Portable micro method for quantitative determination of vitamin C in fruit and vegetable juices.

A portable rapid and accurate micro method is described for the quantitative determination of vitamin C in fruit and vegetable juices. Chromatographic paper is impregnated with DCP by immersion in 95% ethanol solution and sprayed with a protective starch solution. Papers are usable indefinitely when protected from moisture, light, air, and high temperatures. Determinations can be completed in 60 s with an accuracy of +/- 2.0 mg/100 mL fruit or vegetable juice. Cloudy or lightly colored samples do not interfere with the determination. The method was compared with the official AOAC 2,6-dichloroindophenol (DCP) titration method and gave a linear correlation coefficient of 0.99749.