On the fluorometric measurement of ammonium in oligotrophic seawater: Assessment of reagent blanks and interferences
On the fluorometric measurement of ammonium in oligotrophic seawater: Assessment of reagent blanks and interferences
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贫营养海水中铵的荧光测量：试剂空白和干扰的评估
DOI：
10.1002/lom3.10263
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发表时间：
2018-08
影响因子：
2.7
通讯作者：
Dai Minhan
中科院分区：
文献类型：
--
作者：
Zhu Yifan;Liu Jing;Huang Tao;Wang Lifang;Trull Thomas W.;Dai Minhan
铵是海洋环境中最重要的活性氮化合物之一，在公海中以痕量水平动态分布。因此，获得可靠的铵浓度测量值是充分了解其在海洋生物地球化学过程中的作用的先决条件，但仍然具有挑战性。其中，空白的不同来源的量化和识别是一个突出的问题，部分原因是无铵水非常难以制备和/或保存。基于最近开发的固相萃取结合荧光检测（SPE-Flu）的方法，我们研究了邻苯二甲醛-亚硫酸盐-铵反应的动力学，并引入了一种新的方法，通过“试剂添加”方法来定量试剂空白。该方法的试剂空白，相当于6.7 +/- 1.5 nmol L-1的铵在我们的实验设置下，占27%的贫营养海洋中收集的海水样品中的铵背景。我们还表明，SPE-Flu方法具有高度特异性，在纳摩尔浓度下，三种类型的胺和15种类型的氨基酸的干扰可以忽略不计，这是典型的开放海洋制度。试剂空白的测定允许优化的数据简化，这是适用于在贫营养的南中国海的研究。水柱剖面显示出一个非常明确的结构和平稳的铵浓度分布，与其他参数的分布一致。因此，我们认为，我们提出的方法提供了一种通过SPE-Flu方法进一步优化天然海水中铵浓度定量的方法。
Dynamically distributed at trace levels in the open ocean, ammonium is one of the most important and reactive nitrogen compounds in the marine environment. Obtaining reliable measurements of ammonium concentrations is thus a prerequisite to fully understand its role in marine biogeochemical processes, but remains challenging. Among others, quantification and identification of different sources of blanks is an outstanding issue, due partly to the fact that ammonium-free water is very difficult to prepare and/or preserve. Building on a recently developed method using solid phase extraction combined with fluorescence detection (SPE-Flu), we examined the kinetics of the ortho-phthaldialdehyde-sulfite-ammonium reaction and introduce a new approach to quantifying reagent blanks via a "reagents addition" method. The reagent blank of the method, equivalent to 6.7 +/- 1.5 nmol L-1 of ammonium under our experimental settings, accounted for up to 27% of the ammonium background in seawater samples collected from the oligotrophic ocean. We also showed that the SPE-Flu method is highly specific, with negligible interference from three types of amines and 15 types of amino acids at nanomolar concentrations, which are typical of open ocean regimes. The determination of the reagent blank allowed for optimized data reduction, which was applied to a study in the oligotrophic South China Sea. Water column profiles showed a very well-defined structure and smooth distribution of ammonium concentrations, consistent with the distribution of other parameters. We thus contend that our proposed approach provides a way to further optimize the quantification of ammonium concentrations in natural seawater via the SPE-Flu method.
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DOI：
10.1899/0887-3593(2007)26
发表时间：
2007-06-01
影响因子：
--
作者：
Anderson, Caroline;Cabana, Gilbert
通讯作者：
Cabana, Gilbert
影响因子：
2.5
作者：
Efrat Meeder;K. Mackey;A. Paytan;Yeala Shaked;D. Iluz;N. Stambler;T. Rivlin;A. Post;B. Lazar
通讯作者：
Efrat Meeder;K. Mackey;A. Paytan;Yeala Shaked;D. Iluz;N. Stambler;T. Rivlin;A. Post;B. Lazar
影响因子：
3
作者：
Yong Zhu;D. Yuan;Y. Huang;Jian Ma;Sichao Feng;Kunning Lin
通讯作者：
Yong Zhu;D. Yuan;Y. Huang;Jian Ma;Sichao Feng;Kunning Lin
影响因子：
6.2
作者：
T. Aoki;S. Fukuda;Yasuo Hosoi;H. Mukai
通讯作者：
T. Aoki;S. Fukuda;Yasuo Hosoi;H. Mukai
DOI：
10.1139/cjfas-56-10-1801
发表时间：
1999-10-01
影响因子：
2.4
作者：
Holmes, RM;Aminot, A;Peterson, BJ
通讯作者：
Peterson, BJ