Hydrophobic coefficients of s-triazine and phenylurea herbicides

Hydrophobic parameters (K′, KOW and KOC) were evaluated for 25 s-triazlne and phenylures herbicides. Octanol-water partitioning coefficients (KOW) 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 KOW, KOC, 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 stucturally related compounds, were found between logKOW, logKOC and logk′.