Critical approach to synchronous spectrofluorimetry. I

This article critically reviews the principles and the applications of synchronous spectrofluorimetry as an analytical tool, focusing mainly on the recent innovative advances in this field of research. Unlike other reviews, this article includes not only detection using synchronous fluorescence (SF) but also the entire analytical procedure involving it (i.e. extraction and previous clean-up procedures if needed, derivatization process, use of micellar media, and derivative technique or multivariate-calibration methods applied to treatment of SF signals). The article is in two parts, the first devoted to general features of the synchronous procedure and the second one to analytical applications of different modes of SF - constant-wavelength, constant-energy and variable-angle (in wavelength and energy domains and in linear and non-linear variants). We discuss practical considerations, and evaluate the possibilities and the limitations of each synchronous modality, intending to show the serious drawbacks of applying synchronous spectrofluorimetry to very complex mixtures, avoiding previous clean-up procedures and constructing inaccurate calibration sets. Finally, this review compares SF and other analytical methodologies. It includes more than 200 references to the last advances in this technique, and several tables and figures, to facilitate the readers' rapid comprehension of the relevant aspects in the field of SF. (C) 2010 Elsevier Ltd. All rights reserved.