N-OCTANOL WATER PARTITION-COEFFICIENT ESTIMATION BY MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY

Micellar electrokinetic capillary chromatography (MECC) was evaluated as an a priori predictor of n-octanol-water partition coefficients (log K-ow). Retention measurements for over 100 solutes with widely varying functionality were used to construct a universal calibration for the estimation of octanol-water partition coefficients with r(2) = 0.835. The calibration covers in excess of 9 orders of magnitude in log K-ow and 4 orders of magnitude in log capacity factor. If solute structure, size, and hydrogen-bonding character are known, accuracy can be increased by use of improved calibrations. This method reduces the laboratory-to-laboratory variability and the long analysis time due to the multiple mobile phases necessary in current HPLC methods for estimating log K-ow while retaining many of the desired advantages of chromatographic techniques.