HYDROPHOBIC COEFFICIENTS OF S-TRIAZINE AND PHENYLUREA HERBICIDES

Hydrophobic parameters (K, K-ow, and K-oc) were evaluated for 25 s-triazine and phenylurea herbicides. Octanol water partitioning coefficients (K-ow) were measured for 13 s-triazine and 9 phenylurea herbicides by a UV spectrophotometric method. Soil sorption isotherms were determined for chlorotoluron, chloroxuron, cyanazine, and metoxuron in four types of soil. Relationships between K-ow, K-oc, and the retention capacity factor (k') measured in a reversed phase HPLC system, were analyzed for these two classes of herbicides. Very significant linear regression equations, showing predictive value for structurally related compounds, were found between logK(ow) logK(oc) and logk'.