Rapid Estimation of Octanol–Water Partition Coefficient for Triazole Fungicides by MEKC with Sodium Deoxycholate as Surfactant

Abstract

A rapid estimation of octanol–water partition coefficient (log Pow) was developed for triazole fungicides by micellar electrokinetic chromatography (MEKC). Five standard compounds with known log Pow values from 2.9 to 4.3 (cyproconazole, bromuconazole, epoxiconazole, bitertanol and difenoconazole) were used for constructing the calibration curve of the log Pow against the MEKC retention factor, log k. A linear relationship was achieved between log Pow and log k, in the MEKC system containing 40 mM sodium deoxycholate (SDC) and 4 mM borate buffer at pH 9.3, with a correlation of determination, r2 = 0.9905. The log Pow values of four test compounds of triazole fungicides (triadimenol, myclobutanil, propiconazole and penconazole) were calculated based on the log k values measured by MEKC and the slope and intercept of the calibration curve. This MEKC method can give good estimation of the log Pow of the four test compounds of triazole fungicides with the differences between the literature log Pow values and estimated log Pow from the MEKC method were from 0.15 to 0.23 log units.