Precipitation of organic compounds in soils

Precipitation samples collected in Hannover in 1990/1991 were analyzed for various organic compound classes. The following average concentrations were observed: formaldehyde (111 μg/l), acetaldehyde (12.0 μg/l), propionaldehyde (4.7 μg/l), n-alkanes from n-C18H38 to n-C33H68 (52.2 μg/l), polycyclic aromatic hydrocarbons (PAHs) (in summer 1989: 351.0 ng/l, in fall 1989: 765 ng/l) higher fatty acids from C9-C26 (24.9 μg/l), phenol (8.4 μg/l), 3-/4-methylphenol (3.3 μg/l), 2-nitrophenol (0.18 μg/l) 4-nitrophenol (6.1. μg/l) and higher alkanols. These compounds are of predominantly biogenic origin (n-alkanes, fatty acids, n-alkanols), formed by photochemical reaction in the atmosphere (aldehydes, phenols) or due to direct antropogenic sources (PAHs). (orig.)