Abstract
The partitioning of formic and acetic acid between liquid and gaseous phase are computed at various liquid water contents. It can be shown, that at low liquid water supply distinctly more formic than acetic acid will be dissolved. A selective transport by washout by clouds is concluded. Further an example is given on the ability of dew to act as a temporary sink and source for organic acids. The assessment shows that the diurnal variation of mixing ratios often found during surface measurements to a great extent will be due to dissolution in dew and subsequent evaporation on the next day.