大气硝酸盐氧同位素异常及应用进展

近年来人为活动导致的大气硝酸盐不断增加,危害人体健康和生态环境。厘清大气硝酸盐的来源及形成机理至关重要。多氧稳定同位素技术是一种强有力的示踪手段,能够有效指示大气硝酸盐生成的氧化路径,在气溶胶、水体、土壤、森林、古气候研究中得到了广泛应用。本文总结了大气硝酸盐氧同位素异常(Δ17O)的测定方法(热裂解法、反硝化细菌法、化学法),探讨了Δ17O的产生原因,并围绕硝酸盐的形成过程阐明硝酸盐Δ17O的示踪机制,综述了Δ17O在大气化学反应机制研究中的应用。在此基础上,本文提出目前Δ17O研究的不足并对未来需要开展的研究进行了展望。

Research advances and applications on oxygen isotope anomaly in atmospheric nitrate.

In recent years,increasing atmospheric nitrate resulted from anthropogenic activities negatively affects human health and ecological environment.It is important to identify the sources and formation mechanisms of nitrate.As a powerful tracer,the multi-oxygen stable isotopes in nitrate are widely used for investigations of aerosol,aquatic ecosystems,soils,forests,and paleoclimate.In this review,experimental methods and causes of oxygen isotope anomaly(Δ17 O)in atmospheric nitrate are introduced,and the tracing mechanisms ofΔ17 O are discussed according to the differences of nitrate formation processes.Finally,the applications ofΔ17 O are reviewed in the studies of atmospheric chemical reaction mechanism.According to the progress and problems in literature,we proposed the future directions of the researches onΔ17 O in nitrate.