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

这项研究的重点是量化大西洋盆地表层和深水中溶解、胶体、小颗粒和大颗粒之间的转化速率。该方法是使用高灵敏的热电离质谱和放射化学方法来确定不同尺寸类别中的第234、228和230。传统上与滤液一起收集的胶体相将使用错流过滤技术进行现场采样。现场采样方法将包括使用过滤器(33um)收集大颗粒，并使用原位错流过滤直接分离和收集胶体(5,000毫微米-0.2微米)和溶解(5,000毫微米)组分。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/解聚分开。特别是，将评估胶体Th的质量贡献，以及胶体在海洋颗粒循环和金属清除中作为活性中间体发挥的潜在重要作用。

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.