In this article, a method of ionic liquid-based solvent bar microextraction combined with high performance liquid chromatography was developed to measure organophosphorus pesticides (OPPs) in water samples. The solvent bar microextraction was based on applying hydrophobic ionic liquid to the lumen and wall pores of a hollow fiber. The main factors influencing the extraction including types of ionic liquid, stirring speed, extraction time, extraction temperature, and salt effect were investigated. The proposed method was successfully applied in the analysis of real environmental water samples under the optimal extraction conditions and good spiked recoveries of 86.71–103.7% were obtained. The linear range was 1–200 μg L−1 and the detection limits were 0.015–0.026 μg L−1 for the four OPPs analyzed. These results demonstrated that solvent bar microextraction was a simple and accurate technique with a high enrichment factor.
