PARTITION-COEFFICIENTS (N-OCTANOL WATER) FOR PESTICIDES

Data for the partition coefficients (n-octanol-water) (P(ow)) of 221 pesticides and pesticide metabolites are presented with their method of derivation and source. The methods of measurement and calculating log P(ow) are reviewed. Octanol-water partition coefficients are measured by shake-flask methods, reversed-phase HPLC, reversed-phase TLC, slow-stirring partition methods and column generator method. Octanol-water partition coefficients are calculated from substituent constants, molecular fragment summation and solubilities. It has been proposed that the HPLC operating conditions for any compound should be applicable to other compounds which have the same log P(ow). The log P(ow) may be used in estimating the environmental behaviour of pesticides. A classification of pesticides as fat-soluble has been proposed for compounds with a log P(ow) > 4.