Seasonal variation of the distribution of polycyclic aromatic hydrocarbons in poplar leaves

To investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in plant leaves, the partitioning of 13 PAHs between the soluble cuticular lipids (SCL) and the remaining leaf (RL) of poplar trees (Populus nigra cv. Loenen) was studied during one growing season. PAHs with relatively low molecular weights are absorbed by the SCL and penetrate into the RL whereas PAHs with higher molecular weights are not present in the RL. The particular distribution of individual PAHs in the SCL and the RL depends on the leaf age. It is assumed that only PAHs in the RL possess a phytotoxical potential.