Sorption behavior of prochloraz in different soils.
The sorption behavior of the imidazole fungicide prochloraz [PCZ; N-propyl-N-[2-(2,4,6-trichlorophenoxy)ethyl]imidazole-1-carboxamide] was studied in batch experiments with different soils. The soil organic matter content was found to control the amount sorbed by different soils. K(d) values ranged from 56 +/- 0 to 552 +/- 10 (mean = 221 +/- 5) and K(OC) values from 7273 +/- 0 to 16250 +/- 1300 (mean = 11829 +/- 303). As calculated from a linear regression of K(d) versus %OC, K(OC) was 12900 +/- 1300. Additionally, the pH value of the soil had considerable influence on the sorption of the weakly basic PCZ (pK(a) = 3.8), giving rise to stronger sorption at lower pH. K(d) values determined on pH-modified soils confirmed the pH dependency. Sorption isotherms on two soils were recorded, initial concentrations ranging from 0.09 to 5.71 mg L(-)(1). The Freundlich isotherm was fitted to the values measured. The Freundlich exponents calculated were significantly smaller than unity, indicating nonlinear sorption. Sorption experiments with two metabolites of PCZ (PCZ-formylurea and PCZ-urea) revealed K(d) values one-fourth to one-third those for PCZ on two soils.
Rütters
H
H
Institute of Ecological Chemistry and Waste Analysis, Technical University of Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany.
Höllrigl-Rosta
A
A
Kreuzig
R
R
Bahadir
M
M
D000327:Adsorption; D005659:Fungicides, Industrial / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D007700:Kinetics; D012987:Soil
D005659:Fungicides, Industrial; D007093:Imidazoles; D012987:Soil; C045362:prochloraz