Application of DLLME Based on the Solidification of Floating Organic Droplets for the Determination of Dinitrobenzenes in Aqueous Samples

Dispersive liquid-liquid microextraction (DLLME) based on the solidification of floating organic droplets (DLLME-SFO) combined with gas chromatography-electron-capture detection (GC-ECD) has been developed for extraction and analysis of three dinitrobenzenes. The extraction conditions including extraction solvent, disperser solvent, extraction time, salt effect and temperature were investigated and optimized systematically. The limits of detection were 0.019 mu g L-1 for 1,4-dinitrobenzene, 0.079 mu g L-1 for 1,3-dinitrobenzene and 0.034 mu g L-1 for 1,2-dinitrobenzene. Moreover, it offered good repeatability and high recovery. This method was successfully applied to monitor DNBs in different water samples.