Spectrophotometric determination of vitamin C with iron(II)-4-(2-pyridylazo)resorcinol complex

A spectrophotometric method has been developed for the determination of vitamin C in a variety of samples. The procedure is based on the reduction of iron(III) to iron(II) and complexation of iron(II) with 4-(2-pyridylazo)resorcinol, followed by its extraction into nbutanol. The absorbance is measured at 710nm. Beerʹs law is observed up to 5.5µgml-1 ascorbic acid. Interference effects of various substances including sugars, vitamins, amino acids, inorganic cations and anions and some organic substances have been studied.