Partitioning of diuron in a novel aqueous two-phase system based on polyols and tetrahydrofuran

Abstract

Diuron is an herbicide widely used in agriculture as a soil sterilant to control a large variety of weeds. This compound is considered moderately toxic and dangerous to the environment. This study examined the formation of an aqueous two-phase system (ATPS) based on tetrahydrofuran (THF) and polyols (glycerol, erythritol, xylitol, sorbitol and maltitol) in order to promote a simple recovery method that is low cost since diuron can be found in the uptake of water for human consumption. The binodal curves were determined at 25 °C and atmospheric pressure. The ability of the polyols to promote the formation of ATPS with THF preferably occurred in the growing direction of hydroxyl groups, glycerol (3-OH) to maltitol (9-OH). To explore the differences induced by the presence of the distinct polyols, the partition behavior of diuron was monitored by determining of the partition coefficient (KDIU) and recovery in the top phase (RT). In all systems, THF was in the top phase and the polyols in the bottom phase. Preferably, diuron was best partitioned to the top phase (KDIU ≈ 20 and RT ≈ 93) due the effect salting-out caused by maltitol on the diuron molecules.