Fig. 2. (A) Temporal variation of the concentration of deethylatrazine (DEA) and deisopropylatrazine (DIA) in surface runoff. (B) Scatter plots showing the relationship of DIA to DEA for surface runoff from the cyanazine and atrazine field plots. (C) Temporal variation of the concentration ratio of DIA to DEA (D²R) for samples from the cyanazine and atrazine field plots.