Electrospray Ionization Mass-Spectrometry of Ionic Liquids and Determination of Their Solubility in Water

Published

January 1, 2003

Author(s)

Z B. Alfassi, Robert E. Huie, B L. Milman, Pedatsur Neta

Abstract

Electrospray ionization-mass spectrometry is used to detect both the cations (C⁺) and the anions (A') of ionic liquids (CA) in aqueous methanol solutions. In addition to the main peaks of the parent ions, fragmentation products are observed upon increasing the cone voltage, whereas aggregates of the parent ion with one or more ionic liquid molecules (e.g., C(CA)n⁺, A(CA)n') are observed upon decreasing the cone voltage. A method is developed to determine quantitatively the concentration of an ionic liquid or a mixture of several ionic liquids in solution. By using this method, the solubilities in water at room temperature (22 1 C) of three typical hydrophobic ionic liquids are determined: (0.70 0.07) g L^-1 for methyltributylammonium bis (trifluoromethylsulfonyl) imide (MeBu₃NNTf₂), (6.0 0.4) g L^-1 for butylmethlpyrrolidinium bis (trifluoromethylsulfonyl) imide (BuMePyrNTf₂), and (18.6 0.8) g L^-1 for 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF₆).

Citation

Analytical and Bioanalytical Chemistry

Pub Type

Journals

Keywords

analytical chemistry, electro spray, green chemistry, ionic liquid, mass spectrometry

Citation

Alfassi, Z. , Huie, R. , Milman, B. and Neta, P. (2003), Electrospray Ionization Mass-Spectrometry of Ionic Liquids and Determination of Their Solubility in Water, Analytical and Bioanalytical Chemistry (Accessed October 29, 2025)