Determination of Octanol–Water Partition Coefficients by MEEKC Based on Peak-Shift Assay

Abstract

A novel microemulsion electrokinetic chromatography method based on peak-shift assay (p-s MEEKC) has been developed for the determination of octanol–water partition coefficients (log P o/w) of compounds. The log P o/w values of 12 compounds were determined. The RSD of obtained values were less than 5.0% except 4-tert-butylphenol (RSD = 5.9%). All log P o/w values of the investigated compounds measured by p-s MEEKC were within 0.51 logarithm unit variation as compared to the literature values, with mean difference of 0.27. Compared to the conventional MEEKC method, the novel method does not suffer from the deficiencies related to the reference compounds and migration time of microemulsion phase, and showed the potential of being an alternative method for the determination of log P o/w values of compounds without reference compounds.