Abstract: NaFeEDTA as a five-cycle chelating compound can be totally disassembled to produced Fe3+under acid condition (pH≤1.35). Fe3+ can react with ammonium thiocyanate and forms red color complex. This red color complex has special absorption at 483 nm and the absorption is linear with the concentration of the complex. To take advantage of this principle, the content of NaFeEDTA in fortified soy sauce could be accurately measured. The results showed that the absorption has good linear relationship with the concentration of NaFeEDTA between 2.028～24.336 μg/ml and the correlation coefficient is 0.99992. The method is a simple quick and accurate approach for the determination of the content of NaFeEDTA in iron fortified soy sauce.

Key words: spctrophotometry, iron fortified soy sauce, NaFeEDTA