Characterization of Dissolved Organic Matter in Seawater by Ultrafiltration and Chemical Analysis

在接下来的三年里，双方将继续对海水中溶解有机物（DOM）的来源和反应进行联合研究。研究将主要集中在总溶解有机物的20-30%，这些有机物可以通过切向流超滤相对大量地轻轻分离出来。本研究的三个中心目标是：1。识别主要DOM组件的生物来源和转换。2. 阐明不同大小的DOM构件之间的组成趋势。详细描述海水DOM中各种有机物质的组成和组合。确定DOM的生物学和遗传学起源的研究将强调发生在上层水柱的快速过程，在那里观察到DOM浓度和成分的巨大差异。更好地了解不同尺寸的溶解有机物质的组成趋势将有助于描述影响DOM循环的过程，并判断具有代表性的超滤分离物是如何形成大块DOM的。对超过滤DOM的组成和形式进行更详细的描述，将有助于区分其生物来源、识别关键转换，以及消除DOM组成之间的功能关系。这一系列的研究已经为巨大的海水DOM池的反应性和难熔性成分提供了新的见解，并将继续为广泛的海洋学研究提供有用的信息。

9402361 HEDGES Over the next three years joint research will continue on the sources and reactions of dissolved organic matter (DOM) in seawater. Studies will focus primarily on the 20-30% of total dissolved organic matter which can be gently isolated in relatively large amounts by tangential-flow ultrafiltration. The three central objectives of the research are: 1. To identify the biological sources and transformations of the major DOM components. 2. To elucidate compositional trends among DOM constitutes of different size. 3 To characterize in detail the compositions and associations of the various organic materials comprising seawater DOM. Research to determine the biological and digenetic origins of DOM will emphasize rapid processes occurring in the upper water column where large differences in DOM concentrations and compositions are observed. A better understanding of compositional trends among dissolved organic materials of different size will help to delineate processes affecting DOM cycling and to judge how representative ultrafiltered isolates are of bulk DOM. More detailed characterizations of the compositions and forms of ultra- fitered DOM will aid in distinguishing its biological sources, identifying key transformations, and deconvoluting functional re- lationships among DOM constitutes. This line of research has already provided new insights on both the reactive and refractory components of the immense seawater DOM pool and should continue to yield information useful over wide range of oceanographic studies.