Application of liquid-phase microextraction for the determination of phoxim in water samples by high performance liquid chromatography with diode array detector

A new method, which involves liquid-phase microextraction (LPME) followed by high performance liquid chromatography (HPLC) with diode array detector (DAD), was developed to determine phoxim in water sample. Experimental parameters affecting the extraction efficiency, such as extraction solvent, solvent volume, agitation speed of the sample and extraction time were investigated. Under the optimal extraction conditions, phoxim was found to yield a good linear calibration curve in the concentration range from 0.01 to 5 μg mL⁻¹. The limit of detection (LOD) is 10 ng mL⁻¹, and relative standard deviation (RSD) at the 100 ng mL⁻¹ levels is 8.4%. Lake water and tap water samples were successfully analyzed using the proposed method.