Development of a Microextraction Method Based on Dissolved Carbon Dioxide Flotation after Emulsification for the Determination of Triazole Pesticides Residues in Water Samples by Gas Chromatography-Mass Spectrometry.

A novel dissolved carbon dioxide flotation after emulsification microextraction (DCF-EME) method was proposed for the determination of four triazole pesticides in water samples coupled with gas chromatography-mass spectrometry (GC-MS) in a home-made glass round flask. The DCF-EME method is based on a rapid and simple phase separation of low-density organic solvent (toluene) from the aqueous phase via introducing a saturated NaHCO3 solution into the acidified sample (0.1 mol L-1 HCl); then analytes were extracted in toluene. Various parameters affecting the extraction process were optimized. Under the optimal conditions, the recoveries for four pesticides ranged from 82.8 to 121.2%. Meanwhile the limits of detection were at the range of 0.14 - 1.04 μg L-1 , and the preconcentration factors were varied between 342 and 473 for different triazoles. The method is simple, fast and environmentally friendly, being successfully applied for the determination of triazole pesticides in water samples.