Journal: Environmental Science. Nano

Article Title: Visualization of pore water colloids in intact soil using a new diffusive gradients in thin films (DGT)-based approach

doi: 10.1039/d5en01069a

Figure Lengend Snippet: FlFFF fractograms of the FYM pore water sample showing elemental signals (a–e) and the UV signal (f) as a function of colloid retention time ( T r ), which corresponds to increasing colloid size. Organic colloids (<5 nm) elute at T r < 300 s, while larger mineral colloids (5–450 nm) elute at T r > 300 s. The red line in (a) shows the molar Si/Al ratio of the mineral colloids, the dotted red line indicates the Si/Al ratio of the clay fraction isolated from the soil. In the largest size fraction ( T r > 3700 s), the Si/Al ratio (2.1), matches that of the isolated clay. The blue line in (b) shows the molar Fe/Al ratio of the mineral colloids, the dotted blue line the ratio of the isolated clay. The Fe/Al ratio in the mineral colloids is only slightly higher than in the isolated clay.

Article Snippet: The colloids in pore waters were characterised with field flow fractionation (FlFFF) (AF2000, Postnova Analytics) online coupled with a UV/vis detector (SPD-20A Postnova Analytics) and with ICP-MS with a previously described method, further instrumental details are in Section S3.

Techniques: Isolation