[Capillary zone electrophoretic determination of NaFeEDTA in iron fortified soy sauce]

An analytical method for separation and determination of sodium iron (III) ethylenediaminetetraacetate (NaFeEDTA) in iron fortified soy sauce by capillary zone electrophoresis (CZE) has been developed.

The electrolyte, which contains 30 mmol/L citric acid, 20 mmol/L Tris, 0.15 mmol/L CTAB and 0.05 mmol/L SDS, was used to improve the peak shape and reduce the retention time at the voltage of - 25.0 kV. The sample can be determined at UV 254 nm after diluted.

In this method, which enjoyed a wide linear range and good precision, the RSD (n = 6) was 2.15%, the average recoveries for samples ranged from 94.3% - 101.2% and the detection limit of the NaFeEDTA in iron fortified soy sauce is 4 microg/ml (S/N = 3).

The results of application of different kinds of soy sauce showed that the method was direct, accurate, fast and simple.