A single-drop microextraction (SDME) procedure with a modified microsyringe was developed for the analysis of six organophosphorus pesticides (OPPs) in water. Microsyringe was modified by attaching a 2-mm cone onto the needle tip end. The conditions affecting SDME performance including microextraction solvent, stirring speed, extraction time, ionic strength and sample pH were optimized. Under the optimized conditions, the linear ranges of the SDME with ethion as internal standard were 0.05–50 μg L−1 (except for dimethoate 5–5,000 μg L−1) and limits of detection (LOD) were 0.012–0.020 μg L−1 (except for dimethoate 0.45 μg L−1). Recoveries of six pesticides were in the range of 70.6–107.5 % with relative standard deviation lower than 6.0 %. The modified method is simple, rapid and sensitive, and acceptable in the analysis of OPPs pesticides in water samples.
Tian, F., Liu, W., Fang, H., An, M., & Duan, S. (2014). Determination of six organophosphorus pesticides in water by single-drop microextraction coupled with GC-NPD. Chromatographia, 77(5-6), 487-492. https://doi.org/10.1007/s10337-013-2609-1