Unnatural isotopic composition of lithium reagents

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	Unnatural isotopic composition of lithium reagents
	Qi, HP; Coplen, TB; Wang, QZ; Wang, YH
	1997
发表期刊	ANALYTICAL CHEMISTRY
ISSN	0003-2700
卷号	69 期号:19 页码:4076-4078
摘要	Isotopic analysis of 39 lithium reagents from several manufacturers indicates that seven were artificially depleted in Li-6 significantly in excess of the variation found in terrestrial materials. The atomic weight of lithium in analyzed reagents ranged from 6.939 to 6.996, and delta(7)-Li, reported relative to L-SVEC lithium carbonate, ranged from -11 to +3013 parts per thousand. This investigation indicates that Li-6-depleted reagents are now found on chemists' shelves, and the labels of these Li-6-depleted regents do not accurately reflect the atomic and (or) molecular weights of these reagents. In 1993, IUPAC issued the following statement: ''Commercially available Li materials have atomic weights that range between 6.94 and 6.99; if a more accurate value is required, it must be determined for the specific material.'' This statement has been found to be incorrect. In two of the 39 samples analyzed, the atomic weight of Li was in excess of 6.99. Isotopic analysis of 39 lithium reagents from several manufacturers indicates that seven were artificially depleted in Li-6 significantly in excess of the variation found in terrestrial materials. The atomic weight of lithium in analyzed reagents ranged from 6.939 to 6.996, and delta(7)-Li, reported relative to L-SVEC lithium carbonate, ranged from -11 to +3013 parts per thousand. This investigation indicates that Li-6-depleted reagents are now found on chemists' shelves, and the labels of these Li-6-depleted regents do not accurately reflect the atomic and (or) molecular weights of these reagents. In 1993, IUPAC issued the following statement: ''Commercially available Li materials have atomic weights that range between 6.94 and 6.99; if a more accurate value is required, it must be determined for the specific material.'' This statement has been found to be incorrect. In two of the 39 samples analyzed, the atomic weight of Li was in excess of 6.99.
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/2384
专题	青海盐湖研究所知识仓储中国科学院青海盐湖研究所
推荐引用方式 GB/T 7714	Qi, HP,Coplen, TB,Wang, QZ,et al. Unnatural isotopic composition of lithium reagents[J]. ANALYTICAL CHEMISTRY,1997,69(19):4076-4078.
APA	Qi, HP,Coplen, TB,Wang, QZ,&Wang, YH.(1997).Unnatural isotopic composition of lithium reagents.ANALYTICAL CHEMISTRY,69(19),4076-4078.
MLA	Qi, HP,et al."Unnatural isotopic composition of lithium reagents".ANALYTICAL CHEMISTRY 69.19(1997):4076-4078.