Ascorbic acid determined with Fe(III)-5-Br-PAN-S system by spectrophotometic method

As ascorbic acid can reduce Fe(Ⅲ)-5-Br-PAN-S to Fe(Ⅱ)-5-Br-PAN-S,spectrophotometic method was adopted to determine ascorbic acid in this paper.Fe(Ⅱ)-5-Br-PAN-S complex has main high peaks at λ 550 nm and 750 nm in NaH -2PO -4-Na -2HPO -4 buffer solution at pH=5.0(750 nm),the content of ascorbic acid (in ρ(VC)=0～2.4 μg/mL) is just in accordance with Beer′s law.This method is very easy to manipulate and highly selective,especially for the determination of ascorbic acid of the pharmaceuticals and the fruits.