Determination of potassium bromate in flour by flow injection analysis

Abstract

Potassium bromate was determined in flour by aqueous extraction and photometric FIA based on its reaction with acidified potassium iodide and starch. The recovery was 90.0% and the FIA linear range was 0.5–5.0 mg l^–1 with between-injection and between-extraction standard deviations of 0.04 and 0.11 mg l^–1, respectively. For 22 samples of commercial flour the mean differences between the results obtained by the FIA method and by the current official titration method was 0.14 mg kg^–1 and the standard deviation of differences between the two methods was 0.74 mg kg^–1 in the range 0–20 mg kg^–1.