The phenolic compounds phenol, 4-nitrophenol, 2,4-dinitrophenol, 2,6-dinitrophenol, 1-naphthol, 2-naphthol, and 4-chlorophenol are extracted nearly quantitatively from aqueous solution into the room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMImPF6) in molecular form at pH < p Ka. Picric acid is extracted efficiently in anionic form. Recovery of pyrocatechol and resorcinol is much lower. The effect of pH, phenol concentration, and volume ratio of aqueous and organic phases were studied. Ionic liquid BMImPF6 is shown to be suitable for extraction-voltammetric determination of phenols without back-extraction or addition of support electrolyte. The electrochemical window of BMImPF6 at various electrodes was determined, and voltammetric oxidation of phenols and reduction of nitrophenols in BMImPF6 was studied.

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Polyvinyl chloride-plasticized membrane ion-selective electrodes (ISE) based on conventional ion-exchangers have been proposed as a cheap universal tool to measure the solubilities of ionic liquids (ILs) in water. They are applicable for ILs with a wide range of solubilities in water, since the linear range of a potentiometric response spans several orders of magnitude. As an example, we have fabricated and tested ISEs for widely used alkylimidazolium ionic liquids. The aqueous solubilities of four typical ILs have been determined at 21 degrees C: 0.075 +/- 0.001 mol l(-1) (1-butyl-3-methylimidazolium, BMIm, hexafluorophosphate); 0.018 +/- 0.001 mol l(-1) (BMIm bis(triflylimide)); 0.054 +/- 0.007 mol l(-1) (1-butyl-2,3-dimethylimidazolium, BDMIm, hexafluorophosphate); 0.014 +/- 0.001 mol l(-1) (BDMIm bis(triflylimide)).

Due to the polymer plasticizing ability and ionic nature of ionic liquids (bistrifluoromethanesulfonimidate salts of 1-butyl-2,3-dimethylimidazolium and dodecylethyldiphenylphosphonium, BDMIm Tf 2 N and DEDPP Tf 2 N, respectively), they were found to be excellent compounds for preparing ion-selective membrane electrodes. Membrane polymers studied were poly(methyl methacrylate) and poly(vinyl chloride). The electrodes demonstrated good and extremely stable response to both cations and anions (including surfactants) and were successfully applied to the analysis of detergents.

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