Collaborative Research: Sampling and Analysis of Iron, an International Collaboration

摘要：虽然近年来在测量海水中溶解铁浓度方面取得了很大的进展，但正如2002年12月5日在旧金山举行的一次研讨会上所显示的那样，各种方法之间仍然存在显著差异。在此期间，对来自南大西洋的一个样本的数据进行评估，并由20多个不同的实验室进行分析，结果显示铁值的范围为0.6 nM，几乎与北太平洋从表面到1000 m的浓度范围一样大。考虑到这种元素作为一种微量营养素的重要性，它可以限制初级生产，因此必须查明结果变化的原因。因此，一个由经验丰富的铁分析师组成的指导委员会将与美国、欧洲和日本在测量铁方面拥有丰富经验的研究小组合作，解决海水中铁测量的差异。该小组约有22个实验室将参加一次巡航，前往一个低铁浓度（0.05至0.08 nM）的开放海洋站（30'N, 140'W）和一个高铁浓度的沿海站，目的是建立以下内容：(1)各种测量方法（同位素稀释高分辨率电感耦合等离子体质谱法、有机萃取石墨炉原子吸收光谱法、阴极溶出伏安法、流动注射分析-长径比色法、流动注射分析-鲁米诺化学发光检测、DPD流动注射分析）的可比性；(2)使用的取样策略的差异（在凯夫拉丝上的Go-Flo瓶，自动化的，无金属取样器- mitess，改良的“微量金属玫瑰花”，地面泵送系统）；(3)过滤的差异（Nuclepore, Anotop，孔径为0.1至0.45 um的胶囊过滤器）；(4)适当的样品储存和分发机制。铁的测量将在海上和实验室进行。此外，表层和1000米深度的样品将分发给美国和国外的其他分析人员，以确保所有类型的铁分析方法都被考虑在内，并可能作为临时铁标准分发。该项目的最终目标是使海洋科学界能够对海洋中不同地点和时间的溶解铁的测量结果进行比较，并对所检测到的差异或相似性具有高度的信心。

ABSTRACTOCE-0325031OCE-0326736OCE-0326697OCE-0324727OCE-0326633OCE-0326111Although great progress has been made in recent years to measure dissolved iron concentrations in seawater, significant differences remain between methods as was shown during a recent workshop held on December 5, 2002 in San Francisco. During this worship, evaluation of data obtained for one sample from the South Atlantic and analyzed by more than twenty different laboratories showed a range in iron values of 0.6 nM, nearly as large as the concentration range from the surface to 1000 m in the North Pacific. Given the importance of this element as a micronutrient which can limit primary production, it is imperative that the reasons for the variability in results be identified. For this reason, a Steering Committee of experienced iron analysts will collaborate with research groups with extensive experience in measuring iron both here in the United States as well as Europe and Japan to resolve the differences that remain in measurements of iron in seawater. This group of about 22 laboratories will participate in one cruise to one open ocean station (30'N, 140'W) with low iron concentrations (0.05 to 0.08 nM) and one coastal station with high iron concentrations with the goal of establishing the following: (1) the comparability of various measurements (isotope dilution high resolution inductively coupled plasma mass spectrometry, organic extraction graphite furnace atomic absorption spectrometry, cathodic stripping voltammetry, flow injection analysis-long path length colorimetry, flow injection analysis-luminol chemiluminescence detection, flow injection analysis with DPD); (2) the differences, if any, in the sampling strategies used (Go-Flo bottles on a Kevlar wire, automated, metal free samplers-MITESS, modified "trace metal rosettes", surface pumping systems; (3) the differences in filtration (Nuclepore, Anotop, capsule filters with pore sizes of 0.1 to 0.45 um); and (4) appropriate sample storage and distribution mechanisms. Measurements of iron will be made both at sea and in the laboratory. In addition, surface and 1000 m depth samples will be distributed to other analysts both in the United States and abroad to ensure that all types of analytical methods for iron are considered and possibly for distribution as an interim iron standard. The ultimate goal of this project is to enable the ocean science community to compare measurements of dissolved iron made at different places and times in the ocean with a high degree of confidence in the differences or similarities that are detected.