Storage (accumulation) and stabilization (slow decomposition rate, long turnover) of organic matter in the soil depends on mechanisms of its stabilization. Iron oxides contribute significantly to the soil's potential for accumulation and stabilization of carbon because they can make up considerable fraction of soil, have high surface area, and by chelation of organic biomolecules with Fe (III) to form metastable intermediate complexates that slow down its decomposition. But we don't yet understand how increasing the concentration of oxides in the soil affects the amount, quality, and stability of organic matter that is stored by adsorbing onto their surfaces. In this study we show that increasing the concentration of goethite in solution from 5g/lt to 10g/lt increases the amount of sorbed humic acid by 6 percent; but the amount of humic acid sorbed per unit mass of goethite decreases by 47 percent. We find that at low oxide concentrations aromatic functional groups are preferentially sorbed but at higher oxide concentrations there preferential sorption of aromatics decreases. Moreover, we find that at 5 g/lt oxide concentration 70 percent of the humic acid sorbed into the oxide surfaces can be desorbed while at 10 g/lt the amount of humic that can be desorbed increases by 10%. Findings from this study indicate that provision of additional surface area by increasing the amount of oxides in the soil does not necessarily increase effectiveness of C accumulation but it does contribute significantly to organic matter stabilization.