VITAMIN-C DOSAGE IN FRUITS AND VEGETABLES

An spectrophotometric technique is proposed for vitamin C dosage in the presence of potential interfering compounds, usually present in fruits and vegetables. The 2,6-diclorophenol-indophenol is used as indicator; its excess is extracted with xylene to increase the sensibility of the method. Iron(II), tin(II), copper(II), lysine, sulphite, reductones and natural occurring pigments produce no interference. The proposed technique shows good accuracy (variation coefficient smaller than 10%) and good recovery.