Rapid determination of trace chromium in food with standard addition calibrating technique by flow injection chemiluminescence method

With vigna minima, corn and oats as samples, a new method of rapid determination food trace chromium was established. The total content of chromium was determined by standard addition calibrating technique with flow injection chemiluminescence analysis, which based on Cr³⁺ linear catalysis properties to Luminol-H₂O₂ system.The results indicated that the relative standard deviation was 3.2% ( n = 11) for 1.00 × 10^-12mol/L Cr³⁺standard solution under the optimal determination condition for the p H2.50 of test solution and transmission gain of 1.The lowest detection limit of Cr³⁺ was 2.30 ×10^-13mol/L.The average mass of Cr in vigna minima, corn, oats sample was 46.64, 31.22 and 38.66 μg/g.The recoveries were in the range of 92.0% ⁹8.1%. This method is fast, sensitive with good selectivity and good linear relationship.Therefore it can be used to determine the micro chromium in food samples with satisfactory analytical results.