This request for a credit research grant support concerns when purchasing an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) within the framework of the second period of my current FWO post-doctoral research and in various other projects (BOF, VLIR PhD, FWO). These basic research on the interactions between biological, physical and biochemical aspects of soil organic matter (BOS) to stabilize against microbial and euml; le degradation. A first portion is focused on the specific isolation of BOS protected by various mechanisms on the basis of chemical and physical fractionation techniques. The need for the element analysis by means ICPOES in here, relates to the quantification of a number of specific extractable Fe and Al are separated in the bottoms. In particular, will allow the quantification of Fe and Al (hydr) oxides and uncomplexed Fe3 + and Al3 + (and Mg2 +, Ca2 + and Mn2 +) in these fractions, in view of their large binding potential for BOS and role in the mutual bonding of BOS molecules and to clay minerals. A second part of this study, the effect of X-ray computed tomography (CT) as a technique for visualization of in situ to BOS purpose. In addition, the applicability of a number of doping agents is examined to increase the phase contrast of BOS in CT volumes of undisturbed soil samples (ranging from soil columns to micro-aggregates). The quantification of the respective elements (Os, Pb, La, Ag, U) with ICP-OES, together with separate measurement of C and N will allow for the efficient & euml; to evaluate luminance of these dopants of physically separate bottoms.