A new class of ionic liquids (ILs) containing the tris(pentafluoroethyl)trifluorophosphate (FAP) anion are paired with imidazolium, phosphonium, and pyrrolidinium cations and used as extraction solvents in direct immersion single drop microextraction (SDME) studies coupled to high performance liquid chromatography (HPLC). The selectivity and sensitivity of the extraction method can be tuned and manipulated by varying the cationic component of the IL, thereby providing larger enrichment factors for a variety of analytes, including polycyclic aromatic hydrocarbons (PAHs). Compared to other hydrophobic ILs containing the hexafluorophosphate (PF(6)(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf(2)(-)) anions, FAP-based ILs are significantly more hydrophobic and hydrolytically stable permitting them to be used in the sampling of large volumes of aqueous solutions without dissolution or loss of the IL. The highest enrichment factors were obtained with the trihexyl(tetradecyl)phosphonium FAP ([PH(3)T] [FAP]) IL for compounds with high molecular weight and fused rings while high enrichment factors were obtained for smaller, more polar molecules using the 1-hexyl-3-methylimidazolium FAP ([HMIM] [FAP]) IL. The detection limits for nine studied PAHs ranged from 0.1 to 0.6, 0.03 to 0.4, 0.04 to 0.7 and 0.1 to 1.2 microg L(-1) for [HMIM] [FAP], [PH(3)T] [FAP], 1-butyl-1-methylpyrrolidinium FAP ([BMPL] [FAP]), and 1-(6-amino-hexyl)-1-methylpyrrolidinium FAP ([HNH(2)MPL] [FAP]), respectively. The reproducibility of the extraction method at 20 degrees C using the FAP-based ILs was in the range of 1.5-9.4%. Three real water samples including tap water, creek water, and river water were analyzed and yielded recoveries ranging from 79-114%.

A novel microextraction method is introduced based on dispersive liquid-liquid microextraction (DLLME) in which an in situ metathesis reaction forms a water-immiscible ionic liquid (IL) that preconcentrates aromatic compounds from water followed by separation using high-performance liquid chromatography. The simultaneous extraction and metathesis reaction forming the IL-based extraction phase greatly decreases the extraction time as well as provides higher enrichment factors compared to traditional IL DLLME and direct immersion single-drop microextraction methods. The effects of various experimental parameters including type of extraction solvent, extraction and centrifugation times, volume of the sample solution, extraction IL and exchanging reagent, and addition of organic solvent and salt were investigated and optimized for the extraction of 13 aromatic compounds. The limits of detection for seven polycyclic aromatic hydrocarbons varied from 0.02 to 0.3 microg L(-1). The method reproducibility produced relative standard deviation values ranging from 3.7% to 6.9%. Four real water samples including tap water, well water, creek water, and river water were analyzed and yielded recoveries ranging from 84% to 115%.

Previously reported ion-specific equation coefficients for both the Abraham general solvation model and Goss modified Abraham model are updated using recently measured activity coefficient, gas chromatographic retention factor, and solubility data for solutes dissolved in room temperature ionic liquids (RTILs). Reported for the first time are equation coefficients for 1-propyl-2,3-dimethylimidazolium cation, and octylsulfate and thiocyanate anions. In total nine sets of cation-specific and eight sets of anion-specific equation coefficients have been determined for each model. The derived correlations describe the 976 experimental gas-to-RTIL partition coefficients to within a standard deviation of 0.12 log units and the 955 experimental water-to-RTIL partitions to within a standard deviation of 0.15 log units.

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