合作导师李秋立研究员及合作者，成功建立了SIMS白云石氧同位素“在线”基体效应校正新方法，首次实现了SIMS准确且匹配Analysis of oxygen isotope (Δ18O) and Fe#values ​​(Figure 1). Based on their newly developed white cloud stone oxygen isotopes, using SIMS to measure the 18O-16O-56FE16O-24MG16O at the same time. The study found that the 56FE16O/24mg16O ratio can be used to replace the FE#value as the correction of the substrate effect (Figure 1) to observe the logistic equation. is based on

56Fe16O/24mg16o Δ18O online matrix effect correction of the best experience equation (Figure 2), which demonstrates that the "online" correction method is the preferably optional scheme of the accurate analysis of the white cloudstone Δ18o (Figure 3). In addition, the study also found that samples that have not changed Δ18O on the Δ18O of Δ18O may have uniform oxygen isotope composition, such as CTD-4 white cloud stone from fire carbonate (Figure 3); while the changes in the apparent Δ18O are not much The sample does not represent its real change range, such as 1006 white clouds with relatively low temperature causes (Figure 4). Therefore, the new "online" method can be used as a new strategy for the discipline of the same aspect -sample of the micro -region in the future. At the same time, CTD-4, a white cloud stone sample that has a large FE#change, but has an average oxygen isotope. It is a good label of online analysis. This sample can reduce the demand for the number of benchmarks to a certain extent. It is a micro area. Analyze the burden.

Figure 1 The correlation between the average FE/(Fe+Mg) value (EPMA) and the average 56FE16O/24mg18o ratio (SIMS) of the average FE/(Fe+Mg) value (EPMA)

Figure 2 SIMS online measurement data Hill (a) and logistic (b) equation fit results comparison. IMF*(RM-1001) (‰) is the value of the measuring deviation (IMF) to the 1001 standard of the instrument. The IMF*residual diagram of Hill (C) and Logistic (D) equation

Figure 3 CTD-4 Baiyun Stone Online and Offline Method Correcting the range of Δ18O changes observed

Figure 4 1006 Baiyun Stone Online and Offline Method Correcting the Δ18O change trend observed

Compared with the traditional offline correction method, the new "online" correction method is more accurate, simpler, more economical, and more efficient. The new method not only opens up a new idea for other complex matrix minerals (such as olives, garnet, and lone stone) in the future. The analysis of the earth and outside material has great potential.

J] Analytical Chemistry, 2022, 94,22,7944-7951. Doi: 10.1021/Acs.analchem.2C00759).The achievement was affected by the Fund Commission Youth Fund (42103023), the Chinese Postdoctoral Science Fund (2020M670447), and the National Key Laboratory of the National Key Laboratory (SKL-K202001) of the Institute of Geology and Geophysics of the Chinese Academy of Sciences (SKL-K202001) and the key deployment project (IGGCAS-201901) Commonly funded.Beautiful editor: Chen Feifei

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