双稀释剂—多接收器电感耦合等离子体质谱铬同位素分析方法
发布时间：2018-08-03 10:12
【摘要】：本研究建立了阳离子交换树脂分离铬元素的化学流程和多接收器电感耦合等离子体质谱仪铬同位素分析方法。在分析过程中,采用50Cr-54Cr双稀释剂法对化学分离和质谱分析过程中产生质量分馏进行校正。本研究采用AG50W-X8阳离子交换树脂,经过两次化学分离,将纯橄岩、玄武岩和页岩中的铬与基质元素分开。第一次化学分离铬元素的回收率约90%,第二次的回收率为98%,总回收率约为90%。研究发现,玄武岩和页岩样中的Al、Ti元素会在树脂中出现过载现象,因而提前被洗脱,经过第二次化学分离后,可以将Al、Ti等元素进一步的除去。经过两次化学分离后,样品中的Ti/Cr小于5.3×10-4,V/Cr小于2.5×10-4,Fe/Cr小于2.4×10-4。Al、Ti和V的基质效应研究表明,样品纯化后含有极少量的Ti、Fe、V,不会影响样品的Cr同位素组成。经The double-spike软件模拟计算,双稀释剂的最优组成为50Cr/54Cr=1.41;样品与双稀释剂的最佳混合质量比例为28.33:71.67。实际标定的双稀释剂组成为50Cr/54Cr=1.74。采用双稀释剂法校正仪器的质量分馏,NIST SRM979自测的长期重现性为δ~(53)Cr(‰)=0.00±0.06(2SD,N=20)。NIST3112a相对于NIST SRM979的结果为δ~(53)Cr(‰)=-0.05±0.07(2SD,N=8)。NIST3112a的结果与已发表的结果在误差范围内一致,且精度相当。以NIST SRM979为标准,玄武岩标准样品BIR-1a和BHVO-2的铬同位素组成δ~(53)Cr(‰)分别为-0.16±0.11(2SD,N=5),-0.19±0.11(N=10,2SD),该结果与已发表的数据在误差范围内一致。纯橄岩标准DTS-2b的铬同位素组成为δ~(53)Cr(‰)=-0.05±0.11(N=4,2SD),其结果在硅酸盐地球范围内。实验室内部黑色页岩标准样品CAGS-BS的铬同位素组成结果为δ~(53)Cr(‰)=0.2±0.11(N=6,2SD)。实验结果表明本论文所建立的铬同位素分析方法适用玄武岩、纯橄岩及黑色页岩。
[Abstract]:The chemical process of separation of chromium by cation exchange resin and the method of chromium isotope analysis by multi-receiver inductively coupled plasma mass spectrometer have been established in this paper. In the process of analysis, 50Cr-54Cr double diluent method was used to correct mass fractionation in chemical separation and mass spectrometry. In this study, AG50W-X8 cation exchange resin was used to separate chromium from matrix elements in pure olivine, basalt and shale after two chemical separations. The recovery of chromium was about 90 for the first chemical separation, 98 for the second, and about 90 for the second. It is found that the Alnti element in basalt and shale samples will be overloaded in the resin, so it can be eluted in advance. After the second chemical separation, Alnti and other elements can be further removed. After two chemical separations, the substrate effect of Ti/Cr < 5.3 脳 10 ~ (-4) V / Cr < 2.5 脳 10 ~ (-4) Fe / Cr < 2.4 脳 10 ~ (-4) Al _ (4) Ti and V was studied. The results show that the sample contains a very small amount of Ti _ (10 ~ (-4) Fe _ (10) V, which will not affect the Cr isotopic composition of the sample. The results of The double-spike software show that the optimum composition of the double diluent is 50Cr / 54CrN1.41, and the optimum mass ratio of the sample to the double diluent is 28.33: 71.67. The actual calibrated double diluent composition is 50Cr / 54CrN 1.74. The long-term reproducibility of NIST SRM979 self-determined by using double diluent method is 未 ~ (53) Cr (鈥，
本文编号：2161421
[Abstract]:The chemical process of separation of chromium by cation exchange resin and the method of chromium isotope analysis by multi-receiver inductively coupled plasma mass spectrometer have been established in this paper. In the process of analysis, 50Cr-54Cr double diluent method was used to correct mass fractionation in chemical separation and mass spectrometry. In this study, AG50W-X8 cation exchange resin was used to separate chromium from matrix elements in pure olivine, basalt and shale after two chemical separations. The recovery of chromium was about 90 for the first chemical separation, 98 for the second, and about 90 for the second. It is found that the Alnti element in basalt and shale samples will be overloaded in the resin, so it can be eluted in advance. After the second chemical separation, Alnti and other elements can be further removed. After two chemical separations, the substrate effect of Ti/Cr < 5.3 脳 10 ~ (-4) V / Cr < 2.5 脳 10 ~ (-4) Fe / Cr < 2.4 脳 10 ~ (-4) Al _ (4) Ti and V was studied. The results show that the sample contains a very small amount of Ti _ (10 ~ (-4) Fe _ (10) V, which will not affect the Cr isotopic composition of the sample. The results of The double-spike software show that the optimum composition of the double diluent is 50Cr / 54CrN1.41, and the optimum mass ratio of the sample to the double diluent is 28.33: 71.67. The actual calibrated double diluent composition is 50Cr / 54CrN 1.74. The long-term reproducibility of NIST SRM979 self-determined by using double diluent method is 未 ~ (53) Cr (鈥，
本文编号：2161421
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