Simultaneous determination of stable chlorine and bromine isotopic ratios for bromochlorinated trihalomethanes using GC-qMS
Simultaneous determination of stable chlorine and bromine isotopic ratios for bromochlorinated trihalomethanes using GC-qMS
复制标题
使用 GC-qMS 同时测定溴氯化三卤甲烷的稳定氯和溴同位素比
DOI：
10.1016/j.chemosphere.2020.128529
复制
发表时间：
2021
期刊：
影响因子：
8.8
通讯作者：
Zhang Gan
中科院分区：
文献类型：
--
作者：
Jin Biao;Zhang Jiyun;Xu Wenli;Rolle Massimo;Liu Jinzhong;Zhang Gan
溴氯化化合物是一种有机污染物，来自不同的自然和人为来源，在不同的环境分区中发现的数量越来越多。本工作提出了一种在线的方法，使用气相色谱-四极杆质谱（GC-qMS）的化合物特定的稳定同位素分析的氯和溴的同位素比溴氯化三卤甲烷。基于二溴氯甲烷和二氯溴甲烷两种目标化合物的质谱数据，建立了同时测定氯和溴稳定同位素比值的评价方案。通过评估不同仪器参数（包括停留时间、分流比和电离能）的影响，对分析技术进行了优化。连续，静态顶空样品含有两种目标化合物的水溶液浓度范围为0.1 mg/L至5 mg/L进行了分析，以测试所提出的方法的精密度和重现性。结果表明，在优化的仪器条件下，氯和溴同位素分析的相对标准偏差在0.05%~ 0.5%之间，具有良好的精密度。最后，该方法进行了测试，在一个源识别问题中，同时测定氯和溴的稳定同位素比值允许明确区分二溴氯甲烷从三个不同的制造商。
Bromochlorinated compounds are organic contaminants originating from different natural and anthropic sources and increasingly found in different environmental compartments. This work presents an online approach for compound specific stable isotope analysis of chlorine and bromine isotope ratios for bromochlorinated trihalomethanes using gas chromatography coupled to quadrupole mass spectrometry (GC-qMS). An evaluation scheme was developed to simultaneously determine stable chlorine and bromine isotope ratios based on the mass spectral data of two target compounds: dibromochloromethane and dichlorobromomethane. The analytical technique was optimized by assessing the impact of different instrumental parameters, including dwell time, split ratios, and ionization energy. Successively, static headspace samples containing the two target compounds at aqueous concentrations ranging from 0.1 mg/L to 5 mg/L were analyzed in order to test the precision and reproducibility of the proposed approach. The results showed a good precision under the optimized instrumental conditions, with relative standard deviations ranging between 0.05% and 0.5% for chlorine and bromine isotope analysis. Finally, the method was tested in a source identification problem in which the simultaneous determination of chlorine and bromine stable isotope ratios allowed the clear distinction of dibromochloromethane from three different manufacturers.