The most obvious chemical activity of VC is that reduce Fe3+ to Fe2+, then promote iron absorption in the intestine, promote the storage and utilization of iron. Fe3+ react immediately with reducing ascorbic acid to form Fe2+. then Fe2+ react with phenanthroline and the color developing reaction occurs. The content of vitamin C in sample can be determined. Measure the OD value and calculate the VC content indirectly.
Normal saline (0.9% NaCl) or PBS (0.01 M, pH 7.4), Absolute ethanol