**7. Analytical methods for the determination of folic acid**

Methods reported in the literature for the determination of folic acid include HPLC with different detectors [57], electrophoresis [2], electrochemical methods [58], flow injection analysis [59], and spectrophotometric methods. Recently, some novel spectroscopic methods were reported for routine determination of folic acid. These methods are based on the formation of colored species on binding of folic acid with sodium nitroprusside and ammonia reagent to produce a dark yellow-colored chromogen (λmax at 390). A new, simple, easy, accurate, precise, economic, and sensitive UV spectrophotometric method for the determination of folic acid in commercial tablets has been reported. It was possible to determine the concentration of folic acid in commercial tablets at a λmax of 282.5 nm in a linear range of 1.0–17.5 μg mL − 1 with an *R*2 > 0.9999 and recovery between 100.6 and 101.1% using a phosphate buffer solution at pH 9.0. De Moura Ribeiro Vinicus et al. [60] reported the spectrophotometric methods for the determination of folic acid in different pharmaceutical formulations, using 0.1 mol L−1 NaOH as solvent. This method is simple, selective, and robust.
