Specific interactions of organic compounds with soil organic carbon

The distribution of solutes between hydrated soil organic carbon and the gas phase (Loc) was compared with solute molar refraction (MR). Solutes which cannot undergo hydrogen bonding are linearly correlated with MR with a slope nearly identical to that obtained for log Lh (distribution between hexadecane and the gas phase) versus MR. Solutes which can undergo specific interactions (hydrogen bonding) deviate in many instances from the regression line. In other words, soil organic matter can undergo specific interactions with hydrogen bonding organic compounds. For a number of solutes, the magnitude of these deviations has a strong linear dependence on the free energy of hydrogen bonding.