A Novel Temperature-Controlled Ionic Liquid Dispersive Liquid Phase Microextraction for Determination of Dicofol and DDT in Environmental Water Samples Prior to Gas Chromatography Mass Spectrometry

A novel dispersive liquid phase microextraction using a new temperature-controlled ionic liquid 1-isooctyl-3- methylimidazolium hexafluorophosphate was proposed as novel medium for the determination of dicofol and DDT in environmental water. For one new extraction, a 1.0 ml methanol solution containing 250 mg of the ionic liquid was sprayed into 25 ml of water sample. Meantime the ionic liquid will rapidly congregate, solidify and finally form large solid particles. The ionic liquid was collected and dissolved in 30 μl of acetone for analysis. Under optimal conditions, the enrichment factors were 532 for dicofol and 540 for DDT. Because developed extraction procedure includes all performance during liquid/liquid extraction and co-precipitation extraction, thus it has a wide application with very high extraction efficiency. Proposed extraction combined with gas chromatography mass spectrometry was a valuable alternative for analysis of dicofol and DDT in environmental water samples within the concentration range 0.005-3.0 μg l-1. The detection limits were 1.3 ng l-1 for DDT and 3.2 ng l-1 for dicofol.