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近年来汞(Hg)稳定同位素研究进展显著。Hg具有七种稳定同位素。以往研究不但报道了Hg同位素质量分馏,也报道了Hg同位素非质量分馏,使Hg成为目前唯一在自然界中具有同位素非质量分馏的重金属元素。本文阐述了Hg同位素的研究背景,总结了Hg同位素分析方法和引起Hg同位素分馏的生物化学过程,介绍了地球各圈层样品中Hg同位素组成的国内外最新研究现状。而最新发现的大气降雨中异常的、呈季节性变化的偶数Hg同位素非质量分馏(Δ200 Hg),更开辟了Hg同位素研究的新领域。不同于奇数Hg同位素非质量分馏,偶数Hg同位素非质量分馏还未经任何实验验证,其分馏机理也完全不清楚,亟待深入研究。Hg可能的“三维”同位素体系(质量分馏、奇数以及偶数Hg同位素非质量分馏)的研究和应用将有希望为进一步认识Hg环境过程、生物累积、大尺度迁移以及全球性的生物地球化学循环提供更加丰富的信息,具有重要的科学意义。
In recent years, mercury (Hg) stable isotope research advances. Hg has seven stable isotopes. Previous studies not only reported Hg isotope mass fractionation, but also reported Hg isotope non-mass fractionation, making Hg the only heavy metal element with isotopic non-mass fractionation in nature. This paper describes the research background of Hg isotopes, summarizes the Hg isotope analysis methods and the biochemical processes that cause Hg isotopic fractionation, and introduces the latest research status at home and abroad about the Hg isotope composition in the samples of the Earth’s rings. The most recent discovery of anomalous, seasonal Hg isotope fractional mass fractionation (Δ200 Hg) in the atmospheric rains has opened up new areas of Hg isotope research. Different from odd Hg isotope mass fractionation, even fraction Hg isotope mass fractionation has not been verified by any experiment, and its fractionation mechanism is completely unclear, which needs further study. The research and application of Hg possible “three-dimensional ” isotopic systems (mass fractionation, odd-numbered and even-numbered Hg isotopes non-mass fractionation) will be promising for further understanding of Hg environmental processes, bioaccumulation, large-scale migration and global biogeochemistry Circulation to provide richer information has important scientific implications.