EXPRESS: Green Chemistry Spectrofluorimetric Assessment of Folic Acid in Pharmaceutical Formulations Using Acriflavine as an Efficient Fluorescent Probe

A sensitive, simple, inexpensive, rapid, and eco-friendly spectrofluorimetric method was created to assess the folic acid (FA) concentration in tablets using acriflavine (ACF) as an eco-friendly photoprobe. Based on its ability to quench the ACF fluorescence intensity in water at pH 8.0 and λ_ex = 460 nm. FA concentration was measured by quenching the fluorescence intensity of the ACF at λ_em = 508 nm within the linear range of 3.5×10^-6 - 30.0×10^-6 mol L^-1 with a correlation coefficient <i>r</i>² = 0.9991. The limit of quantification (LOQ) and the limit of detection (LOD) are 1.159 × 10^-6 mol·L^-1 and 0.383 × 10^-6 mol·L^-1, respectively. This method was easy to use and accurately and effectively evaluated FA in pharmaceutical tablet samples. No influence was observed from the excipients usually contained in pharmaceutical formulations. The method was verified as valid according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. In addition, its greenness has been estimated using environmental assessment tools.