Phase-transfer catalysis in analytical chemistry

Phase-transfer catalysis (PTC) has been a well-established technique on the synthesis of organic chemicals for more than three decades. Its scope and underlying mechanistic features have been the subject of numerous studies and appear to be recognized and understood. This review is intended to approach the subject by focusing on the extraction-preconcentration-derivatization/reaction prior to analysis and to chronicle recent progress made. We present the salient aspects of PTC modes followed by a brief review of mechanistic considerations including reaction mechanisms, selectivity, rates and kinetics pointing out to the potency of PTC in analytical chemistry. Specific guidelines are given on how to optimize a PTC-based analysis with respect to catalyst, solvent, reaction conditions and more, based on reaction characteristics. Finally, using the PTC principles as a framework, selected real-life applications are provided, the capabilities and limitations of PTC are addressed for the purpose of direct analysis of organic analytes and certain advantages are highlighted. (c) 2005 Elsevier B.V All rights reserved.