A technique for the determination of 18O/16O and 17O/16O isotopic ratios in water from small liquid and solid samples
A technique for the determination of 18O/16O and 17O/16O isotopic ratios in water from small liquid and solid samples
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DOI：
10.1021/ac010509s
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发表时间：
2002-04-01
影响因子：
7.4
通讯作者：
Pillinger, CT
中科院分区：
文献类型：
--
作者：
Baker, L;Franchi, IA;Pillinger, CT
我们开发了一种新技术，使用固体试剂氟化钴（III）来从直接注入或固体样品热解产生的水中制备氧气，用于同位素比测量。该技术使用连续流、同位素比监测、气相色谱/质谱 (irmGC/MS) 来测量氧气的 δ(18)O 和 δ(17)O。在流动的氦载气流下，通过逐步热解（0-1000 摄氏度，通常以 50 摄氏度增量）从适当的样品中产生水。与其他用于水分析的方法相比，该方法具有显着的优势，因为它快速；仅需要少量样品，通常为 1-50 毫克全岩样品（相当于 0.2 微摩尔 H2O）；该试剂操作简单、安全。从陆地固体标准样品的热解获得的同位素比测量的再现性为δ(18)O +/- 0.54、δ(17)O +/- 0.33和δ(17)O +/- 0.10千分之1，在所有情况下均为1sigma。该技术主要是为了分析陨石而开发的，本文通过水标准、固体参考材料和默奇森 CM2 陨石样本的结果说明了该方法的效率。
We have developed a new technique in which a solid reagent, cobalt(III) fluoride, is used to prepare oxygen gas for isotope ratio measurement from water derived either from direct injection or from the pyrolysis of solid samples. The technique uses continuous flow, isotope ratio monitoring, gas chromatography/mass spectrometry (irmGC/ MS) to measure the delta(18)O and delta(17)O of the oxygen gas. Water from appropriate samples is evolved by a procedure of stepped pyrolysis (0-1000 degreesC, typically in 50 degreesC increments) under a flowing stream of helium carrier gas. The method has considerable advantages over others used for water analysis in that it is quick; requires only small samples, typically 1-50 mg of whole rock samples (corresponding to similar to0.2 mumol of H2O); and the reagent is easy and safe to handle. Reproducibility in isotope ratio measurement obtained from pyrolysis of samples of a terrestrial solid standard are delta(18)O +/- 0.54, delta(17)O +/- 0.33, and Delta(17)O +/- 0.10parts per thousand, 1sigma in all cases. The technique was developed primarily for the analysis of meteorites, and the efficiency of the method is illustrated herein by results from water standards, solid reference materials, and a sample of the Murchison CM2 meteorite.