Abstract Fluorescence emission behavior of polycyclic aromatic hydrocarbons (PAHs), polycyclic aromatic nitrogen heterocycles (PANHs), polycyclic aromatic sulfur heterocycles (PASHs) and benzofluoranthenes dissolved in organic solvents of varying polarity is reviewed. Measured fluorescence properties are used to divide aromatic solutes into two categories, probe and nonprobe molecules, depending upon whether the molecule's emission intensity ratios vary systematically with solvent polarity. Seventeen polycyclic aromatic hydrocarbon solute probes are identified and possible probe character versus molecular structure correlations are examined. Also discussed are instrumental and chemical artifacts associated with accurate determination of fluorescence emission intensities.