Demonstration of compound-specific isotope analysis of hydrogen isotope ratios in chlorinated ethenes.
Demonstration of compound-specific isotope analysis of hydrogen isotope ratios in chlorinated ethenes.
复制标题
氯化乙烯中氢同位素比率的化合物特异性同位素分析演示。
DOI：
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发表时间：
2013
影响因子：
11.4
通讯作者：
P. Philp
中科院分区：
文献类型：
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作者：
T. Kuder;P. Philp
氢同位素比化合物特异性同位素分析（CSIA）中有机物高温热解转化为H（2）的方法不适用于三氯乙烯（TCE）和顺式-1，2-二氯乙烯（DCE）等氯代化合物。由于这个原因，氯化乙烯的氢同位素比值的信息潜力仍未开发。我们提出了一种替代方法，其中氯化分析物与铬金属反应，形成H（2）和少量的HCl的演示。δ（2）H值以令人满意的精密度（± 10至15 ‰）获得，但原始数据需要通过TCE和/或DCE标准品进行每日校准，以校正随时间变化的分析偏倚。铬反应器已被纳入吹扫和陷阱CSIA方法，适用于CSIA的水环境样品。一个样本数据集，获得了六个样本的商业产品三氯乙烯。δ（2）H值在-184 ‰ ~+682 ‰之间，大大拓宽了以往工作中识别的人工TCE δ（2）H信号范围。这一发现的影响TCE污染的评估进行了讨论。
High-temperature pyrolysis conversion of organic analytes to H(2) in hydrogen isotope ratio compound-specific isotope analysis (CSIA) is unsuitable for chlorinated compounds such as trichloroethene (TCE) and cis-1,2-dichloroethene (DCE), due to competition from HCl formation. For this reason, the information potential of hydrogen isotope ratios of chlorinated ethenes remains untapped. We present a demonstration of an alternative approach where chlorinated analytes reacted with chromium metal to form H(2) and minor amounts of HCl. The values of δ(2)H were obtained at satisfactory precision (± 10 to 15 per thousand), however the raw data required daily calibration by TCE and/or DCE standards to correct for analytical bias that varies over time. The chromium reactor has been incorporated into a purge and trap-CSIA method that is suitable for CSIA of aqueous environmental samples. A sample data set was obtained for six specimens of commercial product TCE. The resulting values of δ(2)H were between -184 and +682 ‰, which significantly widened the range of manufactured TCE δ(2)H signatures identified by past work. The implications of this finding to the assessment of TCE contamination are discussed.