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

ABSTRACTOCE-0325031OCE-0326736OCE-0326697OCE-0324727OCE-0326633OCE-0326111尽管近年来在测量海水中溶解铁浓度方面取得了很大进展，但正如 2002 年 12 月 5 日在旧金山举行的最近一次研讨会所表明的那样，方法之间仍然存在显着差异。 在这次崇拜期间，对从南大西洋获得的一个样本的数据进行了评估，并由二十多个不同的实验室进行了分析，结果显示铁值范围为 0.6 nM，几乎与北太平洋从表面到 1000 m 的浓度范围一样大。 鉴于该元素作为一种微量营养素的重要性，可以限制初级生产，因此必须确定结果变化的原因。 因此，由经验丰富的铁分析师组成的指导委员会将与美国、欧洲和日本在铁测量方面拥有丰富经验的研究小组合作，以解决海水中铁测量方面仍然存在的差异。 这组约 22 个实验室将参加一次航行，前往一个铁浓度低（0.05 至 0.08 nM）的公海站（北纬 30 英尺，西行 140 英尺）和一个铁浓度高的沿海站，目的是建立以下目标：（1）各种测量的可比性（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-长光程比色法、流动注射分析-鲁米诺化学发光检测、DPD流动注射分析）； (2) 所用采样策略的差异（如果有的话）（Kevlar 线上的 Go-Flo 瓶、自动化、无金属采样器 MITESS、改进的“痕量金属玫瑰花结”、表面泵送系统；(3) 过滤的差异（Nuclepore、Anotop、孔径为 0.1 至 0.45 um 的胶囊过滤器）；以及 (4) 适当的样品存储和分配机制。铁的测量将在海上和实验室进行。此外，表面和 1000 米深度样本将分发给美国和国外的其他分析人员，以确保考虑所有类型的铁分析方法，并可能将其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比较在海洋中不同地点和时间进行的溶解铁测量，并对检测到的差异或相似之处具有高度的置信度。

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.