Mesoporous carbon reinforced hollow fiber liquid-phase microextraction for the enrichment of phenylurea herbicides followed by their determination with high performance liquid chromatography

In this paper, a new sample preparation method based on mesoporous carbon reinforced hollow fiber liquid phase microextraction (MC-HF-LPME) was developed for the extraction of some phenylurea herbicides (chlortoluron, isoproturon, monolinuron and buturon) in river water and soil samples prior to high performance liquid chromatography-diode array detection. Mesoporous carbon was synthesized using MCM-41 as a template and sucrose as a carbon precursor. The as-prepared mesoporous carbon was characterized by SEM, TEM and nitrogen adsorption. Several important parameters that affect the extraction efficiencies, such as concentration of ordered porous carbon, fiber length, extraction time, sample solution pH, salt addition and stirring rate, were investigated and optimized. Under the optimum conditions, the linearity for buturon was in the range of 0.3-100.0 ng mL(-1) and 5.0-300.0 ng g(-1) for river water and soil samples, respectively. The linearity for the other three analytes was in the range of 0.2-100.0 ng mL(-1) for the river water sample and 2.0-300.0 ng g(-1) for the soil sample. The limits of detection (S/N = 3) of the method ranged from 0.05 to 0.1 ng mL(-1) for the river water sample and 0.5 to 1.0 ng g(-1) for the soil sample. The results indicated that the developed method is a simple, efficient and environmentally friendly method for the extraction and determination of phenylurea herbicides in river water and soil samples.