尽管氯与溴有着十分相似的化学性质,但溴与海水蒸发、氧化以及被有机体代谢方面有着独特的性质,这决定了溴同位素的测试和应用方面与氯同位素显著不同。在回顾稳定溴同位素(81Br)研究历程的基础上,重点介绍了2种测定新技术,即CF-IRMS法和GC/MC-ICP-MS法。这两种技术的优点在于:①用样量少,分别为1μmol的Br-(CF-IRMS法)和0.3 nmol的Br(GC/MC-ICP-MS法);②精度高,CF-IRMS法的内部精度优于±0.1‰,外部精度优于±0.06‰;③样品分析时间短;(4)测定对象由溴代无机物拓展到有机物。稳定溴同位素(81Br)在解决地下水的起源及演化历程、示踪地下水中有机和无机溴的污染源及降解过程、更有效地示踪海水、探讨咸水成因、为CO2地质储存提供有效依据方面的水文地质问题时有着广阔的应用前景。
This paper gives an overview of the research in bromine stable isotope(81Br) since the 1920′s.It discusses the novel measurements for bromine stable isotope,including CF-IRMS and GC/MC-ICPMS,and the applications of bromine stable isotope on indicating the origin or the formation processes of groundwater and the contamination in soil and groundwater.As a new isotope indicator,bromine stable isotope(81Br)will be widely used in such research fields as geochemistry,hydrogeology,oil field exploration and environmental protection.