An argon-ion laser fluorometer optimal for concentration detection of 5-bromomethyl fluorescein derivatized carboxylic acids

A continuous wave, argon ion laser-induced fluorescence detector was designed for use with conventional high performance liquid chromatography. Palmitic acid was selected as a model analyte to evaluate the performance of the detector. Using the intense 488.0 nm emission line, a concentration detection limit of 7.5 × 10^–10 M (38 femtomoles on-column) was established for palmitic acid at a signal to noise ratio of three. The linear dynamic range extended over two orders of magnitude with a correlation coefficient of 0.9998. The contribution of scattered radiation to the analytical signal was minimal. The concentration detection limit achieved with the constructed laser fluorometer was superior to other reports for fatty acids.