A COMPARISON OF FLUORESCENCE INNER-FILTER EFFECTS FOR DIFFERENT CELL CONFIGURATIONS

In conventional fluorescence spectroscopy, fluorescence intensity at h igh fluorophore concentration is often not proportional to fluorophore concentration, owing to primary and secondary absorption (inner-filte r effects). In this paper, fluorescence calibration curves for anthrac ene solutions mere obtained using a conventional right angle cell, a f rontal reflection cell, a short pass cell, and a total internal reflec tion fluorescence (TIRF) cell for comparing the observed primary inner -filter effects. Measurements were also made of a two-component mixtur e using the nonfluorescent 9-nitrofluorene with anthracene for compari ng primary and secondary inner-filter effects. A conventional right an gle cell exhibited the widest linear dynamic range and fewest detectab le anthracene concentration, whereas the TIRF cell provided the best l inearity at high concentrations. The TIRF cell was determined to have significant potential for quantitative analysis of highly concentrated and/or turbid solutions.