Temperature-controlled ionic liquid dispersive liquid phase micro-extraction

The present study reports a novel, green and environmental benign sample enrichment method termed temperature-controlled ionic liquid dispersive liquid phase micro-extraction. An ionic liquid [C6MIM][PF6], was used as the extraction solvent and pyrethroid pesticides as the model compounds. The ionic liquid was dispersed completely into the aqueous solution under the drive of temperature, and the analytes will more easily migrate into the ionic liquid phase because of the much larger contact area than that of conventional single drop liquid micro-extraction. Results obtained indicated that this system could be tuned to a great extent because ionic liquids can be designable, and the method does not suffer from the limitations of that in conventional solvent micro-extraction. Analytical parameters of the proposed method were investigated and good linear range (1.5-100 mu g L-1), detection limits (0.28-0.6 mu g L-1), and precision (RSD of 2.7-9.3%, n = 6) was obtained. Good spiked recoveries from six real water samples proved that this method was competitive in practical applications. Considering the large variety of ionic liquids and the tunable amounts of used ionic liquids in different experiments, the proposed method earns many merits and will have a wide application perspective in the future. (C) 2007 Elsevier B.V. All rights reserved.