GC-MS Determination of Ultra-trace Amount of Dicofol in Environmental Water Samples After Extraction with Thermal Control Ionic Liquid

A new thermal control ionic liquid,1-isooctyl-3-methylimidazolium hexafluorophosphate,was synthesized,and used to extract dicofol (DCF) in environmental water samples.Factors influential to the extraction rate,including the temperature and time of extraction,amount of ionic liquid added,pH value of the medium,were studied.Under the optimized testing conditions,an aliquot of 1 μL of the extract was taken for GC-MS determination.Value of detection limit (3S/N) found was 1.6 ng·L-1.Linear relationship between values of peak area and mass concentration of DCF was obtained in the range within 2.4 μg·L-1.The proposed method was used in the analysis of environmental water samples,giving values of recovery in the range of 96.0%-101.0%.