Application of pneumatic nebulization single-drop microextraction for the determination of organophosphorous pesticides by gas chromatography-mass spectrometry.

Organophosphorous pesticides (OPPs) including dichlorvos, diazinon, malathion, phenamiphos and chlorpyrifos, in water samples were extracted by pneumatic nebulization single-drop microextraction (PN-SDME) and then determined by gas chromatography-mass spectrometry (GC-MS). Experimental parameters affecting the performances of PN-SDME, such as flow rate of carrier gas, extraction time and microdrop volume, were examined and optimized. The limits of detection for the analytes were in the range of 0.0014-0.0019 μg/mL. The linear range was 0.0050-0.50 μg/mL, except dichlorvos (0.0070-0.50 μg/mL). Water samples were analyzed and the recoveries of the analytes in the spiked water samples were from 75.2 to 105.3%. The relative standard deviations were lower than 12.7%.