The Application of In-Situ CFF and TIMS to the Study of Oceanic Particle Dynamics

本研究的重点是量化转化率 溶解、胶体、小颗粒和大颗粒之间 在大西洋盆地的表层和深层沃茨的大小等级。 该方法是使用高灵敏度的热电离质量 光谱法和放射化学方法来测定234 Th，228 Th， 和230 Th在各种大小的类。 胶体相， 传统上与滤液一起沿着收集，将进行采样 原位使用错流过滤技术。 野外采样 方法将涉及收集大颗粒， 过滤器（33 um）和直接分离和收集 胶体（5，000 NMW-0.2 μ m）和溶解（5，000 NMW）级分 使用原位错流过滤。 这些数据将允许 将吸附到颗粒表面的过程与 胶体和悬浮颗粒的聚集/解聚。 特别是，胶体Th和 胶体作为活性中间体的潜在重要作用 将评估海洋颗粒循环和金属清除的影响。

The focus of this research is to quantify transformation rates between dissolved, colloidal, small particle, and large particle size classes in the surface and deep waters of the Atlantic basin. The approach is to use highly sensitive thermal ionization mass spectrometry and radiochemical procedures to determine 234Th, 228Th, and 230Th in the various size classes. The colloidal phase, traditionally collected along with the filtrate, will be sampled in-situ using a cross-flow filtration technique. Field sampling methods will involve the collection of large particles using filters (33um) and the direct separation and collection of colloidal (5,000 NMW-0.2 um) and dissolved (5,000 NMW) fractions using in-situ cross-flow filtration. These data will allow for a separation of the processes of sorption onto particle surfaces from the aggregation/disaggregation of colloids and suspended particles. In particular, the mass contribution of colloidal Th and the potentially important role colloids play as reactive intermediates in oceanic particle cycling and metal scavenging will be assessed.