The size partitioning of dissolved trace metals is an important factor for determining reactivity and bioavailability of metals in marine environments. This, alongside the advent of more routine shipboard ultrafiltration procedures, has led to increased attention in determining the colloidal phase of metals such as Fe in seawater. While clean and efficient filtration, prompt acidification, and proper storage have long been tenets of trace metal biogeochemistry, few studies aim to quantify the kinetics of colloidal exchange and metal adsorption to bottle walls during storage and acidification. This study evaluates the effect of storage conditions on colloidal size partitioning, the kinetics of colloid exchange over time, and the timescale of bottle wall adsorption and desorption for dissolved Fe, Cu, Ni, Zn, Cd, Pb, Mn and Co. We report that preservation of dissolved size partitioning is possible only for Fe and only under frozen conditions. All metals except Mn and Cd show regeneration of the colloidal phase following its removal in as short as 14 h, validating the importance of prompt ultrafiltration. Adsorption of metals to bottle walls is a well-known sampling artifact often cited for Fe and assumed to be potentially significant for other metals as well. However, only Fe and Co showed significant proclivity to adsorption onto low density polyethylene bottle walls, sorbing a maximum of 91 and 72% over 40 months, respectively. After 20 weeks of acidification neither Fe nor Co desorbed to their original concentrations, leading to an acidified storage recommendation of 30 weeks prior to analyses following storage of unacidified samples for long periods of time. This study provides empirical recommendations for colloidal and dissolved trace metal methodology while also paving the way for much-needed future methods testing.

溶解的痕量金属的尺寸分配是确定金属在海洋环境中的反应性和生物利用度的重要因素。伴随着更常规的船上超滤程序的出现，在确定海水中诸如Fe等金属的胶体相时，引起了更多的关注。长期以来，清洁，高效的过滤，迅速的酸化和适当的存储一直是痕量金属生物地球化学的宗旨，但鲜有研究旨在量化在存储和酸化过程中胶体交换和金属吸附到瓶壁的动力学。这项研究评估了储存条件对胶体尺寸分配，胶体交换动力学的影响以及瓶壁对溶解的Fe，Cu，Ni，Zn，Cd，Pb，Mn和Co吸附和解吸的时间尺度的影响。我们报告说，仅铁和仅在冷冻条件下才可能保留溶解的尺寸分区。除Mn和Cd外，所有金属均在短短14 h内被去除后显示出胶体相的再生，证明了快速超滤的重要性。金属对瓶壁的吸附是众所周知的采样伪影，通常会引用Fe元素，并假定对其他金属也具有潜在意义。但是，只有铁和钴表现出明显的吸附在低密度聚乙烯瓶壁上的倾向，在40个月内分别最多吸附91％和72％。酸化20周后，Fe和Co均不会解吸到其原始浓度，因此建议将酸化的储存时间建议为30周，然后再将未酸化的样品储存较长时间后再进行分析。