| 摘要: |
| 本研究研制了由气压棒、气体控制阀、不锈钢管冷阱、石英毛细管冷阱、杜瓦瓶、化学阱等构成的Ｎ２Ｏ预富集装置，通过扩展ＧａｓｂｅｎｃｈⅡ功能控制冷阱的升降，改造气体回路、进样针和样品盘，实现Ｎ２Ｏ的预富集以及ＧａｓｂｅｎｃｈⅡ自动进样与ＩＲＭＳ联机测定．通过将海水中的硝酸盐经化学方法转化成Ｎ２Ｏ，建立了海水硝酸盐氮、氧同位素的分析方法．研究表明，所建立方法对海水硝酸盐氮、氧同位素的分析具有很好的精度，硝酸盐δ１５Ｎ、δ１８Ｏ及峰面积的相对标准偏差分别小于１％、３％和５％．对采自南极普里兹湾海水样品中硝酸盐氮、氧同位素的分析结果与文献报道值吻合，也与海水硝酸盐氮、氧同位素组成的变化规律相一致，证明所建立的技术方法可成功运用于海水硝酸盐氮、氧同位素的分析． |
| 关键词: 海洋化学 海水 硝酸盐氮氧同位素 Ｎ２Ｏ预富集装置 Ｇａｓｂｅｎｃｈ ＩＲＭＳ |
| DOI： |
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| 基金项目:高等学校仪器设备和优质资源共享系统大型仪器示范机组建设资助项目（CERS176）；国家重点基础研究发展计划资助项（2015CB452903）；南北极环境综合考察与评估专项资助项目（CHINARE2016010403）；国家自然科学基金杰出青年基金资助项目（41125020） |
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| N2 O preconcentration device upgraded for Gasbench || -IRMS
analyzing N and O isotopes of seawater nitrate |
| ZHENG Minfang,HU Wangjiang,QIU Yusheng,CHEN Min |
| (College of Ocean end Earth Sciences. Xiamen University. Xiamen 361005. China;State Key Laboratory of Marine Environmental Science, Xiamen University. Xiamen 361005. China) |
| Abstract: |
| The preconcentration device for N2O analysis was upgraded and assembled by a series of components, including air pressure bar, gas control valve, stainless steel cyro trap, fused silica capillary cyro trap, dewar, chemi
cal trap and etc. The function of Gasbench II was extended to control the lifting of cyro traps while the gas circuit,
sampling syringe, and sample plate were altered to realize the on-line determination with N2O preconcentration de
vice, Gasbench II and IRMS. Nitrate was chemically converted to N2O to build the method for analysis of N and O
isotope in seawater nitrate. Our results showed that the developed method has a very good precision. The standard
deviation of 15N,18Oand peak area of nitrate was less than 1% , 3% and 5%, respectively. Tlie N and O iso
topes of nitrate in seawater collected from the Piydz Bay, Antarctica, were measured with this method. The values
of 15N,18O of nitrate obtained were agreed well with literature reports, The profiles of 15N, 18O of nitrate in
the Prydz Bay showed the typical characteristics of the ocean. The developed technique for analyzing N and O iso
topes of seawater nitrate was feasible. |
| Key words: marine chemistry sea water nitrogen and oxygen isotopes in nitrate N2O preconcentration device Gasbench-IRMS |
