Impact of mechanical disturbance and acidification on the metal(loid) and C, P, S mobility at the sediment water interface examined using a fractionation meso profiling ICP-QQQ-MS approach.

The impact of mechanical disturbance and oxygen induced acidification on the concentration and size fractionation of the 12 metal(loid)s As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Tl, V and the polyatomic nonmetals C, P and S in the pore water was studied. Using the meso profiling and sampling system (messy) 12 pore water depth profiles were sampled from two incubation experiments undertaken in parallel, which were both mechanically disturbed in the lab and subsequently exposed to a different air supply. In parallel to the low invasive, automated sampling process the redox potential, the pH value and the O2 concentration were detected. Simultaneous quantification of all analytes by inductively coupled plasma-triple quad-mass spectrometry in the two different size classes dissolved (<0.45 μm) and colloidal (0.45-16 μm) showed: i) the predominant influence of the pH on the mobility of metals; ii) the mobility of metalloids was strongly impacted by the mechanical disturbance; and iii) the colloidal release is less important except for Fe, P, and Ni.