ON-LINE DIALYSIS-ION CHROMATOGRAPHIC DETERMINATION OF BROMATE IN FLOUR AND ITS PRODUCTS

Ion chromatography with on-line dialysis technique was applied to the determination of bromate in flour and its products.Metrosep A supp 5250 and Metrosep A Supp 1 Guard were used as separation column.A mixed solution of 3.2 mmol·L-1 Na2CO3 and 1.0 mmol·L-1 NaHCO3 was used as eluent,passing through the column at a flow-rate of 0.65 mL·min-1.Volume of sample solution introduced was 100 μL,and suppressed conductance detection was used in the measurement.Linear relationships between the peak area and concentration of bromate was obtained in the range of 0.005 to 10.0 mg·L-1 with correlation coefficient of 0.999 9.Precision test was made at 3 concentration levels of 1.0,50.0 and 100.0 mg·kg-1,and the RSD′s obtained were 1.75%,0.55% and 0.85% respectively.Recovery test by standard addition method was made and values of recovery found were in the range of 80.8%-95.2%.Detection limit found was 0.10 mg·kg-1 based on 10 g of sample.