In situ Sr-Nd Isotopic Measurement of Apatite Using Laser Ablation Multi-collector Inductively Coupled Plasma-Mass Spectrometry
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摘要: 磷灰石是常见的副矿物，具有较高的Sr-Nd含量和较低的Rb含量，对其微区Sr-Nd同位素组成的准确测定可以为精细地质作用过程的探讨提供重要的地球化学信息。激光剥蚀-多接收器电感耦合等离子体质谱(LA-MC-ICPMS)具有分析速度快、分析精度高和空间分辨率高的特点，特别适合大量细颗粒磷灰石样品的Sr-Nd同位素分析，而同位素干扰的精确扣除和仪器质量歧视校正是原位微区分析准确获得Sr-Nd同位素比值的关键。本文利用 LA-MC-ICPMS技术，综合最新发表的Kr、Rb、稀土二价离子及钙聚合物对Sr同位素的干扰扣除方法和Sm对Nd同位素的干扰扣除方法，对仪器的质量歧视进行了校正，建立了磷灰石原位Sr-Nd同位素分析方法。用此方法对一个磷灰石国际标准样品Durango和两个实验室标准Apatite 1 和 PE进行了详细的Sr-Nd同位素测定，结果表明，对Sr-Nd含量足够高的磷灰石样品可以准确地获得其Sr-Nd同位素组成，测试结果与文献报道值或热电离质谱(TIMS)测试值在误差范围内一致，Sr同位素的测试精度 < 0.015%(2SD)，Nd同位素的测试精度 < 0.005%(2SD)，达到了国际同类实验室水平；且三个磷灰石标准样品同位素组成较为均一，都是理想的原位Sr-Nd同位素分析参考物质。
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关键词:
- 磷灰石 /
- Sr-Nd同位素 /
- 多接收器电感耦合等离子体质谱法 /
- 原位微区分析
Abstract: Apatite is a common accessory mineral, having a high Sr-Nd content and a low Rb content. The precise determination of micro-area Sr-Nd isotopic composition for apatite will provide important geochemical information for discussing the details of the geological process. Laser Ablation Multi-collector Inductively Coupled Plasma-Mass Spectrometry (LA-MC-ICPMS) technique has the characteristics of rapid analysis, high analytical precision and high spatial resolution, and is particularly suitable for Sr-Nd isotopic analysis of a large quantity of fine-grained apatite samples. The precise deduction of isotopic interference and calibration of instrument mass bias are crucial for in-situ analysis to obtain Sr-Nd isotopic ratio. In this article a method is described, which adopts LA-MC-ICPMS and combines with the newly published method for deduction of interferences, like Kr, Rb, divalent ions of REEs and calcium-containing polymer for Sr isotopes, Sm for Nd isotopes. The calibration of instrument mass bias is carried out, and the in-situ Sr-Nd isotopic analysis approach for apatite is established. The test results of Durango apatite standard, Apatite 1 and PE show that Sr-Nd isotopic composition of apatite sample with high Sr-Nd content can be accurately determined. The specific results are consistent with literature or the measured values by Thermal Ionization Mass Spectrometry (TIMS) within error. The measurement precision of Sr isotopes is < 0.015% (2SD), and that of Nd isotopes is < 0.005% (2SD). The established method is applied for Sr-Nd isotopic analysis of Durango apatite standard, Apatite 1 and PE (laboratory standard), respectively. The analysis results indicate that the Sr-Nd isotopic compositions of the three apatite samples are basically consistent, and can serve as ideal reference samples for in-situ Sr-Nd isotopic analysis. -
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表 1 激光测定Sr-Nd同位素的法拉第杯结构
Table 1. Collector cup configuration of the LA-MC-ICPMS for Sr-Nd isotopic measurement
Sr法拉第杯结构 法拉第杯 L4 L3 L2 L1 C H1 H2 H3 H4 质量数 83 83.5 84 85 85.5 86 86.5 87 88 待测元素同位素 83Kr+43Ca40Ar+43Ca40Ca+166Er 167Er 84Sr+84Kr+44Ca40Ar+44Ca40Ca+42Ca42Ca+168Er+168Yb+68Zn16O 85Rb+43Ca42Ca+170Yb 171Yb 86Sr+86Kr+46Ca40Ar+48Ca38Ar+46Ca40Ca+44Ca42Ca+43Ca43Ca+172Yb+54Fe32O 173Yb 87Sr+87Rb+44Ca43Ca+174Hf+71Ga16O 88Sr+48Ca40Ca+48Ca40Ca+46Ca42Ca+44Ca44Ca+176Hf+176Yb+176Lu+56Fe32O Nd法拉第杯结构 法拉第杯 L4 L3 L2 L1 C H1 H2 H3 H4 质量数 142 143 144 145 146 147 149 - - 待测元素同位素 142Nd+142Ce 143Nd 144Nd+144Sm 145Nd 146Nd 147Sm 149Sm - - 
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表 2 MC-ICP-MS仪器工作参数
Table 2. Instrumental parameters of MC-ICP-MS
工作参数 设定条件 RF功率 1250 W 冷却气流量 ~16.5 L/min 辅助气流量 ~0.9 L/min 样品气流量 ~1.2 L/min 积分时间 0.131 s,200 cycles 激光剥蚀系统 Newwave UP 213 nm 氦气流量 ~0.85 L/min 能量密度 13～15 J/cm2 剥蚀直径 80 μm,65 μm 剥蚀频率 20 Hz
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表 3 标准样品测试结果比较
Table 3. Comparison of analytical results for three potential reference apatites between different Laboratories
标准样品名称 w/10-6 87Sr/86Sr 147Sm/144Nd 143Nd/144Nd 方法 备注 Rb Sr Sm Nd Durango - - - ~1600 - 0.0867 0.512483±0.000004 溶液法MC-ICP-MS Foster等[9] Durango 0.05±0.02(2SD,N=6) 483±8(2SD,N=6) 224±5(2SD,N=6) 1568±24(2SD,N=6) 0.70634±0.00003(2SD,N=6) 0.0865±0.0017(2SD,N=6) 0.512487±0.000013(2SD,N=6) TIMS 本文 Durango - - - - 0.70629±0.00009(2SD,N=27) 0.0852±0.0010(2SD,N=25) 0.512498±0.000025(2SD，N=25) LA-MC-ICPMS(80 μm) 本文 Apatite 1 0.17±0.61(1SD,N=20,EPMA) 2582±23(1SD,N=20,EPMA) 206±5(1SD,N=20,EPMA) 1581±43(1SD,N=20,EPMA) 0.71138±0.00002(2SD,N=4)0.71137±0.00007(2SD,N=61) 0.0866±0.0005(2SD,N=90) 0.511334±0.000025(2SD,N=8)0.511342±0.000031(2SD,N=90) 溶液法MC-ICP-MSLA-MC-ICPMS 杨岳衡等[8]杨岳衡等[13] Apatite 1 - - - - 0.71136±0.00009(2SD,N=16) 0.0867±0.0010(2SD,N=15) 0.511336±0.000025(2SD,N=15) LA-MC-ICPMS(80 μm) 本文 PE 0.11±0.01(2SD,N=6) 490±21(2SD,N=6) 84±3(2SD,N=6) 626±24(2SD,N=6) 0.70868±0.00004(2SD,N=6) 0.0814±0.0008(2SD,N=6) 0.512145±0.000007(2SD,N=6) TIMS 本文 PE - - - - 0.70867±0.00009(2SD,N=42) 0.0820±0.0010(2SD,N=30) 0.512152±0.000025(2SD,N=30) LA-MC-ICPMS(80 μm) 本文
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[1] Chen F K, Hegner E, Todt W. Zircon ages, Nd isotopic and chemical compositions of orthogneisses from the Black Forest, Germany—Evidence for a Cambrian magmatic arc [J].International Journal of Earth Science, 2000, 88: 791-802. doi: 10.1007/s005310050306
[2] 祝禧艳,陈福坤,杨一增,胡蓉.微区-微量样品Rb-Sr同位素分析技术及其应用前景[J].岩石学报,2010,26(1): 325-332. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201001037.htm
[3] Rehkamper M, Schonbachler M, Stirling C H. Multiple collector ICP-MS: Introduction to instrumentation, measurement techniques and analytical capabilities [J].Geostandard Newsletter, 2001,25: 23-40. doi: 10.1111/ggr.2001.25.issue-1
[4] Ramos F C, Woff J A, Tollstrup D L. Measuring 87Sr/86Sr variation in minerals and groundmass from basalts using LA-MC-ICPMS [J].Chemical Geology, 2004, 211: 135-158. doi: 10.1016/j.chemgeo.2004.06.025
[5] Woodhead J, Swearer S, Hergt J, Maas R. In situ Sr-isotope analysis of carbonates by LA-MC-ICPMS: Interference corrections, high spatial resolution and an example from otolith studies [J].Journal of Analytical Atomic Spectrometry, 2005,20: 22-27. doi: 10.1039/b412730g
[6] Yang Y H, Wu F Y, Wilde S A, Liu X M, Zhang Y B, Xie L W, Yang J H. In situ perovskite Sr-Nd isotope constrains on petrogenesis of the Mengyin kimberlites in the North China Craton [J].Chemical Geology, 2009,264:24-42. doi: 10.1016/j.chemgeo.2009.02.011
[7] 宗克清,刘勇胜,高长贵,袁洪林,陈海红.CCSD榴辉岩中磷灰石微区微量元素和Sr同位素组成研究[J].岩石学报,2007,23(12): 3267-3274. doi: 10.3969/j.issn.1000-0569.2007.12.019
[8] 杨岳衡,吴福元,谢烈文,杨进辉,张艳斌.地质样品Sr同位素激光原位等离子体质谱(LA-MC-ICPMS)测定[J].岩石学报,2009,25(12): 3431-3441. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200805013.htm
[9] Foster G L, Vance D. In situ Nd isotopic analysis of geological materials by laser ablation MC-ICP-MS [J].Journal of Analytical Atomic Spectrometry, 2006,21: 288-296. doi: 10.1039/b513945g
[10] Foster G L, Carter A.Insights into the patterns and locations of erosion in the Himalaya—A combined fission-track and in situ Sm-Nd isotopic study of detrital apatite [J].Earth and Planet Science Letter, 2007, 257: 407-418. doi: 10.1016/j.epsl.2007.02.044
[11] McFarlane C R M, McCulloch M T. Coupling of in-situ Sm-Nd systematics and U-Pb dating of monazite and allanite with applications to crustal evolution studies [J].Chemical Geology, 2007, 245: 45-60. doi: 10.1016/j.chemgeo.2007.07.020
[12] Fisher C F, McFarlane C R M, Hanchar J M, Schmitz M D, Sylvester P J, Lam R, Longerich H P. Sm-Nd isotope systematics by laser ablation-multicollector-inductively coupled plasma mass spectrometry: Methods and potential natural and synthetic reference materials [J].Chemical Geology,2011,284: 1-20. doi: 10.1016/j.chemgeo.2011.01.012
[13] 杨岳衡,孙金凤,谢烈文,范宏瑞,吴福元.地质样品Nd同位素激光原位等离子体质谱(LA-MC-ICPMS)测定[J].科学通报,2008,53(5): 568-576. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200805013.htm
[14] Wu F Y, Yang Y H, Mitchell R H, Bellatreccia F, Li Q L, Zhao Z F. In situ U-Pb and Nd-Hf-(Sr) isotopic investigations of zirconolite and calzirtite [J].Chemical Geology, 2010, 277: 178-195. doi: 10.1016/j.chemgeo.2010.08.007
[15] Donnelly C L, Griffin W L, Yang J H, O’Reilly S Y, Li Q L,Pearson N J,Li X H. In situ U-Pb dating and Sr-Nd isotopic analysis of perovskite: Constraints on the age and petrogenesis of the Kuruman Kimberlite Province, Kaapvaal Craton, South Africa [J].Journal of Petrology, 2012,53(12): 2497-2522. doi: 10.1093/petrology/egs057
[16] Jochum K P, Wilson S A, Abouchami W, Amini M, Chmeleff J, Eisenhauer A, Hegner E, Iaccheri L M, Kieffer B, Krause J, McDonough W F, Mertz-Kraus R, Raczek I, Rudnick R L, Scholz D, Steinhoefel G, Stoll B, Stracke A, Tonarini S, Weis D, Weis U, Woodhead J D.GSD-1G and MPI-DING reference glasses for in situ and bulk isotopic determination [J].Geostandards and Geoanalytical Research,2010,35(2): 193-226.
[17] Straub S M, Goldstein S L, Class C, Schmidt A, Gomez-Tuena A. Slab and mantle controls on the Sr-Nd-Pb-Hf isotope evolution of the post 42Ma Izu-Bonin volcanic arc [J].Journal of Petrology,2010,51(5): 993-1026. doi: 10.1093/petrology/egq009
[18] Dilek Y, Furnes H, Shallo M. Geochemistry of the Jurassic Mirdita Ophiolite (Albania) and the MORB to SSZ evolution of a marginal basin oceanic crust [J].Lithos,2008,100: 174-209. doi: 10.1016/j.lithos.2007.06.026
[19] BeierC, Turner S P, Sinton J M, Gill J B. Influence of subducted components on back-arc melting dynamics in the Manus Basin, Geochem [J]. Geochemistry, Geophysics, Geosystems, 2010,11, Q0AC03, doi:10.1029/2010GC003037.
[20] Stouraiti C, Mitropoulos P, Tarney J, Berreiro B, McGrath A M, Baltatzis E. Geochemistry and petrogenesis of late Miocene granitoids, Cyclades, southern Aegean: Nature of source components [J].Lithos, 2010,114: 337-352. doi: 10.1016/j.lithos.2009.09.010
[21] Vroon P Z, Wagt B V D, Koornneef J M, Davies G R. Problems in obtaining precise and accurate Sr isotope analysis from geological materials using laser ablation MC-ICP-MS [J]. Analytical and Bioanalytical Chemistry, 2008,390: 465-476. doi: 10.1007/s00216-007-1742-9
[22] Paton C, Woodhead J, Hergt J, Phillips D, Shee S. Sr isotope analysis of Kimberlitic groundmass perovskite via LA-MC-ICPMS[J].Geostandards and Geoanalyitical Research, 2007, 31: 321-320.
[23] Waight T, Baker J, Peate D. Sr isotope ratio measure-ments by double-focusing MC-ICP-MS: Techniques, observations and pitfalls [J].International Journal of Mass Spectrometry, 2002, 221: 229-244. doi: 10.1016/S1387-3806(02)01016-3
[24] Dubois J C, Retali G, Cesario J. Isotopic analysis of rare earth elements by total vaporization of samples in thermal ionization mass spectrometry [J].International Journal of Mass Spectrometry and Ion Processes, 1992,120: 163-177. doi: 10.1016/0168-1176(92)85046-3
[25] Isnard H, Brennetot R, Caussignac C, Caussignac N, Chartier F.Investigations for determination of Gd and Sm isotopic compositions in spent nuclear fuels samples by MC ICPMS [J].International Journal of Mass Spectrometry, 2005, 246: 66-73. doi: 10.1016/j.ijms.2005.08.008
[26] 杨岳衡,张宏福,谢烈文,吴福元.多接收器电感耦合等离子体质谱精确测定钕同位素组成[J].分析化学,2007,35(1): 71-74. http://www.cnki.com.cn/Article/CJFDTOTAL-FXHX200701018.htm
[27] McDowell F W, McIntosh W C, Farley K A. A precise 40Ar-39Ar reference age for the Durango apatite (U-Th)/He and fission- track dating standard [J].Chemical Geology, 2005,214: 249-263. doi: 10.1016/j.chemgeo.2004.10.002
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