Cheng Gen, Gao Shutao, Gao Yang, Yu Zhiqiang, Peng Ping'an
State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.
University of the Chinese Academy of Sciences, Beijing, 100039, China.
Rapid Commun Mass Spectrom. 2019 Aug 30;33(16):1318-1323. doi: 10.1002/rcm.8472.
Compound-specific stable isotope analysis (CSIA) is a powerful tool for the source apportionment and characterization of environmental transformation processes, especially for new emerging contaminants. In this study, we have developed an effective method for determination of the stable carbon isotope ratios of hexabromocyclododecane diastereoisomers.
Three diastereoisomers of hexabromocyclododecane (HBCD), α-, β-, and γ-HBCD, were separated on a preparative high-performance liquid chromatography (HPLC) system. Their carbon isotope ratios were determined using gas chromatography/isotope ratio mass spectrometry (GC/IRMS), and compared with data obtained by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS).
α-, β-, and γ-HBCD were well separated by the preparative HPLC system. Method validation results indicated excellent precision and reproducibility. For a series of injection volumes (0.5 to 3 μL), the average carbon isotope ratios for α-HBCD, β-HBCD, and γ-HBCD were -26.42‰, -26.88‰, and -26.43‰, respectively, and their deviations from those of the HBCD standard (-26.52‰) were all lower than the analytical uncertainty of 0.5‰. Relative standard deviations of intra-day and inter-day injections of HBCD were in the ranges 0.35-0.64% and 0.37-0.76%, respectively. Comparison with EA/IRMS further verified the accuracy of the HBCD stable carbon isotope ratio measured by GC/IRMS.
This work offers a novel approach to separate and concentrate the three major isomers of HBCD and to determine their stable carbon isotope ratios. This permits analysis of their carbon isotope ratios in environmental samples in order to elucidate the sources and abiotic or biological transformation processes of HBCD in the environment.
化合物特异性稳定同位素分析（CSIA）是一种用于环境转化过程源解析和特征描述的强大工具，尤其适用于新出现的污染物。在本研究中，我们开发了一种测定六溴环十二烷非对映异构体稳定碳同位素比值的有效方法。
在制备型高效液相色谱（HPLC）系统上分离六溴环十二烷（HBCD）的三种非对映异构体α-、β-和γ-HBCD。使用气相色谱/同位素比率质谱（GC/IRMS）测定它们的碳同位素比值，并与元素分析仪/同位素比率质谱（EA/IRMS）获得的数据进行比较。
制备型HPLC系统能很好地分离α-、β-和γ-HBCD。方法验证结果表明具有出色的精密度和重现性。对于一系列进样体积（0.5至3μL），α-HBCD、β-HBCD和γ-HBCD的平均碳同位素比值分别为-26.42‰、-26.88‰和-26.43‰，它们与HBCD标准品（-26.52‰）的偏差均低于0.5‰的分析不确定度。HBCD日内和日间进样的相对标准偏差分别在0.35 - 0.64%和0.37 - 0.76%范围内。与EA/IRMS的比较进一步验证了GC/IRMS测定的HBCD稳定碳同位素比值的准确性。
本工作提供了一种分离和浓缩HBCD三种主要异构体并测定其稳定碳同位素比值的新方法。这使得能够分析环境样品中它们的碳同位素比值，以阐明环境中HBCD的来源以及非生物或生物转化过程。
