Chapter 6. Air–Organic Solvent and Air–Water Partitioning

Summary

Transfers of chemicals between air and various liquid solutions are often important exchanges affecting the fates of organic compounds in the environment. One of the key chemical properties controlling such transfers is the air-solution or Henry's Law partition coefficient for the compound of interest. This parameter is directly related to the product of a particular compound's (liquid) vapor pressure and its solution activity coefficient. Since both the (liquid) vapor pressure and the activity coefficient can be estimated for compounds of interest using linear free energy relationships (LFERs) to quantify van der Waals and hydrogen bonding interactions, in this chapter it is demonstrated how air-solution partition coefficients can also be modeled and understood via such LFERs. Additionally, it is shown how a bond contribution method can be used to estimate a particular air-solution partition coefficient, the air-water value.