Downloaded By: [Marquette University] At: 21:29 15 November 2007 MINI-REVIEW Ionic Liquids for and by Analytical Spectroscopy Chieu D. Tran Department of Chemistry, Marquette University, Milwaukee, Wisconsin Abstract: In this mini-review we highlight two aspects of ionic liquids that to date have either no or limited studies. They are (1) exploitation of unique features of ionic liquids to develop novel spectroscopic methods and (2) development of novel spectroscopic methods, for the sensitive and accurate determination of thermal physical properties of ionic liquids. In the first category, we will describe several novel methods which were developed utilizing unique properties of ionic liquids for measurements which are not possible otherwise. They include the sensitive and accurate method to determine enantiomeric compositions of a variety of pharmaceutical products with different size, shape, and functional groups. This method is based on the use of a chiral IL which serves both as a solvent and also as a chiral selector. Ionic liquids have also been successfully used to substantially enhance the sensitivity of thermal lens measurements. In the second category, we will describe recent development in which transient grating technique and thermal lens technique have been successfully used for the sensitive, accurate, nondestructive determination of thermal physical prop- erties of ILs. Keywords: Pharmaceutical products, ionic liquid, near-infrared, fluorescence, chiral, enantiomeric excess, thermal lens, transient grating, thermal physical properties Received 20 May 2007; accepted 1 June 2007 The author wishes to thank his present and former coworkers and collaborators whose work is cited in the references. Acknowledgment is made to NATO for financial support part of this work (through NATO Collaborative Linkage Grant, Grant CBP. EAP. CLG981394). Address correspondence to Chieu D. Tran, Department of Chemistry, Marquette University, P. O. Box 1881, Milwaukee, Wisconsin 53201-1881. E-mail: chieu. tran@mu.edu Analytical Letters, 40: 2447–2464, 2007 Copyright # Taylor & Francis Group, LLC ISSN 0003-2719 print/1532-236X online DOI: 10.1080/00032710701583417 2447