Automatic Purification of Li Isotopes from Geological Samples by High-Pressure Ion Chromatography
-
摘要:
利用MC-ICP-MS进行Li同位素准确测定的前提是Li与其他元素(特别是Na)的完全分离，以避免同质异位素干扰和基体效应，并且回收率需要接近100%。多位学者对淋洗液种类、树脂种类、树脂粒度、柱管尺寸和树脂体积等进行交叉组合，提出了不少传统手工过柱Li同位素分离纯化方法，回收率达100%，但耗时1天或2天不等，流程繁琐。高压离子色谱仪在同位素分离纯化应用中，具有一次分离到位、分离时间短、在线量化分离组分的含量和纯度等优势，已成为同位素分离纯化的新趋势；但高压离子色谱仪同位素分离纯化应用案例报道中缺乏对高压离子色谱仪淋洗过程的系统研究，导致该分离方法应用有限。本文从同位素分离纯化角度，设计了多组条件实验，系统探索了高压离子色谱仪阳离子色谱柱的酸耐受性、载荷能力以及基体效应，并针对Li同位素，获得最佳淋洗条件，从而建立了利用高压离子色谱仪自动分离纯化Li的方法。实验结果表明，CS16阳离子色谱柱对样品溶液的酸度要求高(＜50mmol/L)，但载荷能力大(允许上样量为500ng/g的多元素混合标准溶液+2.5μg/g的K-Na-Ca-Mg溶液，1.5mL)，且基体效应不明显(50μg/g的K、Na、Ca、Mg，500ng/g的Fe以及500ng/g的Al加入对元素出峰位置没有影响)。本文通过优化样品溶样步骤，使样品溶液酸度降到30mmol/L，同时优化淋洗条件(淋洗液浓度30mmol/L，色谱柱流速1mL/min，温度60℃)，25min内完成Li的分离纯化。对4个国家地质标准物质(GBW07333、GBW07103、GBW07159和GBW07180)进行Li分离纯化，Li的回收率达99.3%以上，空白低于传统手工过柱方法，分离纯化的Li量也能满足MC-ICP-MS进行Li同位素分析测试需求。
Abstract:High-quality purification of lithium (Li) is crucial in measuring 7Li/6Li ratios of whole rocks precisely by MC-ICP-MS. Many scholars have proposed traditional manual Li purification methods by cross-combining the types of eluents, types of resin, resin particle size, column tube size, and resin volume. However, the process is still cumbersome. In contrast, high-pressure ion chromatography (HP-IC) provides single-step separation, shorter durations, and online quantification; it is underutilized due to insufficient systematic research on its elution processes. Here, an automatic purification method of Li by HP-IC was established by optimizing IC parameters, laying a foundation for the wide application of IC in the field of isotope purification. The testing results of Li collections for four national geological standard samples indicate that the recovery rate exceeds 99.3%, and the blank measurement is lower than that of the traditional manual column method. The amount of separated Li also meets the demand of MC-ICP-MS for Li isotope analysis. The BRIEF REPORT is available for this paper at
http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202407310165 . -
-
表 1 天然地质标准物质中相关元素含量的推荐值
Table 1. The recommended values of relevant element contents in natural geological reference materials
标准物质编号 元素含量推荐值 Li(μg/g) Na2O(%) K2O(%) MgO(%) CaO(%) GBW07103 (花岗岩) 131±7 3.13±0.09 5.01±0.10 0.42±0.05 1.55±0.07 GBW07104 (安山岩) 18.3±0.9 3.86±0.11 1.89±0.07 1.72±0.08 5.20±0.11 GBW07105 (玄武岩) 9.5±1.3 3.38±0.07 2.32±0.08 7.77±0.26 8.81±0.14 GBW07101 (超基性岩) 1.3±0.5 0.008±0.003 0.010±0.001 41.03±0.13 0.10±0.01 GBW07107 (页岩) 44±2 （0.35） 4.16±0.15 2.01±0.07 0.60±0.06 GBW07333 (黄海海洋沉积物) （88.5） 2.93±0.11 3.53±0.09 3.08±0.12 1.47±0.06 GBW07159 (稀土矿石) （69.68） 0.158±0.014 4.98±0.12 0.077±0.010 （0.026） GBW07180 (铝土矿) 567±40 （0.04） 0.19±0.02 0.31±0.03 （0.12） 注：括号内的数据为参考值。 
下载: 导出CSV
表 2 国家地质标准物质的元素测定值与推荐值对比
Table 2. Comparison of measured values and recommended values of elements in national geological reference materials
元素 GBW07103 GBW07104 GBW07105 测定值 推荐值 测定值 推荐值 测定值 推荐值 Li 134 131±7 17.3 18.3±0.9 8.5 9.50±1.30 Be 13 12.4±2.1 1.28 1.10±0.20 2.83 2.50±0.60 Sc 5.96 6.10±0.60 8.53 9.50±1.10 14.7 15.2±1.8 V 18.6 24.0±3.0 108 94±6 86.3 167.0±17.0 Cr 4.19 3.60±1.10 28.1 32.0±5.0 146 134±16 Co 2.75 3.40±1.00 11.3 13.2±1.5 53.3 32.0±5.2 Ni 2.3 2.30±1.20 16 17.0±2.0 140 140±11 Cu 3.55 3.20±1.30 54.6 55.0±4.0 50 49.0±4.0 Zn 31.4 28.0±4.0 76.3 71.0±7.0 166 150±15 Ga 18.2 19.0±2.0 17.3 18.1±2.1 23.8 24.8±1.3 Ge 0.09 2.00±0.80 0.05 0.93±0.40 0.11 0.98±0.23 Rb 450 466±26 37.7 38.0±5.0 22.2 37±6 Sr 107 106±9 782 790±54 1125 1100±64 Y 68 62.0±7.0 8.6 9.30±1.80 24.9 22.0±5.0 Zr 92.3 167±14 103 99±16 271 277±30 Nb 43 40.0±4.0 5.64 6.80±2.20 5.45 68±12 Mo 2.51 3.50±0.30 0.55 0.54±0.14 0.43 2.60±0.30 Cd 0.02 0.029±0.014 0.05 0.061±0.021 0.07 0.067±0.024 Cs 39.1 38.4±1.5 2.14 2.30±0.70 0.28 (0.7) Ba 354 343±45 1078 1020±70 572 527±40 La 57.4 54.0±5.0 25.2 22.0±3.0 59.2 56±7 Ce 104 108±11 38.6 40.0±3.0 98.9 105±12 Pr 14.1 12.7±0.8 4.54 4.90±0.40 14.2 13.2±1.6 Nd 47.5 47.0±5.0 20 19.0±2.0 54.1 54±5 Sm 10.3 9.7±1.2 3.68 3.40±0.30 11 10.2±0.7 Eu 0.91 0.85±0.10 1.16 1.02±0.07 3.51 3.20±0.30 Tb 1.64 1.65±0.13 0.39 0.41±0.07 1.27 1.20±0.20 Gd 9.41 9.30±0.80 2.97 2.70±0.40 9.48 8.50±0.70 Dy 10.1 10.2±0.4 1.9 1.85±0.20 5.73 5.60±0.30 Ho 2.08 2.05±0.22 0.35 0.34±0.03 0.92 0.88±0.05 Er 6.59 6.50±0.40 0.97 0.85±0.16 2.18 2.00±0.30 Tm 1.15 1.06±0.09 0.14 0.15±0.05 0.26 0.28±0.04 Yb 7.93 7.40±0.70 0.9 0.89±0.20 1.38 1.50±0.50 Lu 1.18 1.15±0.12 0.13 0.12±0.04 0.19 0.19±0.07 Hf 3.39 6.30±0.80 2.81 2.90±0.50 6.2 6.50±0.80 Ta 6.54 7.20±0.70 0.43 0.40±0.09 0.25 4.30±0.60 W 7.99 8.40±0.70 0.54 (0.45) 0.06 0.40±0.02 Tl 2.28 1.93±0.55 0.19 0.16±0.06 0.09 (0.12) Pb 33.6 31.0±4.0 9.8 11.30±2.80 2.5 7.00±4.00 Th 59.5 54.0±4.0 2.53 2.60±0.40 3.64 6.00±1.20 U 20.2 18.8±2.2 0.96 0.90±0.28 1.19 1.40±0.40 注：括号内的数据为参考值，单位均为μg/g。
下载: 导出CSV
表 3 国家地质标准样品Li馏分中Li元素含量和回收率
Table 3. Content and recovery rate of Li element in Li fractions in national geological samples
标准物质编号 样品溶液Li浓度
(ng/mL)进样量
(ng)收集溶液Li浓度
(ng/mL)收集量
(ng)回收率
(%)GBW07159 (稀土矿石) 70.0 14.0 13.0 14.3 101.9 GBW07333 (黄海海洋沉积物) 88.5 17.7 17.0 18.7 105.6 GBW07103 (花岗岩) 131 26.2 24.5 27.0 102.9 GBW07180 (铝土矿) 567 113.4 102.4 112.6 99.3
下载: 导出CSV
-
[1] Li W S, Liu X M, Chadwick O A, et al. Lithium isotope behavior in Hawaiian regoliths: Soil-atmosphere-biosphere exchanges[J]. Geochimica et Cosmochimica Acta, 2020, 285: 175−192. doi: 10.1016/j.gca.2020.07.012
[2] Liu X M, Rudnick R L. Constraints on continental crustal mass loss via chemical weathering using lithium and its isotopes[J]. Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(52): 20873−20880. doi: 10.1073/pnas.1115671108
[3] Zhang J W, Zhao Z Q, Yan, Y N, et al. Lithium and its isotopes behavior during incipient weathering of granite in the eastern Tibetan Plateau, China[J]. Chemical Geology, 2021, 559: 119969. doi: 10.1016/j.chemgeo.2020.119969
[4] Bergquist B A, Boyle E A. Iron isotopes in the Amazon river system: Weathering and transport signatures[J]. Earth and Planetary Science Letters, 2006, 248: 54−68. doi: 10.1016/j.jpgl.2006.05.004
[5] Ma L, Teng F Z, Jin L X, et al. Magnesium isotope fractionation during shale weathering in the shale hills critical zone observatory: Accumulation of light Mg isotopes in soils by clay mineral transformation[J]. Chemical Geology, 2015, 397: 37−50. doi: 10.1016/j.chemgeo.2015.01.010
[6] Teng F Z, Hu Y, Ma J L, et al. Potassium isotope fractionation during continental weathering and implications for global K isotopic balance[J]. Geochimica et Cosmochimica Acta, 2020, 278: 261−271. doi: 10.1016/j.gca.2020.02.029
[7] Liu X M, Rudnick R L, McDonough W F, et al. Influence of chemical weathering on the composition of the continental crust: Insights from Li and Nd isotopes in bauxite profiles developed on Columbia River basalts[J]. Geochimica et Cosmochimica Acta, 2013, 115: 73−91. doi: 10.1016/j.gca.2013.03.043
[8] Hindshaw R S, Tosca R, Goût T L, et al. Experimental constraints on Li isotope fractionation during clay formation[J]. Geochimica et Cosmochimica Acta, 2019, 250: 219−237. doi: 10.1016/j.gca.2019.02.015
[9] Murphy M J, Porcelli D, von Strandmann P V, et al. Tracing silicate weathering processes in the permafrost-dominated Lena River watershed using lithium isotopes[J]. Geochimica et Cosmochimica Acta, 2019, 245: 154−171. doi: 10.1016/j.gca.2018.10.024
[10] Yang C H, Vigier N, Yang S Y, et al. Clay Li and Nd isotopes response to hydroclimate changes in the Changjiang (Yangtze) Basin over the past 14,000 years[J]. Earth and Planetary Science Letters, 2021, 561: 116793. doi: 10.1016/j.jpgl.2021.116793
[11] Zhu G H, Ma J L, Wei G J, et al. Lithium isotope fractionation during the weathering of granite: Responses to pH[J]. Geochimica et Cosmochimica Acta, 2023, 345: 117−129. doi: 10.1016/j.gca.2022.12.028
[12] Elliott T, Thomas A, Jeffcoate A, et al. Lithium isotope evidence for subduction-enriched mantle in the source of mid-ocean-ridge basalts[J]. Nature, 2006, 443: 565−568. doi: 10.1038/nature05144
[13] Fan J J, Tang G J, Wei G J, et al. Lithium isotope fractionation during fluid exsolution: Implications for Li mineralization of the Bailongshan pegmatites in the West Kunlun, NW Tibet[J]. Lithos, 2020, 352−353: 105236. doi: 10.1016/j.lithos.2019.105236
[14] Miao W L, Zhang X Y, Li Y L, et al. Lithium and strontium isotopic systematics in the Nalenggele River catchment of Qaidam Basin, China: Quantifying contributions to lithium brines and deciphering lithium behavior in hydrological processes[J]. Journal of Hydrology (Part B), 2022, 614: 128630. doi: 10.1016/j.jhydrol.2022.128630
[15] 刘丽君, 王登红, 侯可军, 等. 锂同位素在四川甲基卡新三号矿脉研究中的应用[J]. 地学前缘, 2017, 24(5): 167−171. doi: 10.13745/j.esf.yx.2017-1-16
Liu L J, Wang D H, Hou K J, et al. Application of lithium isotope to Jiajika new No.3 pegmate lithium polymetallic vein in Sichuan[J]. Earth Science Frontiers, 2017, 24(5): 167−171. doi: 10.13745/j.esf.yx.2017-1-16
[16] Misra S, Froelich P N. Lithium isotope history of cenozoic seawater: Changes in silicate weathering and reverse weathering[J]. Science, 2012, 335(6070): 818−823. doi: 10.1126/science.1214697
[17] Liu M C, McKeegan K D, Goswami J N, et al. Isotopic records in CM hibonites: Implications for timescales of mixing of isotope reservoirs in the Solar nebula[J]. Geochimica et Cosmochimica Acta, 2009, 73: 5051−5079. doi: 10.1016/j.gca.2009.02.039
[18] Kaplan L, Wilzbach K E. Lithium isotope determination by neutron activation[J]. Analytical Chemistry, 1954, 26: 1797−1798. doi: 10.1021/ac60095a031
[19] Magna T, Wiechert U H, Halliday A N. Low-blank isotope ratio measurement of small samples of lithium using multiple-collector ICP-MS[J]. International Journal of Mass Spectrometry, 2004, 239: 67−76. doi: 10.1016/j.ijms.2004.09.008
[20] 唐清雨, 陈露, 田世洪, 等. 锂硼同位素MC-ICP-MS分析中的记忆效应研究[J]. 岩矿测试, 2024, 43(2): 201−212. doi: 10.15898/j.ykcs.202310260167
Tang Q Y, Chen L, Tian S H, et al. A study on memory effects in lithium and boron isotope analysis using MC-ICP-MS[J]. Rock and Mineral Analysis, 2024, 43(2): 201−212. doi: 10.15898/j.ykcs.202310260167
[21] Zhu G H, Ma J L, Wei G J, et al. A rapid and simple method for lithium purification and isotopic analysis of geological reference materials by MC-ICP-MS[J]. Frontiers in Chemistry, 2020, 8: 557489. doi: 10.3389/fchem.2020.557489
[22] Li X, Han G, Zhang Q, et al. Accurate lithium isotopic analysis of twenty geological reference materials by multi-collector inductively coupled plasma mass spectrometry[J]. Spectrochimica Acta Part B: Atomic Spectroscopy, 2022, 188: 106348. doi: 10.1016/j.sab.2021.106348
[23] Macpherson G L, Phan T T, Stewart B W. Direct determination (without chromatographic separation) of lithium isotopes in saline fluids using MC-ICP-MS: Establishing limits on water chemistry[J]. Journal of Analytical Atomic Spectrometry, 2015, 30(7): 1673−1678. doi: 10.1039/c5ja00060b
[24] Yoshimura T, Araoka D, Tamenori Y, et al. Lithium, magnesium and sulfur purification from seawater using an ion chromatograph with a fraction collector system for stable isotope measurements[J]. Journal of Chromatography A, 2018, 1531: 157−162. doi: 10.1016/j.chroma.2017.11.052
[25] Zhu Z Y, Yang T, Zhu X K. Achieving rapid analysis of Li isotopes in high-matrix and low-Li samples with MC-ICPMS: New developments in sample preparation and mass bias behavior of Li in ICPMS[J]. Journal of Analytical Atomic Spectrometry, 2019, 34(7): 1503−1513. doi: 10.1039/c9ja00076c
[26] Li W S, Liu X M, Godfrey L V. Optimisation of lithium chromatography for isotopic analysis in geological reference materials by MC-ICP-MS[J]. Geostandards and Geoanalytical Research, 2019, 43(2): 261−276. doi: 10.1111/ggr.12254
[27] Gou L F, Jin Z D, Deng L, et al. Effects of different cone combinations on accurate and precise determination of Li isotopic composition by MC-ICP-MS[J]. Spectrochimica Acta Part B: Atomic Spectroscopy, 2018, 146: 1−8. doi: 10.1016/j.sab.2018.04.015
[28] He M Y, Luo C G, Lu H, et al. Measurements of lithium isotopic compositions in coal using MC-ICP-MS[J]. Journal of Analytical Atomic Spectrometry, 2019, 34(9): 1773−1778. doi: 10.1039/c9ja00204a
[29] Lin J, Liu Y S, Hu Z C, et al. Accurate determination of lithium isotope ratios by MC-ICP-MS without strict matrix-matching by using a novel washing method[J]. Journal of Analytical Atomic Spectrometry, 2016, 31(2): 390−397. doi: 10.1039/c5ja00231a
[30] 苏嫒娜, 田世洪, 李真真, 等. MC-ICP-MS高精度测定Li同位素分析方法[J]. 地学前缘, 2011, 18(2): 304−314.
Su Y N, Tian S H, Li Z Z, et al. High-precision measurement of lithium isotopes using MC-ICP-MS[J]. Earth Science Frontiers, 2011, 18(2): 304−314.
[31] Tomascak P B, Magna T, Dohemen R. Advances in lithium isotope geochemistry[M]. Switzerland: Springer International Publishing, 2016: 1−195.
[32] Xu L, Luo C, Wen H. A revisited purification of Li for ‘Na breakthrough’ and its isotopic determination by MC-ICP-MS[J]. Geostandards and Geoanalytical Research, 2020, 44(1): 201−214. doi: 10.1111/ggr.12305
[33] Chan L H. Lithium isotope analysis by thermal ionization mass spectrometry of lithium tetraborate[J]. Analytical Chemistry, 1987, 59(22): 2662−2665. doi: 10.1021/ac00149a007
[34] Nishio Y, Nakai S I. Accurate and precise lithium isotopic determinations of igneous rock samples using multi-collector inductively coupled plasma mass spectrometry[J]. Analytica Chimica Acta, 2002, 456(2): 271−281. doi: 10.1016/S0003-2670(02)00042-9
[35] Misra S, Froelich P N. Measurement of lithium isotope ratios by quadrupole-ICP-MS: Application to seawater and natural carbonates[J]. Journal of Analytical Atomic Spectrometry, 2009, 24(11): 1524−1533. doi: 10.1039/b907122a
[36] Bohlin M S, Misra S, Lloyd N, et al. High-precision determination of lithium and magnesium isotopes utilising single column separation and multi-collector iductively coupled plasma mass spectrometry[J]. Rapid Communications in Mass Spectrometry, 2018, 32(2): 93−104. doi: 10.1002/rcm.8020
[37] 宋以龙, 刘敏, 侯可军. 锂同位素阳离子交换树脂分离提纯方法与应用进展[J]. 岩矿测试, 2024, 43(5): 677−692. doi: 10.15898/j.ykcs.202409050181
Song Y L, Liu M, Hou K J. Research progress on separation and purification methods of lithium isotopes using cation exchange resin and their applications[J]. Rock and Mineral Analysis, 2024, 43(5): 677−692. doi: 10.15898/j.ykcs.202409050181
[38] Latkoczy C, Prohaska T, Watkins M, et al. Strontium isotope ratio determination in soil and bone samples after on-line matrix separation by coupling ion chromatography (HPIC) to an inductively coupled plasma sector field mass spectrometer (ICP-SFMS)[J]. Journal of Analytical Atomic Spectrometry, 2001, 16(8): 806−811. doi: 10.1039/b102797m
[39] Karasinski J, Bulska E, Wojciechowski M, et al. On-line separation of strontium from a matrix and determination of the 87Sr/86Sr ratio by ion chromatography/multi-collector-ICPMS[J]. Journal of Analytical Atomic Spectrometry, 2016, 31(7): 1459−1463. doi: 10.1039/c6ja00109b
[40] Schmitt A D, Gangloff S, Cobert F, et al. High performance automated ion chromatography separation for Ca isotope measurements in geological and biological samples[J]. Journal of Analytical Atomic Spectrometry, 2009, 24(8): 1089−1097. doi: 10.1039/b903303c
[41] Morgan L E, Santiago Ramos D P, Davidheiser-Kroll B, et al. High-precision 41K/39K measurements by MC-ICPMS indicate terrestrial variability of δ41K[J]. Journal of Analytical Atomic Spectrometry, 2018, 33(2): 175−186. doi: 10.1039/c7ja00257b
[42] Karasinski J, Bulska E, Wojciechowski M, et al. High precision direct analysis of magnesium isotope ratio by ion chromatography/multicollector-ICPMS using wet and dry plasma conditions[J]. Talanta, 2017, 165: 64−68. doi: 10.1016/j.talanta.2016.12.033
[43] Zakon Y, Halicz L, Gelman F. Isotope analysis of sulfur, bromine, and chlorine in individual anionic species by ion chromatography/multicollector-ICPMS[J]. Analytical Chemistry, 2014, 86(13): 6495−6500. doi: 10.1021/ac5010025
[44] Shimizu K, Suzuki K, Saitoh M, et al. Simultaneous determinations of fluorine, chlorine, and sulfur in rock samples by ion chromatography combined with pyrohydrolysis[J]. Geochemical Journal, 2015, 49(1): 113−124. doi: 10.2343/geochemj.2.0338
[45] García-Ruiz S, Moldovan M, Alonso J I G. Measurement of strontium isotope ratios by MC-ICP-MS after on-line Rb-Sr ion chromatography separation[J]. Journal of Analytical Atomic Spectrometry, 2008, 23(1): 84−93. doi: 10.1039/b708936h
[46] 董学林. 典型地质样品的前处理方法及其应用[D]. 武汉: 华中科技大学, 2020.
Dong X L. A study on new pretreatment methods for typical geological samples and their applications in trace analysis[D]. Wuhan: Huazhong University of Science and Technology, 2020.
-
图(6)
表(3)
计量
- 文章访问数: 135
- PDF下载数: 36
- 施引文献: 0