Organized media for fluorescence analysis of complex samples: comparison of bile salt and conventional detergent micelles in coal liquids

Accurate quantitative determinations are often difficult to obtain from fluorescence analysis of complex samples due to sample matrix effects and intermolecular interactions between solutes. Organized media can be used to minimize these unwanted processes without physical separation or extraction of the analytes from the sample matrix by isolating the analyte molecules in a uniform microenvironment within the sample. The advantages of bile salt micellar media over conventional detergent micelles are demonstrated for analysis of coal liquids. The bile salt media is shown to increase the sensitivity and dynamic range of fluorescence measurements relative to simple ethanolic solutions, without promoting gound-state and excited-state interactions that occur in the detergent micellar media.