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同位素等LA-ICP-MS分析数据处理软件ICPMSDataCal7.2

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发表于 2011-10-10 23:42:51 | 显示全部楼层 |阅读模式


为了方便大家写论文时对本实验室分析方法及仪器的正确描述,对中国地质大学地质过程与矿产资源国家重点实验室(GPMR)的元素和同位素等LA-ICP-MS分析方法描述如下,以供参考(2010.2.6)


l      U-Pb dating and traceelement analyses of zircon by LA-ICP-MS

U-Pb dating and trace element analyses of zircon wereconducted synchronously by LA-ICP-MS at the State Key Laboratory of GeologicalProcesses and Mineral Resources, China University of Geosciences, Wuhan. Detailed operatingconditions for the laser ablation system and the ICP-MS instrument and datareduction are the same as description by Liu et al. (2008a; 2010a; 2010b). Laser sampling was performedusing a GeoLas 2005. An Agilent 7500aICP-MS instrument was used to acquire ion-signal intensities. Helium wasapplied as a carrier gas. Argon was used as the make-up gas and mixed with thecarrier gas via a T-connector before entering the ICP. Nitrogen was added into the central gas flow(Ar+He) of the Ar plasma to decrease the detection limit and improve precision(Hu et al.,2008). Each analysisincorporated a background acquisition of approximately 20-30 s (gas blank)followed by 50 s data acquisition from the sample. The Agilent Chemstation was utilized for theacquisition of each individual analysis. Off-line selection andintegration of background and analyte signals, and time-drift correction and quantitative calibration for trace element analysesand U-Pb dating were performed by ICPMSDataCal (Liu et al.,2008a; Liu et al., 2010a).
Zircon 91500 was used as external standard for U-Pbdating, and was analyzed twice every 5 analyses. Time-dependent drifts of U-Th-Pb isotopicratios were corrected using a linearinterpolation (with time) for every fiveanalyses according to the variations of 91500 (i.e., 2 zircon 91500 + 5 samples + 2 zircon 91500)(Liu et al.,2010a). PreferredU-Th-Pb isotopic ratios used for 91500 are from Wiedenbeck et al. (1995). Uncertainty of preferred values for theexternal standard 91500 was propagated to the ultimateresults of the samples. Concordiadiagrams and weighted mean calculations were made using Isoplot/Ex_ver3 (Ludwig,2003). Trace elementcompositions of zircons were calibrated against multiple-referencematerials (BCR-2G and BIR-1G) combined with internal standardization(Liuet al., 2010a) (或者without applying internalstandardization (Liuet al., 2008a),具体分析采用的方法会因个人处理数据的方式不同而有变化,如不清楚可咨询实验室管理员). The preferred values of element concentrations for the USGS referenceglasses are from the GeoReM database (http://georem.mpch-mainz.gwdg.de/).
如果采用对薄片中锆石直接分析的方法,则请同时引用如下论文:
*ZongKQ, Liu YS, Gao CG, Hu ZC, Gao S, Gong HJ, 2010. In situ U-Pb dating and traceelement analysis of zircons in thin sections of eclogite: Refining constraintson the ultra-high pressure metamorphism of the Sulu terrane, China. Chem. Geol.269: 237-251. DOI: 10.1016/j.chemgeo.2009.09.021.

l      Trace element analysesby LA-ICP-MS

Major and traceelement analyses were conducted by LA-ICP-MS at the State Key Laboratory ofGeological Processes and Mineral Resources, China University of Geosciences, Wuhan.Detailedoperating conditions for the laser ablation system and the ICP-MS instrumentand data reduction are the same as description by Liu et al. (2008a). Laser sampling was performedusing a GeoLas 2005. An Agilent 7500aICP-MS instrument was used to acquire ion-signal intensities. Helium wasapplied as a carrier gas. Argon was used as the make-up gas and mixed with thecarrier gas via a T-connector before entering the ICP. Nitrogen was added into the central gas flow(Ar+He) of the Ar plasma to decrease the detection limit and improve precision(Hu et al.,2008). Each analysisincorporated a background acquisition of approximately 20-30 s (gas blank)followed by 50 s data acquisition from the sample. The Agilent Chemstation was utilized for theacquisition of each individual analysis. Element contentswerecalibrated against multiple-reference materials (BCR-2G, BIR-1G and BHVO-2G)without applying internal standardization (Liu et al., 2008a).Thepreferred values of element concentrations for the USGS reference glasses arefrom the GeoReM database (http://georem.mpch-mainz.gwdg.de/). Off-line selection and integration ofbackground and analyte signals, and time-drift correction and quantitative calibration were performedby ICPMSDataCal (Liu et al.,2008a; Liu et al., 2010a).

l      Analytic methods ofwhole rock

Whole rock samples were crushed in a corundum jaw crusher (to 60 mesh).About 60 g was powdered in an agate ring mill to less than 200 mesh. Thesamples were then digested by HF + HNO3 in Teflon bombs and analyzed with an Agilent7500a ICP-MS at the State Key Laboratory of Geological Processes and MineralResources, China University of Geosciences, Wuhan. The detailed sample-digestingprocedure for ICP-MS analyses and analytical precision and accuracy for traceelements are the same as description by Liuet al. (2008b).

l       锆石U-Pb同位素定年和微量元素含量分析


锆石微量元素含量和U-Pb同位素定年在中国地质大学(武汉)地质过程与矿产资源国家重点实验室(GPMR)利用LA-ICP-MS同时分析完成。激光剥蚀系统为GeoLas 2005,ICP-MS为Agilent 7500a。激光剥蚀过程中采用氦气作载气、氩气为补偿气以调节灵敏度,二者在进入ICP之前通过一个T型接头混合。在等离子体中心气流(Ar+He)中加入了少量氮气,以提高仪器灵敏度、降低检出限和改善分析精密度(Hu et al.,2008)。每个时间分辨分析数据包括大约20-30s的空白信号和50s的样品信号。对分析数据的离线处理(包括对样品和空白信号的选择、仪器灵敏度漂移校正、元素含量及U-Th-Pb同位素比值和年龄计算)采用软件ICPMSDataCal(Liu et al.,2008a; Liu et al., 2010a)完成。详细的仪器操作条件和数据处理方法同Liu etal. (2008a; 2010a; 2010b)。

锆石微量元素含量利用多个USGS参考玻璃(BCR-2G, BIR-1G)作为多外标、Si作内标的方法进行定量计算(Liu et al., 2010a).这些USGS玻璃中元素含量的推荐值据GeoReM数据库 (http://georem.mpch-mainz.gwdg.de/)。U-Pb同位素定年中采用锆石标准91500作外标进行同位素分馏校正,每分析5个样品点,分析2次91500。对于与分析时间有关的U-Th-Pb同位素比值漂移,利用91500的变化采用线性内插的方式进行了校正(Liu et al., 2010a). 锆石标准91500的U-Th-Pb同位素比值推荐值据Wiedenbecket al. (1995)。锆石样品的U-Pb年龄谐和图绘制和年龄权重平均计算均采用Isoplot/Ex_ver3 (Ludwig, 2003)完成。
如果采用对薄片中锆石直接分析的方法,则请同时引用如下论文:
*ZongKQ, Liu YS, Gao CG, Hu ZC, Gao S, Gong HJ, 2010. In situ U-Pb dating and traceelement analysis of zircons in thin sections of eclogite: Refining constraintson the ultra-high pressure metamorphism of the Sulu terrane, China. Chem. Geol.269: 237-251. DOI: 10.1016/j.chemgeo.2009.09.021.


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 楼主| 发表于 2011-10-10 23:42:58 | 显示全部楼层
l       矿物微区元素含量LA-ICP-MS分析

微区元素含量分析在中国地质大学(武汉)地质过程与矿产资源国家重点实验室(GPMR)利用LA-ICP-MS完成。激光剥蚀系统为GeoLas 2005,ICP-MS为Agilent 7500a。激光剥蚀过程中采用氦气作载气、氩气为补偿气以调节灵敏度,二者在进入ICP之前通过一个T型接头混合。在等离子体中心气流(Ar+He)中加入了少量氮气,以提高仪器灵敏度、降低检出限和改善分析精密度(Hu et al., 2008)。每个时间分辨分析数据包括大约20-30s的空白信号和50s的样品信号。详细的仪器操作条件同Liu et al. (2008a)。以USGS参考玻璃(如BCR-2G, BIR-1G 和BHVO-2G) 为校正标准,采用多外标、无内标法(Liu et al., 2008a)或多外标、内标法(Liu et al., 2010a)对元素含量进行定量计算(具体分析采用何种方法会因个人处理数据方式不同而有变化,如不清楚请咨询实验室管理员)。这些USGS玻璃中元素含量的推荐值据GeoReM数据库 (http://georem.mpch-mainz.gwdg.de/)。对分析数据的离线处理(包括对样品和空白信号的选择、仪器灵敏度漂移校正、元素含量计算)采用软件ICPMSDataCal (Liu et al., 2008a; Liu et al., 2010a)完成。

l       全岩微量元素含量分析

全岩微量元素含量在中国地质大学(武汉)地质过程与矿产资源国家重点实验室(GPMR)利用Agilent 7500a ICP-MS分析完成。用于ICP-MS分析的样品处理如下:(1)称取粉碎至大约200目的岩石粉末50mg于Teflon溶样器中;(2)采用Teflon溶样弹将样品用 HF + HNO3在195ºC条件下消解48小时;(3)将在120ºC条件下蒸干除Si后的样品用2%HNO3稀释2000倍,定容于干净的聚酯瓶。详细的样品消解处理过程、分析精密度和准确度同Liu et al. (2008b).





References

Hu, Z. C., Gao, S., Liu, Y. S., Hu, S. H., Chen, H. H. & Yuan, H. L. (2008). Signal enhancement in laser ablation ICP-MS by addition of nitrogen in the central channel gas. Journal of Analytical Atomic Spectrometry 23, 1093–1101.



Liu, Y., Gao, S., Hu, Z., Gao, C., Zong, K. & Wang, D. (2010a). Continental and oceanic crust recycling-induced melt-peridotite interactions in the Trans-North China Orogen: U-Pb dating, Hf isotopes and trace elements in zircons of mantle xenoliths. Journal of Petrology 51, 537-571.



Liu, Y., Hu, Z., Zong, K., Gao, C., Gao, S., Xu, J. & Chen, H. (2010b). Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS. Chinese Science Bulletin in press.



Liu, Y. S., Hu, Z. C., Gao, S., Günther, D., Xu, J., Gao, C. G. & Chen, H. H. (2008a). In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chemical Geology 257, 34-43.



Liu, Y. S., Zong, K. Q., Kelemen, P. B. & Gao, S. (2008b). Geochemistry and magmatic history of eclogites and ultramafic rocks from the Chinese continental scientific drill hole: Subduction and ultrahigh-pressure metamorphism of lower crustal cumulates. Chemical Geology 247, 133-153.



Ludwig, K. R. (2003). ISOPLOT 3.00: A Geochronological Toolkit for Microsoft Excel. Berkeley: Berkeley Geochronology Center, California.



Wiedenbeck, M., Alle, P., Corfu, F., Griffin, W. L., Meier, M., Oberli, F., Quadt, A. V., Roddick, J. C. & Spiegel, W. (1995). Three natural zircon standards for U-Th-Pb, Lu-Hf, trace element and REE analyses. Geostandards and Geoanalytical Research 19, 1-23.



发表于 2011-11-17 11:40:12 | 显示全部楼层

回帖奖励 +5 个铜币

好东西啊,谢谢
发表于 2014-5-19 14:20:54 | 显示全部楼层

回帖奖励 +5 个铜币

抱歉,该附件无法读取,怎么破~~
发表于 2015-10-15 10:09:13 | 显示全部楼层
同求,望解答
发表于 2016-5-1 12:19:19 | 显示全部楼层

好东西啊,谢谢谢谢分享
发表于 2018-2-24 00:45:13 | 显示全部楼层
很有价值。学习学习。
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