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

在未来三年内，将继续对海水中溶解有机物(DOM)的来源和反应进行9402361项联合研究。研究将主要集中在总溶解有机物的20%-30%，它们可以通过切向流超滤以相对较大的量温和地分离出来。本研究的三个中心目标是：1.确定主要DOM组分的生物来源和转化。2.阐明不同大小DOM组成的组成趋势。3详细描述组成海水DOM的各种有机材料的组成和缔合。确定DOM的生物和成岩来源的研究将强调在上层水柱中发生的快速过程，在那里观察到DOM浓度和组成的巨大差异。更好地了解不同大小的溶解有机物质之间的组成趋势，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菌株对整体DOM的影响。对超滤DOM的组成和形式进行更详细的表征将有助于区分其生物来源，识别关键的转化，并解卷DOM组成之间的功能关系。这一系列研究已经为巨大的海水DOM池的活性成分和耐火成分提供了新的见解，并应继续在广泛的海洋研究中提供有用的信息。

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.