Analysis of salicylic acid based on the fluorescence enhancement of the As(III)–salicylic acid system Original Research Article

A new, simple and sensitive spectrofluorimetric method for the determination of salicylic acid (λex = 315 nm, λem = 408 nm) using As(III) as a sensitizing reagent has been investigated by measuring the increase of fluorescence intensity of salicylic acid due to the complexation of As(III)–salicylic acid in presence of sodium dodecyl sulfate (SDS) 10−3 M. Under optimum conditions, a significant relationship was obtained between the fluorescence intensity and salicylic acid concentration. A linear calibration curve was obtained in the range 13.8–13812 μg l−1 with product-moment correlation coefficient (R) 0.99985 and detection limit 4.2 μg l−1. The R.S.D. is 2.35% (n = 5).The method was applied successfully to the determination of salicylic acid in human serum.