Establishment of High Precision Cd Isotope Analysis Method and Its Geological Application
-
摘要:
镉（Cd）有8个稳定同位素，且具有高度挥发性（半凝聚温度Tc=430 K，1 Pa），导致其在地球和陨石中的丰度都很低，这给精确测试Cd同位素带来了极大难度。近年来随着多接收电感耦合等离子质谱（MC-ICP MS）的广泛应用，使得精确测定Cd同位素比值成为可能。笔者优化了Cd的分离纯化步骤，并建立了采用双稀释剂校正的高精度Cd同位素测试方法。通过优化酸性体系、树脂体积、淋洗液浓度和淋洗液量，Cd的回收率达到 99.5%，残留元素/Cd比率＜0.07%，可以有效地实现Cd与基质元素（Zn、Ga、Ge、Zr、Nb、Mo、Pd、Ag、In、Sn、Sm、Pb）的分离，能更好地满足Cd同位素的测定要求。已有研究表明，热液系统中的地质过程（如硫化物沉淀、流体运移及温度变化等）会导致Cd同位素分馏，尤其是在低温体系中分馏作用显著，而高温体系中分馏作用较弱。Cd同位素数据在铅锌矿床的成因类型判别、成矿流体演化以及成矿物质来源示踪等矿床学研究中具有重要意义。使用文中建立的新方法，笔者对铜陵地区的新桥和荷花山矿区的闪锌矿样品进行了测试，测得的Cd同位素数据指示了铅锌矿床的成因类型判别、成矿流体演化以及成矿物质来源等地质问题。
Abstract:Cadmium (Cd) has eight stable isotopes and is highly volatile (semi-condensed temperature Tc=430 K, 1 Pa), resulting in low abundance in the earth and meteorites, which makes it very difficult to accurately measure Cd isotopes. In recent years, with the wide application of multi-receiver inductively coupled plasma mass spectrometry (MC-ICP MS), it is possible to accurately determine the isotope ratio of Cd. In this paper, the separation and purification steps of Cd were optimized, and a high precision Cd isotope measurement method with double diluent correction was established. By optimizing the acid system, resin volume, eluent concentration and eluent volume, the recovery rate of Cd is 99.5%, and the residual element/Cd ratio & lt≤0.07%, which can effectively realize the separation of Cd from matrix elements (Zn, Ga, Ge, Zr, Nb, Mo, Pd, Ag, In, Sn, Sm, Pb) and better meet the requirements of Cd isotope determination. Previous studies have shown that geological processes in hydrothermal systems, such as sulfide precipitation, fluid migration and temperature changes, will lead to Cd isotope fractionation, especially in low temperature systems, while in high temperature systems, fractionation is weak. Cd isotope data are of great significance in the discrimination of genetic types of lead-zinc deposits, the evolution of ore-forming fluids and the tracing of ore-forming material sources. Using the new method established in this paper, we have tested the sphalerite samples from Xinqiao and Hehuashan mining areas in Tongling area. The measured Cd isotope data indicate the geological problems such as genetic type discrimination, ore-forming fluid evolution and ore-forming material sources of lead-zinc deposits.
-
Key words:
- Cd isotope /
- separation and purification /
- MC-ICP MS /
- Double diluents
-
-
表 1 Cd在层析柱中分离纯化过程
Table 1. Separation and purification process of Cd in chromatography column
试剂 用量 备注 AG-MP-1M树脂 1.3 ml 填充树脂 0.5 N HNO3 5 ml 清洗树脂 Mini Q H2O 5 ml 清洗树脂 0.25 N HBr 5 ml 平衡树脂 0.25 N HBr 2 ml 上样 0.25 N HBr 12 ml 淋洗基质 2 N HCl 2 ml 转换体系 0.05 N HCl 14 ml 洗脱Pb 0.0006 N HCl12 ml 回收Cd Mini Q H2O 10 ml 清洗树脂 
下载: 导出CSV
表 2 NIST 3108和双稀释剂Cd同位素组成
Table 2. Isotope composition of NIST 3108 and double diluent Cd
同位素 NIST 3108 双稀释剂 110Cd 0.127 0.008 111Cd 0.131 0.502 112Cd 0.246 0.015 113Cd 0.125 0.461 114Cd 0.294 0.013 116Cd 0.077 0.001
下载: 导出CSV
表 3 Neptune Plus测试过程中的仪器参数
Table 3. Instrument parameters during Neptune Plus testing
参数 值 冷却气 ～16 l/min 辅助气 ～0.8 l/min 雾化气 ～0.85 l/min 分辨率 低分辨 锥组合 Jet + X （nickel） RF能量 1200 膜去溶 Aridus II 吹扫气 ～1.1/min 雾化流量器 ～100 μl/min 检测器 Faraday cup 灵敏度 ～300 V/ppm 114Cd 循环次数 30 cycle/次*2次 积分时间 4.194 s 清洗时间 240 s
下载: 导出CSV
-
[1] 段桂玲, 段瑞春, 等. 土壤样品镉同位素分析中Cd与Sn有效分离方法的改进[J]. 岩矿测试, 2016, 35（1）: 10−16.
DUAN Guiling, DUAN Ruichun, et al. Improvement on Effective Separation between Cadmium and Tin in Soil Samples for the Determination of Cadmium Isotopic Composition[J]. Rock and Mineral Analysis, 2016, 35(1): 10−16.
[2] 冯新斌, 曹晓斌, 付学吾, 等. 环境地球化学研究近十年若干新进展[J]. 矿物岩石地球化学通报, 2021, 40（2）: 253−289+516−517.
FENG Xinbin, CAO Xiaobin, FU Xuewu, et al. Some Progresses in Environmental Geochemistry Study in China in the Past Decade[J]. Bulletin of Mineraligy, Petrology and Geochemistry, 2021, 40(2): 253−289+516−517.
[3] 李海涛, 杨鑫, 雷华基, 等. 镉稳定同位素研究进展[J]. 岩矿测试, 2024, 44（7）: 1852−1857.
LI Haitao, YANG Xin, LEI Huaji, et al. Research Progress of Cadmium Stable Isotopes[J]. Rock and Mineral Analysis, 2024, 44(7): 1852−1857.
[4] 吕树彬, 杨婉琪, 李福生. 基于主成分分析和宽度学习系统的土壤铅镉重金属元素定量分析[J]. 光谱学与光谱分析, 2024, 44（7）: 1852−1857.
LÜ Shubin, YANG Wanqi, LI Fusheng. Quantitative Analysis of Lead and Cadmium Heavy Metal Elements in Soil Based on Principal Component Analysis and Broad Learning System[J]. Spectro-scopy and Spectral Analysis, 2024, 44(7): 1852−1857.
[5] 刘光贤, 袁峰, 邓宇峰, 等. 铜陵荷花山铅锌矿区闪长岩类LA-ICP-MS锆石U-Pb年代学、地球化学特征及地质意义[J]. 岩石学报, 2017, 33（11）: 3581−3598.
LIU Guangxian, YUAN Feng, DENG Yufeng, et al. Chronology, geochemical characteristics and geological significance of diorite LA-ICP-MS ZIRCON U-Pb in Hehuashan lead-zinc mining area, Tongling[J]. Acta Petrologica Sinica, 2017, 33(11): 3581−3598.
[6] 万丹, 陈玖斌, 张婷, 等. 镉同位素分馏及其在示踪土壤镉来源和迁移转化过程中的应用进展[J]. 岩矿测试, 2022, 41（3）: 341−352. doi: 10.3969/j.issn.0254-5357.2022.3.ykcs202203001
WAN Dan, CHEN Jiubin, ZHANG Ting, et al. Cadmium Isotope Fractionation and Its Applications in Tracing the Source and Fate of Cadmium in the Soil: A Review[J]. Rock and Mineral Analysis, 2022, 41(3): 341−352. doi: 10.3969/j.issn.0254-5357.2022.3.ykcs202203001
[7] 王伟中, 张朝晖, 温汉捷, 等. 镉同位素在古环境重建中的应用: 以晚泥盆世弗拉期-法门期生物灭绝事件为例[J]. 矿物岩石地球化学通报, 2020, 39（1）: 80−88.
WANG Weizhong, ZHANG Zhaohui, WEN Hanjie, et al. The Application of Cd Isotopes in the Paleo-environment Reconstruction: A Case Study of the Frasnian-Famennian Mass Extinction Event in the Late Devonian[J]. Bulletin of Mineraligy, Petrology and Geochemistry, 2020, 39(1): 80−88.
[8] 王银泉. 铜陵市新桥矿区土壤重金属污染评价及源解析研究[D]. 合肥: 合肥工业大学, 2014.
WANG Yinquan. Pollution Assessment and Source Apportionment ofHeavy Metals in Soils around XinQiao Mining Area inTongling, Anhui ProvinceByWang Yinquan[D]. Hefei: Hefei University of Technology, 2014.
[9] 谢胜凯, 曾远, 刘瑞萍, 等. AG-MP-1M在氢溴酸体系中分离镉的方法[J]. 核化学与放射化学, 2020, 42（4）: 256−261. doi: 10.7538/hhx.2020.YX.2019094
XIE Shengkai, ZENG Yuan, LIU Ruiping, et al. Separation of Cadmium in Hydrobromic Acid by Anion Resin AG-MP-1M[J]. Journal of Nuclear and Radiochemistry, 2020, 42(4): 256−261. doi: 10.7538/hhx.2020.YX.2019094
[10] 张羽旭, 温汉捷, 樊海峰, 等. Cd同位素地质样品的预处理方法研究[J]. 分析测试学报, 2010, 29（6）: 633−637.
ZHANG Yuxu, WEN Hanjie, FAN Haifeng, et al. Chemical Pre-treatment Methods For Measurement of Cd Isotopeic Ratio on Geological Samples[J]. Journal of Instrumental Analysis, 2010, 29(6): 633−637.
[11] 朱传威, 温汉捷, 张羽旭, 等. Cd稳定同位素测试技术进展及其应用[J]. 地学前缘, 2015, 22（5）: 115−123.
ZHU Chuanwei, WEN Hanjie, ZHANG Yuxu, et al. Analtical technique for cadmium stable isotopes and its applications.[J]. Earth Science Frontiers, 2015, 22(5): 115−123.
[12] Abouchami W, Galer G J S, Horner J T, et al. A Common Reference Material for Cadmium Isotope Studies–NIST SRM 3108[J]. Geostandards and Geoanalytical Research, 2013, 37(1): 5−17.
[13] Albarède F, Beard B. Analytical Methods for Non-Traditional Isotopes[J]. Reviews in Mineralogy and Geochemistry, 2004, 55(1): 113−152.
[14] Bao Zhongwen, Al Tom, Bain J, et al. Sphalerite weathering and controls on Zn and Cd migration in mine waste rock: An integrated study from the molecular scale to the field scale[J]. Geochimica et Cosmochimica Acta, 2022, 318: 1−18.
[15] Cloquet C, Rouxel O, Carignan J, et al. Natural Cadmium Isotopic Variations in Eight Geological Reference Materials (NIST SRM 2711, BCR 176, GSS-1, GXR-1, GXR-2, GSD-12, Nod-P-1, Nod-A-1) and Anthropogenic Samples, Measured by MC-ICP-MS[J]. Geostandards and Geoanalytical Research, 2005, 29(1): 95−106.
[16] Feng L, Zhou L, Yang L, et al. Optimization of the double spike technique using peak jump collection by a Monte Carlo method: an example for the determination of Ca isotope ratios[J]. Journal of Analytical Atomic Spectrometry, 2015, 30(12): 2403−2411.
[17] Guo C, Li T, Li G, et al. Precise/small sample size determination of stable Cd isotope ratios of geological samples with double spike MC-ICP-MS[J]. Journal of Analytical Atomic Spectrometry, 2022, 37(11): 2470−2479.
[18] Lacan F, Francois R, Ji Y, et al. Cadmium isotopic composition in the ocean[J]. Geochimica Et Cosmochimica Acta, 2006, 70(20): 5104−5118.
[19] Klaver M, Coath D C. Obtaining Accurate Isotopic Compositions with the Double Spike Technique: Practical Considerations[J]. Geostandards and Geoanalytical Research, 2019, 43(1): 5−22.
[20] Lodders, Katharina. Solar System Abundances and Condensation Temperatures of the Elements[J]. Astrophysical Journal, 2003, 591(2): 1220−1247.
[21] Rehkämper M, Wombacher F, Horner T J, et al. Natural and anthropogenic cd isotope variations. Handbook of Environmental Isotope Geochemistry Advances in Isotope Geochemistry[M]. Berlin: Springer, 2012: 125–154.
[22] Rosman K J R, Laeter J R D. Cadmium mass fractionation in unequilibrated ordinary chondrites[J]. Earth & Planetary Science Letters, 1988, 89(2): 163−169.
[23] Rosman K J R, deLaeter J R. The isotopic composition of cadmium in terrsetrial minerals[J]. International Journal of Mass Spectrometry and Ion Physic, 1975, 16: 385−394.
[24] Rudge J F, Reynolds B C, Bourdon B. The double spike toolbox[J]. Chemical Geology, 2009, 265(3−4): 420−431.
[25] Strelow F W E. Distribution coefficients and anion exchange behavior of some elements in hydro bromicnitric acid mixtures[J]. Analytical Chemistry, 1978, 50(9): 1359−1361. doi: 10.1021/ac50031a041
[26] Wen H, Zhu C, Zhang Y, et al. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits[J]. Scientific Reports, 2016, 6: 25273.
[27] Wombacher F, Rehkämper M, et al. Cadmium stable isotope cosmochemistry[J]. Geochimica et Cosmochimica Acta, 2008, 72(2): 646−667.
[28] Wombacher F, Rehkämper M, Mezger K, et al. Stable isotope compositions of cadmium in geological materials and meteorites determined by multiple-collector ICPMS[J]. Geochimica et Cosmochimica Acta, 2003, 67(23): 4639−4654.
[29] Xu C, Zhong H, Hu R, et al. Sources and ore-forming fluid pathways of carbonate-hosted Pb–Zn deposits in Southwest China: implications of Pb–Zn–S–Cd isotopic compositions[J]. Mineralium Deposita, 2020, 55: 491−513.
[30] Xue Z, Rehkamper M, Schonbachler M, et al. A new methodology for precise cadmium isotope analyses of seawater[J]. Analytical and Bioanalytical Chemistry, 2012, 402(2): 883−8933.
[31] Zhao Z, Li G, Wei J, et al. Zinc and cadmium isotopic constraints on metal sources of the Xitieshan Zn–Pb deposit, NW China[J]. Ore Geology Reviews. 2023, 162, 105723.
[32] Zhong Q H, Li J, Yin L, et al. A two-stage Cd purification method with anion exchange resin and BPHA extraction resin for high precision determination of Cd isotopic compositions by double spike MC-ICP-MS[J]. Journal of Analytical Atomic Spectrometry, 2023, 38: 939−949.
[33] Zhong Q H, Yin L, Li J, et al. A single-stage anion exchange separation method for Cd isotopic analysis in geological and environmental samples by MC-ICP-MS[J]. Journal of Analytical Atomic Spectrometry, 2023b, 38(11): 2291−2301.
[34] Zhong Qiaohui, Zhou Yuchen, Tsang D C W, et al. Cadmium isotopes as tracers in environmental studies: A review[J]. Science of The Total Environment, 2020, 736:139585.
[35] Zhu C, Wen H. Cadmium isotopic constraints on metal sources in the Huize Zn–Pb deposit, SW China[J]. Geoscience Frontiers, 2021, 12(6): 101241.
[36] Zhu C W, Wen H J, Fan H F, et al. Analytical technique of germanium stable isotopes and its geological applications[J]. Acta Petrologica et Mineralogica, 2014, 33(5): 965−970.
[37] Zhu C W, Wen H J, Zhang Y X, et al. Characteristics of Cd isotopic compositions and their genetic significance in the lead-zincdeposits of SW China[J]. Science China Earth Sciences, 2013, 56(12): 2056−2065.
-
图(5)
表(3)
计量
- 文章访问数: 89
- PDF下载数: 13
- 施引文献: 0