A Comparison of Fluorescence Inner-Filter Effects for Different Cell Configurations

Abstract
In conventional fluorescence spectroscopy, fluorescence intensity at high fluorophore concentration is often not proportional to fluorophore concentration, owing to primary and secondary absorption (inner-filter effects). In this paper, fluorescence calibration curves for anthracene solutions were obtained using a conventional right angle cell, a frontal reflection cell, a short pass cell, and a total internal reflection fluorescence (TIRF) cell for comparing the observed primary inner-filter effects. Measurements were also made of a two-component mixture using the nonfluorescent 9-nitrofluorene with anthracene for comparing primary and secondary inner-filter effects. A conventional right angle cell exhibited the widest linear dynamic range and lowest detectable anthracene concentration, whereas the TIRF cell provided the best linearity at high concentrations. The TIRF cell was determined to have significant potential for quantitative analysis of highly concentrated and/or turbid solutions.