Mobility of elements in soil and aquatic environments are regulated not only by complexation with simple ligands with low molecular masses, but also by formation of or sorption to nano-sized inorganic or organic colloids or macromolecules. In this research we have determined and compared the size distribution and elemental composition of various elements in granitic and sedimentary deep groundwater by flow-field flow fraction (Fl-FFF) hyphenated with ICP-MS. Fl-FFF is a non-invasive chromatographic size fractionation technique. Thanks to the selectivity on both size and elemental composition of colloids, we have successfully analyzed heterogeneous natural colloids in the deep groundwater.

This research was conducted under collaboration with Radioactive Waste Processing and Disposal Research Department, JAEA. This research was partly supported by the Ministry of Economy, Trade and 15 Industry (METI), Japan, and “Grant-in-Aid for Young Scientists (B)” (Grant No. 25820446), the Japan Society for the Promotion of Science.

Saito, T.*, Hamamoto, T., Mizuno, T., Iwatsuki, T., Tanaka, T., “Comparative study of granitic and sedimentary groundwater colloids by flow field flow fractionation coupled with ICP-MS”, J. Anal. At. Spectrom. 30, 1229-1236 (2015).