溶液进样与飞秒激光剥蚀多接收等离子体质谱分析硫化物矿物中S-Pb同位素组成研究

发布时间：2018-06-06 08:10

本文选题：多接收电感耦合等离子体质谱 + 飞秒激光剥蚀　；参考：《西北大学》2015年硕士论文

【摘要】：本文建立了以溶液雾化(SN)和飞秒激光剥蚀(fsLA)的进样方式,应用多接收等离子体质谱(MC-ICPMS)分析硫化物中S与Pb同位素组成的方法。研究内容如下：建立硫化物样品化学消解方法与溶液样品中S同位素分离纯化流程；研究SN与膜去溶雾化进样方式(DSN)的MC-ICPMS分析测试方法；利用266nm飞秒激光剥蚀与多接收等离子体质谱联用(fsLA-MC-ICPMS)原位微区分析测试硫化物中Pb同位素；本文应用不同类型MC-ICPMS仪器(小型Nu Plasma II与大型Nu Plasma 1700)初步建立S同位素分析测试方法,结果表明经化学消解、分离后测试结果的精密度和准确度均与国际现有报道值一致,可用于实际硫化物中S同位素研究。1.建立硫化物化学消解方法,用浓HNO3与浓HCl可将样品溶解并氧化至最高价态,利用AG 50-X8阳离子交换树脂分离纯化,S回收率大于97%。2.建立S同位素分析测试方法,采用标准-样品交叉(SSB)法,校正仪器的质量歧视效应及空间电荷效应；通过对比实验研究进样方式即溶液进样(湿法进样,wet plasma)与膜去溶进样(干法进样,dry plasma);S同位素分析采用TRA (Time Resolved Analysis)模式进行On-Peak-Zero方式扣除背景干扰；采用高纯水(MQ-H2O)比常用的2%HN03具有更快速背景清洗能力,并可扩大浓度匹配范围；对比不同分辨率(中分辨与高分辨模式)对分析测试结果影响,仪器分析所需分辨率与进样方式相关,DSN干法进样可消除多原子离子(O2+离子)干扰,采用中分辨率分析以提高灵敏度,而湿法进样中O2+离子干扰无法消除,采用高分辨模式分开干扰峰以获得准确结果；加入内标元素(C1元素)校正S同位素分析测试中存在的分馏效应, Cl同位素与S同位素在MC-ICPMS中的分馏效应不同无法有效校正S同位素；分析测试国际标准样品：IAEA-S-1, NBS-123及标准溶液Alfa-S,结果与文献报道值误差范围内完全一致,表明研究建立的分析方法可行,可用于实际硫化物样品中S同位素研究。3.通过Nu Plasma 1700大型高分辨多接收等离子体质谱(MC-ICPMS),采用高分辨率可消除S同位素分析测试中存在的多原子离子干扰,测试不同进样方式、浓度效应影响,分析测试国际标准样品(IAEA-S-2, IAEA-S-3与NBS.123)及标准溶液样品(Spex-S和Alfa-S) S同位素组成,实验结果与文献报道值误差范围内一致。4.建立fsLA-MC-ICPMS研究硫化物中Pb同位素组成原位微区分析技术,分馏效应及质量歧视效应采用内标TI (NIS TNBS 997)和外标(NIST SRM 610)相结合方式进行校正。利用研究建立的方法分析了都龙锡锌铟多金属矿带中的黄铜矿、黄铁矿和闪锌矿中Pb同位素组成。结果表明,不同矿物间及相同矿物不同颗粒间Pb含量差异大,Pb含量高于10μg/g的黄铜矿和闪锌矿颗粒显示了一致的Pb同位素分布,而Pb含量高于100μg/g的所有硫化物颗粒均具有误差范围内一致的Pb同位素组成,且与化学法得到的结果误差范围内吻合,表明本研究方法结果可靠。
[Abstract]:In this paper, a method for the determination of S and Pb isotopic compositions in sulfides by multi-receiver plasma mass spectrometry (MC-ICPMSs) has been established by using the injection method of solution atomization (SNN) and femtosecond laser denudation (fsla). The main contents of the study are as follows: to establish the chemical digestion method of sulfide sample and the separation and purification process of S isotope in solution sample, to study the MC-ICPMS analysis and test method of SN and membrane desolvent atomization injection method; 266nm femtosecond laser denudation and multi-receiver plasma-mass spectrometry were used to analyze the Pb isotopes of sulfides in situ, and different types of MC-ICPMS instruments (small Nu Plasma II and large Nu Plasma 1700) were used to establish a S-isotope analysis method. The results show that the precision and accuracy of the test results after chemical digestion are consistent with those reported in the world and can be used for the study of S isotopes in actual sulfides. The sulphide chemical digestion method was established. The sample could be dissolved and oxidized to the highest valence state by using concentrated HNO3 and concentrated HCl. The recovery of S was more than 97. 2 by using AG 50-X8 cation exchange resin. The S isotope analysis and measurement method was established, and the quality discrimination effect and space charge effect of the instrument were corrected by the standard sample crossover SSBs method. The contrast experiment was carried out to study the methods of injection, that is, wet injection (wet injection) and dry injection (dry water Resolved analysis) to deduct background interference by using TRA time Resolved analysis model. The use of high purity water MQ-H2O has faster background cleaning ability than conventional 2%HN03, and can expand the range of concentration matching, and compare the effect of different resolution (medium resolution and high resolution mode) on the analysis and test results. The resolution required by instrument analysis is related to the way of injection. The interference of polyatomic ion O 2 ion can be eliminated by dry sampling with DSN. The medium resolution analysis is used to improve the sensitivity, but the interference of O 2 ion in wet method can not be eliminated. The interference peaks are separated by high resolution mode to obtain accurate results. The fractionation effect in the analysis and testing of S isotopes is corrected by adding the internal standard element C 1. The fractionation effect of Cl isotope and S isotope in MC-ICPMS can not be corrected effectively by adding the fractionation effect of Cl isotope and S isotope in MC-ICPMS. The analytical results of the international standard sample: 1 IAEA-S-1, NBS-123 and standard solution Alfa-Sare in full agreement with the reported error range, which indicates that the established analytical method is feasible and can be used in the study of S isotopes in actual sulphide samples .3. By means of Nu Plasma 1700 large scale high resolution multi-receiver plasma mass spectrometry (MC-ICPMS), the interference of polyatomic ions in S isotope analysis can be eliminated by using high resolution, and the influence of different sampling methods and concentration effect can be tested. The isotopic compositions of IAEA-S-2, IAEA-S-3 and NBS.123 and standard solution samples were analyzed and tested. The experimental results were in agreement with the reported error range of .4. An in situ microanalysis technique for Pb isotopic composition in sulfides was established by fsLA-MC-ICPMS. The fractionation effect and mass discrimination effect were corrected by the combination of internal standard TI NIS TNBS 997) and external standard NIST SRM 610). The Pb isotopic compositions of chalcopyrite, pyrite and sphalerite in the Dulong tin, zinc and indium polymetallic ore belt were analyzed by the established method. The results show that the Pb contents of chalcopyrite and sphalerite with Pb content higher than 10 渭 g / g show consistent Pb isotopic distribution among different minerals and different particles of the same mineral. All sulphide particles with Pb content above 100 渭 g / g have the same Pb isotopic composition in the error range, which is consistent with that obtained by the chemical method, which indicates that this method is reliable.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P575;O657.63

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